# Monkey patch MUST be first - before any other imports!
import eventlet
eventlet.monkey_patch()

import os
import json
import subprocess
import threading
import queue
import time
import collections
from flask import Flask, send_from_directory, jsonify, request, session, Response, stream_with_context
from flask_socketio import SocketIO, emit
from dotenv import load_dotenv
# Load environment variables from .env file
load_dotenv()



def _load_config():
    """Loads optional config.json from the project root.

    If missing or invalid, returns an empty dict.
    """
    try:
        with open('config.json', 'r', encoding='utf-8') as f:
            data = json.load(f)
        return data if isinstance(data, dict) else {}
    except FileNotFoundError:
        return {}
    except Exception:
        return {}


CONFIG = _load_config()
DJ_PANEL_PASSWORD = (CONFIG.get('dj_panel_password') or '').strip()
DJ_AUTH_ENABLED = bool(DJ_PANEL_PASSWORD)

# Relay State
broadcast_state = {
    'active': False,
}
listener_sids = set()
dj_sids = set()

# === Optional MP3 fallback stream (server-side transcoding) ===
# This allows listeners on browsers that don't support WebM/Opus via MediaSource
# (notably some Safari / locked-down environments) to still hear the stream.
_ffmpeg_proc = None
_ffmpeg_in_q = queue.Queue(maxsize=40)
_current_bitrate = "192k"
_mp3_clients = set()  # set[queue.Queue]
_mp3_lock = threading.Lock()
_transcode_threads_started = False
_transcoder_bytes_out = 0
_transcoder_last_error = None
_last_audio_chunk_ts = 0.0
_mp3_preroll = collections.deque(maxlen=256)  # Pre-roll (~10s at 192k with 1KB chunks)


def _start_transcoder_if_needed(is_mp3_input=False):
    global _ffmpeg_proc, _transcode_threads_started, _transcoder_last_error
    
    # If already running, check if we need to restart for mode change
    if _ffmpeg_proc is not None and _ffmpeg_proc.poll() is None:
        return

    # Local broadcast mode: input from pipe (Relay mode removed)
    # If input is already MP3, we just use 'copy' to avoid double-encoding
    codec = 'copy' if is_mp3_input else 'libmp3lame'
    
    cmd = [
        'ffmpeg',
        '-hide_banner',
        '-loglevel', 'error',
        '-fflags', 'nobuffer',
        '-flags', 'low_delay',
        '-probesize', '32',
        '-analyzeduration', '0'
    ]
    
    if is_mp3_input:
        cmd.extend(['-f', 'mp3'])
        
    cmd.extend([
        '-i', 'pipe:0',
        '-vn',
        '-acodec', codec,
    ])
    
    if not is_mp3_input:
        cmd.extend(['-b:a', _current_bitrate])
        
    cmd.extend([
        '-tune', 'zerolatency',
        '-flush_packets', '1',
        '-f', 'mp3',
        'pipe:1',
    ])

    try:
        _ffmpeg_proc = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            bufsize=0,
        )
    except FileNotFoundError:
        _ffmpeg_proc = None
        print('⚠️ ffmpeg not found; /stream.mp3 fallback disabled')
        return

    mode_str = "PASSTHROUGH (copy)" if is_mp3_input else f"TRANSCODE ({_current_bitrate})"
    print(f'🎛️ ffmpeg transcoder started for /stream.mp3 ({mode_str})')
    
    # Reset error state
    _transcoder_last_error = None

    # Always ensure threads are running if we just started/restarted the process
    # Clear the input queue to avoid old data being sent to new process
    while not _ffmpeg_in_q.empty():
        try: _ffmpeg_in_q.get_nowait()
        except: break

    def _writer():
        global _transcoder_last_error, _transcode_threads_started
        print("🧵 Transcoder writer thread started")
        while True:
            try:
                chunk = _ffmpeg_in_q.get(timeout=2)
                if chunk is None:
                    break
                proc = _ffmpeg_proc
                if proc is None or proc.stdin is None or proc.poll() is not None:
                    continue
                proc.stdin.write(chunk)
                proc.stdin.flush()
            except queue.Empty:
                if _ffmpeg_proc is None or _ffmpeg_proc.poll() is not None:
                    break
                continue
            except Exception as e:
                if _ffmpeg_proc is not None:
                    print(f"⚠️ Transcoder writer error: {e}")
                _transcoder_last_error = f'stdin write failed: {e}'
                break
        _transcode_threads_started = False
        print("🧵 Transcoder writer thread exiting")

    def _reader():
        global _transcoder_bytes_out, _transcoder_last_error, _transcode_threads_started
        print("🧵 Transcoder reader thread started")
        proc = _ffmpeg_proc
        while proc and proc.poll() is None:
            try:
                # Smaller read for smoother delivery (1KB)
                # This prevents buffering delays at lower bitrates
                data = proc.stdout.read(1024)
                if not data:
                    break
                _transcoder_bytes_out += len(data)

