"""
Mind CLI — 系统拾音引擎 (Phase 4)

双层架构·音频服务层：
  CLI 作为音频服务层的一个独立源，只负责采集系统音频。
  浏览器/APK 负责麦克风。双工模式下两路各走各的 Cloud ASR session。

支持两种采集模式（由调用方指定）：
  - "system"（默认）：ScreenCaptureKit 系统音频（macOS only）
  - "mic"：sounddevice 麦克风（无浏览器的 fallback 场景）

不做混音。混音 = 伪需求。"关联两份转写"是 Agent 层的智力工作。

Cloud 端复用 dashscope_realtime.py 管线，零新增代码。
协议与前端 RecordingService 完全一致：
  客户端→服务端: binary PCM16 帧 / {"type":"stop"}
  服务端→客户端: {"type":"partial/final","text":"..."}
"""

import asyncio
import json
import logging
import threading
import time
from typing import Callable, Literal

logger = logging.getLogger("mindcli.recorder")

# ── 常量 ──────────────────────────────────────────────────
TARGET_SAMPLE_RATE = 16000   # Cloud ASR 要求 16kHz
CHUNK_DURATION_MS = 100      # 每帧 100ms
CHUNK_SAMPLES = TARGET_SAMPLE_RATE * CHUNK_DURATION_MS // 1000  # 1600

# ── 全局单例 ──────────────────────────────────────────────
_recorder: "SystemRecorder | None" = None


def get_recorder() -> "SystemRecorder":
    """获取全局 SystemRecorder 单例。"""
    global _recorder
    if _recorder is None:
        _recorder = SystemRecorder()
    return _recorder


class SystemRecorder:
    """
    系统拾音引擎 — 音频服务层的一个独立源。

    只负责单一音频源的采集 + WS 推送。
    不做混音（双工模式下浏览器和 CLI 各自独立推送到 Cloud ASR）。
    """

    def __init__(self):
        self._running = False
        self._ws = None
        self._source: str = "system"
        self._start_time = 0.0
        self._chat_id = ""
        self._meeting_id = ""
        # 音频缓冲区（线程安全）
        self._audio_buf: bytearray = bytearray()
        self._buf_lock = threading.Lock()
        # 采集资源
        self._mic_stream = None       # sounddevice.InputStream
        self._sc_stream = None        # SCStream
        self._sc_delegate = None
        # 推送线程
        self._push_thread: threading.Thread | None = None
        # asyncio 事件循环引用（start 时保存）
        self._loop: asyncio.AbstractEventLoop | None = None
        # 事件回调
        self._on_text: Callable[[str, str], None] | None = None

    @property
    def is_running(self) -> bool:
        return self._running

    def status(self) -> dict:
        """返回当前录音状态。"""
        return {
            "running": self._running,
            "source": self._source if self._running else None,
            "duration": round(time.time() - self._start_time, 1) if self._running else 0,
            "chatId": self._chat_id,
            "meetingId": self._meeting_id,
        }

    async def start(
        self,
        ws_url: str,
        chat_id: str = "",
        meeting_id: str = "",
        source: Literal["system", "mic"] = "system",
        on_text: Callable[[str, str], None] | None = None,
    ) -> dict:
        """
        开始录音（单一源）。

        Args:
            ws_url: Cloud ASR WebSocket URL（含 token/chatId/meetingId query）
            chat_id: 对话 ID
            meeting_id: 录音批次 ID
            source: "system"（ScreenCaptureKit）或 "mic"（sounddevice）
            on_text: 收到转写文本的回调 (type, text)

        Returns:
            {"ok": True, "meetingId": "..."} 或 {"error": "..."}
        """
        if self._running:
            return {"error": "录音已在进行中"}

        self._chat_id = chat_id
        self._meeting_id = meeting_id or f"cli_rec_{int(time.time() * 1000)}"
        self._source = source
        self._on_text = on_text
        self._audio_buf.clear()
        self._loop = asyncio.get_running_loop()

        # 1. 连接 Cloud ASR WebSocket
        try:
            import websockets
            self._ws = await websockets.connect(ws_url)
            logger.info("[Recorder] WS 已连接: %s", ws_url[:80])
        except Exception as e:
            logger.error("[Recorder] WS 连接失败: %s", e)
            return {"error": f"WebSocket 连接失败: {e}"}

        # 2. 启动音频采集
        try:
            if source == "system":
                self._start_system_audio()
            else:
                self._start_mic()
        except Exception as e:
            logger.error("[Recorder] 音频源 '%s' 启动失败: %s", source, e)
            await self._ws.close()
            self._ws = None
            return {"error": f"音频源启动失败: {e}"}

        # 3. 启动推送线程
        self._running = True
        self._start_time = time.time()
        self._push_thread = threading.Thread(target=self._push_loop, daemon=True)
        self._push_thread.start()

