"""文件管理接口（Basic Auth，鉴权同 docs）。

与公开的 /api/files 区分：本路由面向「文件浏览页」，提供列表 / 查询 / 下载 / 删除，
均需 docs 凭据。公开路由（user.py 依赖的查重、查询、下载）保留不变。

硬删除策略：删 DB 行 + 删磁盘文件（unlink missing_ok），列表只展示仍存在的行。
"""

from __future__ import annotations

from pathlib import Path

from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import FileResponse
from pydantic import BaseModel
from sqlalchemy.orm import Session

from ..database import get_db
from ..dao.uploaded_file_dao import UploadedFileDAO
from ..schemas.file import FileListResponse, UploadedFileOut
from ..security import require_docs_auth
from ..services.upload_service import UploadService

router = APIRouter(prefix="/api/admin/files", tags=["files-admin"])


def _service(db: Session = Depends(get_db)) -> UploadService:
    return UploadService(UploadedFileDAO(db))


class DeleteResult(BaseModel):
    deleted: bool


@router.get(
    "",
    response_model=FileListResponse,
    summary="列出已上传文件（需鉴权）",
    description="供文件浏览页使用；字段同公开 /api/files，但要求 docs Basic Auth。",
)
def list_files(
    limit: int = 100,
    offset: int = 0,
    service: UploadService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> FileListResponse:
    total, items = service.list_files(limit=limit, offset=offset)
    return FileListResponse(total=total, items=items)


@router.get(
    "/{file_id}",
    response_model=UploadedFileOut,
    summary="查询单个文件元数据（需鉴权）",
)
def get_file(
    file_id: int,
    service: UploadService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> UploadedFileOut:
    out = service.get_out(file_id)
    if out is None:
        raise HTTPException(404, "文件不存在")
    return out


@router.get(
    "/{file_id}/download",
    summary="下载文件（需鉴权，校验磁盘存在）",
    description="文件实体不在磁盘上时返回 410 Gone。",
)
def download_file(
    file_id: int,
    service: UploadService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> FileResponse:
    out, path = service.get_out_with_disk_path(file_id)
    if out is None:
        raise HTTPException(404, "文件不存在")
    if path is None or not path.exists():
        raise HTTPException(410, "文件实体已不在磁盘上")
    return FileResponse(
        path=str(path),
        media_type=out.content_type or "application/octet-stream",
        filename=out.original_filename,
    )


@router.delete(
    "/{file_id}",
    response_model=DeleteResult,
    summary="硬删除文件（需鉴权）",
    description="删除 DB 行与磁盘文件实体；不可恢复。列表随后不再显示。",
)
def delete_file(
    file_id: int,
    service: UploadService = Depends(_service),
    _: str = Depends(require_docs_auth),
) -> DeleteResult:
    out, path = service.get_out_with_disk_path(file_id)
    if out is None:
        return DeleteResult(deleted=False)
    # 先删磁盘文件，再删 DB 行；磁盘文件缺失不阻断 DB 清理
    if path is not None:
        try:
            Path(path).unlink(missing_ok=True)
        except Exception:
            # 即使磁盘删除失败也继续清 DB 行，保证列表不再显示
            pass
    service.dao.delete(file_id)
    return DeleteResult(deleted=True)