from __future__ import annotations

import asyncio
import logging
import os
import re
import random
from typing import Optional

from dotenv import load_dotenv
from telegram import Update
from telegram.ext import (
    ApplicationBuilder,
    CommandHandler,
    ContextTypes,
    MessageHandler,
    filters,
)

logging.basicConfig(
    format="%(asctime)s %(levelname)s %(name)s %(message)s",
    level=logging.INFO,
)
logger = logging.getLogger(__name__)


# 信用卡生成相关函数
def luhn_checksum(card_number: str) -> int:
    """计算Luhn校验和"""
    def digits_of(n):
        return [int(d) for d in str(n)]
    
    digits = digits_of(card_number)
    odd_digits = digits[-1::-2]  # 从右到左，奇数位
    even_digits = digits[-2::-2]  # 从右到左，偶数位
    
    checksum = 0
    checksum += sum(odd_digits)
    
    for d in even_digits:
        checksum += sum(digits_of(d * 2))
    
    return checksum % 10


def is_luhn_valid(card_number: str) -> bool:
    """验证卡号是否符合Luhn算法"""
    return luhn_checksum(card_number) == 0


def generate_luhn_valid_number(prefix: str, length: int = 16) -> str:
    """生成符合Luhn算法的卡号"""
    # 确保前缀是数字字符串
    prefix = str(prefix)
    
    # 如果前缀已经达到指定长度，直接验证并返回
    if len(prefix) >= length:
        if is_luhn_valid(prefix[:length]):
            return prefix[:length]
        else:
            raise ValueError("前缀长度已达到但不符合Luhn算法")
    
    # 生成随机数字填充到长度-1（最后一位是校验位）
    remaining_length = length - len(prefix) - 1
    random_digits = ''.join([str(random.randint(0, 9)) for _ in range(remaining_length)])
    
    # 组合前缀、随机数字和临时校验位0
    card_number = prefix + random_digits + '0'
    
    # 计算正确的校验位
    checksum = luhn_checksum(card_number)
    correct_check_digit = (10 - checksum) % 10
    
    # 替换最后一位为正确的校验位
    valid_card_number = card_number[:-1] + str(correct_check_digit)
    
    return valid_card_number


def parse_and_generate_card(input_string: str) -> dict:
    """解析输入字符串并生成完整的信用卡信息"""
    # 更灵活的正则表达式匹配：前缀|月份|年份|CVV
    # 前缀可以包含x，CVV部分可以包含x或省略
    pattern = r'^(\d+x*)\|(\d{1,2})\|(\d{2,4})(?:\|(x*))?$'
    match = re.match(pattern, input_string)
    
    if not match:
        raise ValueError("输入格式不正确，应为：前缀|月份|年份|CVV (CVV可选)")
    
    prefix_part = match.group(1)
    month = match.group(2)
    year = match.group(3)
    cvv_part = match.group(4) if match.group(4) else 'xxx'  # 默认CVV长度
    
    # 分离前缀中的数字和x
    prefix_match = re.match(r'^(\d+)(x*)$', prefix_part)
    if not prefix_match:
        raise ValueError("前缀格式不正确，应为数字后跟x")
    
    prefix = prefix_match.group(1)
    
    # 确定卡号总长度（通常是16位，但Amex是15位）
    if prefix.startswith('34') or prefix.startswith('37'):
        total_length = 15  # American Express
    else:
        total_length = 16  # Visa, Mastercard, Discover等
    
    # 生成完整的卡号
    full_card_number = generate_luhn_valid_number(prefix, total_length)
    
    # 格式化月份和年份
    month = month.zfill(2)
    if len(year) == 2:
        # 假设是20xx年
        year = '20' + year
    
    # 生成随机CVV（通常是3位，Amex是4位）
    if prefix.startswith('34') or prefix.startswith('37'):
        cvv_length = 4
    else:
        cvv_length = 3
    
    cvv = ''.join([str(random.randint(0, 9)) for _ in range(cvv_length)])
    
    return {
        'card_number': full_card_number,
        'expiry_month': month,
        'expiry_year': year,
        'cvv': cvv,
        'formatted': f"{full_card_number}|{month}|{year}|{cvv}"
    }


def is_credit_card_format(text: str) -> bool:
    """检测文本是否为信用卡格式"""
    # 检测格式：数字+x|数字|数字|可选的x
    pattern = r'^\d+x*\|\d{1,2}\|\d{2,4}(?:\|x*)?$'
    return bool(re.match(pattern, text.strip()))


