import gradio as gr
import requests
import re
import time
import logging
from functools import lru_cache
from urllib.parse import urlparse, urljoin
from typing import Dict, Any, Optional, List
from dataclasses import dataclass
from datetime import datetime

# 配置日志
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s'
)

@dataclass
class ProxyResponse:
    """代理响应数据类"""
    status: int
    content: str
    headers: Dict[str, str]
    redirect_url: Optional[str] = None
    error: Optional[str] = None

class Config:
    """配置类"""
    ASSET_URL = "https://1pages.nbid.bid/"
    PREFIX = "/"
    JSDELIVR = 0
    CACHE_TTL = 3600
    MAX_RETRIES = 3
    TIMEOUT = 10
    RATE_LIMIT = {
        "window_ms": 15 * 60 * 1000,  # 15分钟
        "max": 100  # 限制每个IP最多100个请求
    }
    WHITE_LIST: List[str] = []  # 白名单
    
    # 请求头
    DEFAULT_HEADERS = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36"
    }
    
    # CORS设置
    CORS = {
        "allow_origins": ["*"],
        "allow_methods": ["GET", "POST", "OPTIONS"],
        "allow_headers": ["*"],
        "max_age": 1728000
    }
    
    # URL模式
    PATTERNS = {
        "releases": r"^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:releases|archive)\/.*$",
        "blob": r"^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:blob|raw)\/.*$",
        "git": r"^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:info|git-).*$",
        "raw": r"^(?:https?:\/\/)?raw\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+?\/.+$",
        "gist": r"^(?:https?:\/\/)?gist\.(?:githubusercontent|github)\.com\/.+?\/.+?\/.+$",
        "tags": r"^(?:https?:\/\/)?github\.com\/.+?\/.+?\/tags.*$"
    }

class RateLimiter:
    """请求频率限制器"""
    def __init__(self):
        self.request_records: Dict[str, List[float]] = {}
    
    def is_allowed(self, ip: str) -> bool:
        now = time.time() * 1000
        window_start = now - Config.RATE_LIMIT["window_ms"]
        
        if ip not in self.request_records:
            self.request_records[ip] = []
        
        # 清理过期记录
        self.request_records[ip] = [t for t in self.request_records[ip] if t > window_start]
        
        if len(self.request_records[ip]) >= Config.RATE_LIMIT["max"]:
            return False
        
        self.request_records[ip].append(now)
        return True
    
    def get_remaining(self, ip: str) -> int:
        """获取剩余请求次数"""
        if ip not in self.request_records:
            return Config.RATE_LIMIT["max"]
        return Config.RATE_LIMIT["max"] - len(self.request_records[ip])

class GitHubProxy:
    """GitHub代理核心类"""
    def __init__(self):
        self.rate_limiter = RateLimiter()
        self.session = requests.Session()
        self.session.headers.update(Config.DEFAULT_HEADERS)
    
    def check_url(self, url: str) -> bool:
        """检查URL是否匹配GitHub模式"""
        return any(re.search(pattern, url, re.I) for pattern in Config.PATTERNS.values())
    
    def check_white_list(self, url: str) -> bool:
        """检查白名单"""
        if not Config.WHITE_LIST:
            return True
        return any(white_item in url for white_item in Config.WHITE_LIST)
    
    @lru_cache(maxsize=1000)
    def fetch_github_content(self, url: str, method: str = "GET") -> ProxyResponse:
        """获取GitHub内容（带缓存）"""
        try:
            response = self.session.request(
                method=method,
                url=url,
                timeout=Config.TIMEOUT,
                allow_redirects=False
            )
            
            headers = dict(response.headers)
            
            # 处理重定向
            if response.is_redirect:
                redirect_url = response.headers["Location"]
                if self.check_url(redirect_url):
                    redirect_url = Config.PREFIX + redirect_url
                return ProxyResponse(
                    status=response.status_code,
                    content="",
                    headers=headers,
                    redirect_url=redirect_url
                )
            
            return ProxyResponse(
                status=response.status_code,
                content=response.text,
                headers=headers
            )
            
        except requests.Timeout:
            return ProxyResponse(
                status=504,
                content="Request Timeout",
                headers={},
                error="请求超时"
            )
        except Exception as e:
            logging.error(f"Fetch error: {str(e)}")
            return ProxyResponse(
                status=500,
                content=str(e),
                headers={},
                error="服务器内部错误"
            )
    
    def proxy_request(self, url: str, request: gr.Request) -> Dict[str, Any]:
        """处理代理请求"""
        # 记录请求
        logging.info(f"Proxy request from {request.client.host} to {url}")
        
