import type {Bot} from '@wp2508/mineflayer';
import type {BaseFunction, FunctionArgument} from '../../../types/bot/function/function.ts';
import {Mutex} from 'async-mutex';
import {cancellation_generation} from '../cancellation.ts';

const locks = new WeakMap<Bot, Mutex>();

export class init implements BaseFunction<number[]> {
    readonly name = 'slot_switch_slot';
    readonly i18n = {
        lang: 'zh-CN', name: '物品交换', description: '依次左键点击源槽位、目标槽位，并将鼠标剩余物品放回源槽位；同类物品按原生规则合并',
    };
    readonly args: FunctionArgument[] = [
        {name: 'slot', type: 'number', i18n: {lang: 'zh-CN', name: '物品槽位', description: '第一个槽位编号'}},
        {name: 'new_slot', type: 'number', i18n: {lang: 'zh-CN', name: '目标槽位', description: '第二个槽位编号'}},
    ];

    async run(bot: Bot, args: number[]): Promise<boolean> {
        if (!Array.isArray(args) || args.length !== 2 || !args.every(Number.isSafeInteger)) return false;
        const window = bot.currentWindow ?? bot.inventory;
        if (!window) return false;
        const generation = cancellation_generation(bot);
        const active = () => cancellation_generation(bot) === generation;
        let lock = locks.get(bot);
        if (!lock) locks.set(bot, lock = new Mutex());
        return lock.runExclusive(async () => {
            const [slot, new_slot] = args;
            if (!active() || (bot.currentWindow ?? bot.inventory) !== window || window.selectedItem
                || slot === new_slot || args.some(value => value < 0 || value >= window.slots.length)) return false;
            try {
                await bot.clickWindow(slot, 0, 0);
                if (!active() || (bot.currentWindow ?? bot.inventory) !== window) return false;
                await bot.clickWindow(new_slot, 0, 0);
                if (!active() || (bot.currentWindow ?? bot.inventory) !== window) return false;
                // An empty cursor means a final click would pick the source item up again.
                if (window.selectedItem) {
                    await bot.clickWindow(slot, 0, 0);
                }
                return active() && (bot.currentWindow ?? bot.inventory) === window && !window.selectedItem;
            } catch {
                return false;
            }
        });
    }
}