package upload

import (
	"context"
	"os"
	"path/filepath"
	"strings"

	"tyc-server/app/main/api/internal/svc"
	"tyc-server/app/main/api/internal/types"
	"tyc-server/common/xerr"

	"github.com/pkg/errors"
	"github.com/zeromicro/go-zero/core/logx"
)

type ServeUploadedFileLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewServeUploadedFileLogic(ctx context.Context, svcCtx *svc.ServiceContext) *ServeUploadedFileLogic {
	return &ServeUploadedFileLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *ServeUploadedFileLogic) ServeUploadedFile(req *types.ServeUploadedFileReq) (resp *types.ServeUploadedFileResp, err error) {
	fileName := strings.TrimSpace(req.FileName)
	if fileName == "" {
		return nil, errors.Wrap(xerr.NewErrMsg("缺少文件名"), "fileName empty")
	}
	// 只允许文件名，禁止路径穿越
	if strings.Contains(fileName, "..") || filepath.Base(fileName) != fileName {
		return nil, errors.Wrap(xerr.NewErrMsg("非法文件名"), fileName)
	}

	candidates := []string{
		"data/uploads",
		"../data/uploads",
		"../../data/uploads",
		"../../../data/uploads",
	}
	for _, c := range candidates {
		abs, _ := filepath.Abs(c)
		fullPath := filepath.Join(abs, fileName)
		if info, err := os.Stat(fullPath); err == nil && !info.IsDir() {
			contentType := "image/jpeg"
			if strings.HasSuffix(strings.ToLower(fileName), ".png") {
				contentType = "image/png"
			} else if strings.HasSuffix(strings.ToLower(fileName), ".gif") {
				contentType = "image/gif"
			} else if strings.HasSuffix(strings.ToLower(fileName), ".webp") {
				contentType = "image/webp"
			}
			return &types.ServeUploadedFileResp{
				FilePath:    fullPath,
				ContentType: contentType,
			}, nil
		}
	}
	return nil, errors.Wrapf(xerr.NewErrMsg("文件不存在"), "fileName=%s", fileName)
}