        # 检查频率限制
        if not self.rate_limiter.is_allowed(request.client.host):
            return {
                "status": 429,
                "content": "Too Many Requests",
                "headers": {},
                "error": "请求过于频繁，请稍后再试",
                "rate_limit": {
                    "remaining": self.rate_limiter.get_remaining(request.client.host),
                    "reset": int((time.time() * 1000 + Config.RATE_LIMIT["window_ms"]) / 1000)
                }
            }
        
        # 检查白名单
        if not self.check_white_list(url):
            return {
                "status": 403,
                "content": "Access Denied",
                "headers": {},
                "error": "访问被拒绝"
            }
        
        # 处理URL
        if not url.startswith(("http://", "https://")):
            url = "https://" + url
        
        # 检查URL是否为GitHub链接
        if not self.check_url(url):
            return {
                "status": 400,
                "content": "Invalid GitHub URL",
                "headers": {},
                "error": "无效的GitHub URL"
            }
        
        # 处理jsDelivr重定向
        if Config.JSDELIVR and re.search(Config.PATTERNS["blob"], url):
            url = url.replace("/blob/", "@").replace("github.com", "cdn.jsdelivr.net/gh")
            return {
                "status": 302,
                "content": "",
                "headers": {"Location": url},
                "redirect_url": url
            }
        
        # 获取内容
        response = self.fetch_github_content(url)
        result = {
            "status": response.status,
            "content": response.content,
            "headers": response.headers,
            "timestamp": datetime.now().isoformat()
        }
        
        if response.redirect_url:
            result["redirect_url"] = response.redirect_url
        if response.error:
            result["error"] = response.error
            
        return result

def create_interface():
    """创建Gradio界面"""
    proxy = GitHubProxy()
    
    with gr.Blocks(title="GitHub Proxy", theme=gr.themes.Soft()) as app:
        gr.Markdown("""
        # 🚀 GitHub Proxy
        
        ### 功能特点
        - ✨ 支持多种GitHub URL格式
        - 🔄 自动处理重定向
        - 💾 响应缓存
        - ⚡ CDN加速支持
        - 🛡️ 请求频率限制
        
        ### 支持的URL类型
        - GitHub Release/Archive
        - GitHub Raw/Blob
        - GitHub Gist
        - Raw GitHub Content
        """)
        
        with gr.Row():
            url_input = gr.Textbox(
                label="GitHub URL",
                placeholder="输入GitHub URL，例如：github.com/user/repo/blob/master/file.txt",
                scale=4
            )
            submit_btn = gr.Button("获取内容", scale=1)
        
        with gr.Row():
            with gr.Column():
                status = gr.Textbox(label="状态")
                headers = gr.JSON(label="响应头")
            with gr.Column():
                content = gr.Textbox(label="内容", max_lines=20)
                error = gr.Textbox(label="错误信息", visible=False)
        
        def handle_request(url: str, request: gr.Request):
            result = proxy.proxy_request(url, request)
            
            # 更新UI
            error_visible = "error" in result
            error_msg = result.get("error", "")
            
            return {
                status: f"状态码: {result['status']}",
                headers: result["headers"],
                content: result["content"],
                error: error_msg,
                error: gr.update(visible=error_visible, value=error_msg)
            }
        
        submit_btn.click(
            fn=handle_request,
            inputs=[url_input],
            outputs=[status, headers, content, error]
        )
        
        # 添加示例
        gr.Examples(
            examples=[
                ["github.com/microsoft/vscode/blob/main/README.md"],
                ["raw.githubusercontent.com/microsoft/vscode/main/README.md"],
                ["gist.github.com/username/gist_id/raw/file.txt"]
            ],
            inputs=url_input
        )
    
    return app

if __name__ == "__main__":
    app = create_interface()
    app.launch(
        server_name="0.0.0.0",
        server_port=7860,
        show_error=True,
        quiet=False
    )