AIHostingTycoon/apps/web/src/pages/InfrastructurePage.tsx

import { useState, useMemo } from 'react';
import {
  Plus, Server, MapPin, Zap, HardDrive, Wrench,
  ChevronRight, Thermometer, Shield,
  Rocket, Clock, Lock, Cpu,
  Activity, DollarSign, Globe, Building2, Layers,
  Network, ArrowLeft, RefreshCw, ChevronDown,
  X, CheckCircle,
} from 'lucide-react';
import { TutorialHint } from '@/components/game/TutorialHint';
import { ConfirmModal } from '@/components/common/ConfirmModal';
import { useGameStore, type InfraNav, computeFillForDC } from '@/store';
import {
  formatMoney, formatNumber, formatPercent,
  LOCATION_CONFIGS, DC_TIER_CONFIGS, RACK_SKU_CONFIGS,
  CAMPUS_TIER_COSTS, CLUSTER_COST_CONFIG, FIRST_CAMPUS_BUILD_TICKS,
  estimateNetworkSlots, maxComputeRacks,
  SWITCH_TIER_CONFIGS,
  DC_UPGRADE_COST_FRACTION, DC_UPGRADE_INCREMENT,
  skuTotalFlops,
} from '@token-empire/shared';
import type {
  DCTier, RackSkuId, LocationId, PipelineStage, Era,
  Cluster, Campus, DataCenter, DeploymentCohort,
} from '@token-empire/shared';

const ERA_ORDER: Era[] = ['startup', 'scaleup', 'bigtech', 'agi'];

const STAGE_LABELS: Record<PipelineStage, string> = {
  ordered: 'Ordered', manufacturing: 'Mfg', receiving: 'Recv',
  installation: 'Install', testing: 'Testing', repair: 'Repair',
  'network-down': 'Net Down', decommission: 'Decom',
};

const STAGE_COLORS: Record<PipelineStage, string> = {
  ordered: 'bg-surface-600', manufacturing: 'bg-blue-500', receiving: 'bg-cyan-500',
  installation: 'bg-violet-500', testing: 'bg-amber-500', repair: 'bg-danger',
  'network-down': 'bg-red-600', decommission: 'bg-surface-500',
};

// ─── Shared Components ──────────────────────────────────────────

function FleetStat({ label, value, sub, icon: Icon }: {
  label: string; value: string; sub?: string; icon: typeof Server;
}) {
  return (
    <div className="bg-surface-900 border border-surface-700 rounded-lg p-3">
      <div className="flex items-center gap-1.5 mb-1">
        <Icon size={14} className="text-surface-400" />
        <span className="text-[11px] text-surface-400 uppercase">{label}</span>
      </div>
      <div className="text-lg font-bold font-mono">{value}</div>
      {sub && <div className="text-[11px] text-surface-500">{sub}</div>}
    </div>
  );
}

function CapacityBar({ label, used, total }: { label: string; used: number; total: number }) {
  const pct = total > 0 ? (used / total) * 100 : 0;
  const color = pct > 90 ? 'bg-danger' : pct > 70 ? 'bg-amber-500' : 'bg-green-500';
  return (
    <div>
      <div className="flex justify-between text-xs mb-1">
        <span className="text-surface-400">{label}</span>
        <span className="font-mono">{formatNumber(used)} / {formatNumber(total)}</span>
      </div>
      <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
        <div className={`h-full ${color} rounded-full transition-all`} style={{ width: `${Math.min(100, pct)}%` }} />
      </div>
    </div>
  );
}

function Breadcrumb({ nav }: { nav: InfraNav }) {
  const setNav = useGameStore((s) => s.setInfraNav);
  const clusters = useGameStore((s) => s.infrastructure.clusters);

  const crumbs: { label: string; nav: InfraNav }[] = [
    { label: 'Infrastructure', nav: { level: 'clusters' } },
  ];

  if (nav.level !== 'clusters' && nav.clusterId) {
    const cluster = clusters.find(c => c.id === nav.clusterId);
    if (cluster) {
      crumbs.push({ label: cluster.name, nav: { level: 'cluster', clusterId: nav.clusterId } });
    }
    if ((nav.level === 'campus' || nav.level === 'datacenter') && nav.campusId) {
      const campus = cluster?.campuses.find(c => c.id === nav.campusId);
      if (campus) {
        crumbs.push({ label: campus.name, nav: { level: 'campus', clusterId: nav.clusterId, campusId: nav.campusId } });
      }
      if (nav.level === 'datacenter' && nav.datacenterId) {
        const dc = campus?.dataCenters.find(d => d.id === nav.datacenterId);
        if (dc) {
          crumbs.push({ label: dc.name, nav: { level: 'datacenter', clusterId: nav.clusterId, campusId: nav.campusId, datacenterId: nav.datacenterId } });
        }
      }
    }
  }

  return (
    <div className="flex items-center gap-1 text-sm mb-4">
      {crumbs.map((crumb, i) => (
        <span key={i} className="flex items-center gap-1">
          {i > 0 && <ChevronRight size={14} className="text-surface-500" />}
          {i < crumbs.length - 1 ? (
            <button onClick={() => setNav(crumb.nav)} className="text-accent hover:underline">{crumb.label}</button>
          ) : (
            <span className="text-surface-200 font-medium">{crumb.label}</span>
          )}
        </span>
      ))}
    </div>
  );
}

function DeploymentProgressBar({ dc }: { dc: DataCenter }) {
  const tierConfig = DC_TIER_CONFIGS[dc.tier];
  const maxCompute = maxComputeRacks(tierConfig.rackSlots, dc.tier);
  const pipelineRacks = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((s, c) => s + c.count, 0);
  const totalTarget = dc.computeRacksOnline + pipelineRacks;
  const pct = totalTarget > 0 ? (dc.computeRacksOnline / totalTarget) * 100 : 0;

  if (totalTarget === 0 && dc.status === 'operational') return null;

  return (
    <div>
      <div className="flex justify-between text-xs mb-1">
        <span className="text-surface-400">Deployment</span>
        <span className="font-mono">{dc.computeRacksOnline} / {totalTarget} online</span>
      </div>
      <div className="h-2.5 bg-surface-700 rounded-full overflow-hidden">
        <div className="h-full bg-green-500 rounded-full transition-all" style={{ width: `${Math.min(100, pct)}%` }} />
      </div>
    </div>
  );
}

function CohortStageBreakdown({ cohorts }: { cohorts: DeploymentCohort[] }) {
  const stages: PipelineStage[] = ['ordered', 'manufacturing', 'receiving', 'installation', 'testing', 'repair'];
  const counts: Record<string, number> = {};
  for (const stage of stages) counts[stage] = 0;
  for (const c of cohorts) {
    if (c.stage in counts) counts[c.stage] += c.count;
  }

  const hasAny = stages.some(s => counts[s] > 0);
  if (!hasAny) return null;

  return (
    <div className="flex gap-3 flex-wrap text-xs">
      {stages.map(stage => counts[stage] > 0 && (
        <div key={stage} className="flex items-center gap-1.5">
          <span className={`w-2 h-2 rounded-full ${STAGE_COLORS[stage]}`} />
          <span className="text-surface-400">{STAGE_LABELS[stage]}:</span>
          <span className="font-mono">{counts[stage]}</span>
        </div>
      ))}
    </div>
  );
}

function NetworkHealthIndicator({ dc }: { dc: DataCenter }) {
  const ns = dc.networkSummary;
  const torTotal = ns.totalByTier?.tor ?? 0;
  if (torTotal === 0) return null;

  const hasDisconnected = ns.racksDisconnected > 0;
  const hasDegraded = ns.racksDegraded > 0;
  const coreDown = (ns.healthyByTier?.t3 ?? 0) < (ns.totalByTier?.t3 ?? 0);

  const color = coreDown ? 'text-danger'
    : hasDisconnected ? 'text-danger'
    : hasDegraded ? 'text-amber-400'
    : 'text-green-400';

  const bwPct = Math.round(ns.averageBandwidth * 100);

  return (
    <div className={`flex items-center gap-1 text-xs ${color}`}>
      <Network size={12} />
      <span>
        {coreDown ? 'Core Down'
          : hasDisconnected ? `${ns.racksDisconnected} disconnected`
          : hasDegraded ? `${bwPct}% bandwidth`
          : 'Healthy'}
      </span>
    </div>
  );
}

// ─── Clusters List View ─────────────────────────────────────────

function ClustersListView() {
  const clusters = useGameStore((s) => s.infrastructure.clusters);
  const totalFlops = useGameStore((s) => s.infrastructure.totalFlops);
  const totalRacks = useGameStore((s) => s.infrastructure.totalRackCount);
  const totalUptime = useGameStore((s) => s.infrastructure.totalUptime);
  const totalDCs = useGameStore((s) => s.infrastructure.totalDataCenterCount);
  const setNav = useGameStore((s) => s.setInfraNav);

  const [showBuild, setShowBuild] = useState(false);