                # Store in pre-roll
                with _mp3_lock:
                    _mp3_preroll.append(data)
                    clients = list(_mp3_clients)

                for q in clients:
                    try:
                        q.put_nowait(data)
                    except Exception:
                        pass
            except Exception as e:
                print(f"⚠️ Transcoder reader error: {e}")
                _transcoder_last_error = f'stdout read failed: {e}'
                break
        _transcode_threads_started = False
        print("🧵 Transcoder reader thread exiting")

    if not _transcode_threads_started:
        _transcode_threads_started = True
        threading.Thread(target=_writer, daemon=True).start()
        threading.Thread(target=_reader, daemon=True).start()


def _stop_transcoder():
    global _ffmpeg_proc, _transcode_threads_started
    try:
        _ffmpeg_in_q.put_nowait(None)
    except Exception:
        pass

    proc = _ffmpeg_proc
    _ffmpeg_proc = None
    
    # Reset thread flag so they can be re-launched if needed
    # (The existing threads will exit cleanly on None/EOF)
    _transcode_threads_started = False
    _mp3_preroll.clear()

    if proc is None:
        return
        
    # Signal all listening clients to finish their stream
    with _mp3_lock:
        clients = list(_mp3_clients)
        for q in clients:
            try:
                q.put_nowait(None)
            except:
                pass
        _mp3_clients.clear()

    try:
        proc.terminate()
    except Exception:
        pass


def _feed_transcoder(data: bytes):
    global _last_audio_chunk_ts
    if _ffmpeg_proc is None or _ffmpeg_proc.poll() is not None:
        return
    _last_audio_chunk_ts = time.time()
    try:
        _ffmpeg_in_q.put_nowait(data)
    except Exception:
        # Queue full; drop to keep latency bounded.
        pass
MUSIC_FOLDER = "music"
# Ensure music folder exists
if not os.path.exists(MUSIC_FOLDER):
    os.makedirs(MUSIC_FOLDER)

# Helper for shared routes
def setup_shared_routes(app):
    @app.route('/library.json')
    def get_library():
        library = []
        if os.path.exists(MUSIC_FOLDER):
            for filename in sorted(os.listdir(MUSIC_FOLDER)):
                if filename.lower().endswith(('.mp3', '.m4a', '.wav', '.flac', '.ogg')):
                    library.append({
                        "title": os.path.splitext(filename)[0],
                        "file": f"music/{filename}"
                    })
        return jsonify(library)


    @app.route('/<path:filename>')
    def serve_static(filename):
        response = send_from_directory('.', filename)
        if filename.endswith(('.css', '.js', '.html')):
            response.headers['Cache-Control'] = 'no-store, no-cache, must-revalidate, max-age=0'
        return response

    @app.route('/')
    def index():
        return send_from_directory('.', 'index.html')
    
    @app.route('/upload', methods=['POST'])
    def upload_file():
        if 'file' not in request.files:
            return jsonify({"success": False, "error": "No file provided"}), 400
        
        file = request.files['file']
        
        if file.filename == '':
            return jsonify({"success": False, "error": "No file selected"}), 400
        
        if not file.filename.endswith('.mp3'):
            return jsonify({"success": False, "error": "Only MP3 files are allowed"}), 400
        
        # Sanitize filename (keep extension)
        import re
        name_without_ext = os.path.splitext(file.filename)[0]
        name_without_ext = re.sub(r'[^\w\s-]', '', name_without_ext)
        name_without_ext = re.sub(r'[-\s]+', '-', name_without_ext)
        filename = f"{name_without_ext}.mp3"
        
        filepath = os.path.join(MUSIC_FOLDER, filename)
        
        try:
            file.save(filepath)
            print(f"✅ Uploaded: {filename}")
            return jsonify({"success": True, "filename": filename})
        except Exception as e:
            print(f"❌ Upload error: {e}")
            return jsonify({"success": False, "error": str(e)}), 500

