feat: add image upload functionality for articles

- Implemented image upload API in the article service, allowing users to upload images associated with articles.
- Added validation for image size and type, ensuring only supported formats (PNG, JPG, GIF, WebP) are accepted.
- Created a new Aliyun object storage client to handle image storage and retrieval.
- Updated the article handler to include an endpoint for image uploads.
- Enhanced error handling for image upload failures and added relevant error messages.
- Introduced public URL generation for stored images, allowing access via signed tokens.
- Updated localization files to include new messages related to image upload functionality.
- Added tests for image upload and retrieval processes.

server/internal/shared/objectstorage/url.go

@@ -0,0 +1,116 @@
+package objectstorage
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+
+	"github.com/geo-platform/tenant-api/internal/shared/config"
+)
+
+func buildPublicURL(cfg config.ObjectStorageConfig, objectKey string, bucketInHost bool) (string, error) {
+	objectKey = strings.TrimSpace(objectKey)
+	if objectKey == "" {
+		return "", fmt.Errorf("object key is required")
+	}
+
+	defaultScheme := "http"
+	if cfg.UseSSL {
+		defaultScheme = "https"
+	}
+
+	if publicBaseURL := strings.TrimSpace(cfg.PublicBaseURL); publicBaseURL != "" {
+		baseURL, err := parseURLWithScheme(publicBaseURL, defaultScheme)
+		if err != nil {
+			return "", fmt.Errorf("parse public_base_url: %w", err)
+		}
+		baseURL.Path = joinEscapedPath(baseURL.Path, objectKey)
+		baseURL.RawPath = ""
+		return baseURL.String(), nil
+	}
+
+	endpoint := strings.TrimSpace(cfg.Endpoint)
+	bucket := strings.TrimSpace(cfg.Bucket)
+	if endpoint == "" || bucket == "" {
+		return "", fmt.Errorf("%w: object storage endpoint or bucket is missing", ErrNotConfigured)
+	}
+
+	endpointURL, err := parseURLWithScheme(endpoint, defaultScheme)
+	if err != nil {
+		return "", fmt.Errorf("parse object storage endpoint: %w", err)
+	}
+
+	if bucketInHost {
+		hostname := endpointURL.Hostname()
+		if hostname == "" {
+			return "", fmt.Errorf("invalid object storage endpoint host")
+		}
+
+		host := hostname
+		if !strings.HasPrefix(host, bucket+".") {
+			host = bucket + "." + host
+		}
+		if port := endpointURL.Port(); port != "" {
+			host += ":" + port
+		}
+
+		endpointURL.Host = host
+		endpointURL.Path = joinEscapedPath("", objectKey)
+		endpointURL.RawPath = ""
+		return endpointURL.String(), nil
+	}
+
+	endpointURL.Path = joinEscapedPath(endpointURL.Path, bucket, objectKey)
+	endpointURL.RawPath = ""
+	return endpointURL.String(), nil
+}
+
+func parseURLWithScheme(raw string, defaultScheme string) (*url.URL, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return nil, fmt.Errorf("url is empty")
+	}
+
+	if !strings.Contains(raw, "://") {
+		raw = defaultScheme + "://" + raw
+	}
+
+	parsed, err := url.Parse(raw)
+	if err != nil {
+		return nil, err
+	}
+	if parsed.Host == "" {
+		return nil, fmt.Errorf("url host is empty")
+	}
+	return parsed, nil
+}
+
+func joinEscapedPath(basePath string, extra ...string) string {
+	segments := make([]string, 0)
+
+	appendPath := func(value string) {
+		value = strings.TrimSpace(value)
+		value = strings.Trim(value, "/")
+		if value == "" {
+			return
+		}
+
+		for _, segment := range strings.Split(value, "/") {
+			segment = strings.TrimSpace(segment)
+			if segment == "" {
+				continue
+			}
+			segments = append(segments, url.PathEscape(segment))
+		}
+	}
+
+	appendPath(basePath)
+	for _, value := range extra {
+		appendPath(value)
+	}
+
+	if len(segments) == 0 {
+		return "/"
+	}
+	return "/" + strings.Join(segments, "/")
+}