"""MediaKit 客户端 — 封装火山引擎 AI MediaKit 对口型 API.

接口文档：https://docs.volcengine.com/docs/6448/2656064

异步任务流程：
1. POST /api/v1/tools/lip-sync  提交对口型任务 → 返回 task_id
2. GET  /api/v1/tasks/{task_id} 轮询任务状态 → running/completed/failed
3. completed 时 result.video_url 为口型对齐视频（临时链接 24h 有效）

设计原则：
- API Key 从配置读取（settings.mediakit_api_key）
- 未配置 API Key 时所有方法返回降级响应，不阻塞主流程
- HTTP 超时/网络异常统一包装为 MediaKitError
"""

from __future__ import annotations

import logging
from typing import Any, Optional

import httpx

from packages.config import get_api_settings

logger = logging.getLogger(__name__)

# ── 任务状态常量 ──────────────────────────────────────────────────────────
STATUS_RUNNING = "running"
STATUS_COMPLETED = "completed"
STATUS_FAILED = "failed"


class MediaKitError(Exception):
    """MediaKit API 调用异常."""

    def __init__(self, message: str, code: str = "", request_id: str = ""):
        self.code = code
        self.request_id = request_id
        super().__init__(message)


class MediaKitClient:
    """火山引擎 AI MediaKit 对口型 API 客户端.

    用法：
        client = get_mediakit_client()
        result = client.submit_lipsync(video_url="...", audio_url="...")
        task_id = result["task_id"]

        status = client.get_task_status(task_id)
        # {"status": "completed", "result": {"video_url": "...", "duration": 60.5}}
    """

    def __init__(self) -> None:
        settings = get_api_settings()
        self._api_key = settings.mediakit_api_key
        self._base_url = settings.mediakit_base_url.rstrip("/")
        self._timeout = settings.mediakit_timeout

    @property
    def is_available(self) -> bool:
        """是否已配置 API Key（未配置时自动降级）."""
        return bool(self._api_key)

    def _headers(self) -> dict[str, str]:
        return {
            "Authorization": f"Bearer {self._api_key}",
            "Content-Type": "application/json",
        }

    # ── 提交对口型任务 ────────────────────────────────────────────────────

    def submit_lipsync(
        self,
        *,
        video_url: str,
        audio_url: str,
        enable_video_loop: bool = False,
        callback_url: Optional[str] = None,
        callback_args: Optional[str] = None,
        client_token: Optional[str] = None,
    ) -> dict[str, Any]:
        """提交视频口型对齐任务.

        Args:
            video_url: 人物视频 URL（MP4，≤30min，单人真人）
            audio_url: 驱动音频 URL（mp3/aac/wav/m4a/flac）
            enable_video_loop: 音频长于视频时是否循环画面
            callback_url: 任务完成回调 URL
            callback_args: 回调时原样返回的自定义参数
            client_token: 幂等控制 token

        Returns:
            {"success": True, "task_id": "...", "request_id": "..."}

        Raises:
            MediaKitError: API 调用失败
        """
        if not self.is_available:
            raise MediaKitError("MediaKit API Key 未配置", code="NotConfigured")

        payload: dict[str, Any] = {
            "video_url": video_url,
            "audio_url": audio_url,
        }
        if enable_video_loop:
            payload["enable_video_loop"] = True
        if callback_url:
            payload["callback_url"] = callback_url
        if callback_args:
            payload["callback_args"] = callback_args[:512]  # API 限制 512 字节
        if client_token:
            payload["client_token"] = client_token[:64]  # API 限制 64 字符

        try:
            with httpx.Client(timeout=self._timeout) as client:
                resp = client.post(
                    f"{self._base_url}/tools/lip-sync",
                    headers=self._headers(),
                    json=payload,
                )
                resp.raise_for_status()
                data = resp.json()
        except httpx.TimeoutException as exc:
            raise MediaKitError(f"MediaKit API 超时 ({self._timeout}s)", code="Timeout") from exc
        except httpx.HTTPStatusError as exc:
            body = exc.response.text[:500]
            raise MediaKitError(
                f"MediaKit API HTTP {exc.response.status_code}: {body}",
                code="HttpError",
            ) from exc
        except httpx.RequestError as exc:
            raise MediaKitError(f"MediaKit API 网络错误: {exc}", code="NetworkError") from exc
        except Exception as exc:
            raise MediaKitError(f"MediaKit API 未知错误: {exc}", code="UnknownError") from exc

        if not data.get("success"):
            error = data.get("error", {})
            raise MediaKitError(
                error.get("message", "提交任务失败"),
                code=error.get("code", "SubmitFailed"),
                request_id=data.get("request_id", ""),
            )

        return {
            "success": True,
            "task_id": data["task_id"],
            "request_id": data.get("request_id", ""),
        }

    # ── 查询任务状态 ──────────────────────────────────────────────────────

    def get_task_status(self, task_id: str) -> dict[str, Any]:
        """查询异步任务状态和结果.

        Args:
            task_id: 提交任务时返回的任务 ID

        Returns:
            {
                "success": True,
                "task_id": "...",
                "status": "running" | "completed" | "failed",
                "result": {"video_url": "...", "duration": 60.5} | None,
                "error": {"code": "...", "message": "..."} | None,
                "created_at": 1777291767,
                "finished_at": 1777291851 | None,
                "expires_at": 1777464650 | None,
            }

        Raises:
            MediaKitError: API 调用失败
        """
        if not self.is_available:
            raise MediaKitError("MediaKit API Key 未配置", code="NotConfigured")

        try:
            with httpx.Client(timeout=self._timeout) as client:
                resp = client.get(
                    f"{self._base_url}/tasks/{task_id}",
                    headers=self._headers(),
                )
                resp.raise_for_status()
                data = resp.json()
        except httpx.TimeoutException as exc:
            raise MediaKitError(f"MediaKit API 超时 ({self._timeout}s)", code="Timeout") from exc
        except httpx.HTTPStatusError as exc:
            body = exc.response.text[:500]
            raise MediaKitError(
                f"MediaKit API HTTP {exc.response.status_code}: {body}",
                code="HttpError",
            ) from exc
        except httpx.RequestError as exc:
            raise MediaKitError(f"MediaKit API 网络错误: {exc}", code="NetworkError") from exc
        except Exception as exc:
            raise MediaKitError(f"MediaKit API 未知错误: {exc}", code="UnknownError") from exc

        if not data.get("success"):
            error = data.get("error", {})
            raise MediaKitError(
                error.get("message", "查询任务失败"),
                code=error.get("code", "QueryFailed"),
                request_id=data.get("request_id", ""),
            )

        result: dict[str, Any] = {
            "success": True,
            "task_id": data.get("task_id", task_id),
            "status": data.get("status", STATUS_RUNNING),
            "result": data.get("result"),
            "created_at": data.get("created_at"),
            "finished_at": data.get("finished_at"),
            "expires_at": data.get("expires_at"),
        }

        # 失败时提取错误信息
        if data.get("status") == STATUS_FAILED:
            error_obj = data.get("error", {})
            result["error"] = {
                "code": error_obj.get("code", "TaskFailed"),
                "message": error_obj.get("message", "任务执行失败"),
            }

        return result


# ── 单例 ──────────────────────────────────────────────────────────────────

_client: Optional[MediaKitClient] = None


def get_mediakit_client() -> MediaKitClient:
    """获取 MediaKit 客户端单例."""
    global _client
    if _client is None:
        _client = MediaKitClient()
    return _client


def reset_mediakit_client() -> None:
    """重置客户端（测试用）."""
    global _client
    _client = None