import type { GameState } from '@ai-tycoon/shared';
import { processTick, setAchievementDefinitions, ACHIEVEMENT_DEFINITIONS, resetResearchBonusCache, resetFleetCache } from '@ai-tycoon/game-engine';
import type { TickNotification } from '@ai-tycoon/game-engine';
import type { Strategy, SimulationMetrics } from './strategies/types';
import { collectMetrics } from './analysis/metrics';
import { createInitialState } from './initialState';
import { createSeededRNG } from './rng';
import { resetIds } from './actions/ids';

export interface SimulationConfig {
  totalTicks: number;
  decisionInterval: number;
  strategy: Strategy;
  seed?: number;
  verbose?: boolean;
  silent?: boolean;
  onProgress?: (tick: number, totalTicks: number, era: string) => void;
}

export interface EraTransition {
  from: string;
  to: string;
  tick: number;
}

export interface SimulationResult {
  metrics: SimulationMetrics[];
  notifications: TickNotification[];
  eraTransitions: EraTransition[];
  finalState: GameState;
  wallTimeMs: number;
}

function formatEra(era: string): string {
  switch (era) {
    case 'startup': return 'Startup';
    case 'scaleup': return 'Scale-up';
    case 'bigtech': return 'Big Tech';
    case 'agi': return 'AGI';
    default: return era;
  }
}

function formatMoney(n: number): string {
  if (n >= 1e9) return `$${(n / 1e9).toFixed(1)}B`;
  if (n >= 1e6) return `$${(n / 1e6).toFixed(1)}M`;
  if (n >= 1e3) return `$${(n / 1e3).toFixed(1)}K`;
  return `$${n.toFixed(0)}`;
}

const isTTY = process.stdout.isTTY ?? false;

function printProgress(tick: number, total: number, state: GameState, startTime: number): void {
  const pct = ((tick / total) * 100).toFixed(1);
  const elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
  const ticksPerSec = tick > 0 ? (tick / ((Date.now() - startTime) / 1000)).toFixed(0) : '—';
  const eta = tick > 0 ? (((total - tick) / (tick / ((Date.now() - startTime) / 1000)))).toFixed(0) : '?';

  const barWidth = 30;
  const filled = Math.round((tick / total) * barWidth);
  const bar = '█'.repeat(filled) + '░'.repeat(barWidth - filled);

  const era = formatEra(state.meta.currentEra);
  const cash = formatMoney(state.economy.money);
  const rev = formatMoney(state.economy.revenuePerTick);

  const line = `  ${bar} ${pct}% | tick ${tick.toLocaleString().padStart(7)}/${total.toLocaleString()} | ${elapsed}s (${ticksPerSec} t/s, ETA ${eta}s) | ${era} | Cash: ${cash} | Rev/t: ${rev}`;

  if (isTTY) {
    process.stdout.write(`\r${line}   `);
  } else {
    console.log(line);
  }
}

export function runSimulation(config: SimulationConfig): SimulationResult {
  const startTime = Date.now();

  resetIds();
  resetResearchBonusCache();
  resetFleetCache();

  let rng: ReturnType<typeof createSeededRNG> | null = null;
  if (config.seed !== undefined) {
    rng = createSeededRNG(config.seed);
    rng.install();
  }

  setAchievementDefinitions(ACHIEVEMENT_DEFINITIONS);

  const state = createInitialState('GreedyAI Corp');

  const allMetrics: SimulationMetrics[] = [];
  const allNotifications: TickNotification[] = [];
  const eraTransitions: EraTransition[] = [];
  let lastEra = state.meta.currentEra;

  const progressInterval = isTTY
    ? Math.max(1, Math.floor(config.totalTicks / 200))
    : Math.max(1, Math.floor(config.totalTicks / 20));

  for (let tick = 0; tick < config.totalTicks; tick++) {
    if (tick % config.decisionInterval === 0) {
      config.strategy.decide(state, allMetrics);
    }

    const result = processTick(state);

    const notifications = (result as Record<string, unknown>)['_notifications'] as TickNotification[] | undefined;
    if (notifications && notifications.length > 0) {
      allNotifications.push(...notifications);
    }

    // Apply tick result directly — keys are known and fixed
    if (result.meta) state.meta = result.meta;
    if (result.economy) state.economy = result.economy;
    if (result.infrastructure) state.infrastructure = result.infrastructure;
    if (result.compute) state.compute = result.compute;
    if (result.research) state.research = result.research;
    if (result.models) state.models = result.models;
    if (result.market) state.market = result.market;
    if (result.talent) state.talent = result.talent;
    if (result.reputation) state.reputation = result.reputation;
    if (result.data) state.data = result.data;
    if (result.competitors) state.competitors = result.competitors;
    if (result.achievements) state.achievements = result.achievements;

    if (state.meta.currentEra !== lastEra) {
      eraTransitions.push({
        from: lastEra,
        to: state.meta.currentEra,
        tick: state.meta.tickCount,
      });
      if (!config.silent && process.stdout.isTTY) {
        process.stdout.write(`\n  >> Era transition: ${formatEra(lastEra)} -> ${formatEra(state.meta.currentEra)} at tick ${state.meta.tickCount.toLocaleString()}\n`);
      }
      lastEra = state.meta.currentEra;
    }

    if (tick % config.decisionInterval === 0) {
      allMetrics.push(collectMetrics(state));
    }

    if (tick % progressInterval === 0) {
      if (!config.silent) {
        printProgress(tick, config.totalTicks, state, startTime);
      }
      config.onProgress?.(tick, config.totalTicks, state.meta.currentEra);
    }
  }

  if (!config.silent) {
    printProgress(config.totalTicks, config.totalTicks, state, startTime);
    if (isTTY) process.stdout.write('\n');
  }

  if (rng) rng.uninstall();

  return {
    metrics: allMetrics,
    notifications: allNotifications,
    eraTransitions,
    finalState: state,
    wallTimeMs: Date.now() - startTime,
  };
}