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <h2 className="text-2xl font-bold">Infrastructure</h2>
        <button
          onClick={() => setShowBuild(true)}
          className="flex items-center gap-1.5 bg-accent hover:bg-accent-dark text-white rounded-lg px-4 py-2 text-sm font-medium"
        >
          <Plus size={16} /> New Cluster
        </button>
      </div>

      {clusters.length === 0 && (
        <TutorialHint id="first-cluster">
          Build your first cluster to establish a regional presence. Your first cluster is free!
        </TutorialHint>
      )}

      {clusters.length > 0 && (
        <div className="grid grid-cols-5 gap-3">
          <FleetStat icon={Globe} label="Clusters" value={clusters.length.toString()} />
          <FleetStat icon={Server} label="Data Centers" value={totalDCs.toString()} />
          <FleetStat icon={Cpu} label="Racks" value={formatNumber(totalRacks)} />
          <FleetStat icon={Zap} label="FLOPS" value={formatNumber(totalFlops)} />
          <FleetStat icon={Activity} label="Uptime" value={formatPercent(totalUptime)} />
        </div>
      )}

      <div className="grid grid-cols-1 gap-4">
        {clusters.map(cluster => (
          <button
            key={cluster.id}
            onClick={() => cluster.status === 'operational' && setNav({ level: 'cluster', clusterId: cluster.id })}
            className={`bg-surface-800 border border-surface-700 rounded-xl p-5 text-left transition-colors ${
              cluster.status === 'operational' ? 'hover:border-accent/50 cursor-pointer' : 'cursor-default'
            }`}
            title={cluster.status === 'constructing' ? 'Available when construction completes' : undefined}
          >
            <div className="flex items-center justify-between mb-3">
              <div className="flex items-center gap-2">
                <Globe size={18} className="text-accent" />
                <h3 className="font-bold text-lg">{cluster.name}</h3>
                {cluster.status === 'constructing' && (
                  <span className="text-xs bg-amber-500/20 text-amber-400 px-2 py-0.5 rounded">Building...</span>
                )}
              </div>
              <div className="flex items-center gap-1 text-surface-400">
                <MapPin size={14} />
                <span className="text-sm">{LOCATION_CONFIGS[cluster.locationId].name}</span>
              </div>
            </div>

            {cluster.status === 'constructing' ? (
              <div>
                <div className="flex justify-between text-xs mb-1">
                  <span className="text-surface-400">Construction</span>
                  <span className="font-mono">{Math.floor((cluster.constructionProgress / cluster.constructionTotal) * 100)}%</span>
                </div>
                <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
                  <div className="h-full bg-amber-500 rounded-full transition-all" style={{ width: `${(cluster.constructionProgress / cluster.constructionTotal) * 100}%` }} />
                </div>
              </div>
            ) : (
              <div className="grid grid-cols-4 gap-4 text-sm">
                <div><span className="text-surface-400">Campuses:</span> <span className="font-mono">{cluster.campuses.length}</span></div>
                <div><span className="text-surface-400">DCs:</span> <span className="font-mono">{cluster.campuses.reduce((s, c) => s + c.dataCenters.length, 0)}</span></div>
                <div><span className="text-surface-400">Racks:</span> <span className="font-mono">{
                  formatNumber(cluster.campuses.reduce((s, c) => s + c.dataCenters.reduce((s2, d) => s2 + d.computeRacksOnline + d.computeRacksFailed, 0), 0))
                }</span></div>
                <div className="flex items-center justify-end gap-1 text-surface-400">
                  <ChevronRight size={16} />
                </div>
              </div>
            )}
          </button>
        ))}
      </div>

      {showBuild && <BuildClusterModal onClose={() => setShowBuild(false)} />}
    </div>
  );
}

// ─── Build Cluster Modal ────────────────────────────────────────

function BuildClusterModal({ onClose }: { onClose: () => void }) {
  const era = useGameStore((s) => s.meta.currentEra);
  const money = useGameStore((s) => s.economy.money);
  const existingClusters = useGameStore((s) => s.infrastructure.clusters);
  const buildCluster = useGameStore((s) => s.buildCluster);

  const [name, setName] = useState('');
  const [location, setLocation] = useState<LocationId>('us-west');

  const isFirst = existingClusters.length === 0;
  const cost = isFirst ? 0 : CLUSTER_COST_CONFIG.baseCost;
  const alreadyExists = existingClusters.some(c => c.locationId === location);
  const locationConfig = LOCATION_CONFIGS[location];
  const eraUnlocked = ERA_ORDER.indexOf(era) >= ERA_ORDER.indexOf(locationConfig.availableAt);
  const canBuild = name.trim() !== '' && !alreadyExists && eraUnlocked && money >= cost;

  return (
    <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={onClose}>
      <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-md w-full mx-4 shadow-2xl" onClick={e => e.stopPropagation()}>
        <h3 className="text-lg font-bold mb-4">Build New Cluster</h3>

        <div className="space-y-4">
          <div>
            <label className="text-xs text-surface-400 mb-1 block">Cluster Name</label>
            <input value={name} onChange={e => setName(e.target.value)} placeholder="e.g., US West Cluster"
              className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
          </div>

          <div>
            <label className="text-xs text-surface-400 mb-1 block">Region</label>
            <select value={location} onChange={e => setLocation(e.target.value as LocationId)}
              className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm">
              {Object.values(LOCATION_CONFIGS).map(loc => {
                const locked = ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(loc.availableAt);
                const taken = existingClusters.some(c => c.locationId === loc.id);
                return (
                  <option key={loc.id} value={loc.id} disabled={locked || taken}>
                    {loc.name} ({loc.energyCostMultiplier}x energy) {locked ? '🔒' : ''} {taken ? '(exists)' : ''}
                  </option>
                );
              })}
            </select>
          </div>

          {alreadyExists && <p className="text-xs text-amber-400">You already have a cluster in this region.</p>}

          <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1">
            <div className="flex justify-between"><span className="text-surface-400">Cost:</span><span className="font-mono">{isFirst ? 'Free' : formatMoney(cost)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Build Time:</span><span className="font-mono">{isFirst ? 'Instant' : `${CLUSTER_COST_CONFIG.buildTimeTicks}s`}</span></div>
          </div>

          <div className="flex gap-3">
            <button onClick={onClose} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
            <button onClick={() => { buildCluster(name.trim(), location); onClose(); }} disabled={!canBuild}
              className="flex-1 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
              {isFirst ? 'Create Cluster' : `Build (${formatMoney(cost)})`}
            </button>
          </div>
        </div>
      </div>
    </div>
  );
}

// ─── Cluster Fill All Modal ─────────────────────────────────────

function ClusterFillAllModal({ cluster, money, era, research, onConfirm, onClose }: {
  cluster: Cluster;
  money: number;
  era: Era;
  research: string[];
  onConfirm: (skuId: RackSkuId) => void;
  onClose: () => void;
}) {
  const availableSkus = Object.values(RACK_SKU_CONFIGS).filter(s => {
    if (ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(s.era)) return false;
    if (s.requiredResearch.length > 0 && !s.requiredResearch.every(r => research.includes(r))) return false;
    return true;
  });

  const allDCs = cluster.campuses.flatMap(c => c.dataCenters);
  const mostCommonSku = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const dc of allDCs) {
      if (dc.rackSkuId) counts[dc.rackSkuId] = (counts[dc.rackSkuId] || 0) + 1;
    }
    const entries = Object.entries(counts);
    return entries.length > 0 ? entries.sort((a, b) => b[1] - a[1])[0][0] as RackSkuId : availableSkus[0]?.id ?? null;
  }, [allDCs, availableSkus]);

  const [selectedSku, setSelectedSku] = useState<RackSkuId | null>(mostCommonSku);

  const preview = useMemo(() => {
    if (!selectedSku) return { campuses: [], totalQty: 0, totalCost: 0 };
    let remaining = money;
    const campuses = cluster.campuses.map(campus => {
      if (campus.status !== 'operational') return { campus, dcs: [], totalQty: 0, totalCost: 0 };
      const dcs = campus.dataCenters.map(dc => {
        const { qty, cost } = computeFillForDC(dc, selectedSku, remaining);
        if (qty > 0) remaining -= cost;
        return { dc, qty, cost };
      });
      return { campus, dcs, totalQty: dcs.reduce((s, d) => s + d.qty, 0), totalCost: dcs.reduce((s, d) => s + d.cost, 0) };
    });
    return {
      campuses,
      totalQty: campuses.reduce((s, c) => s + c.totalQty, 0),
      totalCost: campuses.reduce((s, c) => s + c.totalCost, 0),
    };
  }, [selectedSku, money, cluster.campuses]);

  const fillableDCCount = preview.campuses.reduce((s, c) => s + c.dcs.filter(d => d.qty > 0).length, 0);

  return (
    <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={onClose}>
      <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-lg w-full mx-4 shadow-2xl max-h-[80vh] flex flex-col" onClick={e => e.stopPropagation()}>
        <h3 className="text-lg font-bold mb-4 flex items-center gap-2"><Rocket size={18} className="text-accent" /> Fill All DCs — {cluster.name}</h3>

