# -*- coding: utf-8 -*-
"""数据模型、异常与格式常量。

（自 music_downloader.py 拆出，行为与原实现一致。）
"""

from __future__ import annotations

from dataclasses import dataclass
from enum import Enum

from core import sync_http as requests  # 同步门面（底层 aiohttp，替代 requests）

# ============ 类型定义 ============

class QualityLevel(Enum):
    """音质等级枚举"""
    STANDARD = "standard"
    EXHIGH = "exhigh"
    LOSSLESS = "lossless"
    HIRES = "hires"
    SKY = "sky"
    JYEFFECT = "jyeffect"
    JYMASTER = "jymaster"
    DOLBY = "dolby"


@dataclass
class MusicInfo:
    """音乐信息数据类"""
    id: int
    name: str
    artists: str
    album: str
    pic_url: str
    duration: int
    track_number: int
    download_url: str
    file_type: str
    file_size: int
    quality: str
    lyric: str = ""
    tlyric: str = ""
    publish_year: int | None = None


@dataclass
class DownloadResult:
    """下载结果数据类"""
    success: bool
    file_path: str | None = None
    file_size: int = 0
    error_message: str = ""
    music_info: MusicInfo | None = None


class DownloadException(Exception):
    """下载异常类"""
    pass


class DownloadCanceled(DownloadException):
    """下载被用户取消"""
    pass


class _RetryFromScratch(requests.RequestException):
    """内部信号：断点续传起点失效（HTTP 416 等），清除 .part 后从头重试"""
    pass


# ============ 工具映射表 ============

# API 返回的 type -> 文件扩展名
API_TYPE_TO_EXT = {
    "mp3": ".mp3",
    "flac": ".flac",
    "m4a": ".m4a",
    "mp4": ".mp4",
    "ogg": ".ogg",
    "opus": ".opus",
}


# 支持元数据写入的扩展名（tagging.py 按此表分派到各容器的标签写入器）
METADATA_FORMATS = {".mp3", ".flac", ".m4a", ".mp4", ".ogg", ".opus"}