from wave import open as wave_open
from pathlib import Path
import re
import os
import json
from typing import Optional

import dashscope
from dashscope.api_entities.dashscope_response import SpeechSynthesisResponse
from dashscope.audio.tts import ResultCallback, SpeechSynthesizer, SpeechSynthesisResult

import requests

from ..schemas.speech import TextToSpeechResponse, DataPayload
from ..core.config import get_settings
from ..core.logger import get_logger

settings = get_settings()
# Configure DashScope API key from env/.env
dashscope.api_key = settings.dashscope_api_key or ""
UPLOAD_PATH = settings.upload_path or ""

# module logger
logger = get_logger("speech_provider")


def _safe_filename(name: str) -> str:
    # Keep alphanum, dash, underscore, Chinese; replace others with '_'
    return re.sub(r"[^\w\-\u4e00-\u9fff]+", "_", name).strip("_") or "output"


class SpeechProvider:
    def text_to_speech(self, volume: int, pitch: float, rate: float, filename: str, text: str, *, model: Optional[str] = None, format: Optional[str] = None) -> TextToSpeechResponse:
        # Resolve output path under project-root/temp and ensure directory exists
        project_root = Path(__file__).resolve().parents[2]  # repo root
        audio_dir = project_root / "temp"
        try:
            audio_dir.mkdir(parents=True, exist_ok=True)
        except Exception as e:
            logger.error("Failed to create audio directory %s: %s", audio_dir, e, exc_info=True)
            return TextToSpeechResponse(code=1, data=None, msg=f"create audio dir failed: {e}")

        # Basic input validation
        if not isinstance(text, str) or not text.strip():
            msg = "text is required"
            logger.error(msg)
            return TextToSpeechResponse(code=1, data=None, msg=msg)
        if not isinstance(filename, str) or not filename.strip():
            msg = "filename is required"
            logger.error(msg)
            return TextToSpeechResponse(code=1, data=None, msg=msg)
        if not dashscope.api_key:
            msg = "DASHSCOPE_API_KEY is missing"
            logger.error(msg)
            return TextToSpeechResponse(code=1, data=None, msg=msg)

        # determine desired output format (default mp3 for smaller size)
        audio_format = (format or 'mp3').lower()
        if audio_format not in {"wav", "mp3"}:
            logger.info("unsupported format '%s', fallback to mp3", audio_format)
            audio_format = "mp3"

        # choose extension and sample rate
        ext = "wav" if audio_format == "wav" else "mp3"
        sample_rate = 48000 if audio_format == "wav" else 24000

        filename = f"{_safe_filename(filename)}.{ext}"
        out_path = audio_dir / filename

        # Prepare callback with audio params
        callback = Callback(
            out_path=str(out_path),
            sample_rate=sample_rate,
            channels=1,
            sampwidth=2,
            audio_format=audio_format,
        )

        # Run TTS with robust error handling
        try:
            SpeechSynthesizer.call(
                model=(model or 'sambert-zhifei-v1'),
                volume=volume,
                text=text,
                pitch=pitch,
                rate=rate,
                format=audio_format,
                sample_rate=sample_rate,
                callback=callback,
                word_timestamp_enabled=True,
                phoneme_timestamp_enabled=True,
            )
        except Exception as e:
            logger.error("TTS call failed", exc_info=True)
            # Ensure any open file handles are closed
            try:
                callback.on_complete()
            except Exception:
                pass
            return TextToSpeechResponse(code=1, data=None, msg=str(e))

        if callback.had_error:
            # TTS reported an error via callback
            base_msg = callback.error_message or "speech synthesis failed"
            # Enrich message with model error code/status when available
            if callback.error_code or callback.status_code is not None:
                msg = f"[{callback.error_code or 'Error'}] {base_msg} (status={callback.status_code})"
            else:
                msg = base_msg
            logger.error("TTS callback error: %s", msg)
            return TextToSpeechResponse(code=1, data=None, msg=msg)

        # After synthesis completes, upload the file to OSS
        try:
            url = _upload_file(UPLOAD_PATH, out_path)
            # Upload succeeded; remove local audio file to save space
            try:
                Path(out_path).unlink(missing_ok=True)
            except Exception as del_err:
                logger.warning("Failed to delete local audio %s: %s", out_path, del_err)
            return TextToSpeechResponse(
                code=0,
                data=DataPayload(audio_url=url),
                msg='success'
            )
        except Exception as e:
            # Keep local file for inspection; report error message
            logger.error("Upload failed", exc_info=True)
            return TextToSpeechResponse(code=1, data=None, msg=str(e))


class Callback(ResultCallback):
    def __init__(self, out_path: str, sample_rate: int = 16000, channels: int = 1, sampwidth: int = 2, audio_format: str = "mp3"):
        self.out_path = out_path
        self.sample_rate = sample_rate
        self.channels = channels
        self.sampwidth = sampwidth
        self.wav_file = None
        self._fh = None
        self.audio_format = audio_format
        self.had_error = False
        self.error_message: Optional[str] = None
        self.error_code: Optional[str] = None
        self.status_code: Optional[int] = None

