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

from app.services.oss import generate_upload_policy, get_file_url, generate_presigned_url
from app.config import settings
from app.models.user import User
from app.api.deps import get_current_user

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):
    """TOS 直传凭证响应"""
    x_tos_algorithm: str
    x_tos_credential: str
    x_tos_date: str
    x_tos_signature: str
    policy: 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,
    current_user: User = Depends(get_current_user),
):
    """
    获取 TOS 直传凭证

    前端使用此凭证直接上传文件到火山引擎 TOS，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(
        x_tos_algorithm=policy["x_tos_algorithm"],
        x_tos_credential=policy["x_tos_credential"],
        x_tos_date=policy["x_tos_date"],
        x_tos_signature=policy["x_tos_signature"],
        policy=policy["policy"],
        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,
    current_user: User = Depends(get_current_user),
):
    """
    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,
    )


class SignedUrlResponse(BaseModel):
    """签名 URL 响应"""
    signed_url: str
    expire_seconds: int


@router.get("/sign-url", response_model=SignedUrlResponse)
async def get_signed_url(
    url: str = Query(..., description="文件的原始 URL 或 file_key"),
    expire: int = Query(3600, ge=60, le=43200, description="有效期（秒），默认1小时，最长12小时"),
    current_user: User = Depends(get_current_user),
):
    """
    获取私有桶文件的预签名访问 URL

    前端在展示/下载文件前调用此接口，获取带签名的临时访问链接。
    支持传入完整 URL 或 file_key。
    """
    from app.services.oss import parse_file_key_from_url

    # 如果传入的是完整 URL，先解析出 file_key
    file_key = url
    if url.startswith("http"):
        file_key = parse_file_key_from_url(url)

    if not file_key:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="无效的文件路径",
        )

    try:
        signed_url = generate_presigned_url(file_key, expire_seconds=expire)
    except ValueError as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e),
        )

    return SignedUrlResponse(
        signed_url=signed_url,
        expire_seconds=expire,
    )