package user

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"photography-backend/internal/svc"
	"photography-backend/internal/types"
	"photography-backend/pkg/errorx"
	"photography-backend/pkg/utils/file"

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

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

// 上传用户头像
func NewUploadAvatarLogic(ctx context.Context, svcCtx *svc.ServiceContext) *UploadAvatarLogic {
	return &UploadAvatarLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *UploadAvatarLogic) UploadAvatar(req *types.UploadAvatarRequest, r *http.Request) (resp *types.UploadAvatarResponse, err error) {
	// 1. 验证用户权限
	userId := l.ctx.Value("userId").(int64)
	if userId != req.Id {
		return nil, errorx.New(errorx.Forbidden, "您只能更新自己的头像")
	}

	// 2. 检查用户是否存在
	user, err := l.svcCtx.UserModel.FindOne(l.ctx, req.Id)
	if err != nil {
		return nil, errorx.New(errorx.UserNotFound, "用户不存在")
	}

	// 3. 解析多部分表单
	err = r.ParseMultipartForm(10 << 20) // 10MB
	if err != nil {
		return nil, errorx.New(errorx.ParamError, "解析表单失败")
	}

	// 4. 获取上传的文件
	uploadedFile, header, err := r.FormFile("avatar")
	if err != nil {
		return nil, errorx.New(errorx.ParamError, "获取上传文件失败: "+err.Error())
	}
	defer uploadedFile.Close()

	// 5. 验证文件类型 (头像应该是图片)
	contentType := header.Header.Get("Content-Type")
	if !strings.HasPrefix(contentType, "image/") {
		return nil, errorx.New(errorx.ParamError, "头像必须是图片文件")
	}

	// 6. 验证文件大小 (限制为5MB)
	if header.Size > 5*1024*1024 {
		return nil, errorx.New(errorx.ParamError, "头像文件大小不能超过5MB")
	}

	// 7. 生成头像文件名和路径
	ext := filepath.Ext(header.Filename)
	if ext == "" {
		// 根据Content-Type推断扩展名
		switch contentType {
		case "image/jpeg":
			ext = ".jpg"
		case "image/png":
			ext = ".png"
		case "image/gif":
			ext = ".gif"
		case "image/webp":
			ext = ".webp"
		default:
			ext = ".jpg"
		}
	}

	filename := fmt.Sprintf("avatar_%d_%d%s", req.Id, time.Now().Unix(), ext)
	avatarDir := "uploads/avatars"

	// 8. 确保头像目录存在
	if err := os.MkdirAll(avatarDir, 0755); err != nil {
		return nil, errorx.New(errorx.ServerError, "创建头像目录失败: "+err.Error())
	}

	avatarPath := filepath.Join(avatarDir, filename)

	// 9. 保存原始头像文件
	destFile, err := os.Create(avatarPath)
	if err != nil {
		return nil, errorx.New(errorx.ServerError, "创建头像文件失败: "+err.Error())
	}
	defer destFile.Close()

	_, err = io.Copy(destFile, uploadedFile)
	if err != nil {
		return nil, errorx.New(errorx.ServerError, "保存头像文件失败: "+err.Error())
	}

	// 10. 生成压缩版本的头像 (150x150像素)
	compressedPath := filepath.Join(avatarDir, fmt.Sprintf("avatar_%d_%d_150x150%s", req.Id, time.Now().Unix(), ext))
	err = file.ResizeImage(avatarPath, compressedPath, 150, 150)
	if err != nil {
		l.Errorf("头像压缩失败: %v", err)
		// 压缩失败不影响主流程，使用原图
		compressedPath = avatarPath
	}

	// 11. 删除旧的头像文件 (如果存在)
	if user.Avatar != "" && user.Avatar != compressedPath {
		oldAvatarPath := user.Avatar
		if strings.HasPrefix(oldAvatarPath, "/uploads/") {
			oldAvatarPath = strings.TrimPrefix(oldAvatarPath, "/")
		}
		if _, err := os.Stat(oldAvatarPath); err == nil {
			os.Remove(oldAvatarPath)
			l.Infof("删除旧头像文件: %s", oldAvatarPath)
		}
	}

	// 12. 更新用户头像URL
	avatarUrl := "/" + compressedPath
	user.Avatar = avatarUrl

	err = l.svcCtx.UserModel.Update(l.ctx, user)
	if err != nil {
		// 更新失败，删除已上传的文件
		os.Remove(avatarPath)
		if avatarPath != compressedPath {
			os.Remove(compressedPath)
		}
		return nil, errorx.New(errorx.ServerError, "更新用户头像失败: "+err.Error())
	}

	return &types.UploadAvatarResponse{
		BaseResponse: types.BaseResponse{
			Code:    200,
			Message: "头像上传成功",
		},
		Data: types.UploadAvatarData{
			AvatarUrl: avatarUrl,
		},
	}, nil
}