    @app.route('/save_keymaps', methods=['POST'])
    def save_keymaps():
        try:
            data = request.get_json()
            with open('keymaps.json', 'w', encoding='utf-8') as f:
                json.dump(data, f, indent=4)
            print("💾 Keymaps saved to keymaps.json")
            return jsonify({"success": True})
        except Exception as e:
            print(f"❌ Save keymaps error: {e}")
            return jsonify({"success": False, "error": str(e)}), 500

    @app.route('/load_keymaps', methods=['GET'])
    def load_keymaps():
        try:
            if os.path.exists('keymaps.json'):
                with open('keymaps.json', 'r', encoding='utf-8') as f:
                    data = json.load(f)
                return jsonify({"success": True, "keymaps": data})
            else:
                return jsonify({"success": True, "keymaps": None})
        except Exception as e:
            print(f"❌ Load keymaps error: {e}")
            return jsonify({"success": False, "error": str(e)}), 500

    @app.route('/stream.mp3')
    def stream_mp3():
        # Streaming response from the ffmpeg transcoder output.
        # If ffmpeg isn't available, return 503.
        if _ffmpeg_proc is None or _ffmpeg_proc.poll() is not None:
            return jsonify({"success": False, "error": "MP3 stream not available"}), 503

        print(f"👂 New listener joined stream (Bursting {_mp3_preroll.maxlen} frames)")
        client_q: queue.Queue = queue.Queue(maxsize=100)
        with _mp3_lock:
            # Burst pre-roll to new client so they start playing instantly
            for chunk in _mp3_preroll:
                try:
                    client_q.put_nowait(chunk)
                except Exception:
                    break
            _mp3_clients.add(client_q)

        def gen():
            try:
                while True:
                    chunk = client_q.get()
                    if chunk is None:
                        break
                    yield chunk
            finally:
                with _mp3_lock:
                    _mp3_clients.discard(client_q)

        return Response(stream_with_context(gen()), content_type='audio/mpeg', headers={
            'Cache-Control': 'no-cache, no-store, must-revalidate',
            'Connection': 'keep-alive',
            'Pragma': 'no-cache',
            'Expires': '0',
            'X-Content-Type-Options': 'nosniff'
        })

    @app.route('/stream_debug')
    def stream_debug():
        proc = _ffmpeg_proc
        running = proc is not None and proc.poll() is None
        return jsonify({
            'broadcast_active': broadcast_state.get('active', False),
            'broadcast_mimeType': broadcast_state.get('mimeType'),
            'ffmpeg_running': running,
            'ffmpeg_found': (proc is not None),
            'mp3_clients': len(_mp3_clients),
            'transcoder_bytes_out': _transcoder_bytes_out,
            'transcoder_last_error': _transcoder_last_error,
            'last_audio_chunk_ts': _last_audio_chunk_ts,
        })

# === DJ SERVER (Port 5000) ===
dj_app = Flask(__name__, static_folder='.', static_url_path='')
dj_app.config['SECRET_KEY'] = 'dj_panel_secret'
setup_shared_routes(dj_app)


@dj_app.before_request
def _protect_dj_panel():
        """Optionally require a password for the DJ panel only (port 5000).

        This does not affect the listener server (port 5001).
        """
        if not DJ_AUTH_ENABLED:
                return None

        # Allow login/logout endpoints
        if request.path in ('/login', '/logout'):
                return None

        # If already authenticated, allow
        if session.get('dj_authed') is True:
                return None

        # Redirect everything else to login
        return (
                "<!doctype html><html><head><meta http-equiv='refresh' content='0; url=/login' /></head>"
                "<body>Redirecting to <a href='/login'>/login</a>...</body></html>",
                302,
                {'Location': '/login'}
        )


@dj_app.route('/login', methods=['GET', 'POST'])
def dj_login():
        if not DJ_AUTH_ENABLED:
                # If auth is disabled, just go to the panel.
                session['dj_authed'] = True
                return (
                        "<!doctype html><html><head><meta http-equiv='refresh' content='0; url=/' /></head>"
                        "<body>Auth disabled. Redirecting...</body></html>",
                        302,
                        {'Location': '/'}
                )

        error = None
        if request.method == 'POST':
                pw = (request.form.get('password') or '').strip()
                if pw == DJ_PANEL_PASSWORD:
                        session['dj_authed'] = True
                        return (
                                "<!doctype html><html><head><meta http-equiv='refresh' content='0; url=/' /></head>"
                                "<body>Logged in. Redirecting...</body></html>",
                                302,
                                {'Location': '/'}
                        )
                error = 'Invalid password'

