from typing import Optional
from fastapi import FastAPI, HTTPException, Query
from youtube_transcript_api import YouTubeTranscriptApi
from youtube_transcript_api.formatters import SRTFormatter
from youtube_transcript_api._errors import TranscriptsDisabled, NoTranscriptFound
from yt_dlp import YoutubeDL

app = FastAPI(
    title="YouTube Transcript & Metadata API",
    version="1.0.0"
)

def extract_video_id(url: str) -> str:
    import re
    match = re.search(r"(?:v=|youtu\.be/)([A-Za-z0-9_-]{11})", url)
    if not match:
        raise ValueError("URL inválida do YouTube")
    return match.group(1)

@app.get("/get-transcript")
def get_transcript(
    url: Optional[str] = Query(None, description="URL completa do vídeo"),
    videoId: Optional[str] = Query(None, alias="videoId", description="ID do vídeo no YouTube")
):
    if not url and not videoId:
        raise HTTPException(status_code=400, detail="Informe 'url' ou 'videoId'")
    if url:
        try:
            video_id = extract_video_id(url)
        except ValueError as e:
            raise HTTPException(status_code=400, detail=str(e))
    else:
        video_id = videoId
    

    try:
        ytt_api = YouTubeTranscriptApi()
        result = ytt_api.fetch(video_id, languages=['pt'])
        formatter = SRTFormatter()

        if not result:
            raise NoTranscriptFound("Nenhuma transcrição encontrada para este vídeo")
    except TranscriptsDisabled:
        raise HTTPException(status_code=404, error="Transcrição desativada para este vídeo")
    except NoTranscriptFound:
        raise HTTPException(status_code=404, error="Nenhuma transcrição encontrada")
    except Exception as e:
        raise HTTPException(status_code=500, error=f"Erro ao obter transcrição: {e}")


    return {
        "video_id": video_id,
        "transcript": formatter.format_transcript(result),
    }

@app.get("/get-video-metadata")
def get_video_metadata(
    url: Optional[str] = Query(None, description="URL completa do vídeo"),
    videoId: Optional[str] = Query(None, alias="videoId", description="ID do vídeo no YouTube")
):
    if not url and not videoId:
        raise HTTPException(status_code=400, detail="Informe 'url' ou 'videoId'")
    if url:
        target = url
    else:
        target = f"https://www.youtube.com/watch?v={videoId}"

    ydl_opts = {
        "quiet": True,
        "skip_download": True,
        "nocheckcertificate": True,
        "restrictfilenames": True,
        "simulate": True,
        "forcejson": True,
    }

    try:
        with YoutubeDL(ydl_opts) as ydl:
            info = ydl.extract_info(target, download=False)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Erro ao extrair metadata: {e}")

    return info