        <div className="space-y-4 overflow-y-auto flex-1 min-h-0">
          <div>
            <label className="text-xs text-surface-400 mb-2 block">Rack SKU</label>
            <div className="space-y-1.5">
              {availableSkus.map(s => (
                <label key={s.id} className={`flex items-center gap-3 p-2.5 rounded-lg cursor-pointer border text-sm ${selectedSku === s.id ? 'border-accent bg-accent/10' : 'border-surface-600 hover:border-surface-500'}`}>
                  <input type="radio" name="clusterFillSku" checked={selectedSku === s.id} onChange={() => setSelectedSku(s.id)} className="accent-accent" />
                  <span className="font-medium">{s.name}</span>
                  <span className="text-xs text-surface-400 ml-auto">{formatMoney(s.baseCost)}/rack</span>
                </label>
              ))}
            </div>
          </div>

          {selectedSku && (
            <div>
              <label className="text-xs text-surface-400 mb-2 block">Preview by campus</label>
              <div className="space-y-2 max-h-48 overflow-y-auto">
                {preview.campuses.map(({ campus, totalQty, totalCost }) => (
                  <div key={campus.id} className="flex items-center justify-between text-xs px-2 py-1.5 rounded bg-surface-800">
                    <span className="truncate flex-1 mr-2">{campus.name} ({campus.dataCenters.length} DCs)</span>
                    {totalQty > 0 ? (
                      <span className="text-green-400 font-mono shrink-0">+{totalQty} racks ({formatMoney(totalCost)})</span>
                    ) : (
                      <span className="text-surface-500 shrink-0">No change</span>
                    )}
                  </div>
                ))}
              </div>
            </div>
          )}

          <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1">
            <div className="flex justify-between"><span className="text-surface-400">Total racks:</span><span className="font-mono">{formatNumber(preview.totalQty)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Total cost:</span><span className="font-mono">{formatMoney(preview.totalCost)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Remaining budget:</span><span className="font-mono">{formatMoney(money - preview.totalCost)}</span></div>
          </div>
        </div>

        <div className="flex gap-3 mt-4">
          <button onClick={onClose} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
          <button
            onClick={() => selectedSku && onConfirm(selectedSku)}
            disabled={!selectedSku || preview.totalQty === 0}
            className="flex-1 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
            Fill {fillableDCCount} DCs ({formatNumber(preview.totalQty)} racks, {formatMoney(preview.totalCost)})
          </button>
        </div>
      </div>
    </div>
  );
}

// ─── Cluster Detail View ────────────────────────────────────────

function ClusterDetailView({ clusterId }: { clusterId: string }) {
  const cluster = useGameStore((s) => s.infrastructure.clusters.find(c => c.id === clusterId));
  const setNav = useGameStore((s) => s.setInfraNav);
  const fillCluster = useGameStore((s) => s.fillClusterToCapacity);
  const money = useGameStore((s) => s.economy.money);
  const era = useGameStore((s) => s.meta.currentEra);
  const research = useGameStore((s) => s.research.completedResearch);
  const [showBuild, setShowBuild] = useState(false);
  const [showFillAll, setShowFillAll] = useState(false);

  if (!cluster) return <div className="text-surface-400">Cluster not found.</div>;

  const location = LOCATION_CONFIGS[cluster.locationId];

  const allDCs = cluster.campuses.flatMap(c => c.dataCenters);
  const hasOperationalDCs = allDCs.some(dc => dc.status === 'operational');

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-3">
          <Globe size={22} className="text-accent" />
          <div>
            <h2 className="text-xl font-bold">{cluster.name}</h2>
            <p className="text-sm text-surface-400">{location.name} — {location.energyCostMultiplier}x energy cost</p>
          </div>
        </div>
        <div className="flex gap-2">
          {hasOperationalDCs && (
            <button onClick={() => setShowFillAll(true)}
              className="flex items-center gap-1.5 bg-surface-700 hover:bg-surface-600 text-white rounded-lg px-3 py-2 text-sm">
              <Rocket size={14} /> Fill All DCs
            </button>
          )}
          <button onClick={() => setShowBuild(true)}
            className="flex items-center gap-1.5 bg-accent hover:bg-accent-dark text-white rounded-lg px-4 py-2 text-sm font-medium">
            <Plus size={16} /> New Campus
          </button>
        </div>
      </div>

      {cluster.campuses.length === 0 && (
        <TutorialHint id="first-campus">
          Build a campus to start housing data centers. All DCs on a campus share the same tier.
        </TutorialHint>
      )}

      <div className="grid grid-cols-1 gap-4">
        {cluster.campuses.map(campus => (
          <button key={campus.id}
            onClick={() => campus.status === 'operational' && setNav({ level: 'campus', clusterId, campusId: campus.id })}
            className="bg-surface-800 border border-surface-700 rounded-xl p-5 text-left hover:border-accent/50 transition-colors">
            <div className="flex items-center justify-between mb-3">
              <div className="flex items-center gap-2">
                <Building2 size={18} className="text-blue-400" />
                <h3 className="font-bold">{campus.name}</h3>
                <span className="text-xs bg-surface-700 text-surface-300 px-2 py-0.5 rounded">{DC_TIER_CONFIGS[campus.dcTier].name}</span>
                {campus.status === 'constructing' && (
                  <span className="text-xs bg-amber-500/20 text-amber-400 px-2 py-0.5 rounded">Building...</span>
                )}
                {campus.retrofitQueue && (
                  <span className="text-xs bg-violet-500/20 text-violet-400 px-2 py-0.5 rounded">Retrofitting</span>
                )}
              </div>
              <ChevronRight size={16} className="text-surface-400" />
            </div>

            {campus.status === 'constructing' ? (
              <div>
                <div className="flex justify-between text-xs mb-1">
                  <span className="text-surface-400">Construction</span>
                  <span className="font-mono">{Math.floor((campus.constructionProgress / campus.constructionTotal) * 100)}%</span>
                </div>
                <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
                  <div className="h-full bg-amber-500 rounded-full transition-all" style={{ width: `${(campus.constructionProgress / campus.constructionTotal) * 100}%` }} />
                </div>
              </div>
            ) : (
              <div className="grid grid-cols-3 gap-4 text-sm">
                <div><span className="text-surface-400">DCs:</span> <span className="font-mono">{campus.dataCenters.length}</span></div>
                <div><span className="text-surface-400">Racks:</span> <span className="font-mono">{
                  formatNumber(campus.dataCenters.reduce((s, d) => s + d.computeRacksOnline + d.computeRacksFailed, 0))
                }</span></div>
                <div><span className="text-surface-400">FLOPS:</span> <span className="font-mono">{
                  formatNumber(campus.dataCenters.reduce((s, d) => {
                    const sku = d.rackSkuId ? RACK_SKU_CONFIGS[d.rackSkuId] : null;
                    return s + (sku ? d.effectiveComputeRacks * skuTotalFlops(sku) : 0);
                  }, 0))
                }</span></div>
              </div>
            )}
          </button>
        ))}
      </div>

      {showBuild && <BuildCampusModal clusterId={clusterId} onClose={() => setShowBuild(false)} />}

      {showFillAll && (
        <ClusterFillAllModal
          cluster={cluster}
          money={money}
          era={era}
          research={research}
          onConfirm={(skuId) => { fillCluster(clusterId, skuId); setShowFillAll(false); }}
          onClose={() => setShowFillAll(false)}
        />
      )}
    </div>
  );
}

// ─── Build Campus Modal ─────────────────────────────────────────

function BuildCampusModal({ clusterId, onClose }: { clusterId: string; onClose: () => void }) {
  const era = useGameStore((s) => s.meta.currentEra);
  const money = useGameStore((s) => s.economy.money);
  const research = useGameStore((s) => s.research.completedResearch);
  const buildCampus = useGameStore((s) => s.buildCampus);
  const isFirstCampus = useGameStore((s) => s.infrastructure.clusters.every(c => c.campuses.length === 0));

  const [name, setName] = useState('');
  const [tier, setTier] = useState<DCTier>('small');

  const tierConfig = DC_TIER_CONFIGS[tier];
  const campusCost = CAMPUS_TIER_COSTS[tier];
  const effectiveCost = isFirstCampus ? 0 : campusCost.baseCost;
  const eraUnlocked = ERA_ORDER.indexOf(era) >= ERA_ORDER.indexOf(tierConfig.requiredEra);
  const researchUnlocked = !tierConfig.requiredResearch || research.includes(tierConfig.requiredResearch);
  const canBuild = name.trim() !== '' && eraUnlocked && researchUnlocked && money >= effectiveCost;

  return (
    <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={onClose}>
      <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-md w-full mx-4 shadow-2xl" onClick={e => e.stopPropagation()}>
        <h3 className="text-lg font-bold mb-4">Build New Campus</h3>