        # Minimal inline login page (no new assets)
        return f"""<!doctype html>
<html lang=\"en\">
    <head>
        <meta charset=\"utf-8\" />
        <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />
        <title>TechDJ - DJ Login</title>
        <style>
            body {{ background:#0a0a12; color:#eee; font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial; margin:0; }}
            .wrap {{ min-height:100vh; display:flex; align-items:center; justify-content:center; padding:24px; }}
            .card {{ width:100%; max-width:420px; background:rgba(10,10,20,0.85); border:2px solid #bc13fe; border-radius:16px; padding:24px; box-shadow:0 0 40px rgba(188,19,254,0.25); }}
            h1 {{ margin:0 0 16px 0; font-size:22px; }}
            label {{ display:block; margin:12px 0 8px; opacity:0.9; }}
            input {{ width:100%; padding:12px; border-radius:10px; border:1px solid rgba(255,255,255,0.15); background:rgba(0,0,0,0.35); color:#fff; }}
            button {{ width:100%; margin-top:14px; padding:12px; border-radius:10px; border:2px solid #bc13fe; background:rgba(188,19,254,0.15); color:#fff; font-weight:700; cursor:pointer; }}
            .err {{ margin-top:12px; color:#ffb3ff; }}
            .hint {{ margin-top:10px; font-size:12px; opacity:0.7; }}
        </style>
    </head>
    <body>
        <div class=\"wrap\">
            <div class=\"card\">
                <h1>DJ Panel Locked</h1>
                <form method=\"post\" action=\"/login\">
                    <label for=\"password\">Password</label>
                    <input id=\"password\" name=\"password\" type=\"password\" autocomplete=\"current-password\" autofocus />
                    <button type=\"submit\">Unlock DJ Panel</button>
                    {f"<div class='err'>{error}</div>" if error else ""}
                    <div class=\"hint\">Set/disable this in config.json (dj_panel_password).</div>
                </form>
            </div>
        </div>
    </body>
</html>"""


@dj_app.route('/logout')
def dj_logout():
        session.pop('dj_authed', None)
        return (
                "<!doctype html><html><head><meta http-equiv='refresh' content='0; url=/login' /></head>"
                "<body>Logged out. Redirecting...</body></html>",
                302,
                {'Location': '/login'}
        )
dj_socketio = SocketIO(
    dj_app, 
    cors_allowed_origins="*", 
    async_mode='eventlet',
    max_http_buffer_size=1e8, # 100MB buffer
    ping_timeout=10, 
    ping_interval=5,
    logger=False,
    engineio_logger=False
)

@dj_socketio.on('connect')
def dj_connect():
    if DJ_AUTH_ENABLED and session.get('dj_authed') is not True:
        print(f"⛔ DJ socket rejected (unauthorized): {request.sid}")
        return False
    print(f"🎧 DJ connected: {request.sid}")
    dj_sids.add(request.sid)

@dj_socketio.on('disconnect')
def dj_disconnect():
    dj_sids.discard(request.sid)
    print("⚠️ DJ disconnected - broadcast will continue until manually stopped")

def stop_broadcast_after_timeout():
    """No longer used - broadcasts don't auto-stop"""
    pass

@dj_socketio.on('start_broadcast')
def dj_start(data=None):
    broadcast_state['active'] = True
    session['is_dj'] = True
    print("🎙️ Broadcast -> ACTIVE")

    is_mp3_input = False
    if data:
        if 'bitrate' in data:
            global _current_bitrate
            _current_bitrate = data['bitrate']
            print(f"📡 Setting stream bitrate to: {_current_bitrate}")
        if data.get('format') == 'mp3':
            is_mp3_input = True

    # Clear pre-roll for fresh start
    _mp3_preroll.clear()
    
    _start_transcoder_if_needed(is_mp3_input=is_mp3_input)
    
    listener_socketio.emit('broadcast_started', namespace='/')
    listener_socketio.emit('stream_status', {'active': True}, namespace='/')

