honeyDueAPI/internal/handlers/upload_handler.go

package handlers

import (
	"net/http"

	"github.com/labstack/echo/v4"
	"github.com/rs/zerolog/log"

	"github.com/treytartt/honeydue-api/internal/apperrors"
	"github.com/treytartt/honeydue-api/internal/dto/requests"
	"github.com/treytartt/honeydue-api/internal/dto/responses"
	"github.com/treytartt/honeydue-api/internal/i18n"
	"github.com/treytartt/honeydue-api/internal/middleware"
	"github.com/treytartt/honeydue-api/internal/models"
	"github.com/treytartt/honeydue-api/internal/services"
)

// FileOwnershipChecker verifies whether a user owns a file referenced by URL.
// Implementations should check associated records (e.g., task completion images,
// document files, document images) to determine ownership.
type FileOwnershipChecker interface {
	IsFileOwnedByUser(fileURL string, userID uint) (bool, error)
}

// UploadHandler handles file upload endpoints
type UploadHandler struct {
	storageService       *services.StorageService
	uploadService        *services.UploadService // optional — only set when S3 storage is configured
	fileOwnershipChecker FileOwnershipChecker
}

// NewUploadHandler creates a new upload handler
func NewUploadHandler(storageService *services.StorageService, fileOwnershipChecker FileOwnershipChecker) *UploadHandler {
	return &UploadHandler{
		storageService:       storageService,
		fileOwnershipChecker: fileOwnershipChecker,
	}
}

// SetUploadService wires the presigned-URL upload service. Called from the
// router only when S3 storage is configured; with local-disk storage the
// presign endpoint is unsupported and returns 503.
func (h *UploadHandler) SetUploadService(s *services.UploadService) {
	h.uploadService = s
}

// DeleteFileRequest is the request body for deleting a file.
type DeleteFileRequest struct {
	URL string `json:"url" validate:"required"`
}

// DeleteFile handles DELETE /api/uploads
// Expects JSON body with "url" field.
// Verifies that the requesting user owns the file by checking associated records
// (task completion images, document files/images) before allowing deletion.
func (h *UploadHandler) DeleteFile(c echo.Context) error {
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	var req DeleteFileRequest

	if err := c.Bind(&req); err != nil {
		return apperrors.BadRequest("error.invalid_request")
	}

	if err := c.Validate(&req); err != nil {
		return apperrors.BadRequest("error.url_required")
	}

	// Verify ownership: the user must own a record that references this file URL
	if h.fileOwnershipChecker != nil {
		owned, err := h.fileOwnershipChecker.IsFileOwnedByUser(req.URL, user.ID)
		if err != nil {
			log.Error().Err(err).Uint("user_id", user.ID).Str("file_url", req.URL).Msg("Failed to check file ownership")
			return apperrors.Internal(err)
		}
		if !owned {
			log.Warn().Uint("user_id", user.ID).Str("file_url", req.URL).Msg("Unauthorized file deletion attempt")
			return apperrors.Forbidden("error.file_access_denied")
		}
	}

	// Log the deletion with user ID for audit trail
	log.Info().
		Uint("user_id", user.ID).
		Str("file_url", req.URL).
		Msg("File deletion requested")

	if err := h.storageService.Delete(req.URL); err != nil {
		return err
	}

	return c.JSON(http.StatusOK, responses.MessageResponse{Message: i18n.LocalizedMessage(c, "message.file_deleted")})
}

// PresignUpload handles POST /api/uploads/presign.
//
// Returns a short-lived signed POST policy that the client uses to upload an
// image or document directly to B2, bypassing the API entirely for the byte
// transfer. The returned `id` is later passed in `upload_ids[]` on the
// task-completion or document creation endpoints to attach the object.
func (h *UploadHandler) PresignUpload(c echo.Context) error {
	if h.uploadService == nil {
		return apperrors.Internal(nil)
	}
	user, err := middleware.MustGetAuthUser(c)
	if err != nil {
		return err
	}

	var req requests.PresignUploadRequest
	if err := c.Bind(&req); err != nil {
		return apperrors.BadRequest("error.invalid_request")
	}
	if err := c.Validate(&req); err != nil {
		return err
	}

	resp, err := h.uploadService.Presign(
		c.Request().Context(),
		user.ID,
		models.UploadCategory(req.Category),
		req.ContentType,
		req.ContentLength,
	)
	if err != nil {
		return err
	}
	return c.JSON(http.StatusCreated, resp)
}