        <div className="space-y-4">
          <div>
            <label className="text-xs text-surface-400 mb-1 block">Campus Name</label>
            <input value={name} onChange={e => setName(e.target.value)} placeholder="e.g., Campus Alpha"
              className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
          </div>

          <div>
            <label className="text-xs text-surface-400 mb-1 block">DC Tier (all DCs on this campus)</label>
            <select value={tier} onChange={e => setTier(e.target.value as DCTier)}
              className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm">
              {Object.values(DC_TIER_CONFIGS).map(tc => {
                const locked = ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(tc.requiredEra)
                  || (tc.requiredResearch && !research.includes(tc.requiredResearch));
                return (
                  <option key={tc.tier} value={tc.tier} disabled={!!locked}>
                    {tc.name} ({tc.rackSlots} slots, {formatMoney(tc.baseCost)}/DC) {locked ? '🔒' : ''}
                  </option>
                );
              })}
            </select>
          </div>

          <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1">
            <div className="flex justify-between"><span className="text-surface-400">Campus Cost:</span><span className="font-mono">{isFirstCampus ? 'Free' : formatMoney(campusCost.baseCost)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Build Time:</span><span className="font-mono">{isFirstCampus ? `${FIRST_CAMPUS_BUILD_TICKS}s` : `${campusCost.buildTimeTicks}s`}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">DC Slots:</span><span className="font-mono">{tierConfig.rackSlots} racks/DC</span></div>
            <div className="flex justify-between"><span className="text-surface-400">DC Power:</span><span className="font-mono">{formatNumber(tierConfig.powerBudgetKW)} kW/DC</span></div>
          </div>

          <div className="flex gap-3">
            <button onClick={onClose} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
            <button onClick={() => { buildCampus(name.trim(), clusterId, tier); onClose(); }} disabled={!canBuild}
              className="flex-1 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
              Build {isFirstCampus ? '(Free)' : `(${formatMoney(effectiveCost)})`}
            </button>
          </div>
        </div>
      </div>
    </div>
  );
}

// ─── Campus Bulk Action Components ─────────────────────────────

function FillAllDCsModal({ campus, money, era, research, onConfirm, onClose }: {
  campus: Campus;
  money: number;
  era: Era;
  research: string[];
  onConfirm: (skuId: RackSkuId) => void;
  onClose: () => void;
}) {
  const availableSkus = Object.values(RACK_SKU_CONFIGS).filter(s => {
    if (ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(s.era)) return false;
    if (s.requiredResearch.length > 0 && !s.requiredResearch.every(r => research.includes(r))) return false;
    return true;
  });

  const mostCommonSku = useMemo(() => {
    const counts: Record<string, number> = {};
    for (const dc of campus.dataCenters) {
      if (dc.rackSkuId) counts[dc.rackSkuId] = (counts[dc.rackSkuId] || 0) + 1;
    }
    const entries = Object.entries(counts);
    return entries.length > 0 ? entries.sort((a, b) => b[1] - a[1])[0][0] as RackSkuId : availableSkus[0]?.id ?? null;
  }, [campus.dataCenters, availableSkus]);

  const [selectedSku, setSelectedSku] = useState<RackSkuId | null>(mostCommonSku);

  const preview = useMemo(() => {
    if (!selectedSku) return { dcs: [], totalQty: 0, totalCost: 0 };
    let remaining = money;
    const dcs = campus.dataCenters.map(dc => {
      if (dc.status !== 'operational') return { dc, qty: 0, cost: 0, reason: dc.status === 'constructing' ? 'Constructing' : 'Retrofitting' as string | null };
      if (dc.status === 'operational' && dc.rackSkuId && dc.rackSkuId !== selectedSku) return { dc, qty: 0, cost: 0, reason: `Different SKU (${RACK_SKU_CONFIGS[dc.rackSkuId].name})` };
      const { qty, cost } = computeFillForDC(dc, selectedSku, remaining);
      if (qty === 0) {
        const tierConfig = DC_TIER_CONFIGS[dc.tier];
        const maxCompute = maxComputeRacks(tierConfig.rackSlots, dc.tier);
        const pipelineCount = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((sum, c) => sum + c.count, 0);
        const isFull = maxCompute - (dc.computeRacksOnline + pipelineCount) <= 0;
        return { dc, qty: 0, cost: 0, reason: isFull ? 'Already full' : 'No budget' };
      }
      remaining -= cost;
      return { dc, qty, cost, reason: null };
    });
    return { dcs, totalQty: dcs.reduce((s, d) => s + d.qty, 0), totalCost: dcs.reduce((s, d) => s + d.cost, 0) };
  }, [selectedSku, money, campus.dataCenters]);

  const fillableDCCount = preview.dcs.filter(d => d.qty > 0).length;

  return (
    <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={onClose}>
      <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-lg w-full mx-4 shadow-2xl max-h-[80vh] flex flex-col" onClick={e => e.stopPropagation()}>
        <h3 className="text-lg font-bold mb-4 flex items-center gap-2"><Rocket size={18} className="text-accent" /> Fill All DCs</h3>

        <div className="space-y-4 overflow-y-auto flex-1 min-h-0">
          <div>
            <label className="text-xs text-surface-400 mb-2 block">Rack SKU</label>
            <div className="space-y-1.5">
              {availableSkus.map(s => (
                <label key={s.id} className={`flex items-center gap-3 p-2.5 rounded-lg cursor-pointer border text-sm ${selectedSku === s.id ? 'border-accent bg-accent/10' : 'border-surface-600 hover:border-surface-500'}`}>
                  <input type="radio" name="fillSku" checked={selectedSku === s.id} onChange={() => setSelectedSku(s.id)} className="accent-accent" />
                  <span className="font-medium">{s.name}</span>
                  <span className="text-xs text-surface-400 ml-auto">{formatMoney(s.baseCost)}/rack</span>
                </label>
              ))}
            </div>
          </div>

          {selectedSku && (
            <div>
              <label className="text-xs text-surface-400 mb-2 block">Preview ({fillableDCCount} of {campus.dataCenters.length} DCs)</label>
              <div className="space-y-1 max-h-48 overflow-y-auto">
                {preview.dcs.map(({ dc, qty, cost, reason }) => (
                  <div key={dc.id} className="flex items-center justify-between text-xs px-2 py-1.5 rounded bg-surface-800">
                    <span className="truncate flex-1 mr-2">{dc.name}</span>
                    {reason ? (
                      <span className="text-surface-500 shrink-0">{reason}</span>
                    ) : (
                      <span className="text-green-400 font-mono shrink-0">+{qty} racks ({formatMoney(cost)})</span>
                    )}
                  </div>
                ))}
              </div>
            </div>
          )}

          <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1">
            <div className="flex justify-between"><span className="text-surface-400">Total racks:</span><span className="font-mono">{formatNumber(preview.totalQty)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Total cost:</span><span className="font-mono">{formatMoney(preview.totalCost)}</span></div>
            <div className="flex justify-between"><span className="text-surface-400">Remaining budget:</span><span className="font-mono">{formatMoney(money - preview.totalCost)}</span></div>
          </div>
        </div>

        <div className="flex gap-3 mt-4">
          <button onClick={onClose} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
          <button
            onClick={() => selectedSku && onConfirm(selectedSku)}
            disabled={!selectedSku || preview.totalQty === 0}
            className="flex-1 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
            Fill {fillableDCCount} DCs ({formatNumber(preview.totalQty)} racks, {formatMoney(preview.totalCost)})
          </button>
        </div>
      </div>
    </div>
  );
}

function RetrofitCampusModal({ campus, era, research, onConfirm, onClose }: {
  campus: Campus;
  era: Era;
  research: string[];
  onConfirm: (skuId: RackSkuId, maxConcurrent: number) => void;
  onClose: () => void;
}) {
  const [selectedSku, setSelectedSku] = useState<RackSkuId | null>(null);
  const [concurrencyMode, setConcurrencyMode] = useState<'1' | '10' | '25' | 'custom'>('10');
  const [customCount, setCustomCount] = useState(1);

  const currentSkuIds = [...new Set(campus.dataCenters.filter(dc => dc.rackSkuId).map(dc => dc.rackSkuId!))];

  const targetSkus = Object.values(RACK_SKU_CONFIGS).filter(s => {
    if (ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(s.era)) return false;
    if (s.requiredResearch.length > 0 && !s.requiredResearch.every(r => research.includes(r))) return false;
    return true;
  });

  const eligible = useMemo(() => {
    if (!selectedSku) return { count: 0, skipped: 0 };
    let count = 0;
    let skipped = 0;
    for (const dc of campus.dataCenters) {
      if (dc.status !== 'operational' || !dc.rackSkuId || dc.rackSkuId === selectedSku) {
        skipped++;
        continue;
      }
      const pipelineCount = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((sum, c) => sum + c.count, 0);
      if (dc.computeRacksOnline + pipelineCount <= 0) { skipped++; continue; }
      count++;
    }
    return { count, skipped };
  }, [selectedSku, campus.dataCenters]);

  const maxConcurrent = useMemo(() => {
    if (eligible.count === 0) return 1;
    switch (concurrencyMode) {
      case '1': return 1;
      case '10': return Math.max(1, Math.ceil(eligible.count * 0.1));
      case '25': return Math.max(1, Math.ceil(eligible.count * 0.25));
      case 'custom': return Math.max(1, Math.min(customCount, eligible.count));
    }
  }, [concurrencyMode, customCount, eligible.count]);

  const capacityMaintained = eligible.count > 0 ? Math.round(((eligible.count - maxConcurrent) / eligible.count) * 100) : 100;

  const estimatedBatches = eligible.count > 0 ? Math.ceil(eligible.count / maxConcurrent) : 0;

  return (
    <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={onClose}>
      <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-lg w-full mx-4 shadow-2xl max-h-[80vh] flex flex-col" onClick={e => e.stopPropagation()}>
        <h3 className="text-lg font-bold mb-4 flex items-center gap-2"><RefreshCw size={18} className="text-violet-400" /> Retrofit Campus</h3>

