/**
 * 分享引导与下载配额
 * - 当日第 1 次满批：须分享解锁，弹窗引导，不分享不可下载
 * - 当日第 2 次及以后满批：直接播放激励广告解锁
 */

import {
    downloadFreeBatchSize,
    enableDownloadLimitInDevelop,
} from '../config/config';

const STORAGE_KEY_DOWNLOAD_DATE = 'downloadDate';
const STORAGE_KEY_DOWNLOAD_COUNT = 'downloadCount';
const STORAGE_KEY_DOWNLOADS_SINCE_UNLOCK = 'downloadsSinceUnlock';
/** 当日已完成解锁次数（分享或广告各计 1 次） */
const STORAGE_KEY_DAILY_UNLOCK_COUNT = 'dailyUnlockCount';

export type DownloadUnlockMethod = 'share' | 'ad';

/** 每批免费下载次数（来自 config，至少为 1） */
export function getFreeDownloadBatchSize(): number {
    const n = Number(downloadFreeBatchSize);
    return Number.isFinite(n) && n >= 1 ? Math.floor(n) : 1;
}

function getTodayDateString(): string {
    const today = new Date();
    const year = today.getFullYear();
    const month = String(today.getMonth() + 1).padStart(2, '0');
    const day = String(today.getDate()).padStart(2, '0');
    return `${year}-${month}-${day}`;
}

/** 跨日时重置当日计数与解锁批次 */
function ensureDailyReset(): void {
    const today = getTodayDateString();
    const downloadDate = wx.getStorageSync(STORAGE_KEY_DOWNLOAD_DATE);
    if (downloadDate !== today) {
        wx.setStorageSync(STORAGE_KEY_DOWNLOAD_DATE, today);
        wx.setStorageSync(STORAGE_KEY_DOWNLOAD_COUNT, 0);
        wx.setStorageSync(STORAGE_KEY_DOWNLOADS_SINCE_UNLOCK, 0);
        wx.setStorageSync(STORAGE_KEY_DAILY_UNLOCK_COUNT, 0);
    }
}

/** 当日已完成解锁次数 */
export function getDailyUnlockCount(): number {
    ensureDailyReset();
    return wx.getStorageSync(STORAGE_KEY_DAILY_UNLOCK_COUNT) || 0;
}

function incrementDailyUnlockCount(): void {
    ensureDailyReset();
    const count = getDailyUnlockCount();
    wx.setStorageSync(STORAGE_KEY_DAILY_UNLOCK_COUNT, count + 1);
}

/**
 * 获取今日总下载次数（供个人中心等展示）
 */
export function getTodayDownloadCount(): number {
    ensureDailyReset();
    return wx.getStorageSync(STORAGE_KEY_DOWNLOAD_COUNT) || 0;
}

/** 当前批次内已下载次数 */
export function getDownloadsSinceUnlock(): number {
    ensureDailyReset();
    return wx.getStorageSync(STORAGE_KEY_DOWNLOADS_SINCE_UNLOCK) || 0;
}

/**
 * 是否已达本批次上限，下载前需先解锁
 */
export function needsUnlockBeforeDownload(): boolean {
    return getDownloadsSinceUnlock() >= getFreeDownloadBatchSize();
}

/**
 * 当前满批时应使用的解锁方式
 */
export function getUnlockMethod(): DownloadUnlockMethod | null {
    if (!isDownloadLimitEnabled() || !needsUnlockBeforeDownload()) {
        return null;
    }
    return getDailyUnlockCount() === 0 ? 'share' : 'ad';
}

/**
 * 分享或看广告成功后，重置批次计数，可再免费下载一批
 */
export function resetUnlockQuota(): void {
    ensureDailyReset();
    wx.setStorageSync(STORAGE_KEY_DOWNLOADS_SINCE_UNLOCK, 0);
}

/**
 * 记录一次下载成功（总次数 + 当前批次次数各 +1）
 */
export function recordDownloadSuccess(): void {
    ensureDailyReset();
    const today = getTodayDateString();
    const total = getTodayDownloadCount();
    const sinceUnlock = getDownloadsSinceUnlock();
    wx.setStorageSync(STORAGE_KEY_DOWNLOAD_DATE, today);
    wx.setStorageSync(STORAGE_KEY_DOWNLOAD_COUNT, total + 1);
    wx.setStorageSync(STORAGE_KEY_DOWNLOADS_SINCE_UNLOCK, sinceUnlock + 1);
}

/**
 * 记录分享解锁成功
 */
export function recordShareSuccess(): void {
    resetUnlockQuota();
    incrementDailyUnlockCount();
}

/**
 * 记录激励广告解锁成功
 */
export function recordAdUnlockSuccess(): void {
    resetUnlockQuota();
    incrementDailyUnlockCount();
}

function isDevelopEnv(): boolean {
    try {
        const env = getApp().globalData.env;
        if (env === 'develop') {
            return true;
        }
        const accountEnv =
            wx.getAccountInfoSync().miniProgram.envVersion || 'release';
        return accountEnv === 'develop';
    } catch {
        return false;
    }
}

/**
 * 是否启用下载配额（分享引导、激励广告）
 */
export function isDownloadLimitEnabled(): boolean {
    if (!isDevelopEnv()) {
        return true;
    }
    return enableDownloadLimitInDevelop;
}

/** 当日首次满批：须分享解锁，弹分享引导窗 */
export function shouldShowShareGuide(): boolean {
    return getUnlockMethod() === 'share';
}

/** 当日第 2 次及以后满批：直接播放激励广告 */
export function shouldUnlockWithAd(): boolean {
    return getUnlockMethod() === 'ad';
}

/** 分享解锁弹窗文案 */
export function getShareGuidePopupCopy(): {
    message: string;
    hint: string;
} {
    const n = getFreeDownloadBatchSize();
    return {
        message: `免费下载次数已用完`,
        hint: '分享给好友后即可继续下载',
    };
}