app.py

import shutil
from fastapi import FastAPI, HTTPException, Request, Body
from deezspot.deezloader import DeeLogin
from deezspot.spotloader import SpoLogin
import requests
import os
import logging
import json
from typing import Optional
from fastapi.staticfiles import StaticFiles
from dotenv import load_dotenv
from pydantic import BaseModel, Field, HttpUrl
from urllib.parse import quote
from pathlib import Path
import uuid
from fastapi import BackgroundTasks
from collections import defaultdict
import time
from datetime import timedelta
import gc
from typing import Dict, Union, Literal
import urllib.parse
from fastapi.responses import JSONResponse

# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(title="Deezer API")
# Load environment variables
load_dotenv()

# Mount a static files directory to serve downloaded files

os.makedirs("downloads", exist_ok=True)
app.mount("/downloads", StaticFiles(directory="downloads"), name="downloads")

# Deezer API base URL
DEEZER_API_URL = "https://api.deezer.com"

# Deezer ARL token (required for deezspot downloads)
ARL_TOKEN = os.getenv('ARL')


class DownloadRequest(BaseModel):
    url: str
    quality: str
    arl: str


def convert_deezer_short_link_async(short_link: str) -> str:
    try:
        response = requests.get(short_link, allow_redirects=True)
        return response.url
    except requests.RequestException as e:
        print(f"An error occurred: {e}")
        return ""

@app.middleware("http")
async def log_errors_middleware(request: Request, call_next):
    try:
        return await call_next(request)
    except Exception as e:
        logger.error("An unhandled exception occurred!", exc_info=True)
        return JSONResponse(status_code=500, content={'detail': 'Internal Server Error'})


@app.get("/")
def read_root():
    return {"message": "running"}


# Helper function to get track info
def get_track_info(track_id: str):
    try:
        response = requests.get(f"{DEEZER_API_URL}/track/{track_id}")
        if response.status_code != 200:
            raise HTTPException(status_code=404, detail="Track not found")
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.error(f"Network error fetching track metadata: {e}")
        raise HTTPException(status_code=500, detail=str(e))
    except Exception as e:
        logger.error(f"Error fetching track metadata: {e}")
        raise HTTPException(status_code=500, detail=str(e))


# Fetch track metadata from Deezer API
@app.get("/track/{track_id}")
def get_track(track_id: str):
    return get_track_info(track_id)


# Rate limiting dictionary
class RateLimiter:
    def __init__(self, max_requests: int, time_window: timedelta):
        self.max_requests = max_requests
        self.time_window = time_window
        self.requests: Dict[str, list] = defaultdict(list)

    def _cleanup_old_requests(self, user_ip: str) -> None:
        """Remove requests that are outside the time window."""
        current_time = time.time()
        self.requests[user_ip] = [
            timestamp for timestamp in self.requests[user_ip]
            if current_time - timestamp < self.time_window.total_seconds()
        ]

    def is_rate_limited(self, user_ip: str) -> bool:
        """Check if the user has exceeded their rate limit."""
        self._cleanup_old_requests(user_ip)

        # Get current count after cleanup
        current_count = len(self.requests[user_ip])

        # Add current request timestamp (incrementing the count)
        current_time = time.time()
        self.requests[user_ip].append(current_time)

        # Check if user has exceeded the maximum requests
        return (current_count + 1) > self.max_requests

    def get_current_count(self, user_ip: str) -> int:
        """Get the current request count for an IP."""
        self._cleanup_old_requests(user_ip)
        return len(self.requests[user_ip])


# Initialize rate limiter with 25 requests per day
rate_limiter = RateLimiter(
    max_requests=5,
    time_window=timedelta(days=1)
)


def get_user_ip(request: Request) -> str:
    """Helper function to get user's IP address."""
    forwarded = request.headers.get("X-Forwarded-For")
    if forwarded:
        return forwarded.split(",")[0]
    return request.client.host


