import type { GameState, RackSkuId } from '@ai-tycoon/shared';
import { RACK_SKU_CONFIGS } from '@ai-tycoon/shared';
import type { SimulationMetrics } from '../strategies/types';

export interface DeadZone {
  startTick: number;
  endTick: number;
  durationTicks: number;
  description: string;
}

function getCheapestSkuCost(state: GameState): number {
  const era = state.meta.currentEra;
  const eraOrder = ['startup', 'scaleup', 'bigtech', 'agi'];
  const eraIdx = eraOrder.indexOf(era);

  let cheapest = Infinity;
  for (const [, sku] of Object.entries(RACK_SKU_CONFIGS)) {
    if (eraOrder.indexOf(sku.era) <= eraIdx) {
      cheapest = Math.min(cheapest, sku.baseCost);
    }
  }
  return cheapest === Infinity ? 100_000 : cheapest;
}

export function detectDeadZones(
  metrics: SimulationMetrics[],
  cheapestSkuCost: number,
  windowSize = 10,
  revenueTolerance = 0.02,
  capabilityTolerance = 0.02,
): DeadZone[] {
  const zones: DeadZone[] = [];
  let zoneStart: number | null = null;

  for (let i = windowSize; i < metrics.length; i++) {
    const current = metrics[i];
    const past = metrics[i - windowSize];

    const revFlat = past.revenue > 0
      ? Math.abs(current.revenue - past.revenue) / past.revenue < revenueTolerance
      : current.revenue === 0;

    const capFlat = past.bestModelCapability > 0
      ? Math.abs(current.bestModelCapability - past.bestModelCapability) / past.bestModelCapability < capabilityTolerance
      : current.bestModelCapability === 0;

    const isStuck = revFlat && capFlat && current.money < cheapestSkuCost * 2;

    if (isStuck) {
      if (zoneStart === null) zoneStart = past.tick;
    } else {
      if (zoneStart !== null) {
        const endTick = metrics[i - 1].tick;
        zones.push({
          startTick: zoneStart,
          endTick,
          durationTicks: endTick - zoneStart,
          description: 'revenue flat, no affordable upgrades',
        });
        zoneStart = null;
      }
    }
  }

  if (zoneStart !== null) {
    const endTick = metrics[metrics.length - 1].tick;
    zones.push({
      startTick: zoneStart,
      endTick,
      durationTicks: endTick - zoneStart,
      description: 'revenue flat, no affordable upgrades (ongoing)',
    });
  }

  return zones;
}

export { getCheapestSkuCost };