import { Component, type EvalContext, type World } from "../core/world";
import { component } from "../core/registry";
import type { RPGAction } from "../types";
import { action, variable } from "../utils/decorators";
import { executeAction } from "../utils/variables";

interface ItemState {
    name: string;
    description: string;
}

@component
export class Item extends Component<ItemState> {
    constructor(name: string, description = '') {
        super({ name, description });
    }

    get name(): string { return this.state.name; }
    get description(): string { return this.state.description; }
}

interface StackableState {
    maxStack: number;
}

@component
export class Stackable extends Component<StackableState> {
    constructor(maxStack: number) {
        super({ maxStack });
    }

    @variable get maxStack(): number { return this.state.maxStack; }
}

interface UsableState {
    actions: RPGAction[];
    consumeOnUse: boolean;
}

@component
export class Usable extends Component<UsableState> {
    constructor(actions: RPGAction[], consumeOnUse = true) {
        super({ actions, consumeOnUse });
    }

    @variable get consumeOnUse(): boolean { return this.state.consumeOnUse; }

    @action
    use(arg?: EvalContext, ctx?: EvalContext): void {
        ctx = arg ?? ctx ?? this.context;
        if (!ctx) return;
        for (const action of this.state.actions) {
            executeAction(action, ctx);
        }
    }
}

export namespace Items {
    export interface RegisterOptions {
        maxStack?: number;
        description?: string;
        usable?: { actions: RPGAction[]; consumeOnUse?: boolean };
    }

    export function register(world: World, id: string, name: string, options?: RegisterOptions) {
        const entity = world.createEntity(id);
        entity.add('item', new Item(name, options?.description));
        if (options?.maxStack !== undefined)
            entity.add('stackable', new Stackable(options.maxStack));
        if (options?.usable)
            entity.add('usable', new Usable(options.usable.actions, options.usable.consumeOnUse));
        return entity;
    }
}