        <div className="space-y-4 overflow-y-auto flex-1 min-h-0">
          <div>
            <label className="text-xs text-surface-400 mb-2 block">Target SKU</label>
            <div className="space-y-1.5">
              {targetSkus.map(s => {
                const isCurrentOnly = currentSkuIds.length === 1 && currentSkuIds[0] === s.id;
                return (
                  <button key={s.id}
                    onClick={() => !isCurrentOnly && setSelectedSku(s.id)}
                    disabled={isCurrentOnly}
                    className={`w-full flex items-center justify-between p-3 rounded-lg border text-left text-sm transition-colors ${
                      selectedSku === s.id ? 'border-violet-500 bg-violet-500/10' :
                      isCurrentOnly ? 'border-surface-700 opacity-40 cursor-not-allowed' :
                      'border-surface-600 hover:border-surface-500 cursor-pointer'
                    }`}>
                    <div>
                      <div className="font-medium">{s.name}</div>
                      <div className="text-xs text-surface-400">{s.trainingFlops}T / {s.inferenceFlops}I FLOPS | {s.totalVramGB}GB | {s.powerDrawKW} kW | {formatMoney(s.baseCost)}/rack</div>
                    </div>
                    {isCurrentOnly && <span className="text-xs text-surface-500">Current</span>}
                    {selectedSku === s.id && <CheckCircle size={16} className="text-violet-400" />}
                  </button>
                );
              })}
            </div>
          </div>

          {selectedSku && eligible.count > 0 && (
            <>
              <div>
                <label className="text-xs text-surface-400 mb-2 block">Concurrency</label>
                <div className="flex gap-1.5">
                  {([
                    { key: '1' as const, label: '1 at a time' },
                    { key: '10' as const, label: `10% = ${Math.max(1, Math.ceil(eligible.count * 0.1))}` },
                    { key: '25' as const, label: `25% = ${Math.max(1, Math.ceil(eligible.count * 0.25))}` },
                    { key: 'custom' as const, label: 'Custom' },
                  ]).map(opt => (
                    <button key={opt.key} onClick={() => setConcurrencyMode(opt.key)}
                      className={`flex-1 py-2 text-xs rounded-lg border transition-colors ${
                        concurrencyMode === opt.key ? 'border-violet-500 bg-violet-500/10 text-violet-300' : 'border-surface-600 text-surface-400 hover:border-surface-500'
                      }`}>
                      {opt.label}
                    </button>
                  ))}
                </div>
                {concurrencyMode === 'custom' && (
                  <input type="number" min={1} max={eligible.count} value={customCount}
                    onChange={e => setCustomCount(Math.max(1, parseInt(e.target.value) || 1))}
                    className="mt-2 w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
                )}
              </div>

              <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1.5">
                <div className="flex justify-between"><span className="text-surface-400">DCs to retrofit:</span><span>{eligible.count} of {campus.dataCenters.length}</span></div>
                <div className="flex justify-between"><span className="text-surface-400">Concurrent retrofits:</span><span>{maxConcurrent}</span></div>
                <div className="flex justify-between"><span className="text-surface-400">Estimated batches:</span><span>{estimatedBatches}</span></div>
                <div className="flex justify-between">
                  <span className="text-surface-400">Capacity maintained:</span>
                  <span className={capacityMaintained >= 75 ? 'text-green-400' : capacityMaintained >= 50 ? 'text-amber-400' : 'text-red-400'}>~{capacityMaintained}%</span>
                </div>
                {eligible.skipped > 0 && (
                  <div className="text-xs text-surface-500 mt-1">{eligible.skipped} DCs skipped (constructing, empty, or already target SKU)</div>
                )}
              </div>
            </>
          )}
        </div>

        <div className="flex gap-3 mt-4">
          <button onClick={onClose} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
          <button
            onClick={() => selectedSku && onConfirm(selectedSku, maxConcurrent)}
            disabled={!selectedSku || eligible.count === 0}
            className="flex-1 bg-violet-600 hover:bg-violet-700 disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
            Start Campus Retrofit
          </button>
        </div>
      </div>
    </div>
  );
}

function CampusRetrofitProgress({ campus, onCancel }: { campus: Campus; onCancel: () => void }) {
  const queue = campus.retrofitQueue;
  if (!queue) return null;

  const total = queue.pendingDCIds.length + queue.activeDCIds.length + queue.completedDCIds.length;
  const completed = queue.completedDCIds.length;
  const active = queue.activeDCIds.length;
  const pending = queue.pendingDCIds.length;
  const pct = total > 0 ? (completed / total) * 100 : 0;

  return (
    <div className="bg-violet-500/10 border border-violet-500/30 rounded-xl p-4 space-y-3">
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-2">
          <RefreshCw size={16} className="text-violet-400 animate-spin" style={{ animationDuration: '3s' }} />
          <span className="text-sm font-medium">Campus Retrofit — {RACK_SKU_CONFIGS[queue.targetSkuId].name}</span>
        </div>
        <button onClick={onCancel} className="flex items-center gap-1 text-xs text-surface-400 hover:text-red-400 transition-colors">
          <X size={12} /> Cancel
        </button>
      </div>
      <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
        <div className="h-full bg-violet-500 rounded-full transition-all" style={{ width: `${pct}%` }} />
      </div>
      <div className="flex justify-between text-xs text-surface-400">
        <span>{completed} of {total} complete</span>
        <span>{active} active | {pending} pending</span>
      </div>
    </div>
  );
}

// ─── Campus Detail View ────────────────────────────────────────���

function CampusDetailView({ clusterId, campusId }: { clusterId: string; campusId: string }) {
  const cluster = useGameStore((s) => s.infrastructure.clusters.find(c => c.id === clusterId));
  const campus = cluster?.campuses.find(c => c.id === campusId);
  const setNav = useGameStore((s) => s.setInfraNav);
  const buildDC = useGameStore((s) => s.buildDataCenter);
  const addDCs = useGameStore((s) => s.addDCsToCampus);
  const fillCampus = useGameStore((s) => s.fillCampusToCapacity);
  const startRetrofit = useGameStore((s) => s.startCampusRetrofit);
  const cancelRetrofit = useGameStore((s) => s.cancelCampusRetrofit);
  const money = useGameStore((s) => s.economy.money);
  const era = useGameStore((s) => s.meta.currentEra);
  const research = useGameStore((s) => s.research.completedResearch);

  const [showAddDC, setShowAddDC] = useState(false);
  const [dcName, setDcName] = useState('');
  const [bulkCount, setBulkCount] = useState(1);
  const [showFillAll, setShowFillAll] = useState(false);
  const [showRetrofit, setShowRetrofit] = useState(false);

  if (!campus || !cluster) return <div className="text-surface-400">Campus not found.</div>;

  const tierConfig = DC_TIER_CONFIGS[campus.dcTier];
  const operationalDCs = campus.dataCenters.filter(dc => dc.status === 'operational');
  const hasRetrofitQueue = !!campus.retrofitQueue;

  const fillableDCs = operationalDCs.filter(dc => {
    const maxCompute = maxComputeRacks(tierConfig.rackSlots, dc.tier);
    const pipelineCount = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((sum, c) => sum + c.count, 0);
    return maxCompute - (dc.computeRacksOnline + pipelineCount) > 0;
  });

  const retrofitEligibleDCs = operationalDCs.filter(dc =>
    dc.rackSkuId && (dc.computeRacksOnline + dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((sum, c) => sum + c.count, 0)) > 0,
  );