# Download a track and return a download URL
@app.post("/download/track")
def download_track(request: Request, download_request: DownloadRequest):
    try:
        user_ip = get_user_ip(request)

        if rate_limiter.is_rate_limited(user_ip):
            current_count = rate_limiter.get_current_count(user_ip)
            raise HTTPException(
                status_code=429,
                detail={
                    "detail": "You have exceeded the maximum number of requests per day. Please try again tomorrow or get the Premium version for unlimited downloads at https://chrunos.com/premium-shortcuts/.",
                    "help": "https://t.me/chrunoss"
                }
            )
        if download_request.arl is None or download_request.arl.strip() == "":
            ARL = ARL_TOKEN
        else:
            ARL = download_request.arl
        logger.info(f'arl: {ARL}')
        url = download_request.url
        if 'dzr.page' in url or 'deezer.page' in url or 'link.deezer' in url:
            url = convert_deezer_short_link_async(url)
        quality = download_request.quality
        dl = DeeLogin(arl=ARL)
        logger.info(f'track_url: {url}')

        if quality not in ["MP3_320", "MP3_128", "FLAC"]:
            raise HTTPException(status_code=400, detail="Invalid quality specified")

        # 提取 track_id （假设 url 格式为 https://api.deezer.com/track/{track_id}）
        track_id = url.split("/")[-1]

        # Fetch track info
        track_info = get_track_info(track_id)
        track_link = track_info.get("link")
        if not track_link:
            raise HTTPException(status_code=404, detail="Track link not found")

        # Sanitize filename
        track_title = track_info.get("title", "track")
        artist_name = track_info.get("artist", {}).get("name", "unknown")
        file_extension = "flac" if quality == "FLAC" else "mp3"
        expected_filename = f"{artist_name} - {track_title}.{file_extension}".replace("/", "_")  # Sanitize filename

        # Clear the downloads directory
        for root, dirs, files in os.walk("downloads"):
            for file in files:
                os.remove(os.path.join(root, file))
            for dir in dirs:
                shutil.rmtree(os.path.join(root, dir))

        # Download the track using deezspot
        try:
            # 下载文件的代码
            dl.download_trackdee(
                link_track=track_link,
                output_dir="downloads",
                quality_download=quality,
                recursive_quality=False,
                recursive_download=False
            )
        except Exception as e:
            logger.error(f"Error downloading file: {e}")
            raise HTTPException(status_code=500, detail="File download failed")

        # Recursively search for the file in the downloads directory
        filepath = None
        for root, dirs, files in os.walk("downloads"):
            for file in files:
                if file.endswith(f'.{file_extension}'):
                    filepath = os.path.join(root, file)
                    break
            if filepath:
                break

        if not filepath:
            raise HTTPException(status_code=500, detail=f"{file_extension} file not found after download")
        if filepath:
            file_size = os.path.getsize(filepath)
            logger.info(f"Downloaded file size: {file_size} bytes")

        # Return the download URL
        relative_path = quote(str(os.path.relpath(filepath, "downloads")))
        # Remove spaces from the relative path
        # Auto-detect base URL from request
        base_url = str(request.base_url).rstrip('/')
        download_url = f"{base_url}/downloads/{relative_path}"
        logger.info(f"Download successful: {download_url}")
        gc.collect()
        return {"download_url": download_url, "requests_remaining": rate_limiter.max_requests - rate_limiter.get_current_count(user_ip)}
    except Exception as e:
        logger.error(f"Error downloading track: {e}")
        raise HTTPException(status_code=500, detail=str(e))



# Pydantic model for album request
class AlbumRequest(BaseModel):
    id: str


# Fetch album data
@app.post("/z_album")
def fetch_album(request: AlbumRequest):
    album_id = request.id
    try:
        response = requests.get(f"{DEEZER_API_URL}/album/{album_id}")
        response.raise_for_status()
        album_data = response.json()
        tracks = album_data.get("tracks", {}).get("data", [])
        result = []
        for track in tracks:
            title = track.get("title")
            link = track.get("link")
            if title and link:
                result.append({
                    "title": title,
                    "link": link
                })
        return result
    except requests.exceptions.RequestException as e:
        logger.error(f"Network error fetching album: {e}")
        raise HTTPException(status_code=500, detail=str(e))
    except Exception as e:
        logger.error(f"Error fetching album: {e}")
        raise HTTPException(status_code=500, detail=str(e))