    def on_open(self):
        logger.info('Speech synthesizer opened')
        try:
            # Ensure parent directory exists (in case not created earlier)
            Path(self.out_path).parent.mkdir(parents=True, exist_ok=True)
            if self.audio_format == "wav":
                self.wav_file = wave_open(self.out_path, 'wb')
                self.wav_file.setnchannels(self.channels)
                self.wav_file.setsampwidth(self.sampwidth)
                self.wav_file.setframerate(self.sample_rate)
            else:
                # For mp3 (and other compressed formats), write raw bytes
                self._fh = open(self.out_path, 'wb')
        except Exception as e:
            self.had_error = True
            self.error_message = f"open output failed: {e}"
            logger.error("Failed to open output file %s: %s", self.out_path, e, exc_info=True)

    def on_complete(self):
        logger.info('Speech synthesizer completed')
        if self.wav_file:
            self.wav_file.close()
            self.wav_file = None
        if self._fh:
            self._fh.close()
            self._fh = None

    def on_error(self, response: SpeechSynthesisResponse):
        # Capture error and mark state for upstream handling
        code, detail, status = _extract_dashscope_error(response)
        self.had_error = True
        self.error_message = detail
        self.error_code = code
        self.status_code = status
        # Log with structured context
        if code or status is not None:
            logger.error('Speech synthesizer failed: code=%s status=%s msg=%s', code, status, detail)
        else:
            logger.error('Speech synthesizer failed: %s', detail)
        # Ensure file handles are closed even on error
        try:
            self.on_complete()
        except Exception:
            pass

    def on_close(self):
        logger.info('Speech synthesizer closed')

    def on_event(self, result: SpeechSynthesisResult):
        frame = result.get_audio_frame()
        if not frame:
            return
        try:
            if self.wav_file:
                self.wav_file.writeframes(frame)
            elif self._fh:
                self._fh.write(frame)
            else:
                # No open handle; mark error to surface upstream
                self.had_error = True
                self.error_message = "audio handle not initialized"
                logger.error("Audio handle not initialized when receiving frame")
        except Exception as e:
            self.had_error = True
            self.error_message = f"write frame failed: {e}"
            logger.error("Failed writing audio frame: %s", e, exc_info=True)


def _extract_url_from_response(resp_json: dict) -> Optional[str]:
    # Try common shapes: {data: {url}}, {url}, {data: "http..."}
    try_keys = [
        ("data", "fileUrl"),
        ("data",),
        ("fileUrl",),
        ("result", "fileUrl"),
        ("payload", "fileUrl"),
    ]
    for path in try_keys:
        cur = resp_json
        ok = True
        for k in path:
            if isinstance(cur, dict) and k in cur:
                cur = cur[k]
            else:
                ok = False
                break
        if ok and isinstance(cur, str) and cur.startswith("http"):
            return cur
    return None


def _extract_dashscope_error(resp: object) -> tuple[Optional[str], str, Optional[int]]:
    """Best-effort extraction of (code, message, http_status) from DashScope response.
    Compatible with SpeechSynthesisResponse or dict-like payloads.
    """
    code: Optional[str] = None
    msg: str = "speech synthesis failed"
    status: Optional[int] = None

    # If it looks like a dict
    if isinstance(resp, dict):
        code = str(resp.get("code")) if resp.get("code") is not None else None
        status = resp.get("status_code") if isinstance(resp.get("status_code"), int) else None
        msg = str(resp.get("message") or msg)
        return code, msg, status

    # Try attribute-style access
    try:
        status_attr = getattr(resp, "status_code", None)
        if isinstance(status_attr, int):
            status = status_attr
    except Exception:
        pass
    try:
        code_attr = getattr(resp, "code", None)
        if code_attr is not None:
            code = str(code_attr)
    except Exception:
        pass
    try:
        msg_attr = getattr(resp, "message", None)
        if msg_attr:
            msg = str(msg_attr)
    except Exception:
        pass

    # As a last resort, try to parse JSON from str(resp)
    try:
        s = str(resp)
        if s and s.strip().startswith("{"):
            data = json.loads(s)
            if isinstance(data, dict):
                code = str(data.get("code")) if data.get("code") is not None else code
                status = data.get("status_code") if isinstance(data.get("status_code"), int) else status
                msg = str(data.get("message") or msg)
    except Exception:
        pass

    return code, msg, status


def _upload_file(upload_url: str, file_path: Path) -> str:
    if not upload_url:
        logger.error("upload_url is empty")
        raise ValueError("upload_url is empty")
    if not Path(file_path).exists():
        logger.error("audio file not found: %s", file_path)
        raise FileNotFoundError(str(file_path))

    filename = Path(file_path).name
    # Guess content type
    content_type = "audio/mpeg" if filename.lower().endswith(".mp3") else "audio/wav"

    with open(file_path, "rb") as f:
        files = {
            "file": (filename, f, content_type),
            "fileType": (None, "VOICE")
        }
        resp = requests.post(upload_url, files=files, timeout=30)
    resp.raise_for_status()

    # Try to parse JSON for a URL; fallback to raw text if JSON invalid
    url: Optional[str] = None
    try:
        data = resp.json()
        url = _extract_url_from_response(data)
    except Exception:
        logger.warning("Upload response is not valid JSON")

    if not url:
        # As a last resort, if the response text looks like a URL, use it
        txt = (resp.text or "").strip()
        if txt.startswith("http"):
            url = txt

    if not url:
        logger.error("upload succeeded but no URL found in response")
        raise RuntimeError("upload succeeded but no URL found in response")

    return url