from fastapi import APIRouter, HTTPException, Query, Response, Request
from fastapi.responses import StreamingResponse
import httpx
import re
from urllib.parse import urlparse, urljoin
import logging
from scraper.extractors.engine import ExtractorEngine

try:
    from curl_cffi.requests import AsyncSession
    HAS_CURL_CFFI = True
except ImportError:
    HAS_CURL_CFFI = False

router = APIRouter(prefix="/proxy", tags=["proxy"])
logger = logging.getLogger("api.proxy")

@router.get("/video")
async def proxy_video(url: str = Query(...), referer: str = Query(None)):
    """
    Proxies video streams to bypass Referer blocking.
    For HLS, it redirects to /hls if .m3u8 is detected.
    """
    if not url:
        raise HTTPException(status_code=400, detail="Missing URL")

    # If it's an HLS playlist, use the HLS proxy for better compatibility
    if ".m3u8" in url.split('?')[0]:
        return await proxy_hls(url, referer)

    try:
        headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36",
        }
        if referer:
            headers["Referer"] = referer
        else:
            domain = urlparse(url).netloc
            headers["Referer"] = f"https://{domain}/"

        async def stream_video():
            async with httpx.AsyncClient(verify=False, follow_redirects=True, timeout=60.0) as client:
                async with client.stream("GET", url, headers=headers) as resp:
                    if resp.status_code >= 400:
                        yield f"Error: {resp.status_code}".encode()
                        return
                    async for chunk in resp.aiter_bytes(chunk_size=1024*64):
                        yield chunk

        return StreamingResponse(
            stream_video(),
            media_type="video/mp4"
        )
    except Exception as e:
        logger.error(f"Video proxy error: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@router.get("/hls")
async def proxy_hls(url: str = Query(...), referer: str = Query(None)):
    """
    Proxies HLS playlists and rewrites them to proxy segments through this backend.
    """
    try:
        headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
            "Referer": referer if referer else f"https://{urlparse(url).netloc}/"
        }
        
        async with httpx.AsyncClient(verify=False, follow_redirects=True, timeout=15.0) as client:
            resp = await client.get(url, headers=headers)
            if resp.status_code != 200:
                raise HTTPException(status_code=resp.status_code, detail="Failed to fetch HLS playlist")
            
            content = resp.text
            base_url = url.rsplit('/', 1)[0] + '/'
            
            # Advanced HLS rewriter using regex to catch URLs in lines and attributes
            def rewrite_url(match):
                full_match = match.group(0)
                # Extract the actual URL part
                if full_match.startswith('URI='):
                    prefix = 'URI="'
                    original_url = match.group(1)
                    suffix = '"'
                else:
                    prefix = ''
                    original_url = match.group(0)
                    suffix = ''
                
                # Make URL absolute
                abs_url = urljoin(base_url, original_url)
                
                from urllib.parse import quote
                safe_url = quote(abs_url, safe=':/')
                safe_referer = quote(referer, safe='') if referer else ''
                
                # Use absolute path for proxy from the root
                return f'{prefix}/proxy/video?url={safe_url}&referer={safe_referer}{suffix}'

            # Regex for pure URLs on lines
            content = re.sub(r'^(?!#)(.+)$', rewrite_url, content, flags=re.MULTILINE)
            # Regex for URI="url" attributes
            content = re.sub(r'URI="([^"]+)"', rewrite_url, content)
            
            return Response(content=content, media_type="application/x-mpegURL")
            
    except Exception as e:
        logger.error(f"HLS proxy error: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@router.get("/image")
async def proxy_image(url: str = Query(...)):
    """
    Proxies images to bypass connection issues or CORS/Referer blocking.
    Uses curl_cffi for better impersonation.
    """
    if not url:
        raise HTTPException(status_code=400, detail="Missing URL")

    try:
        headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
            "Referer": "https://asd.pics/" 
        }
        
        if HAS_CURL_CFFI:
            async with AsyncSession(impersonate="chrome124", verify=False) as session:
                resp = await session.get(url, headers=headers, timeout=20)
                if resp.status_code == 200:
                    return Response(content=resp.content, media_type=resp.headers.get("content-type", "image/jpeg"))
        
        async with httpx.AsyncClient(verify=False, follow_redirects=True, timeout=20.0) as client:
            resp = await client.get(url, headers=headers)
            if resp.status_code == 200:
                return Response(content=resp.content, media_type=resp.headers.get("content-type", "image/jpeg"))
            
        return Response(status_code=404)
    except Exception as e:
        logger.error(f"Image proxy error: {e}")
        return Response(status_code=500)

@router.get("/resolve")
async def resolve_url(url: str = Query(...)):
    """
    Resolves an embed URL into a direct video stream URL.
    """
    if not url:
        raise HTTPException(status_code=400, detail="Missing URL")
    try:
        result = await ExtractorEngine.extract(url)
        if result:
            return {
                "success": True,
                "url": result['url'],
                "type": result.get('type', 'hls'),
                "headers": result.get('headers', {})
            }
        return {"success": False, "message": "Could not resolve stream"}
    except Exception as e:
        logger.error(f"Resolution error for {url}: {e}")
        return {"success": False, "message": str(e)}