import { sys } from 'cc';
import { ANDROID, IOS } from 'cc/env';

const STORAGE_ENCRYPTION_HEAD = 'a6072637';
const STORAGE_ENCRYPTION_PASSWORD = 'xbd4jl';
const STORAGE_ENCRYPTION_ENABLED = true;

/**
 * 将数字格式化为财务展示格式：使用千位分隔符并保留两位小数。
 * 例如：1234567.8 -> 1,234,567.80。
 */
export function formatCurrency(value: number, decimal = 0): string {
    if (!Number.isFinite(value)) value = 0;

    return value.toLocaleString('en-US', {
        minimumFractionDigits: decimal,
        maximumFractionDigits: decimal,
        useGrouping: true,
    });
}

export function formatSCNum(value: number) {
    return formatCurrency(value, 2);
}

export function formatGCNum(value: number) {
    return formatCurrency(value, 0);
}

/**
 * 读取本地数据，并兼容 game_web_us2 写入的加密格式。
 */
export function localStorageGet<T = string>(key: string, defaultValue: T = '' as T): string | T {
    let value = sys.localStorage.getItem(key);
    if (value === null) return defaultValue;

    if (value.startsWith(STORAGE_ENCRYPTION_HEAD)) {
        try {
            value = decrypt(value.substring(STORAGE_ENCRYPTION_HEAD.length));
        } catch {
            // 与原项目保持一致：解密失败时返回空字符串。
            value = '';
        }
    }
    return value;
}

/**
 * 加密并保存本地数据。空字符串不加密，行为与 game_web_us2 保持一致。
 */
export function localStorageSet(key: string, value: unknown): void {
    let storageValue = value;
    if (STORAGE_ENCRYPTION_ENABLED && storageValue !== null && storageValue !== '') {
        const plainValue = typeof storageValue === 'string' ? storageValue : String(storageValue);
        storageValue = plainValue;
        try {
            storageValue = STORAGE_ENCRYPTION_HEAD + encrypt(plainValue);
        } catch {
            // 加密失败时沿用原值保存，兼容原项目行为。
        }
    }
    sys.localStorage.setItem(key, String(storageValue));
}

export function localStorageRemove(key: string): void {
    sys.localStorage.removeItem(key);
}

function encrypt(value: string, password = STORAGE_ENCRYPTION_PASSWORD): string {
    if (value === '') return '';

    const source = encodeURIComponent(value);
    const encodedPassword = encodeURIComponent(password || STORAGE_ENCRYPTION_PASSWORD);
    if (encodedPassword.length === 0) return '';

    let randomSeed = '';
    for (let index = 0; index < encodedPassword.length; index += 1) {
        randomSeed += encodedPassword.charCodeAt(index).toString();
    }

    const seedPosition = Math.floor(randomSeed.length / 5);
    const multiplier = Number.parseInt(
        randomSeed.charAt(seedPosition)
        + randomSeed.charAt(seedPosition * 2)
        + randomSeed.charAt(seedPosition * 3)
        + randomSeed.charAt(seedPosition * 4)
        + randomSeed.charAt(seedPosition * 5),
        10,
    );
    const increment = Math.ceil(encodedPassword.length / 2);
    const modulus = Math.pow(2, 31) - 1;
    if (multiplier < 2) return '';

    let salt = Math.round(Math.random() * 1_000_000_000) % 100_000_000;
    randomSeed += salt;
    randomSeed = reduceSeed(randomSeed);

    let pseudoRandom = (multiplier * Number(randomSeed) + increment) % modulus;
    let encrypted = '';
    for (let index = 0; index < source.length; index += 1) {
        const encryptedChar = source.charCodeAt(index) ^ Math.floor((pseudoRandom / modulus) * 255);
        encrypted += encryptedChar < 16
            ? `0${encryptedChar.toString(16)}`
            : encryptedChar.toString(16);
        pseudoRandom = (multiplier * pseudoRandom + increment) % modulus;
    }

    let saltHex = salt.toString(16);
    while (saltHex.length < 8) saltHex = `0${saltHex}`;
    return encrypted + saltHex;
}

