"""RTLAMR utility meter monitoring routes."""

from __future__ import annotations

import contextlib
import json
import queue
import subprocess
import threading
import time
from datetime import datetime

from flask import Blueprint, Response, jsonify, request

import app as app_module
from utils.event_pipeline import process_event
from utils.logging import sensor_logger as logger
from utils.process import register_process, unregister_process
from utils.responses import api_error
from utils.sse import sse_stream_fanout
from utils.validation import validate_device_index, validate_frequency, validate_gain, validate_ppm

rtlamr_bp = Blueprint('rtlamr', __name__)

# Store rtl_tcp process separately
rtl_tcp_process = None
rtl_tcp_lock = threading.Lock()

# Track which device is being used
rtlamr_active_device: int | None = None
rtlamr_active_sdr_type: str = 'rtlsdr'


def stream_rtlamr_output(process: subprocess.Popen[bytes]) -> None:
    """Stream rtlamr JSON output to queue."""
    try:
        app_module.rtlamr_queue.put({'type': 'status', 'text': 'started'})

        for line in iter(process.stdout.readline, b''):
            line = line.decode('utf-8', errors='replace').strip()
            if not line:
                continue

            try:
                # rtlamr outputs JSON objects, one per line
                data = json.loads(line)
                data['type'] = 'rtlamr'
                app_module.rtlamr_queue.put(data)

                # Log if enabled
                if app_module.logging_enabled:
                    try:
                        with open(app_module.log_file_path, 'a') as f:
                            timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
                            f.write(f"{timestamp} | RTLAMR | {json.dumps(data)}\n")
                    except Exception:
                        pass
            except json.JSONDecodeError:
                # Not JSON, send as raw
                app_module.rtlamr_queue.put({'type': 'raw', 'text': line})

    except Exception as e:
        app_module.rtlamr_queue.put({'type': 'error', 'text': str(e)})
    finally:
        global rtl_tcp_process, rtlamr_active_device, rtlamr_active_sdr_type
        # Ensure rtlamr process is terminated
        try:
            process.terminate()
            process.wait(timeout=2)
        except Exception:
            with contextlib.suppress(Exception):
                process.kill()
        unregister_process(process)
        # Kill companion rtl_tcp process
        with rtl_tcp_lock:
            if rtl_tcp_process:
                try:
                    rtl_tcp_process.terminate()
                    rtl_tcp_process.wait(timeout=2)
                except Exception:
                    with contextlib.suppress(Exception):
                        rtl_tcp_process.kill()
                unregister_process(rtl_tcp_process)
                rtl_tcp_process = None
        app_module.rtlamr_queue.put({'type': 'status', 'text': 'stopped'})
        with app_module.rtlamr_lock:
            app_module.rtlamr_process = None
        # Release SDR device
        if rtlamr_active_device is not None:
            app_module.release_sdr_device(rtlamr_active_device, rtlamr_active_sdr_type)
            rtlamr_active_device = None


@rtlamr_bp.route('/start_rtlamr', methods=['POST'])
def start_rtlamr() -> Response:
    global rtl_tcp_process, rtlamr_active_device, rtlamr_active_sdr_type

    with app_module.rtlamr_lock:
        if app_module.rtlamr_process:
            return api_error('RTLAMR already running', 409)

        data = request.json or {}
        sdr_type_str = data.get('sdr_type', 'rtlsdr')

        if sdr_type_str != 'rtlsdr':
            return api_error(f'{sdr_type_str.replace("_", " ").title()} is not yet supported for this mode. Please use an RTL-SDR device.', 400)

        # Validate inputs
        try:
            freq = validate_frequency(data.get('frequency', '912.0'))
            gain = validate_gain(data.get('gain', '0'))
            ppm = validate_ppm(data.get('ppm', '0'))
            device = validate_device_index(data.get('device', '0'))
        except ValueError as e:
            return api_error(str(e), 400)

        # Check if device is available
        device_int = int(device)
        error = app_module.claim_sdr_device(device_int, 'rtlamr', sdr_type_str)
        if error:
            return api_error(error, 409, error_type='DEVICE_BUSY')

        rtlamr_active_device = device_int
        rtlamr_active_sdr_type = sdr_type_str

        # Clear queue
        while not app_module.rtlamr_queue.empty():
            try:
                app_module.rtlamr_queue.get_nowait()
            except queue.Empty:
                break

        # Get message type (default to scm)
        msgtype = data.get('msgtype', 'scm')
        output_format = data.get('format', 'json')

        # Start rtl_tcp first
        rtl_tcp_just_started = False
        rtl_tcp_cmd_str = ''
        with rtl_tcp_lock:
            if not rtl_tcp_process:
                logger.info("Starting rtl_tcp server...")
                try:
                    rtl_tcp_cmd = ['rtl_tcp', '-a', '0.0.0.0']

                    # Add device index if not 0
                    if device and device != '0':
                        rtl_tcp_cmd.extend(['-d', str(device)])

                    # Add gain if not auto
                    if gain and gain != '0':
                        rtl_tcp_cmd.extend(['-g', str(gain)])