        # 4. 启动 WS 接收协程（转写结果）
        asyncio.create_task(self._ws_recv_loop())

        logger.info("[Recorder] 录音已开始 source=%s chatId=%s meetingId=%s",
                    source, chat_id, self._meeting_id)
        return {"ok": True, "meetingId": self._meeting_id, "source": source}

    async def stop(self) -> dict:
        """停止录音。"""
        if not self._running:
            return {"error": "未在录音"}

        self._running = False
        duration = round(time.time() - self._start_time, 1)

        # 停止音频源
        self._stop_capture()

        # 等待推送线程结束
        if self._push_thread and self._push_thread.is_alive():
            self._push_thread.join(timeout=3)

        # 发送 stop 命令
        if self._ws:
            try:
                await self._ws.send(json.dumps({"type": "stop"}))
                await asyncio.sleep(1)
                await self._ws.close()
            except Exception:
                pass
            self._ws = None

        logger.info("[Recorder] 录音已停止 duration=%.1fs", duration)
        return {"ok": True, "duration": duration, "meetingId": self._meeting_id}

    # ── 麦克风采集（sounddevice）────────────────────────────

    def _start_mic(self):
        """启动麦克风捕获 16kHz mono int16。"""
        import sounddevice as sd

        def _callback(indata, frames, time_info, status):
            if status:
                logger.debug("[Recorder] mic status: %s", status)
            with self._buf_lock:
                self._audio_buf.extend(indata.tobytes())

        self._mic_stream = sd.InputStream(
            samplerate=TARGET_SAMPLE_RATE,
            channels=1,
            dtype="int16",
            blocksize=CHUNK_SAMPLES,
            callback=_callback,
        )
        self._mic_stream.start()
        logger.info("[Recorder] 麦克风已启动 @%dHz", TARGET_SAMPLE_RATE)

    # ── 系统音频采集（ScreenCaptureKit）─────────────────────

    def _start_system_audio(self):
        """启动 macOS 系统音频捕获。"""
        import platform
        if platform.system() != "Darwin":
            raise RuntimeError("系统音频仅支持 macOS")

        try:
            from ScreenCaptureKit import (
                SCStream,
                SCStreamConfiguration,
                SCContentFilter,
                SCStreamOutputTypeAudio,
            )
            from dispatch import dispatch_queue_create, DISPATCH_QUEUE_SERIAL
        except ImportError as e:
            raise RuntimeError(
                f"缺少 pyobjc 依赖，请运行: pip install mindos-cli[audio]\n{e}"
            )

        # 获取主显示器
        content = _sync_get_sharable_content()
        if not content or not content.displays():
            raise RuntimeError("无法获取显示器列表")

        display = content.displays()[0]

        # 配置：只捕获音频
        config = SCStreamConfiguration.alloc().init()
        config.setCapturesAudio_(True)
        config.setExcludesCurrentProcessAudio_(True)
        config.setChannelCount_(1)
        config.setSampleRate_(float(TARGET_SAMPLE_RATE))

        # 内容过滤器
        content_filter = SCContentFilter.alloc().initWithDisplay_excludingWindows_(
            display, []
        )

        # 创建 delegate
        _ensure_delegate_class()
        self._sc_delegate = _SCStreamDelegate.alloc().init()
        self._sc_delegate._recorder = self

        # 创建 stream
        self._sc_stream = SCStream.alloc().initWithFilter_configuration_delegate_(
            content_filter, config, None
        )

        # dispatch queue
        queue = dispatch_queue_create(b"mindcli.audio", DISPATCH_QUEUE_SERIAL)
        self._sc_stream.addStreamOutput_type_sampleHandlerQueue_error_(
            self._sc_delegate, SCStreamOutputTypeAudio, queue, None
        )

        # 启动
        event = threading.Event()
        error_holder = [None]

        def _on_start(error):
            if error:
                error_holder[0] = str(error)
            event.set()

        self._sc_stream.startCaptureWithCompletionHandler_(_on_start)
        event.wait(timeout=5)

        if error_holder[0]:
            raise RuntimeError(f"SCStream 启动失败: {error_holder[0]}")

        logger.info("[Recorder] 系统音频已启动 (ScreenCaptureKit @%dHz)", TARGET_SAMPLE_RATE)

    def _on_system_audio(self, raw_bytes: bytes):
        """系统音频回调。SCStream 输出 float32 PCM，需要转为 int16。"""
        import struct
        # float32: 每个样本 4 字节；int16: 每个样本 2 字节
        n_samples = len(raw_bytes) // 4
        if n_samples == 0:
            return
        # 解包 float32
        floats = struct.unpack(f'<{n_samples}f', raw_bytes[:n_samples * 4])
        # clamp [-1, 1] → scale to int16 range
        int16_data = struct.pack(f'<{n_samples}h',
            *(max(-32768, min(32767, int(s * 32767))) for s in floats)
        )
        with self._buf_lock:
            self._audio_buf.extend(int16_data)

