Rewrite search flow and enrich preview assets

backend/handlers/api.go

@@ -280,7 +280,11 @@ func (a *App) searchMedia(c *gin.Context) {
 	}
 
 	a.Hub.Broadcast("progress", gin.H{"type": "search", "status": "ranking thumbnail candidates", "progress": 55})
-	scored := rankSearchResults(req.Query, results)
+	rankQuery := req.Query
+	if len(queryVariants) > 0 {
+		rankQuery = strings.Join(queryVariants[:min(len(queryVariants), 3)], " ")
+	}
+	scored := rankSearchResults(rankQuery, results)
 	shortlist := scored[:min(len(scored), 10)]
 	a.Hub.Broadcast("progress", gin.H{"type": "search", "status": "analyzing shortlisted thumbnails with Gemini Vision", "progress": 75})
 	recommended, err := a.GeminiService.Recommend(req.Query, shortlist)
@@ -288,12 +292,13 @@ func (a *App) searchMedia(c *gin.Context) {
 		fallback := make([]services.AIRecommendation, 0, min(20, len(scored)))
 		for _, result := range scored[:min(20, len(scored))] {
 			fallback = append(fallback, services.AIRecommendation{
-				Title:        result.Title,
-				Link:         result.Link,
-				ThumbnailURL: result.ThumbnailURL,
-				Source:       result.Source,
-				Reason:       "Keyword-ranked result added without extra Gemini vision tokens.",
-				Recommended:  true,
+				Title:           result.Title,
+				Link:            result.Link,
+				ThumbnailURL:    result.ThumbnailURL,
+				PreviewVideoURL: result.PreviewVideoURL,
+				Source:          result.Source,
+				Reason:          "Keyword-ranked result added without extra Gemini vision tokens.",
+				Recommended:     true,
 			})
 		}
 		warning := err.Error()
@@ -379,9 +384,12 @@ func rankSearchResults(query string, results []services.SearchResult) []services
 		if result.ThumbnailURL != "" {
 			score += 2
 		}
+		if result.PreviewVideoURL != "" {
+			score += 3
+		}
 		switch result.Source {
 		case "Google Video":
-			score += 1
+			score -= 1
 		case "Envato":
 			score += 7
 		case "Artgrid":
@@ -419,12 +427,13 @@ func mergeRecommendations(recommended []services.AIRecommendation, ranked []serv
 		}
 		seen[item.Link] = true
 		merged = append(merged, services.AIRecommendation{
-			Title:        item.Title,
-			Link:         item.Link,
-			ThumbnailURL: item.ThumbnailURL,
-			Source:       item.Source,
-			Reason:       "Keyword-ranked result added without extra Gemini vision tokens.",
-			Recommended:  true,
+			Title:           item.Title,
+			Link:            item.Link,
+			ThumbnailURL:    item.ThumbnailURL,
+			PreviewVideoURL: item.PreviewVideoURL,
+			Source:          item.Source,
+			Reason:          "Keyword-ranked result added without extra Gemini vision tokens.",
+			Recommended:     true,
 		})
 	}
 	return merged

backend/services/cse.go

@@ -3,21 +3,24 @@ package services
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
 	"regexp"
 	"sort"
 	"strings"
+	"sync"
 	"time"
 )
 
 type SearchResult struct {
-	Title        string `json:"title"`
-	Link         string `json:"link"`
-	DisplayLink  string `json:"displayLink"`
-	Snippet      string `json:"snippet"`
-	ThumbnailURL string `json:"thumbnailUrl"`
-	Source       string `json:"source"`
+	Title           string `json:"title"`
+	Link            string `json:"link"`
+	DisplayLink     string `json:"displayLink"`
+	Snippet         string `json:"snippet"`
+	ThumbnailURL    string `json:"thumbnailUrl"`
+	PreviewVideoURL string `json:"previewVideoUrl"`
+	Source          string `json:"source"`
 }
 
 type SearchService struct {
@@ -47,84 +50,169 @@ func (s *SearchService) SearchMedia(queries []string) ([]SearchResult, error) {
 		return nil, fmt.Errorf("searxng base url is not configured")
 	}
 
