import {
  PRODUCTIVITY_THRESHOLD,
  type Desire, type Needs, type NPCBrain, type Position,
} from '@dflike/shared';
import type { World } from '../ecs/World.js';
import type { GameMap } from '../map/GameMap.js';
import type { GatheringState } from './gatheringSystem.js';
import type { CraftingState } from './craftingSystem.js';
import type { BuildingState, StructureData } from './buildingSystem.js';
import type { PickupState } from './pickupSystem.js';
import { RecipeRegistry, type Recipe } from '../industry/recipeRegistry.js';
import { ItemRegistry } from '../industry/itemRegistry.js';
import { getEffectiveStat } from './statHelpers.js';
import { industryConfig } from '../config/industryConfig.js';

function scoreCraftableRecipes(recipes: Recipe[], desires: Desire[], itemRegistry?: ItemRegistry): Recipe {
  if (recipes.length === 1 || desires.length === 0) return recipes[0];

  let bestRecipe = recipes[0];
  let bestScore = 0;

  for (const recipe of recipes) {
    let score = 1; // base score
    for (const desire of desires) {
      const f = desire.fulfillment;
      if (f.type === 'own_item' && f.itemId === recipe.outputItemId) {
        score += desire.priority * 10;
      } else if (f.type === 'own_item_category' && itemRegistry) {
        const outputDef = itemRegistry.get(recipe.outputItemId);
        if (outputDef && outputDef.category === f.category) {
          score += desire.priority * 5;
        }
      }
    }
    if (score > bestScore) {
      bestScore = score;
      bestRecipe = recipe;
    }
  }

  return bestRecipe;
}

const BUILD_RECIPE_MAP: Record<string, { type: 'stockpile' | 'workshop'; subtype: string }> = {
  stockpile: { type: 'stockpile', subtype: 'general' },
  workbench: { type: 'workshop', subtype: 'workbench' },
};

function structureExists(world: World, structureType: string, subtype: string): boolean {
  for (const entity of world.query('structure')) {
    const s = world.getComponent<StructureData>(entity, 'structure')!;
    if (s.type === structureType && s.subtype === subtype && s.buildProgress === undefined) {
      return true;
    }
  }
  return false;
}

function findNearbyWalkable(map: GameMap, from: Position): Position | null {
  for (let r = 1; r <= 3; r++) {
    for (let dx = -r; dx <= r; dx++) {
      for (let dy = -r; dy <= r; dy++) {
        if (Math.abs(dx) !== r && Math.abs(dy) !== r) continue;
        const x = from.x + dx;
        const y = from.y + dy;
        if (map.isWalkable(x, y)) return { x, y };
      }
    }
  }
  return null;
}

export function industrySystem(world: World, map: GameMap): void {
  const registry = world.getSingleton<RecipeRegistry>('recipeRegistry');
  if (!registry) return;

  for (const entity of world.query('npcBrain', 'needs', 'inventory', 'position')) {
    const needs = world.getComponent<Needs>(entity, 'needs')!;
    if (needs.productivity >= PRODUCTIVITY_THRESHOLD) continue;

    const brain = world.getComponent<NPCBrain>(entity, 'npcBrain')!;

    // Skip if already actively doing something productive
    if (brain.currentGoal === 'craft' && world.getComponent<CraftingState>(entity, 'craftingState')) continue;
    if (brain.currentGoal === 'build' && world.getComponent<BuildingState>(entity, 'buildingState')) continue;
    if (brain.currentGoal === 'gather' && world.getComponent<GatheringState>(entity, 'gatheringState')) continue;
    if (brain.currentGoal === 'gather' || brain.currentGoal === 'eat' || brain.currentGoal === 'sleep') continue;
    if (brain.currentGoal === 'dropoff') continue;
    if (brain.currentGoal === 'pickup') continue;

    const inv = world.getComponent<Map<string, number>>(entity, 'inventory')!;
    const pos = world.getComponent<Position>(entity, 'position')!;

    // Try craft first
    const craftRecipes = registry.findCraftable(inv).filter(r => !r.id.startsWith('build_'));
    if (craftRecipes.length > 0) {
      const desires = world.getComponent<Desire[]>(entity, 'desires') ?? [];
      const itemRegistry = world.getSingleton<ItemRegistry>('itemRegistry');
      const recipe = scoreCraftableRecipes(craftRecipes, desires, itemRegistry);
      const dex = getEffectiveStat(world, entity, 'dexterity');
      const baseTicks = industryConfig.craftBaseTicks;
      const ticks = Math.max(1, Math.round(baseTicks * (1 - (dex - 10) * industryConfig.craftDexterityModifier)));
      brain.currentGoal = 'craft';
      world.addComponent<CraftingState>(entity, 'craftingState', {
        recipeId: recipe.id,
        ticksRemaining: ticks,
      });
      continue;
    }

    // Try build
    const buildRecipes = registry.findCraftable(inv).filter(r => r.id.startsWith('build_'));
    let didBuild = false;
    for (const recipe of buildRecipes) {
      const mapping = BUILD_RECIPE_MAP[recipe.outputItemId];
      if (!mapping) continue;
      if (structureExists(world, mapping.type, mapping.subtype)) continue;

      const buildPos = findNearbyWalkable(map, pos);
      if (!buildPos) continue;

      // Consume inputs
      for (const input of recipe.inputs) {
        const current = inv.get(input.itemId) ?? 0;
        const remaining = current - input.quantity;
        if (remaining <= 0) inv.delete(input.itemId);
        else inv.set(input.itemId, remaining);
      }

      const structureEntity = world.createEntity();
      world.addComponent<Position>(structureEntity, 'position', buildPos);
      world.addComponent<StructureData>(structureEntity, 'structure', {
        type: mapping.type,
        subtype: mapping.subtype,
        inventory: new Map(),
        buildProgress: 0,
        builderEntityId: entity,
      });

      brain.currentGoal = 'build';
      world.addComponent<BuildingState>(entity, 'buildingState', {
        structureEntityId: structureEntity,
        recipeId: recipe.id,
      });
      didBuild = true;
      break;
    }
    if (didBuild) continue;

    // Try pickup from stockpile for crafting
    let didPickup = false;
    const allCraftRecipes = registry.getAll().filter(r => !r.id.startsWith('build_'));
    for (const recipe of allCraftRecipes) {
      const neededItems: { itemId: string; quantity: number }[] = [];

      for (const input of recipe.inputs) {
        const haveInInv = inv.get(input.itemId) ?? 0;
        const stillNeed = input.quantity - haveInInv;
        if (stillNeed > 0) {
          neededItems.push({ itemId: input.itemId, quantity: stillNeed });
        }
      }

      if (neededItems.length === 0) continue; // NPC can already craft — handled above

      // Find a stockpile that has all needed items
      let stockpileEntity: number | null = null;
      for (const sEntity of world.query('structure', 'position')) {
        const sData = world.getComponent<StructureData>(sEntity, 'structure')!;
        if (sData.type !== 'stockpile' || sData.buildProgress !== undefined) continue;
        const hasAll = neededItems.every(n => (sData.inventory.get(n.itemId) ?? 0) >= n.quantity);
        if (hasAll) {
          stockpileEntity = sEntity;
          break;
        }
      }

      if (stockpileEntity !== null) {
        brain.currentGoal = 'pickup';
        world.addComponent<PickupState>(entity, 'pickupState', {
          stockpileEntityId: stockpileEntity,
          items: neededItems,
        });
        didPickup = true;
        break;
      }
    }
    if (didPickup) continue;

    // Fallback: gather
    brain.currentGoal = 'gather';
  }
}