import mimetypes
from typing import List
from urllib.parse import quote

from fastapi import APIRouter, Depends, File, HTTPException, Query, UploadFile, status
from fastapi.responses import StreamingResponse
from sqlalchemy.orm import Session

from app.core.bx_auth import BxUserContext, get_bx_current_user
from app.core.database import get_db
from app.core.tenant_context import get_tenant_no
from app.schemas.bx.attachment import AttachmentOut
from app.schemas.bx.common import ApiResponse
from app.services.bx.attachment import AttachmentService
from app.services.bx.storage import (
    download_file_bytes,
    get_preview_url,
    upload_bx_file,
)

router = APIRouter(prefix="/attachments", tags=["附件管理"])


def _tenant(db: Session, user: BxUserContext) -> str:
    return get_tenant_no(db, user.to_tenant_user_dict())


def _parse_id_list(ids: str) -> List[str]:
    return [x.strip() for x in (ids or "").split(",") if x.strip()]


@router.post("/upload", response_model=ApiResponse[AttachmentOut])
def upload_file(
    file: UploadFile = File(...),
    biz_type: str = "",
    biz_id: str = "0",
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    if not file or not file.filename:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="请选择文件")
    file_data = file.file.read()
    content_type = (
        file.content_type
        or mimetypes.guess_type(file.filename or "")[0]
        or "application/octet-stream"
    )
    relative_path, _full_url = upload_bx_file(
        file_data, file.filename or "unknown", biz_type=biz_type or "attachment"
    )
    biz_id_value = str(biz_id).strip() if biz_id else "0"
    data = {
        "biz_type": biz_type or "",
        "biz_id": biz_id_value or "0",
        "file_name": file.filename or "unknown",
        "file_path": relative_path,
        "file_type": content_type,
        "file_size": len(file_data),
    }
    attachment = AttachmentService.create(db, data, user=user)
    db.commit()
    db.refresh(attachment)
    return ApiResponse(data=AttachmentOut.model_validate(attachment))


@router.get("/download/{attachment_id}")
def download_file(
    attachment_id: str,
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    tenant_no = _tenant(db, user)
    attachment = AttachmentService.get_by_id(db, attachment_id, tenant_no, user=user)
    if not attachment:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="附件不存在")
    try:
        file_data = download_file_bytes(attachment.file_path)
    except FileNotFoundError as exc:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="文件不存在") from exc
    except Exception as exc:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail="文件读取失败") from exc
    encoded_name = quote(attachment.file_name or "download")
    headers = {"Content-Disposition": f"attachment; filename*=UTF-8''{encoded_name}"}
    media_type = attachment.file_type or "application/octet-stream"
    return StreamingResponse(iter([file_data]), media_type=media_type, headers=headers)


@router.delete("/{attachment_id}", response_model=ApiResponse[bool])
def delete_attachment(
    attachment_id: str,
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    tenant_no = _tenant(db, user)
    if not AttachmentService.get_by_id(db, attachment_id, tenant_no, user=user):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="附件不存在")
    success = AttachmentService.soft_delete(db, attachment_id, user=user)
    db.commit()
    return ApiResponse(data=success)


@router.get("/preview/{attachment_id}", response_model=ApiResponse[dict])
def preview_attachment(
    attachment_id: str,
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    """返回图片/附件预览 URL（MinIO 预签名或本地公开地址，对齐门户 storage 能力）。"""
    tenant_no = _tenant(db, user)
    attachment = AttachmentService.get_by_id(db, attachment_id, tenant_no, user=user)
    if not attachment:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="附件不存在")
    try:
        url = get_preview_url(attachment.file_path, expires_seconds=3600)
    except Exception as exc:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail="获取预览地址失败") from exc
    return ApiResponse(
        data={
            "url": url,
            "file_name": attachment.file_name,
            "file_type": attachment.file_type,
        }
    )


@router.get("/list", response_model=ApiResponse[List[AttachmentOut]])
def list_by_biz(
    biz_type: str = "",
    biz_id: str = "0",
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    tenant_no = _tenant(db, user)
    biz_id_value = str(biz_id).strip() if biz_id else "0"
    attachments = AttachmentService.get_by_biz(
        db, biz_type=biz_type, biz_id=biz_id_value, tenant_no=tenant_no, user=user
    )
    return ApiResponse(data=[AttachmentOut.model_validate(a) for a in attachments])


@router.put("/bind-biz", response_model=ApiResponse[int])
def bind_biz(
    ids: str = Query(...),
    biz_type: str = Query(...),
    biz_id: str = Query(...),
    db: Session = Depends(get_db),
    user: BxUserContext = Depends(get_bx_current_user),
):
    id_list = _parse_id_list(ids)
    biz_id_value = str(biz_id).strip() or "0"
    count = AttachmentService.bind_biz(db, id_list, biz_type, biz_id_value, user=user)
    db.commit()
    return ApiResponse(data=count)