import os
import requests
from typing import Optional

GENIUS_API_KEY = os.getenv("GENIUS_API_KEY", "")
GENIUS_BASE_URL = "https://api.genius.com"


def fetch_lyrics(song_title: str, artist_name: str) -> Optional[str]:
    if not GENIUS_API_KEY:
        return None
    
    search_query = f"{song_title} {artist_name}"
    
    try:
        search_url = f"{GENIUS_BASE_URL}/search"
        headers = {"Authorization": f"Bearer {GENIUS_API_KEY}"}
        params = {"q": search_query}
        
        response = requests.get(search_url, headers=headers, params=params, timeout=10)
        if response.status_code != 200:
            return None
        
        data = response.json()
        hits = data.get("response", {}).get("hits", [])
        
        if not hits:
            return None
        
        # Get the best match
        best_hit = hits[0]
        song_id = best_hit.get("result", {}).get("id")
        
        if not song_id:
            return None
        
        # Fetch song details
        song_url = f"{GENIUS_BASE_URL}/songs/{song_id}"
        song_response = requests.get(song_url, headers=headers, timeout=10)
        if song_response.status_code != 200:
            return None
        
        song_data = song_response.json()
        lyrics = song_data.get("response", {}).get("lyrics", "")
        
        if lyrics and lyrics != "[Lyrics are not written yet]":
            return lyrics
        
        return None
    
    except (requests.RequestException, KeyError, IndexError):
        return None