def generate_multiple_cards(input_string: str, count: int = 10) -> list:
    """根据输入格式生成多张信用卡"""
    cards = []
    for _ in range(count):
        try:
            card_info = parse_and_generate_card(input_string)
            cards.append(card_info)
        except ValueError as e:
            logger.warning(f"生成信用卡失败: {e}")
            continue
    return cards


def _parse_allowed_users(raw_value: str) -> set[int]:
    """解析允许的用户ID列表"""
    if not raw_value.strip():
        return set()
    allowed = set()
    for token in raw_value.replace(";", ",").split(","):
        token = token.strip()
        if not token:
            continue
        try:
            allowed.add(int(token))
        except ValueError:
            logger.warning("Ignoring invalid user id token: %s", token)
    return allowed


async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    """处理/start命令"""
    if not await _ensure_authorized(update, context):
        return

    await update.message.reply_text(
        "欢迎使用信用卡生成机器人！\n\n"
        "请发送信用卡格式，我将为您生成10张随机信用卡。\n"
        "格式示例：\n"
        "• 440393xxxxx|3|27|xxx\n"
        "• 424242|11|28\n"
        "• 34xxxxx|6|25|xxxx (American Express)\n\n"
        "格式说明：前缀|月份|年份|CVV(CVV可选)"
    )


async def handle_text(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
    """处理文本消息"""
    assert update.message is not None
    if not await _ensure_authorized(update, context):
        return

    text = update.message.text or ""
    
    # 检查是否为信用卡格式
    if is_credit_card_format(text):
        await handle_credit_card_request(update, text)
    else:
        await update.message.reply_text(
            "格式不正确！请使用以下格式：\n"
            "• 440393xxxxx|3|27|xxx\n"
            "• 424242|11|28\n\n"
            "格式说明：前缀|月份|年份|CVV(CVV可选)"
        )


async def handle_credit_card_request(update: Update, input_format: str) -> None:
    """处理信用卡生成请求"""
    try:
        # 生成10张信用卡
        cards = generate_multiple_cards(input_format, 10)
        
        if not cards:
            await update.message.reply_text("生成信用卡失败，请检查输入格式。")
            return
        
        # 格式化输出
        response_lines = [f"🎉 成功生成 {len(cards)} 张信用卡：\n"]
        
        for i, card in enumerate(cards, 1):
            response_lines.append(
                f"{i}. {card['formatted']}"
            )
        
        # 分批发送消息，避免消息过长
        batch_size = 5
        for i in range(0, len(response_lines), batch_size * 2):  # 每批包含标题+5张卡
            batch = response_lines[i:i + batch_size * 2]
            await update.message.reply_text("\n".join(batch))
            
    except Exception as e:
        logger.exception("处理信用卡请求时出错")
        await update.message.reply_text(f"生成信用卡时出错：{str(e)}")


def build_application():
    """构建Telegram应用"""
    load_dotenv()

    bot_token = os.getenv("BOT_TOKEN")
    if not bot_token:
        raise RuntimeError("BOT_TOKEN is not set")

    # Create the application builder
    application_builder = ApplicationBuilder().token(bot_token)

    # Check for custom API URL (for proxy)
    custom_api_url = os.getenv("TELEGRAM_API_URL", "").strip()
    if custom_api_url:
        logger.info(f"Using custom Telegram API URL: {custom_api_url}")
        api_base = f"{custom_api_url}/bot"
        file_base = f"{custom_api_url}/file/bot"
        logger.info(f"Setting API base to: {api_base}")
        logger.info(f"Setting file base to: {file_base}")
        application_builder = application_builder.base_url(api_base).base_file_url(file_base)
    else:
        logger.info("Using default Telegram API URL")

    allowed_ids = _parse_allowed_users(os.getenv("ALLOWED_USER_IDS", ""))

    application = application_builder.build()

    # Store the custom API URL in the application's bot_data
    if custom_api_url:
        application.bot_data["custom_api_url"] = custom_api_url

    application.bot_data["allowed_ids"] = allowed_ids

    application.add_handler(CommandHandler("start", start))
    application.add_handler(MessageHandler(filters.TEXT & (~filters.COMMAND), handle_text))

    return application


def main() -> None:
    """主函数"""
    application = build_application()
    application.run_polling()


if __name__ == "__main__":
    main()


async def _ensure_authorized(update: Update, context: ContextTypes.DEFAULT_TYPE) -> bool:
    """确保用户有权限使用机器人"""
    allowed_ids: set[int] = context.application.bot_data.get("allowed_ids", set())
    if not allowed_ids:
        return True

    user = update.effective_user
    if user and user.id in allowed_ids:
        return True

    message = update.effective_message
    if message:
        await message.reply_text("您没有权限使用此机器人。")

    logger.info("Unauthorized access attempt by user id %s", user.id if user else "unknown")
    return False