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-3">
          <Building2 size={22} className="text-blue-400" />
          <div>
            <h2 className="text-xl font-bold">{campus.name}</h2>
            <p className="text-sm text-surface-400">{tierConfig.name} campus — {campus.dataCenters.length} DCs</p>
          </div>
        </div>
        <div className="flex gap-2">
          {operationalDCs.length > 0 && !hasRetrofitQueue && (
            <>
              <button onClick={() => setShowFillAll(true)}
                disabled={fillableDCs.length === 0}
                className="flex items-center gap-1.5 bg-surface-700 hover:bg-surface-600 disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg px-3 py-2 text-sm">
                <Rocket size={14} /> Fill All DCs
              </button>
              <button onClick={() => setShowRetrofit(true)}
                disabled={retrofitEligibleDCs.length === 0}
                className="flex items-center gap-1.5 bg-violet-600 hover:bg-violet-700 disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg px-3 py-2 text-sm">
                <RefreshCw size={14} /> Retrofit Campus
              </button>
            </>
          )}
          <button onClick={() => setShowAddDC(true)}
            className="flex items-center gap-1.5 bg-accent hover:bg-accent-dark text-white rounded-lg px-4 py-2 text-sm font-medium">
            <Plus size={16} /> Add DC
          </button>
        </div>
      </div>

      {/* Campus Retrofit Progress Banner */}
      {campus.retrofitQueue && (
        <CampusRetrofitProgress campus={campus} onCancel={() => cancelRetrofit(campusId)} />
      )}

      {campus.dataCenters.length === 0 && (
        <TutorialHint id="first-dc">
          Add a data center to this campus. Once built, you can deploy racks to start generating compute.
        </TutorialHint>
      )}

      <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
        {campus.dataCenters.map(dc => {
          const queueStatus = campus.retrofitQueue
            ? campus.retrofitQueue.pendingDCIds.includes(dc.id) ? 'queued'
            : campus.retrofitQueue.completedDCIds.includes(dc.id) ? 'retrofit-done'
            : null
            : null;

          return (
            <button key={dc.id}
              onClick={() => (dc.status === 'operational' || dc.status === 'retrofitting') && setNav({
                level: 'datacenter', clusterId, campusId, datacenterId: dc.id,
              })}
              className="bg-surface-800 border border-surface-700 rounded-xl p-4 text-left hover:border-accent/50 transition-colors">
              <div className="flex items-center justify-between mb-3">
                <div className="flex items-center gap-2">
                  <Server size={16} className="text-violet-400" />
                  <span className="font-bold">{dc.name}</span>
                  {dc.rackSkuId && <span className="text-xs bg-surface-700 text-surface-300 px-2 py-0.5 rounded">{RACK_SKU_CONFIGS[dc.rackSkuId].name}</span>}
                  {dc.status === 'constructing' && <span className="text-xs bg-amber-500/20 text-amber-400 px-2 py-0.5 rounded">Building</span>}
                  {dc.status === 'retrofitting' && <span className="text-xs bg-violet-500/20 text-violet-400 px-2 py-0.5 rounded">Retrofitting</span>}
                  {queueStatus === 'queued' && <span className="text-xs bg-surface-600 text-surface-300 px-2 py-0.5 rounded">Queued</span>}
                  {queueStatus === 'retrofit-done' && <span className="text-xs bg-green-500/20 text-green-400 px-2 py-0.5 rounded flex items-center gap-1"><CheckCircle size={10} /> Done</span>}
                </div>
                <ChevronRight size={14} className="text-surface-500" />
              </div>

              {dc.status === 'constructing' ? (
                <div>
                  <div className="flex justify-between text-xs mb-1">
                    <span className="text-surface-400">Construction</span>
                    <span className="font-mono">{Math.floor((dc.constructionProgress / dc.constructionTotal) * 100)}%</span>
                  </div>
                  <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
                    <div className="h-full bg-amber-500 rounded-full transition-all" style={{ width: `${(dc.constructionProgress / dc.constructionTotal) * 100}%` }} />
                  </div>
                </div>
              ) : (
                <div className="space-y-2">
                  <DeploymentProgressBar dc={dc} />
                  <NetworkHealthIndicator dc={dc} />
                  {dc.deploymentCohorts.length > 0 && <CohortStageBreakdown cohorts={dc.deploymentCohorts} />}
                  <div className="flex justify-between text-xs text-surface-400">
                    <span>Uptime: {formatPercent(dc.currentUptime)}</span>
                    <span>Cost: {formatMoney(dc.energyCostPerTick + dc.maintenanceCostPerTick)}/s</span>
                  </div>
                </div>
              )}
            </button>
          );
        })}
      </div>

      {showAddDC && (
        <div className="fixed inset-0 bg-black/60 flex items-center justify-center z-50" onClick={() => setShowAddDC(false)}>
          <div className="bg-surface-900 border border-surface-700 rounded-xl p-6 max-w-md w-full mx-4 shadow-2xl" onClick={e => e.stopPropagation()}>
            <h3 className="text-lg font-bold mb-4">Add Data Center{bulkCount > 1 ? 's' : ''}</h3>
            <div className="space-y-4">
              <div>
                <label className="text-xs text-surface-400 mb-1 block">DC Name</label>
                <input value={dcName} onChange={e => setDcName(e.target.value)} placeholder={`${campus.name}-DC-${campus.dataCenters.length + 1}`}
                  className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
              </div>
              <div>
                <label className="text-xs text-surface-400 mb-1 block">Quantity</label>
                <input type="number" min={1} max={20} value={bulkCount} onChange={e => setBulkCount(Math.max(1, parseInt(e.target.value) || 1))}
                  className="w-full bg-surface-800 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
              </div>
              <div className="bg-surface-800 rounded-lg p-3 text-sm space-y-1">
                <div className="flex justify-between"><span className="text-surface-400">Tier:</span><span>{tierConfig.name}</span></div>
                <div className="flex justify-between"><span className="text-surface-400">Cost per DC:</span><span className="font-mono">{formatMoney(tierConfig.baseCost)}</span></div>
                <div className="flex justify-between font-medium"><span className="text-surface-400">Total:</span><span className="font-mono">{formatMoney(tierConfig.baseCost * bulkCount)}</span></div>
              </div>
              <div className="flex gap-3">
                <button onClick={() => setShowAddDC(false)} className="flex-1 bg-surface-700 hover:bg-surface-600 rounded-lg py-2 text-sm">Cancel</button>
                <button
                  onClick={() => {
                    if (bulkCount === 1) {
                      buildDC(dcName.trim() || `${campus.name}-DC-${campus.dataCenters.length + 1}`, campusId);
                    } else {
                      addDCs(campusId, bulkCount);
                    }
                    setShowAddDC(false);
                  }}
                  disabled={money < tierConfig.baseCost * bulkCount}
                  className="flex-1 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
                  Build {bulkCount > 1 ? `${bulkCount} DCs` : 'DC'} ({formatMoney(tierConfig.baseCost * bulkCount)})
                </button>
              </div>
            </div>
          </div>
        </div>
      )}

      {showFillAll && (
        <FillAllDCsModal
          campus={campus}
          money={money}
          era={era}
          research={research}
          onConfirm={(skuId) => { fillCampus(campusId, skuId); setShowFillAll(false); }}
          onClose={() => setShowFillAll(false)}
        />
      )}

      {showRetrofit && (
        <RetrofitCampusModal
          campus={campus}
          era={era}
          research={research}
          onConfirm={(skuId, maxConcurrent) => { startRetrofit(campusId, skuId, maxConcurrent); setShowRetrofit(false); }}
          onClose={() => setShowRetrofit(false)}
        />
      )}
    </div>
  );
}

// ─── Data Center Detail View ────────────────────────────────────

function DataCenterDetailView({ clusterId, campusId, datacenterId }: {
  clusterId: string; campusId: string; datacenterId: string;
}) {
  const cluster = useGameStore((s) => s.infrastructure.clusters.find(c => c.id === clusterId));
  const campus = cluster?.campuses.find(c => c.id === campusId);
  const dc = campus?.dataCenters.find(d => d.id === datacenterId);
  const money = useGameStore((s) => s.economy.money);
  const era = useGameStore((s) => s.meta.currentEra);
  const research = useGameStore((s) => s.research.completedResearch);
  const deployRacks = useGameStore((s) => s.deployRacks);
  const fillToCapacity = useGameStore((s) => s.fillDCToCapacity);
  const retrofitDC = useGameStore((s) => s.retrofitDC);
  const cancelRetrofit = useGameStore((s) => s.cancelRetrofit);
  const upgradeDataCenter = useGameStore((s) => s.upgradeDataCenter);

  const [activeTab, setActiveTab] = useState<'deploy' | 'retrofit' | 'upgrades' | 'network'>('deploy');
  const [selectedSku, setSelectedSku] = useState<RackSkuId | null>(null);
  const [deployQty, setDeployQty] = useState(10);
  const [confirmRetrofit, setConfirmRetrofit] = useState<RackSkuId | null>(null);

  if (!dc || !cluster) return <div className="text-surface-400">Data center not found.</div>;

  const tierConfig = DC_TIER_CONFIGS[dc.tier];
  const maxCompute = maxComputeRacks(tierConfig.rackSlots, dc.tier);
  const pipelineCount = dc.deploymentCohorts.filter(c => c.stage !== 'decommission').reduce((s, c) => s + c.count, 0);
  const existingCompute = dc.computeRacksOnline + pipelineCount;
  const availableSlots = maxCompute - existingCompute;
  const sku = dc.rackSkuId ? RACK_SKU_CONFIGS[dc.rackSkuId] : null;
  const netSlots = estimateNetworkSlots(existingCompute, dc.tier);

  const availableSkus = Object.values(RACK_SKU_CONFIGS).filter(s => {
    if (ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(s.era)) return false;
    if (s.requiredResearch.length > 0 && !s.requiredResearch.every(r => research.includes(r))) return false;
    if (dc.rackSkuId && dc.rackSkuId !== s.id) return false;
    return true;
  });

  const effectiveSku = selectedSku ? RACK_SKU_CONFIGS[selectedSku] : null;