    # ── 停止采集 ─────────────────────────────────────────────

    def _stop_capture(self):
        """停止当前音频源。"""
        # 麦克风
        if self._mic_stream:
            try:
                self._mic_stream.stop()
                self._mic_stream.close()
            except Exception:
                pass
            self._mic_stream = None

        # 系统音频
        if self._sc_stream:
            event = threading.Event()
            self._sc_stream.stopCaptureWithCompletionHandler_(lambda e: event.set())
            event.wait(timeout=3)
            self._sc_stream = None
            self._sc_delegate = None

    # ── WS 推送 ──────────────────────────────────────────────

    def _push_loop(self):
        """后台线程：定时取缓冲区 → WS 推送 PCM16 帧。"""
        frame_bytes = CHUNK_SAMPLES * 2  # int16 = 2 bytes/sample = 3200
        send_count = 0

        while self._running:
            time.sleep(CHUNK_DURATION_MS / 1000.0)

            # 一次取尽缓冲区
            with self._buf_lock:
                if len(self._audio_buf) < frame_bytes:
                    continue
                pending = bytes(self._audio_buf)
                self._audio_buf.clear()

            ws = self._ws
            if ws is None:
                continue

            # 按帧大小分片发送
            offset = 0
            while offset + frame_bytes <= len(pending):
                chunk = pending[offset:offset + frame_bytes]
                try:
                    asyncio.run_coroutine_threadsafe(ws.send(chunk), self._loop)
                    send_count += 1
                except Exception as e:
                    logger.debug("[Recorder] WS send err: %s", e)
                    break
                offset += frame_bytes

            # 每 ~5s 打一次发送统计
            if send_count > 0 and send_count % 50 == 0:
                logger.info("[Recorder] WS sent %d frames (%.1fs)",
                            send_count, send_count * CHUNK_DURATION_MS / 1000)

    async def _ws_recv_loop(self):
        """接收 Cloud ASR 的转写结果。"""
        try:
            async for msg in self._ws:
                try:
                    data = json.loads(msg)
                    msg_type = data.get("type", "")
                    text = data.get("text", "")
                    if msg_type in ("partial", "final") and text:
                        logger.info("[Recorder] %s: %s", msg_type, text[:50])
                        if self._on_text:
                            self._on_text(msg_type, text)
                    elif msg_type == "error":
                        logger.error("[Recorder] ASR error: %s", data.get("message"))
                except (json.JSONDecodeError, TypeError):
                    pass
        except Exception as e:
            if self._running:
                logger.warning("[Recorder] WS recv 断开: %s", e)


# ── 工具函数 ──────────────────────────────────────────────

def _sync_get_sharable_content():
    """同步获取 SCShareableContent（阻塞等待 async 回调）。"""
    from ScreenCaptureKit import SCShareableContent

    result = [None]
    event = threading.Event()

    def _handler(content, error):
        if error:
            logger.error("[Recorder] SCShareableContent error: %s", error)
        result[0] = content
        event.set()

    SCShareableContent.getShareableContentExcludingDesktopWindows_onScreenWindowsOnly_completionHandler_(
        False, True, _handler
    )
    event.wait(timeout=5)
    return result[0]


# ── SCStream Delegate ────────────────────────────────────

_SCStreamDelegate = None


def _define_sc_delegate():
    """延迟定义 SCStreamDelegate（避免 import 时要求 pyobjc）。"""
    from Foundation import NSObject
    from ScreenCaptureKit import SCStreamOutputTypeAudio
    import CoreMedia

    class _Delegate(NSObject):
        """接收 SCStream 音频样本的 delegate。"""

        _recorder = None

        def stream_didOutputSampleBuffer_ofType_(self, stream, sample_buffer, output_type):
            if output_type != SCStreamOutputTypeAudio:
                return
            if not self._recorder or not self._recorder.is_running:
                return

            try:
                block_buf = CoreMedia.CMSampleBufferGetDataBuffer(sample_buffer)
                if block_buf is None:
                    return
                length = CoreMedia.CMBlockBufferGetDataLength(block_buf)
                # CMBlockBufferCopyDataBytes 返回 (OSStatus, bytes_data)
                status, raw_data = CoreMedia.CMBlockBufferCopyDataBytes(block_buf, 0, length, None)
                if status == 0 and raw_data:
                    self._recorder._on_system_audio(raw_data)
            except Exception as e:
                logger.warning("[Recorder] SCStream sample error: %s", e, exc_info=True)

    return _Delegate


def _ensure_delegate_class():
    global _SCStreamDelegate
    if _SCStreamDelegate is None:
        _SCStreamDelegate = _define_sc_delegate()
    return _SCStreamDelegate