                    # Add PPM correction if not 0
                    if ppm and ppm != '0':
                        rtl_tcp_cmd.extend(['-p', str(ppm)])

                    rtl_tcp_process = subprocess.Popen(
                        rtl_tcp_cmd,
                        stdout=subprocess.PIPE,
                        stderr=subprocess.PIPE
                    )
                    register_process(rtl_tcp_process)
                    rtl_tcp_just_started = True
                    rtl_tcp_cmd_str = ' '.join(rtl_tcp_cmd)
                except Exception as e:
                    logger.error(f"Failed to start rtl_tcp: {e}")
                    # Release SDR device on rtl_tcp failure
                    if rtlamr_active_device is not None:
                        app_module.release_sdr_device(rtlamr_active_device, rtlamr_active_sdr_type)
                        rtlamr_active_device = None
                    return api_error(f'Failed to start rtl_tcp: {e}', 500)

        # Wait for rtl_tcp to start outside lock
        if rtl_tcp_just_started:
            time.sleep(3)
            logger.info(f"rtl_tcp started: {rtl_tcp_cmd_str}")
            app_module.rtlamr_queue.put({'type': 'info', 'text': f'rtl_tcp: {rtl_tcp_cmd_str}'})

        # Build rtlamr command
        cmd = [
            'rtlamr',
            '-server=127.0.0.1:1234',
            f'-msgtype={msgtype}',
            f'-format={output_format}',
            f'-centerfreq={int(float(freq) * 1e6)}'
        ]

        # Add filter options if provided
        filterid = data.get('filterid')
        if filterid:
            cmd.append(f'-filterid={filterid}')

        filtertype = data.get('filtertype')
        if filtertype:
            cmd.append(f'-filtertype={filtertype}')

        # Unique messages only
        if data.get('unique', True):
            cmd.append('-unique=true')

        full_cmd = ' '.join(cmd)
        logger.info(f"Running: {full_cmd}")

        try:
            app_module.rtlamr_process = subprocess.Popen(
                cmd,
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE
            )
            register_process(app_module.rtlamr_process)

            # Start output thread
            thread = threading.Thread(target=stream_rtlamr_output, args=(app_module.rtlamr_process,))
            thread.daemon = True
            thread.start()

            # Monitor stderr
            def monitor_stderr():
                for line in app_module.rtlamr_process.stderr:
                    err = line.decode('utf-8', errors='replace').strip()
                    if err:
                        logger.debug(f"[rtlamr] {err}")
                        app_module.rtlamr_queue.put({'type': 'info', 'text': f'[rtlamr] {err}'})

            stderr_thread = threading.Thread(target=monitor_stderr)
            stderr_thread.daemon = True
            stderr_thread.start()

            app_module.rtlamr_queue.put({'type': 'info', 'text': f'Command: {full_cmd}'})

            return jsonify({'status': 'started', 'command': full_cmd})

        except FileNotFoundError:
            # If rtlamr fails, clean up rtl_tcp and release device
            with rtl_tcp_lock:
                if rtl_tcp_process:
                    rtl_tcp_process.terminate()
                    rtl_tcp_process.wait(timeout=2)
                    rtl_tcp_process = None
            if rtlamr_active_device is not None:
                app_module.release_sdr_device(rtlamr_active_device, rtlamr_active_sdr_type)
                rtlamr_active_device = None
            return api_error('rtlamr not found. Install from https://github.com/bemasher/rtlamr')
        except Exception as e:
            # If rtlamr fails, clean up rtl_tcp and release device
            with rtl_tcp_lock:
                if rtl_tcp_process:
                    rtl_tcp_process.terminate()
                    rtl_tcp_process.wait(timeout=2)
                    rtl_tcp_process = None
            if rtlamr_active_device is not None:
                app_module.release_sdr_device(rtlamr_active_device, rtlamr_active_sdr_type)
                rtlamr_active_device = None
            return api_error(str(e))


@rtlamr_bp.route('/stop_rtlamr', methods=['POST'])
def stop_rtlamr() -> Response:
    global rtl_tcp_process, rtlamr_active_device, rtlamr_active_sdr_type

    # Grab process refs inside locks, clear state, then terminate outside
    rtlamr_proc = None
    with app_module.rtlamr_lock:
        if app_module.rtlamr_process:
            rtlamr_proc = app_module.rtlamr_process
            app_module.rtlamr_process = None

    if rtlamr_proc:
        rtlamr_proc.terminate()
        try:
            rtlamr_proc.wait(timeout=2)
        except subprocess.TimeoutExpired:
            rtlamr_proc.kill()

    # Also stop rtl_tcp
    tcp_proc = None
    with rtl_tcp_lock:
        if rtl_tcp_process:
            tcp_proc = rtl_tcp_process
            rtl_tcp_process = None

    if tcp_proc:
        tcp_proc.terminate()
        try:
            tcp_proc.wait(timeout=2)
        except subprocess.TimeoutExpired:
            tcp_proc.kill()
        logger.info("rtl_tcp stopped")

    # Release device from registry
    if rtlamr_active_device is not None:
        app_module.release_sdr_device(rtlamr_active_device, rtlamr_active_sdr_type)
        rtlamr_active_device = None

    return jsonify({'status': 'stopped'})


@rtlamr_bp.route('/stream_rtlamr')
def stream_rtlamr() -> Response:
    def _on_msg(msg: dict[str, Any]) -> None:
        process_event('rtlamr', msg, msg.get('type'))

    response = Response(
        sse_stream_fanout(
            source_queue=app_module.rtlamr_queue,
            channel_key='rtlamr',
            timeout=1.0,
            keepalive_interval=30.0,
            on_message=_on_msg,
        ),
        mimetype='text/event-stream',
    )
    response.headers['Cache-Control'] = 'no-cache'
    response.headers['X-Accel-Buffering'] = 'no'
    response.headers['Connection'] = 'keep-alive'
    return response