"""
文件上传 API
"""
from fastapi import APIRouter, HTTPException, status
from pydantic import BaseModel
from typing import Optional
from datetime import datetime

from app.services.oss import generate_upload_policy, get_file_url
from app.config import settings

router = APIRouter(prefix="/upload", tags=["文件上传"])


class UploadPolicyRequest(BaseModel):
    """获取上传凭证请求"""
    file_type: str = "general"  # script, video, image, general
    file_name: Optional[str] = None


class UploadPolicyResponse(BaseModel):
    """上传凭证响应"""
    access_key_id: str
    policy: str
    signature: str
    host: str
    dir: str
    expire: int
    max_size_mb: int


class FileUploadedRequest(BaseModel):
    """文件上传完成回调"""
    file_key: str
    file_name: str
    file_size: int
    file_type: str


class FileUploadedResponse(BaseModel):
    """文件上传完成响应"""
    url: str
    file_key: str
    file_name: str
    file_size: int
    file_type: str


@router.post("/policy", response_model=UploadPolicyResponse)
async def get_upload_policy(
    request: UploadPolicyRequest,
):
    """
    获取 OSS 直传凭证

    前端使用此凭证直接上传文件到阿里云 OSS，无需经过后端。

    文件类型说明：
    - script: 脚本文档 (docx, pdf, xlsx, txt, pptx)
    - video: 视频文件 (mp4, mov, webm)
    - image: 图片文件 (jpg, png, gif)
    - general: 通用文件
    """
    # 根据文件类型设置上传目录
    now = datetime.now()
    base_dir = f"uploads/{now.year}/{now.month:02d}"

    if request.file_type == "script":
        upload_dir = f"{base_dir}/scripts/"
    elif request.file_type == "video":
        upload_dir = f"{base_dir}/videos/"
    elif request.file_type == "image":
        upload_dir = f"{base_dir}/images/"
    else:
        upload_dir = f"{base_dir}/files/"

    try:
        policy = generate_upload_policy(
            max_size_mb=settings.MAX_FILE_SIZE_MB,
            expire_seconds=3600,
            upload_dir=upload_dir,
        )
    except ValueError as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )

    return UploadPolicyResponse(
        access_key_id=policy["accessKeyId"],
        policy=policy["policy"],
        signature=policy["signature"],
        host=policy["host"],
        dir=policy["dir"],
        expire=policy["expire"],
        max_size_mb=settings.MAX_FILE_SIZE_MB,
    )


@router.post("/complete", response_model=FileUploadedResponse)
async def file_uploaded(
    request: FileUploadedRequest,
):
    """
    文件上传完成回调

    前端上传完成后调用此接口，获取文件的完整 URL。
    """
    url = get_file_url(request.file_key)

    return FileUploadedResponse(
        url=url,
        file_key=request.file_key,
        file_name=request.file_name,
        file_size=request.file_size,
        file_type=request.file_type,
    )