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-3">
          <Server size={22} className="text-violet-400" />
          <div>
            <h2 className="text-xl font-bold">{dc.name}</h2>
            <p className="text-sm text-surface-400">
              {tierConfig.name} — {sku?.name ?? 'No racks deployed'} — {LOCATION_CONFIGS[cluster.locationId].name}
            </p>
          </div>
        </div>
        {dc.status === 'retrofitting' && (
          <span className="text-sm bg-violet-500/20 text-violet-400 px-3 py-1 rounded-lg">
            Retrofitting to {dc.retrofitState ? RACK_SKU_CONFIGS[dc.retrofitState.toSkuId].name : '...'}
          </span>
        )}
      </div>

      {/* Stats Grid */}
      <div className="grid grid-cols-5 gap-3">
        <FleetStat icon={Cpu} label="Online" value={formatNumber(dc.computeRacksOnline)} sub={`of ${maxCompute} max compute`} />
        <FleetStat icon={Zap} label="FLOPS" value={`${formatNumber(dc.dcTrainingFlops)}T / ${formatNumber(dc.dcInferenceFlops)}I`} />
        <FleetStat icon={HardDrive} label="VRAM" value={`${formatNumber(dc.dcTotalVramGB)} GB`} />
        <FleetStat icon={Activity} label="Uptime" value={formatPercent(dc.currentUptime)} />
        <FleetStat icon={DollarSign} label="Cost/s" value={formatMoney(dc.energyCostPerTick + dc.maintenanceCostPerTick)} />
      </div>

      {/* Capacity Bars */}
      <div className="grid grid-cols-2 gap-4">
        <CapacityBar label="Rack Slots" used={dc.usedSlots} total={tierConfig.rackSlots} />
        <CapacityBar label="Power (kW)" used={dc.usedPowerKW} total={tierConfig.powerBudgetKW} />
      </div>

      {/* Deployment Progress */}
      <div className="bg-surface-800 border border-surface-700 rounded-xl p-4">
        <DeploymentProgressBar dc={dc} />
        {dc.deploymentCohorts.length > 0 && (
          <div className="mt-3">
            <CohortStageBreakdown cohorts={dc.deploymentCohorts} />
          </div>
        )}
        {dc.computeRacksFailed > 0 && (
          <div className="mt-2 text-xs text-danger flex items-center gap-1">
            <Wrench size={12} /> {dc.computeRacksFailed} rack{dc.computeRacksFailed > 1 ? 's' : ''} under repair
          </div>
        )}
      </div>

      {/* Retrofit Progress */}
      {dc.status === 'retrofitting' && dc.retrofitState && (
        <div className="bg-violet-500/10 border border-violet-500/30 rounded-xl p-4">
          <div className="flex items-center justify-between mb-2">
            <div className="flex items-center gap-2">
              <RefreshCw size={16} className="text-violet-400" />
              <span className="font-medium">Retrofit: {dc.retrofitState.phase}</span>
            </div>
            <button onClick={() => cancelRetrofit(datacenterId)} className="text-xs text-surface-400 hover:text-surface-200">Cancel</button>
          </div>
          <div className="flex justify-between text-xs mb-1">
            <span className="text-surface-400">{RACK_SKU_CONFIGS[dc.retrofitState.fromSkuId].name} → {RACK_SKU_CONFIGS[dc.retrofitState.toSkuId].name}</span>
            <span className="font-mono">{Math.floor((dc.retrofitState.progress / dc.retrofitState.total) * 100)}%</span>
          </div>
          <div className="h-2 bg-surface-700 rounded-full overflow-hidden">
            <div className="h-full bg-violet-500 rounded-full transition-all" style={{ width: `${(dc.retrofitState.progress / dc.retrofitState.total) * 100}%` }} />
          </div>
        </div>
      )}

      {/* Tabs */}
      {dc.status === 'operational' && (
        <>
          <div className="flex gap-1 bg-surface-800 rounded-lg p-1">
            {(['deploy', 'retrofit', 'upgrades', 'network'] as const).map(tab => (
              <button key={tab} onClick={() => setActiveTab(tab)}
                className={`flex-1 py-2 text-sm rounded-md transition-colors ${activeTab === tab ? 'bg-surface-700 text-white' : 'text-surface-400 hover:text-surface-200'}`}>
                {tab === 'deploy' ? 'Deploy Racks' : tab === 'retrofit' ? 'Retrofit' : tab === 'upgrades' ? 'Upgrades' : 'Network'}
              </button>
            ))}
          </div>

          {/* Deploy Tab */}
          {activeTab === 'deploy' && (
            <div className="bg-surface-800 border border-surface-700 rounded-xl p-4 space-y-4">
              {dc.rackSkuId === null ? (
                <>
                  <p className="text-sm text-surface-400">Select a rack SKU for this data center. All racks in a DC must be the same type.</p>
                  <div className="space-y-2">
                    {availableSkus.map(s => (
                      <label key={s.id} className={`flex items-center gap-3 p-3 rounded-lg cursor-pointer border ${selectedSku === s.id ? 'border-accent bg-accent/10' : 'border-surface-600 hover:border-surface-500'}`}>
                        <input type="radio" name="sku" checked={selectedSku === s.id} onChange={() => setSelectedSku(s.id)} className="accent-accent" />
                        <div className="flex-1">
                          <div className="font-medium text-sm">{s.name}</div>
                          <div className="text-xs text-surface-400">{s.trainingFlops}T / {s.inferenceFlops}I FLOPS | {s.totalVramGB}GB | {s.powerDrawKW} kW | {formatMoney(s.baseCost)}</div>
                        </div>
                      </label>
                    ))}
                  </div>
                </>
              ) : (
                <div className="text-sm text-surface-400">
                  This DC runs <span className="text-surface-200 font-medium">{sku!.name}</span>. Available: {availableSlots} compute slots.
                </div>
              )}

              {(dc.rackSkuId || selectedSku) && availableSlots > 0 && (
                <div className="space-y-3">
                  <div>
                    <label className="text-xs text-surface-400 mb-1 block">Quantity</label>
                    <input type="number" min={1} max={availableSlots} value={deployQty}
                      onChange={e => setDeployQty(Math.max(1, Math.min(availableSlots, parseInt(e.target.value) || 1)))}
                      className="w-full bg-surface-900 border border-surface-600 rounded-lg px-3 py-2 text-sm" />
                  </div>

                  {(() => {
                    const skuToUse = dc.rackSkuId ?? selectedSku!;
                    const skuConfig = RACK_SKU_CONFIGS[skuToUse];
                    const newNetSlots = estimateNetworkSlots(existingCompute + deployQty, dc.tier);
                    const addedNet = newNetSlots - netSlots;
                    const totalCost = skuConfig.baseCost * deployQty;
                    return (
                      <div className="bg-surface-900 rounded-lg p-3 text-sm space-y-1">
                        <div className="flex justify-between"><span className="text-surface-400">{deployQty} compute racks ({skuConfig.name})</span><span className="font-mono">{formatMoney(totalCost)}</span></div>
                        <div className="flex justify-between text-xs text-surface-500"><span>+ {addedNet} network racks (auto)</span><span>included</span></div>
                        <div className="flex justify-between text-xs text-surface-500"><span>= {existingCompute + deployQty + newNetSlots} / {tierConfig.rackSlots} total slots</span></div>
                        <div className="flex justify-between text-xs text-surface-500"><span>Power: {formatNumber((existingCompute + deployQty) * skuConfig.powerDrawKW)} / {formatNumber(tierConfig.powerBudgetKW)} kW</span></div>
                      </div>
                    );
                  })()}

                  <div className="flex gap-3">
                    <button
                      onClick={() => deployRacks(datacenterId, dc.rackSkuId ?? selectedSku!, deployQty)}
                      disabled={money < (RACK_SKU_CONFIGS[dc.rackSkuId ?? selectedSku!].baseCost * deployQty)}
                      className="flex-1 flex items-center justify-center gap-1.5 bg-accent hover:bg-accent-dark disabled:opacity-50 disabled:cursor-not-allowed text-white rounded-lg py-2 text-sm font-medium">
                      <Rocket size={14} /> Deploy {deployQty} Racks
                    </button>
                    <button
                      onClick={() => fillToCapacity(datacenterId, dc.rackSkuId ?? selectedSku!)}
                      disabled={availableSlots === 0}
                      className="flex items-center gap-1.5 bg-surface-700 hover:bg-surface-600 disabled:opacity-50 text-white rounded-lg px-4 py-2 text-sm">
                      Fill to Capacity
                    </button>
                  </div>
                </div>
              )}
            </div>
          )}

