import os, logging
import hashlib
import random
import string
import subprocess
import time

import requests
DEBUG = os.environ.get('DEBUG')
logging.basicConfig(
        format='[%(asctime)s] %(levelname)s %(module)s/%(funcName)s - %(message)s',
        level=logging.DEBUG if DEBUG else logging.INFO)

def run_pls_command(playlist_id, playlist_name):
    """Runs the docker exec command for a given playlist."""
    cmd = ['docker', 'exec', 'navidrome-navidrome-1', '/app/navidrome', 'pls', '-l', 'error', '-np', playlist_id]
    try:
        result = subprocess.run(cmd, capture_output=True, text=True, check=False)
        print(f"\n--- Output for playlist '{playlist_name}' ---")
        if result.stdout.strip():
            print(result.stdout.strip())
        if result.stderr.strip():
            print("STDERR:")
            print(result.stderr.strip())
        print("--- End output ---\n")
    except FileNotFoundError:
        logging.error("Command 'docker' not found. Please ensure it is installed and in your PATH.")


def main():
    """Get playlists from a Navidrome server using the Subsonic API."""
    navidrome_url = os.environ.get('NAVIDROME_URL')
    username = os.environ.get('NAVIDROME_USER')

    if not all([navidrome_url, username]):
        logging.error("NAVIDROME_URL and NAVIDROME_USER environment variables must be set.")
        return

    salt = os.environ.get('SUBSONIC_SALT')
    token = os.environ.get('SUBSONIC_TOKEN')

    if not all([salt, token]):
        password = os.environ.get('NAVIDROME_PASSWORD')
        if not password:
            logging.error("Either (SUBSONIC_SALT and SUBSONIC_TOKEN) or NAVIDROME_PASSWORD must be set.")
            return

        # Subsonic API requires a salt and a token (md5(password + salt))
        salt = ''.join(random.choice(string.ascii_lowercase + string.digits) for _ in range(10))
        token = hashlib.md5((password + salt).encode('utf-8')).hexdigest()

    params = {
        'u': username,
        't': token,
        's': salt,
        'v': '1.16.1',
        'c': 'playlist-script',
        'f': 'json'
    }

    known_playlists = {}

    while True:
        api_url = f"{navidrome_url.rstrip('/')}/rest/getPlaylists.view"

        try:
            response = requests.get(api_url, params=params)
            response.raise_for_status()  # Raise an exception for bad status codes
        except requests.exceptions.RequestException as e:
            logging.error(f"Error connecting to Navidrome: {e}")
            time.sleep(5)
            continue

        data = response.json()

        subsonic_response = data.get('subsonic-response')
        if not subsonic_response:
            logging.error("Invalid response format from server.")
            time.sleep(5)
            continue

        if subsonic_response.get('status') == 'failed':
            error = subsonic_response.get('error', {})
            logging.error(f"API Error: {error.get('message')} (code: {error.get('code')})")
            time.sleep(5)
            continue

        playlists = subsonic_response.get('playlists', {}).get('playlist', [])
        current_playlists = {p.get('id'): p for p in playlists}

        # On first successful poll, just populate state and print list
        if not known_playlists and playlists:
            logging.info("Initial scan. Monitoring playlists for changes.")
            print(f"Playlists for {username}:")
            for playlist_id, playlist_data in current_playlists.items():
                print(f"  - [{playlist_id}] {playlist_data.get('name')} ({playlist_data.get('songCount')} songs)")
            known_playlists = current_playlists
            time.sleep(5)
            continue

        # --- Detect changes after initial scan ---
        
        # Newly created playlists
        newly_added_ids = set(current_playlists.keys()) - set(known_playlists.keys())
        for playlist_id in newly_added_ids:
            playlist_data = current_playlists[playlist_id]
            playlist_name = playlist_data.get('name')
            logging.info(f"New playlist detected: '{playlist_name}' ({playlist_id}). Running command.")
            run_pls_command(playlist_id, playlist_name)

        # Deleted playlists
        deleted_ids = set(known_playlists.keys()) - set(current_playlists.keys())
        for playlist_id in deleted_ids:
            playlist_data = known_playlists[playlist_id]
            logging.info(f"Playlist deleted: '{playlist_data.get('name')}' ({playlist_id}).")

        # Check for song count changes in existing playlists
        for playlist_id, playlist_data in current_playlists.items():
            if playlist_id in known_playlists:
                previous_data = known_playlists[playlist_id]
                current_song_count = playlist_data.get('songCount')
                previous_song_count = previous_data.get('songCount')

                if previous_song_count != current_song_count:
                    playlist_name = playlist_data.get('name')
                    logging.info(f"Song count changed for '{playlist_name}' ({playlist_id}): {previous_song_count} -> {current_song_count}. Running command.")
                    run_pls_command(playlist_id, playlist_name)

        # Update the state for the next iteration.
        known_playlists = current_playlists

        time.sleep(5)


if __name__ == "__main__":
    main()