backend/internal/handler/upload_handler.go

package handler

import (
	"github.com/gin-gonic/gin"

	"with_you/internal/pkg/response"
	"with_you/internal/service"
)

// UploadHandler 上传处理器
type UploadHandler struct {
	uploadService service.UploadService
}

// NewUploadHandler 创建上传处理器
func NewUploadHandler(uploadService service.UploadService) *UploadHandler {
	return &UploadHandler{
		uploadService: uploadService,
	}
}

// UploadImage 上传图片
func (h *UploadHandler) UploadImage(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	file, err := c.FormFile("image")
	if err != nil {
		response.BadRequest(c, "image file is required")
		return
	}

	url, previewURL, previewURLLarge, err := h.uploadService.UploadImage(c.Request.Context(), file)
	if err != nil {
		response.InternalServerError(c, "failed to upload image")
		return
	}

	response.Success(c, gin.H{
		"url":               url,
		"preview_url":       previewURL,
		"preview_url_large": previewURLLarge,
	})
}

// UploadAvatar 上传头像
func (h *UploadHandler) UploadAvatar(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	file, err := c.FormFile("image")

	if err != nil {
		response.BadRequest(c, "avatar file is required")
		return
	}

	url, err := h.uploadService.UploadAvatar(c.Request.Context(), userID, file)
	if err != nil {
		response.InternalServerError(c, "failed to upload avatar")
		return
	}

	response.Success(c, gin.H{"url": url})
}

// UploadCover 上传头图（个人主页封面）
func (h *UploadHandler) UploadCover(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	file, err := c.FormFile("image")
	if err != nil {
		response.BadRequest(c, "image file is required")
		return
	}

	url, err := h.uploadService.UploadCover(c.Request.Context(), userID, file)
	if err != nil {
		response.InternalServerError(c, "failed to upload cover")
		return
	}

	response.Success(c, gin.H{"url": url})
}

// UploadFile 上传聊天/通用文件（非图片类资源）
// form 字段：file（必填）、folder（可选，默认 chat）
func (h *UploadHandler) UploadFile(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	file, err := c.FormFile("file")
	if err != nil {
		response.BadRequest(c, "file is required")
		return
	}

	folder := c.DefaultPostForm("folder", "chat")
	// 前端（尤其原生端 expo-file-system）无法自定义 multipart filename，
	// 文件常被复制到缓存目录并以 UUID 命名，导致 header Filename 丢失真实名。
	// 因此前端额外把真实文件名通过 "name" 字段回传，作为权威展示名。
	displayName := c.PostForm("name")

	result, err := h.uploadService.UploadFile(c.Request.Context(), file, folder, userID, displayName)
	if err != nil {
		// 参数类错误（大小/类型）返回 400，其余返回 500
		if file.Size > 0 && file.Size <= 100<<20 {
			response.BadRequest(c, err.Error())
			return
		}
		response.InternalServerError(c, "failed to upload file")
		return
	}

	response.Success(c, gin.H{
		"url":       result.URL,
		"name":      result.Name,
		"size":      result.Size,
		"mime_type": result.MimeType,
	})
}