@dj_socketio.on('get_listener_count')
def dj_get_listener_count():
    emit('listener_count', {'count': len(listener_sids)})

@dj_socketio.on('stop_broadcast')
def dj_stop():
    broadcast_state['active'] = False
    session['is_dj'] = False
    print("🛑 DJ stopped broadcasting")

    _stop_transcoder()
    
    listener_socketio.emit('broadcast_stopped', namespace='/')
    listener_socketio.emit('stream_status', {'active': False}, namespace='/')

    listener_socketio.emit('broadcast_stopped', namespace='/')
    listener_socketio.emit('stream_status', {'active': False}, namespace='/')

@dj_socketio.on('audio_chunk')
def dj_audio(data):
    # MP3-only mode: do not relay raw chunks to listeners; feed transcoder only.
    if broadcast_state['active']:
        # Ensure MP3 fallback transcoder is running (if ffmpeg is installed)
        if _ffmpeg_proc is None or _ffmpeg_proc.poll() is not None:
            # If we don't know the format, default to transcode, 
            # but usually start_broadcast handles this
            _start_transcoder_if_needed()

        if isinstance(data, (bytes, bytearray)):
            _feed_transcoder(bytes(data))

# === LISTENER SERVER (Port 5001) ===
listener_app = Flask(__name__, static_folder='.', static_url_path='')
listener_app.config['SECRET_KEY'] = 'listener_secret'
setup_shared_routes(listener_app)
listener_socketio = SocketIO(
    listener_app, 
    cors_allowed_origins="*", 
    async_mode='eventlet',
    max_http_buffer_size=1e8, # 100MB buffer
    ping_timeout=10, 
    ping_interval=5,
    logger=False,
    engineio_logger=False
)

@listener_socketio.on('connect')
def listener_connect():
    print(f"👂 Listener Socket Connected: {request.sid}")

@listener_socketio.on('disconnect')
def listener_disconnect():
    listener_sids.discard(request.sid)
    count = len(listener_sids)
    print(f"❌ Listener left. Total: {count}")
    # Notify BOTH namespaces
    listener_socketio.emit('listener_count', {'count': count}, namespace='/')
    dj_socketio.emit('listener_count', {'count': count}, namespace='/')

@listener_socketio.on('join_listener')
def listener_join():
    if request.sid not in listener_sids:
        listener_sids.add(request.sid)
        count = len(listener_sids)
        print(f"👂 New listener joined. Total: {count}")
        listener_socketio.emit('listener_count', {'count': count}, namespace='/')
        dj_socketio.emit('listener_count', {'count': count}, namespace='/')
    
    emit('stream_status', {'active': broadcast_state['active']})

@listener_socketio.on('get_listener_count')
def listener_get_count():
    emit('listener_count', {'count': len(listener_sids)})

# DJ Panel Routes (No engine commands needed in local mode)
@dj_socketio.on('get_mixer_status')
def get_mixer_status():
    pass

@dj_socketio.on('audio_sync_queue')
def audio_sync_queue(data):
    pass

def _listener_count_sync_loop():
    """Periodic background sync to ensure listener count is always accurate."""
    while True:
        count = len(listener_sids)
        listener_socketio.emit('listener_count', {'count': count}, namespace='/')
        dj_socketio.emit('listener_count', {'count': count}, namespace='/')
        eventlet.sleep(5)


if __name__ == '__main__':
    print("=" * 50)
    print("🎧 TECHDJ PRO - DUAL PORT ARCHITECTURE")
    print("=" * 50)
    # Ports from environment or defaults
    dj_port = int(os.environ.get('DJ_PORT', 5000))
    listen_port = int(os.environ.get('LISTEN_PORT', 5001))
    
    print(f"👉 DJ PANEL API: http://0.0.0.0:{dj_port}")
    print(f"👉 LISTEN PAGE:  http://0.0.0.0:{listen_port}")
    print("=" * 50)
    
    # Audio engine DISABLED
    print(f"✅ Local Radio server ready on ports {dj_port} & {listen_port}")
    
    # Run both servers using eventlet's spawn
    eventlet.spawn(_listener_count_sync_loop)
    eventlet.spawn(dj_socketio.run, dj_app, host='0.0.0.0', port=dj_port, debug=False)
    listener_socketio.run(listener_app, host='0.0.0.0', port=listen_port, debug=False)