package utils

import (
	"encoding/json"
	"strings"
)

// ExtractImageKeysFromContent parses content and returns all image file keys.
func ExtractImageKeysFromContent(content string) ([]string, error) {
	return extractFileKeysByTypes(content, "image")
}

// ExtractArchiveKeysFromContent parses content and returns all archive file keys.
func ExtractArchiveKeysFromContent(content string) ([]string, error) {
	return extractFileKeysByTypes(content, "archive")
}

// ExtractAudioKeysFromContent parses content and returns all audio file keys.
func ExtractAudioKeysFromContent(content string) ([]string, error) {
	return extractFileKeysByTypes(content, "audio")
}

// ExtractVideoKeysFromContent parses content and returns all video file keys.
func ExtractVideoKeysFromContent(content string) ([]string, error) {
	return extractFileKeysByTypes(content, "video")
}

// ExtractAllFileKeysFromContent returns every supported file key (image, archive, audio, video).
func ExtractAllFileKeysFromContent(content string) ([]string, error) {
	return extractFileKeysByTypes(content, "image", "archive", "audio", "video")
}

// extractFileKeysByTypes walks the rich text JSON and collects file keys that match allowed node types.
func extractFileKeysByTypes(content string, nodeTypes ...string) ([]string, error) {
	var contentData map[string]interface{}
	if err := json.Unmarshal([]byte(content), &contentData); err != nil {
		return nil, err
	}

	typeSet := make(map[string]struct{}, len(nodeTypes))
	for _, nodeType := range nodeTypes {
		typeSet[nodeType] = struct{}{}
	}

	var keys []string
	extractFileKeys(contentData, typeSet, &keys)
	return keys, nil
}

// extractFileKeys recursively searches for nodes whose type appears in typeSet and collects fileKey values.
func extractFileKeys(data interface{}, typeSet map[string]struct{}, keys *[]string) {
	switch v := data.(type) {
	case map[string]interface{}:
		if nodeType, ok := v["type"].(string); ok {
			if _, allowed := typeSet[nodeType]; allowed {
				if fileKey, ok := v["fileKey"].(string); ok && fileKey != "" {
					*keys = append(*keys, fileKey)
				}
			}
		}
		for _, value := range v {
			extractFileKeys(value, typeSet, keys)
		}
	case []interface{}:
		for _, item := range v {
			extractFileKeys(item, typeSet, keys)
		}
	}
}

// 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)
		}
	}
}