import os
import uuid  # 唯一标识符模块
import hashlib  # 哈希算法模块

from fastapi import (
    Cookie,
    Header,
    Depends,
    Security,
    HTTPException,
    Response,
    UploadFile,
    Request,
    Query,
    Form,
    APIRouter,
)
from fastapi.responses import JSONResponse, FileResponse
from fastapi.security import SecurityScopes

from config import settings
from FakeDB import file_db

router = APIRouter()


# 生成唯一命名
def unique_generator(*, length=8):
    unique_name = hashlib.md5(str(uuid.uuid4()).encode("utf-8")).hexdigest()[:length]
    return unique_name


# 保存上传文件，并返回分享名
async def save_file(file):
    if not os.path.exists(settings.UPLOAD_DIR):
        os.makedirs(settings.UPLOAD_DIR, exist_ok=True)
    res = await file.read()
    unique_name = unique_generator()
    file_name = f"{unique_name}.{file.filename.split('.')[-1]}"
    file_path = f"{settings.UPLOAD_DIR}/{file_name}"
    with open(file_path, "wb") as f:
        f.write(res)
    return unique_name


def get_user_token(pan_token: str | None = Cookie(None)):
    # print(pan_token)
    if pan_token is None:
        raise HTTPException(status_code=401, detail="请先登录Login获取权限")
    return pan_token


def get_user_permissions(pan_token: str = Security(get_user_token)):
    token = pan_token.split("-")[0]
    # print("token", token)
    if token == "Admin":
        return "admin"
    if token == "User":
        return "user"
    return "guest"


# 获取请求头授权信息要使用Header,使用Cookie只获取本地浏览器存储的cookie信息
def check_user(
    security_scopes: SecurityScopes, user_permission: str = Depends(get_user_permissions)
):  # pan_token: str | None = Header(None)
    # print("security_scopes", security_scopes.scopes)
    if user_permission not in security_scopes.scopes:
        raise HTTPException(status_code=401, detail=f"{user_permission}权限不足")
    return user_permission
    # pan_token = request.cookies.get("pan_token", None)
    # if pan_token is None:
    #     raise HTTPException(status_code=401, detail="请先登录Login获取权限")
    # role = pan_token.split("-")[0]
    # if role not in ["admin", "user"]:
    #     return "guest"
    # return role


# 上传文件
@router.post("/upload_file", summary="上传文件", dependencies=[Security(check_user, scopes=["admin"])])
async def upload_file(
    *, file: UploadFile, request: Request, user_permission: str = Security(check_user, scopes=["admin"])
):
    print("user_permission:", user_permission)
    unique_name = await save_file(file)
    file_db.create_file(unique_name, file.filename)
    share_code = unique_generator(length=6)
    file_db.create_share_code(unique_name, share_code)

    return {
        "file_name": file.filename,
        "unique_name": unique_name,
        "code": share_code,
        "url": request.url_for("file_page", unique_name=unique_name).path,
    }


@router.get("/share", summary="全部文件页面")
async def share_file(request: Request):
    all_files = file_db.get_all_files()
    return request.app.state.templates.TemplateResponse(
        "share.html", {"request": request, "all_files": all_files}
    )


@router.get("/file/{unique_name}", summary="文件下载页面")
async def file_page(request: Request, unique_name: str, share_code: str | None = Query(None, min_length=6)):
    file_name = file_db.get_file(unique_name)
    if file_name is None:
        return JSONResponse(status_code=404, content={"message": "文件不存在"})
    if share_code is None:
        share_code = ""
    data = {
        "unique_name": unique_name,
        "file_name": str(file_name),
        "share_code": share_code,
    }
    return request.app.state.templates.TemplateResponse("file.html", {"request": request, "data": data})


@router.post(
    "/download/{unique_name}",
    summary="文件下载",
    dependencies=[Security(check_user, scopes=["user", "admin"])],
)
async def download_file(unique_name: str, share: str = Form()):
    code = str(file_db.get_share_code(unique_name))
    if code is None:
        return {"验证码错误": "请检查分享码是否正确， 你无权限下载此文件"}
    file_name = str(file_db.get_file(unique_name))
    download_file = f"{unique_name}.{file_name.split('.',1)[-1]}"
    file_path = f"{settings.UPLOAD_DIR}/{download_file}"
    if not os.path.exists(file_path):
        return JSONResponse(status_code=404, content={"message": "文件不存在"})
    return FileResponse(file_path, media_type="application/octet-stream", filename=file_name)


@router.get("/login", summary="模拟登录")
async def user_login(resp: Response, user: str, token: str):
    resp.set_cookie(key="pan_token", value=f"{user}-{token}", expires=600)
    return {"message": f"Cookie设置{user}-{token}成功"}