from parsers.douyin import DouyinParser
from parsers.tiktok import TikTokParser
from parsers.bilibili import BilibiliMirParser, BilibiliBugPKParser, BilibiliYaohuParser
from models import ParserAPI
import random

class ParserFactory:
    """解析器工厂类"""

    @staticmethod
    def create_parser(api_config: ParserAPI):
        """根据API配置创建解析器实例"""
        platform = api_config.platform.lower()
        api_url = api_config.api_url
        api_key = api_config.api_key

        if platform == 'douyin':
            return DouyinParser(api_url, api_key)
        elif platform == 'tiktok':
            return TikTokParser(api_url, api_key)
        elif platform == 'bilibili':
            # 根据API名称选择不同的解析器
            if 'mir6' in api_url:
                return BilibiliMirParser(api_url, api_key)
            elif 'bugpk' in api_url:
                return BilibiliBugPKParser(api_url, api_key)
            elif 'yaohud' in api_url:
                return BilibiliYaohuParser(api_url, api_key)
            else:
                return BilibiliMirParser(api_url, api_key)
        else:
            raise ValueError(f"不支持的平台: {platform}")

    @staticmethod
    def get_parser_for_platform(platform: str):
        """获取指定平台的解析器（带负载均衡）"""
        from models import db

        # 查询该平台所有启用且健康的API
        apis = ParserAPI.query.filter_by(
            platform=platform.lower(),
            is_enabled=True,
            health_status=True
        ).all()

        if not apis:
            raise Exception(f"没有可用的{platform}解析接口")

        # 如果是哔哩哔哩，使用加权随机选择（负载均衡）
        if platform.lower() == 'bilibili' and len(apis) > 1:
            api = ParserFactory._weighted_random_choice(apis)
        else:
            # 其他平台选择第一个可用的
            api = apis[0]

        return ParserFactory.create_parser(api), api

    @staticmethod
    def _weighted_random_choice(apis):
        """加权随机选择"""
        total_weight = sum(api.weight for api in apis)
        if total_weight == 0:
            return random.choice(apis)

        rand = random.uniform(0, total_weight)
        current = 0

        for api in apis:
            current += api.weight
            if rand <= current:
                return api

        return apis[-1]

    @staticmethod
    def detect_platform(video_url: str) -> str:
        """检测视频链接所属平台"""
        url_lower = video_url.lower()

        if 'douyin.com' in url_lower or 'v.douyin' in url_lower:
            return 'douyin'
        elif 'tiktok.com' in url_lower:
            return 'tiktok'
        elif 'bilibili.com' in url_lower or 'b23.tv' in url_lower:
            return 'bilibili'
        else:
            raise ValueError("无法识别的视频平台")