import os
from fastapi import FastAPI, HTTPException
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
from pydantic import BaseModel
from qbittorrent import Client
from typing import List, Optional

# --- Configuration ---
# The qBittorrent-nox daemon is started on port 8080 inside the container.
# The default credentials for qbittorrent-nox are admin/adminadmin.
# In a real-world scenario, these should be securely managed.
QB_HOST = os.getenv("QB_HOST", "localhost")
QB_PORT = os.getenv("QB_PORT", "8080")
QB_USER = os.getenv("QB_USER", "admin")
QB_PASS = os.getenv("QB_PASS", "adminadmin")

# --- FastAPI App Initialization ---
app = FastAPI(
    title="qBittorrent Magnet Link API",
    description="A simple FastAPI service to add magnet links to a running qBittorrent instance with download tracking.",
    version="2.0.0"
)

# Mount static files (frontend)
app.mount("/static", StaticFiles(directory="app/static"), name="static")

# --- Pydantic Models ---
class MagnetLink(BaseModel):
    magnet_link: str

class StatusResponse(BaseModel):
    status: str
    message: str

class TorrentInfo(BaseModel):
    name: str
    hash: str
    state: str
    progress: float
    downloaded: int
    total_size: int
    upload_speed: int
    download_speed: int
    eta: int
    num_seeds: int
    num_leechs: int

class TorrentListResponse(BaseModel):
    torrents: List[TorrentInfo]
    total_count: int

# --- Utility Function for qBittorrent Client ---
def get_qb_client():
    """Initializes and logs into the qBittorrent client."""
    try:
        qb = Client(f'http://{QB_HOST}:{QB_PORT}')
        qb.login(QB_USER, QB_PASS)
        return qb
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"Could not connect or log in to qBittorrent: {e}")

# --- Endpoints ---

@app.get("/", response_class=FileResponse)
async def serve_frontend():
    """Serves the main HTML frontend."""
    return FileResponse("app/static/index.html")

@app.get("/health", response_model=StatusResponse)
async def health_check():
    """Checks the health of the FastAPI service and qBittorrent connection."""
    try:
        qb = get_qb_client()
        # A simple call to verify connection and authentication
        version = qb.app.version
        return StatusResponse(status="ok", message=f"FastAPI is running and connected to qBittorrent v{version}")
    except HTTPException as e:
        raise e
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error during health check: {e}")

@app.post("/api/add_torrent", response_model=StatusResponse)
async def add_torrent(link: MagnetLink):
    """Adds a magnet link to the qBittorrent download queue."""
    qb = get_qb_client()
    
    try:
        # The add_torrent method handles both magnet links and .torrent files
        qb.torrents_add(urls=link.magnet_link)
        return StatusResponse(
            status="success",
            message=f"Successfully added magnet link to qBittorrent"
        )
    except Exception as e:
        # Log the error and return a user-friendly message
        print(f"Error adding torrent: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to add torrent: {e}")

@app.get("/api/torrents", response_model=TorrentListResponse)
async def get_torrents():
    """Fetches the list of all torrents with their current status."""
    qb = get_qb_client()
    
    try:
        torrents = qb.torrents()
        
        torrent_list = []
        for torrent in torrents:
            torrent_info = TorrentInfo(
                name=torrent.get('name', 'Unknown'),
                hash=torrent.get('hash', ''),
                state=torrent.get('state', 'unknown'),
                progress=torrent.get('progress', 0) * 100,  # Convert to percentage
                downloaded=torrent.get('downloaded', 0),
                total_size=torrent.get('total_size', 0),
                upload_speed=torrent.get('upspeed', 0),
                download_speed=torrent.get('dlspeed', 0),
                eta=torrent.get('eta', 0),
                num_seeds=torrent.get('num_seeds', 0),
                num_leechs=torrent.get('num_leechs', 0),
            )
            torrent_list.append(torrent_info)
        
        return TorrentListResponse(torrents=torrent_list, total_count=len(torrent_list))
    except Exception as e:
        print(f"Error fetching torrents: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to fetch torrents: {e}")

@app.delete("/api/torrents/{torrent_hash}")
async def delete_torrent(torrent_hash: str, delete_files: bool = False):
    """Deletes a torrent from the qBittorrent instance."""
    qb = get_qb_client()
    
    try:
        qb.torrents_delete(torrent_hashes=torrent_hash, delete_files=delete_files)
        return StatusResponse(
            status="success",
            message=f"Successfully deleted torrent"
        )
    except Exception as e:
        print(f"Error deleting torrent: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to delete torrent: {e}")

@app.post("/api/torrents/{torrent_hash}/pause")
async def pause_torrent(torrent_hash: str):
    """Pauses a torrent."""
    qb = get_qb_client()
    
    try:
        qb.torrents_pause(torrent_hashes=torrent_hash)
        return StatusResponse(
            status="success",
            message=f"Successfully paused torrent"
        )
    except Exception as e:
        print(f"Error pausing torrent: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to pause torrent: {e}")

@app.post("/api/torrents/{torrent_hash}/resume")
async def resume_torrent(torrent_hash: str):
    """Resumes a torrent."""
    qb = get_qb_client()
    
    try:
        qb.torrents_resume(torrent_hashes=torrent_hash)
        return StatusResponse(
            status="success",
            message=f"Successfully resumed torrent"
        )
    except Exception as e:
        print(f"Error resuming torrent: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to resume torrent: {e}")