"""导出采集图片：把采集到的源站图片打包成 ZIP 下载到本地。

参考图 URL 可能是源站 CDN（需 Referer 绕过防盗链）或本地上传的 media 文件。
ZIP 内部结构沿用现有分组名建子文件夹（主图 / SKU图片 / 详情图 / 手动上传），
文件名沿用采集 key（main-001 等）+ SKU 规格名；顶层文件夹用商品标题（清洗后）。
"""
from __future__ import annotations

import io
import mimetypes
import re
import zipfile

from fastapi import APIRouter, HTTPException
from fastapi.responses import StreamingResponse
from pydantic import BaseModel, Field

from api.proxy import guess_referer
from services import storage

router = APIRouter(prefix="/api", tags=["export"])

_EXT_BY_CTYPE = {
    "image/jpeg": ".jpg",
    "image/png": ".png",
    "image/webp": ".webp",
    "image/gif": ".gif",
    "image/bmp": ".bmp",
}


class ExportImageItem(BaseModel):
    url: str
    groupName: str = "主图"
    variantName: str | None = None
    key: str = ""  # 采集 key，如 main-001 / sku-002 / upload-001


class ExportImagesRequest(BaseModel):
    title: str | None = Field(default=None, description="商品标题，用作 ZIP 顶层文件夹名")
    images: list[ExportImageItem]


def _clean(name: str) -> str:
    """清洗文件夹/文件名非法字符（与插件 cleanFilename 同规则，Windows 兼容）。"""
    s = re.sub(r'[<>:"/\\|?*\x00-\x1f]', "_", (name or "").strip())
    s = re.sub(r"\s+", "_", s)
    return s.strip(" .")[:80]


def _ext(url: str, ctype: str) -> str:
    """由 content-type（优先）或 URL 后缀决定扩展名。"""
    ctype = ctype.split(";")[0].strip().lower()
    if ctype in _EXT_BY_CTYPE:
        return _EXT_BY_CTYPE[ctype]
    if ctype.startswith("image/"):
        return "." + ctype.split("/")[-1]
    path = url.split("?")[0].lower()
    for ext in (".jpg", ".jpeg", ".png", ".webp", ".gif", ".bmp"):
        if path.endswith(ext):
            return ".jpg" if ext == ".jpeg" else ext
    return ".jpg"


def _is_image(url: str, ctype: str) -> bool:
    ctype = ctype.split(";")[0].strip().lower()
    if ctype.startswith("image/"):
        return True
    return bool(re.search(r"\.(jpe?g|png|webp|gif|bmp)(\?|$)", url, re.IGNORECASE))


async def _download(url: str) -> tuple[bytes, str]:
    """本地 media 文件直读磁盘；远程 URL 带 Referer 下载。"""
    path = storage.local_path(url)
    if path is not None:
        mime = mimetypes.guess_type(path.name)[0] or "image/jpeg"
        return path.read_bytes(), mime
    return await storage.download_bytes(url, referer=guess_referer(url))


@router.post("/export-images")
async def export_images(req: ExportImagesRequest):
    if not req.images:
        raise HTTPException(status_code=400, detail="没有可导出的图片")

    root = _clean(req.title) or "采集图片"
    buf = io.BytesIO()
    used: set[str] = set()

    with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as zf:
        for img in req.images:
            try:
                data, ctype = await _download(img.url)
            except Exception:  # noqa: BLE001
                continue  # 单张失败不中断整包
            if not _is_image(img.url, ctype):
                continue

            ext = _ext(img.url, ctype)
            base = _clean(img.key) or "image"
            if img.variantName:
                base += f"-{_clean(img.variantName)}"
            filename = f"{base}{ext}"
            if filename in used:  # 同名加序号防覆盖
                stem = filename[: -len(ext)]
                n = 2
                while f"{stem}-{n}{ext}" in used:
                    n += 1
                filename = f"{stem}-{n}{ext}"
            used.add(filename)

            group = _clean(img.groupName) or "图片"
            zf.writestr(f"{root}/{group}/{filename}", data)

    buf.seek(0)
    return StreamingResponse(
        buf,
        media_type="application/zip",
        headers={"Content-Disposition": 'attachment; filename="collect.zip"'},
    )