# Pydantic model for playlist request
class PlaylistRequest(BaseModel):
    id: str


# Fetch playlist data
@app.post("/z_playlist")
def fetch_playlist(request: PlaylistRequest):
    playlist_id = request.id
    try:
        response = requests.get(f"{DEEZER_API_URL}/playlist/{playlist_id}")
        response.raise_for_status()
        playlist_data = response.json()
        tracks = playlist_data.get("tracks", {}).get("data", [])
        result = []
        for track in tracks:
            title = track.get("title")
            link = track.get("link")
            if title and link:
                result.append({
                    "title": title,
                    "link": link
                })
        return result
    except requests.exceptions.RequestException as e:
        logger.error(f"Network error fetching album: {e}")
        raise HTTPException(status_code=500, detail=str(e))
    except Exception as e:
        logger.error(f"Error fetching album: {e}")
        raise HTTPException(status_code=500, detail=str(e))



# Search tracks using Deezer API
@app.get("/z_search")
def search_tracks(query: str, limit: Optional[int] = 10):
    try:
        response = requests.get(f"{DEEZER_API_URL}/search", params={"q": query, "limit": limit})
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.error(f"Network error searching tracks: {e}")
        raise HTTPException(status_code=500, detail=str(e))
    except Exception as e:
        logger.error(f"Error searching tracks: {e}")
        raise HTTPException(status_code=500, detail=str(e))


# --- Request Body Model ---
# Defines the expected structure and validation for the request body.
class SpotDlRequest(BaseModel):
    url: HttpUrl = Field(..., description="The URL to be processed.")
    quality: Literal["128", "320", "FLAC"] = Field(
        ...,
        description="The desired quality. Currently, only '128' is supported for link generation."
    )

# --- Response Body Model ---
# Defines the structure for a successful response.
class SpotDlResponse(BaseModel):
    download_url: str

# --- Error Response Model ---
# Defines the structure for an error response.
class ErrorResponse(BaseModel):
    detail: str

# --- API Endpoint ---
@app.post(
    "/spot_dl",
    response_model=SpotDlResponse,
    responses={
        400: {"model": ErrorResponse, "description": "Bad Request - Invalid input"},
        422: {"model": ErrorResponse, "description": "Validation Error - Input data is not valid"}
    },
    summary="Generate SpotDL Link",
    description="Accepts a URL and quality, returns a processed URL if quality is '128', "
                "otherwise returns an error for higher qualities."
)
async def create_spot_dl_link(request: SpotDlRequest = Body(...)):
    """
    Processes a URL and quality to generate a download link.

    - **url**: The URL to process (must be a valid HTTP/HTTPS URL).
    - **quality**: The desired quality. Must be one of "128", "320", "FLAC".
                   Currently, only "128" will result in a successful link generation.
    """
    # Log the received request for debugging (optional)
    print(f"Received request: url='{request.url}', quality='{request.quality}'")

    # Check the quality
    if request.quality == "128":
        # URL-encode the input URL
        encoded_url = urllib.parse.quote(str(request.url), safe='')
        # Construct the target URL
        output_url = f"https://velynapi.vercel.app/api/downloader/spotifydl?url={encoded_url}"
        return SpotDlResponse(download_url=output_url)
    elif request.quality == "320" or request.quality == "FLAC":
        # If quality is 320 or FLAC, return an error as per requirements
        raise HTTPException(
            status_code=400,
            detail=f"Quality '{request.quality}' is for Premium Users Only. '128' is allowed."
        )
    else:
        # This case should ideally be caught by Pydantic's Literal validation,
        # but as a fallback or for more general invalid quality values:
        raise HTTPException(
            status_code=400,
            detail=f"Invalid quality value: '{request.quality}'. Allowed values are '128', '320', 'FLAC'."
        )