          {/* Retrofit Tab */}
          {activeTab === 'retrofit' && (
            <div className="bg-surface-800 border border-surface-700 rounded-xl p-4 space-y-4">
              {!dc.rackSkuId ? (
                <p className="text-sm text-surface-400">No racks deployed yet. Deploy racks first before retrofitting.</p>
              ) : (
                <>
                  <p className="text-sm text-surface-400">
                    Retrofit swaps all {dc.computeRacksOnline + pipelineCount} <span className="text-surface-200">{sku!.name}</span> racks to a new SKU.
                    The DC goes offline during retrofit.
                  </p>
                  <div className="space-y-2">
                    {Object.values(RACK_SKU_CONFIGS).filter(s => {
                      if (s.id === dc.rackSkuId) return false;
                      if (ERA_ORDER.indexOf(era) < ERA_ORDER.indexOf(s.era)) return false;
                      if (s.requiredResearch.length > 0 && !s.requiredResearch.every(r => research.includes(r))) return false;
                      return true;
                    }).map(s => (
                      <button key={s.id} onClick={() => setConfirmRetrofit(s.id)}
                        className="w-full flex items-center justify-between p-3 rounded-lg border border-surface-600 hover:border-accent/50 text-left">
                        <div>
                          <div className="font-medium text-sm">{s.name}</div>
                          <div className="text-xs text-surface-400">{s.trainingFlops}T / {s.inferenceFlops}I FLOPS | {s.totalVramGB}GB | {s.powerDrawKW} kW | {formatMoney(s.baseCost)}/rack</div>
                        </div>
                        <RefreshCw size={14} className="text-surface-400" />
                      </button>
                    ))}
                  </div>
                </>
              )}
            </div>
          )}

          {/* Upgrades Tab */}
          {activeTab === 'upgrades' && (
            <div className="bg-surface-800 border border-surface-700 rounded-xl p-4 space-y-4">
              {/* Cooling & Network Fabric */}
              <div className="grid grid-cols-2 gap-3">
                <div className="flex items-center gap-3 p-3 border border-surface-600 rounded-lg">
                  <Thermometer size={18} className="text-cyan-400" />
                  <div>
                    <div className="text-xs text-surface-400">Cooling Type</div>
                    <div className="font-medium text-sm capitalize">{dc.coolingType}</div>
                  </div>
                </div>
                <div className="flex items-center gap-3 p-3 border border-surface-600 rounded-lg">
                  <Network size={18} className="text-blue-400" />
                  <div>
                    <div className="text-xs text-surface-400">Network Fabric</div>
                    <div className="font-medium text-sm">{dc.networkFabric}</div>
                  </div>
                </div>
              </div>

              {(['cooling', 'redundancy'] as const).map(upgrade => {
                const level = upgrade === 'cooling' ? dc.coolingLevel : dc.redundancyLevel;
                const cost = tierConfig.baseCost * DC_UPGRADE_COST_FRACTION;
                const maxed = level >= 1.0;
                return (
                  <div key={upgrade} className="flex items-center justify-between p-3 border border-surface-600 rounded-lg">
                    <div className="flex items-center gap-3">
                      {upgrade === 'cooling' ? <Thermometer size={18} className="text-cyan-400" /> : <Shield size={18} className="text-green-400" />}
                      <div>
                        <div className="font-medium text-sm capitalize">{upgrade}</div>
                        <div className="text-xs text-surface-400">Level {Math.round(level * 10)}/10 — reduces {upgrade === 'cooling' ? 'test' : 'production'} failure rates</div>
                      </div>
                    </div>
                    <button
                      onClick={() => upgradeDataCenter(datacenterId, upgrade)}
                      disabled={maxed || money < cost}
                      className="bg-surface-700 hover:bg-surface-600 disabled:opacity-50 disabled:cursor-not-allowed px-3 py-1.5 rounded-lg text-xs font-medium">
                      {maxed ? 'Maxed' : `Upgrade (${formatMoney(cost)})`}
                    </button>
                  </div>
                );
              })}
            </div>
          )}

          {/* Network Tab */}
          {activeTab === 'network' && (
            <div className="bg-surface-800 border border-surface-700 rounded-xl p-4 space-y-4">
              <h4 className="font-medium text-sm flex items-center gap-2"><Network size={16} className="text-cyan-400" /> Network Topology</h4>
              {dc.computeRacksOnline === 0 ? (
                <p className="text-sm text-surface-400">No racks online. Deploy racks to see network topology.</p>
              ) : (
                <div className="space-y-3">
                  {/* Bandwidth gauge */}
                  <div className="p-3 border border-surface-600 rounded-lg">
                    <div className="flex items-center justify-between mb-1">
                      <span className="text-sm font-medium">Bandwidth</span>
                      <span className={`text-sm font-mono ${dc.networkSummary.averageBandwidth < 0.8 ? 'text-warning' : dc.networkSummary.averageBandwidth < 0.5 ? 'text-danger' : 'text-green-400'}`}>
                        {formatPercent(dc.networkSummary.averageBandwidth)}
                      </span>
                    </div>
                    <div className="w-full bg-surface-900 rounded-full h-2">
                      <div
                        className={`h-2 rounded-full transition-all ${dc.networkSummary.averageBandwidth >= 0.8 ? 'bg-green-500' : dc.networkSummary.averageBandwidth >= 0.5 ? 'bg-yellow-500' : 'bg-red-500'}`}
                        style={{ width: `${dc.networkSummary.averageBandwidth * 100}%` }}
                      />
                    </div>
                    <div className="flex justify-between mt-1 text-xs text-surface-500">
                      <span>Effective FLOPS: {formatPercent(dc.networkSummary.effectiveFlopsFraction)}</span>
                      <span>{dc.networkSummary.racksDegraded} degraded</span>
                    </div>
                  </div>

                  {/* Per-tier switch health */}
                  {(['tor', 't1', 't2', 't3'] as const).map(tier => {
                    const total = dc.networkSummary.totalByTier[tier] ?? 0;
                    if (total === 0) return null;
                    const healthy = dc.networkSummary.healthyByTier[tier] ?? 0;
                    const failed = total - healthy;
                    const config = SWITCH_TIER_CONFIGS[tier];
                    return (
                      <div key={tier} className="flex items-center justify-between p-3 border border-surface-600 rounded-lg">
                        <div>
                          <div className="font-medium text-sm">{config.name}</div>
                          <div className="text-xs text-surface-400">
                            {tier === 'tor' ? '1 per rack (embedded)' : `Fan-out ${config.fanOut}, ${config.uplinkCount} uplinks`}
                          </div>
                        </div>
                        <div className={`text-sm font-mono ${failed > 0 ? 'text-danger' : 'text-green-400'}`}>
                          {healthy} / {total}
                        </div>
                      </div>
                    );
                  })}

                  {dc.networkSummary.racksDisconnected > 0 && (
                    <div className="text-sm text-danger flex items-center gap-2 p-2">
                      <Activity size={14} /> {dc.networkSummary.racksDisconnected} compute racks disconnected due to network failures
                    </div>
                  )}
                </div>
              )}
            </div>
          )}
        </>
      )}

      {/* Retrofit Confirmation Modal */}
      {confirmRetrofit && (
        <ConfirmModal
          title="Confirm Retrofit"
          message={`This will decommission all ${dc.computeRacksOnline + pipelineCount} ${sku?.name} racks and install ${RACK_SKU_CONFIGS[confirmRetrofit].name}. The DC will go offline during this process.`}
          confirmLabel="Start Retrofit"
          onConfirm={() => { retrofitDC(datacenterId, confirmRetrofit); setConfirmRetrofit(null); }}
          onCancel={() => setConfirmRetrofit(null)}
        />
      )}
    </div>
  );
}

// ─── Main Page ──────────────────────────────────────────────────

export function InfrastructurePage() {
  const nav = useGameStore((s) => s.infraNav);

  return (
    <div>
      <Breadcrumb nav={nav} />
      {nav.level === 'clusters' && <ClustersListView />}
      {nav.level === 'cluster' && nav.clusterId && <ClusterDetailView clusterId={nav.clusterId} />}
      {nav.level === 'campus' && nav.clusterId && nav.campusId && <CampusDetailView clusterId={nav.clusterId} campusId={nav.campusId} />}
      {nav.level === 'datacenter' && nav.clusterId && nav.campusId && nav.datacenterId && (
        <DataCenterDetailView clusterId={nav.clusterId} campusId={nav.campusId} datacenterId={nav.datacenterId} />
      )}
    </div>
  );
}