function decrypt(value: string, password = STORAGE_ENCRYPTION_PASSWORD): string {
    if (value === '') return '';

    const encodedPassword = encodeURIComponent(password || STORAGE_ENCRYPTION_PASSWORD);
    if (value.length < 8 || encodedPassword.length === 0) return '';

    let randomSeed = '';
    for (let index = 0; index < encodedPassword.length; index += 1) {
        randomSeed += encodedPassword.charCodeAt(index).toString();
    }

    const seedPosition = Math.floor(randomSeed.length / 5);
    const multiplier = Number.parseInt(
        randomSeed.charAt(seedPosition)
        + randomSeed.charAt(seedPosition * 2)
        + randomSeed.charAt(seedPosition * 3)
        + randomSeed.charAt(seedPosition * 4)
        + randomSeed.charAt(seedPosition * 5),
        10,
    );
    const increment = Math.round(encodedPassword.length / 2);
    const modulus = Math.pow(2, 31) - 1;
    const salt = Number.parseInt(value.substring(value.length - 8), 16);
    const encrypted = value.substring(0, value.length - 8);

    randomSeed += salt;
    randomSeed = reduceSeed(randomSeed);

    let pseudoRandom = (multiplier * Number(randomSeed) + increment) % modulus;
    let decrypted = '';
    for (let index = 0; index < encrypted.length; index += 2) {
        const decryptedChar = Number.parseInt(encrypted.substring(index, index + 2), 16)
            ^ Math.floor((pseudoRandom / modulus) * 255);
        decrypted += String.fromCharCode(decryptedChar);
        pseudoRandom = (multiplier * pseudoRandom + increment) % modulus;
    }
    return decodeURIComponent(decrypted);
}

function reduceSeed(seed: string): string {
    let result = seed;
    while (result.length > 10) {
        let remaining = result;
        let total = 0;
        while (remaining.length > 0) {
            total += Number.parseInt(remaining.substring(0, 10), 10);
            remaining = remaining.substring(10);
        }
        result = total.toString();
    }
    return result;
}

/**
 * 进入平台判定:0=普通浏览器 1=iOS壳包 2=Android壳包 3=PWA(桌面图标/TWA 进入)
 * 用于按来源差异化展示(如提现页官网引流提示:桌面图标进入的玩家不显示)。
 * 壳包判定优先于 PWA;TWA 判定内联实现,避免 helpers→UAUtils 循环依赖。
 */
export function getEnterPlatform(): 0 | 1 | 2 | 3 {
    if (ANDROID) return 2;
    if (IOS) return 1;
    return 0;
}

export function createUUID() {
    const chars: string[] = [];
    const hexDigits = '0123456789abcdef';

    for (let index = 0; index < 36; index += 1) {
        chars[index] = hexDigits.charAt(
            Math.floor(Math.random() * 16),
        );
    }

    // UUID version 4：0100
    chars[14] = '4';

    // RFC variant：10xx
    const variant = (Number.parseInt(chars[19], 16) & 0x3) | 0x8;

    chars[19] = hexDigits.charAt(variant);

    chars[8] = '-';
    chars[13] = '-';
    chars[18] = '-';
    chars[23] = '-';

    return chars.join('');
}

export function getUrlParams(url: string) {
    const queryIndex = url.indexOf('?');
    const params = {};
    if (queryIndex >= 0) {
        url.slice(queryIndex + 1).split('&').forEach((entry) => {
            if (!entry) return;

            const separatorIndex = entry.indexOf('=');
            const rawKey = separatorIndex >= 0 ? entry.slice(0, separatorIndex) : entry;
            const rawValue = separatorIndex >= 0 ? entry.slice(separatorIndex + 1) : '';

            try {
                const key = decodeURIComponent(rawKey.replace(/\+/g, ' '));
                params[key] = decodeURIComponent(rawValue.replace(/\+/g, ' '));
            } catch {
                // Preserve malformed values instead of crashing the native callback.
                params[rawKey] = rawValue;
            }
        });
    }

    return params;
}

export function waitForSeconds(duration: number) {
    return new Promise((resolve, reject) => {
        setTimeout(resolve, duration * 1000)
    })
}