Add hashtag extraction and management in CreatePost and EditPost logic; improve error handling

app/internal/utils/content.go

@@ -2,6 +2,7 @@ package utils
 
 import (
 	"encoding/json"
+	"strings"
 )
 
 // ExtractImageKeysFromContent parses the rich text JSON and extracts all image fileKey values
@@ -37,3 +38,47 @@ func extractImageKeys(data interface{}, keys *[]string) {
 		}
 	}
 }
+
+// ExtractHashtagsFromContent parses the rich text JSON and extracts all hashtag text values
+func ExtractHashtagsFromContent(content string) ([]string, error) {
+	var contentData map[string]interface{}
+	if err := json.Unmarshal([]byte(content), &contentData); err != nil {
+		return nil, err
+	}
+
+	var hashtags []string
+	hashtagSet := make(map[string]bool) // Use map to avoid duplicates
+	extractHashtags(contentData, hashtagSet)
+
+	// Convert map keys to slice
+	for tag := range hashtagSet {
+		hashtags = append(hashtags, tag)
+	}
+	return hashtags, nil
+}
+
+// extractHashtags recursively searches for hashtag nodes and collects their text values
+func extractHashtags(data interface{}, hashtags map[string]bool) {
+	switch v := data.(type) {
+	case map[string]interface{}:
+		// Check if this is a hashtag node
+		if nodeType, ok := v["type"].(string); ok && nodeType == "hashtag" {
+			if text, ok := v["text"].(string); ok && text != "" {
+				// Remove the # prefix if present
+				tag := strings.TrimPrefix(text, "#")
+				if tag != "" {
+					hashtags[tag] = true
+				}
+			}
+		}
+		// Recurse into all map values
+		for _, value := range v {
+			extractHashtags(value, hashtags)
+		}
+	case []interface{}:
+		// Recurse into all array elements
+		for _, item := range v {
+			extractHashtags(item, hashtags)
+		}
+	}
+}