import { describe, it, expect, beforeEach } from "vitest";
import { ItemManager } from "../../scenes/systems/ItemManager";
import type { World, CombatantActor, Item, EntityId } from "../../core/types";
import { EntityAccessor } from "../../engine/EntityAccessor";
import { ECSWorld } from "../../engine/ecs/World";

describe("ItemManager - Stacking Logic", () => {
    let itemManager: ItemManager;
    let accessor: EntityAccessor;
    let world: World;
    let player: CombatantActor;
    let ecsWorld: ECSWorld;

    beforeEach(() => {
        world = {
            width: 10,
            height: 10,
            tiles: new Array(100).fill(0),
            exit: { x: 9, y: 9 }
        } as any;

        ecsWorld = new ECSWorld();
        accessor = new EntityAccessor(world, 0 as EntityId, ecsWorld);
        itemManager = new ItemManager(world, accessor, ecsWorld);

        player = {
            id: 0 as EntityId,
            pos: { x: 1, y: 1 },
            category: "combatant",
            isPlayer: true,
            type: "player",
            inventory: { gold: 0, items: [] },
            stats: { hp: 10, maxHp: 10 } as any,
            equipment: {} as any,
            speed: 100,
            energy: 0
        };
        
        // Sync player to ECS
        ecsWorld.addComponent(player.id, "position", player.pos);
        ecsWorld.addComponent(player.id, "player", {});
        ecsWorld.addComponent(player.id, "stats", player.stats);
        ecsWorld.addComponent(player.id, "actorType", { type: "player" });
        ecsWorld.addComponent(player.id, "inventory", player.inventory!);
        ecsWorld.addComponent(player.id, "energy", { current: 0, speed: 100 });
    });

    it("should stack stackable items when picked up", () => {
        const potion: Item = {
            id: "potion",
            name: "Potion",
            type: "Consumable",
            textureKey: "items",
            spriteIndex: 0,
            stackable: true,
            quantity: 1
        };

        const playerActor = accessor.getPlayer()!;

        // First potion
        itemManager.spawnItem(potion, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);
        
        expect(playerActor.inventory!.items.length).toBe(1);
        expect(playerActor.inventory!.items[0].quantity).toBe(1);

        // Second potion
        itemManager.spawnItem(potion, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);

        expect(playerActor.inventory!.items.length).toBe(1);
        expect(playerActor.inventory!.items[0].quantity).toBe(2);
    });

    it("should NOT stack non-stackable items", () => {
        const sword: Item = {
            id: "iron_sword",
            name: "Iron Sword",
            type: "Weapon",
            weaponType: "melee",
            textureKey: "items",
            spriteIndex: 1,
            stackable: false,
            stats: { attack: 1 }
        } as any;

        const playerActor = accessor.getPlayer()!;

        // First sword
        itemManager.spawnItem(sword, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);
        
        expect(playerActor.inventory!.items.length).toBe(1);

        // Second sword
        itemManager.spawnItem(sword, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);

        expect(playerActor.inventory!.items.length).toBe(2);
    });

    it("should sum quantities of stackable items correctly", () => {
        const ammo: Item = {
            id: "9mm_ammo",
            name: "9mm Ammo",
            type: "Ammo",
            textureKey: "items",
            spriteIndex: 2,
            stackable: true,
            quantity: 10,
            ammoType: "9mm"
        } as any;

        const playerActor = accessor.getPlayer()!;

        itemManager.spawnItem(ammo, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);
        
        expect(playerActor.inventory!.items[0].quantity).toBe(10);

        const moreAmmo = { ...ammo, quantity: 5 };
        itemManager.spawnItem(moreAmmo, { x: 1, y: 1 });
        itemManager.tryPickup(playerActor);

        expect(playerActor.inventory!.items[0].quantity).toBe(15);
    });
});