-	sources := []struct {
-		name         string
-		categories   string
-		engine       string
-		queryBuilder func(string) string
-		match        func(SearchResult) bool
-	}{
+	type sourceConfig struct {
+		name       string
+		categories string
+		engine     string
+		build      func(string) []string
+		accept     func(SearchResult) bool
+	}
+
+	sources := []sourceConfig{
+		{
+			name:       "Envato",
+			categories: "general",
+			engine:     s.WebEngine,
+			build:      buildEnvatoQueries,
+			accept:     isRenderableEnvatoResult,
+		},
+		{
+			name:       "Artgrid",
+			categories: "general",
+			engine:     s.WebEngine,
+			build:      buildArtgridQueries,
+			accept:     isRenderableArtgridResult,
+		},
 		{
 			name:       "Google Video",
 			categories: "videos",
 			engine:     s.GoogleVideoEngine,
-			queryBuilder: func(query string) string {
-				return buildGoogleVideoQuery(query)
-			},
-			match: isUsefulGoogleVideoResult,
-		},
-		{
-			name:         "Envato",
-			categories:   "general",
-			engine:       s.WebEngine,
-			queryBuilder: buildEnvatoQuery,
-			match:        isRenderableEnvatoResult,
-		},
-		{
-			name:         "Artgrid",
-			categories:   "general",
-			engine:       s.WebEngine,
-			queryBuilder: buildArtgridQuery,
-			match:        isRenderableArtgridResult,
+			build:      buildGoogleVideoQueries,
+			accept:     isUsefulGoogleVideoResult,
 		},
 	}
 
 	seen := map[string]bool{}
-	results := make([]SearchResult, 0, 60)
+	results := make([]SearchResult, 0, 90)
 	var lastErr error
-	for _, query := range queries {
-		query = strings.TrimSpace(query)
-		if query == "" {
+
+	baseQueries := limitQueries(queries, 5)
+	for _, base := range baseQueries {
+		base = strings.TrimSpace(base)
+		if base == "" {
 			continue
 		}
 		for _, source := range sources {
-			searchQuery := source.queryBuilder(query)
-
-			items, err := s.search(searchQuery, source.categories, source.engine, source.name)
-			if err != nil {
-				lastErr = err
-				items, err = s.search(searchQuery, source.categories, "", source.name)
-			}
-			if err != nil {
-				lastErr = err
-				if source.categories != "general" {
-					items, err = s.search(searchQuery, "general", "", source.name)
+			for _, searchQuery := range source.build(base) {
+				items, err := s.search(searchQuery, source.categories, source.engine, source.name)
+				if err != nil {
+					lastErr = err
+					items, err = s.search(searchQuery, source.categories, "", source.name)
 				}
-			}
-			if err != nil {
-				lastErr = err
-				continue
-			}
-			for _, item := range items {
-				if item.Link == "" || seen[item.Link] {
+				if err != nil {
+					lastErr = err
 					continue
 				}
-				if !source.match(item) {
-					continue
+				for _, item := range items {
+					if item.Link == "" || seen[item.Link] || !source.accept(item) {
+						continue
+					}
+					seen[item.Link] = true
+					results = append(results, item)
 				}
-				seen[item.Link] = true
-				results = append(results, item)
 			}
 		}
 	}
 
+	if len(results) == 0 && lastErr != nil {
+		return nil, lastErr
+	}
+
 	sort.SliceStable(results, func(i, j int) bool {
 		return sourceWeight(results[i].Source) > sourceWeight(results[j].Source)
 	})
-	if len(results) == 0 && lastErr != nil {
-		return nil, lastErr
+	return s.EnrichResults(results), nil
+}
+
+func (s *SearchService) EnrichResults(results []SearchResult) []SearchResult {
+	limit := minInt(len(results), 24)
+	if limit == 0 {
+		return results
 	}
-	return results, nil
+
+	enriched := make([]SearchResult, len(results))
+	copy(enriched, results)
+
+	var wg sync.WaitGroup
+	sem := make(chan struct{}, 4)
+	for idx := 0; idx < limit; idx++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			sem <- struct{}{}
+			defer func() { <-sem }()
+			enriched[i] = s.enrichResult(enriched[i])
+		}(idx)
+	}
+	wg.Wait()
+	return enriched
+}
+
+func (s *SearchService) enrichResult(result SearchResult) SearchResult {
+	switch result.Source {
+	case "Envato":
+		return s.enrichEnvato(result)
+	case "Artgrid":
+		return s.enrichArtgrid(result)
+	default:
+		if result.ThumbnailURL == "" {
+			result.ThumbnailURL = deriveThumbnail(result.Link)
+		}
+		return result
+	}
+}
+
+func (s *SearchService) enrichEnvato(result SearchResult) SearchResult {
+	html, err := s.fetchText(result.Link)
+	if err != nil {
+		return result
+	}
+	if result.ThumbnailURL == "" {
+		result.ThumbnailURL = firstNonEmpty(
+			extractMetaContent(html, "og:image"),
+			extractMetaContent(html, "twitter:image"),
+		)
+	}
+	if result.PreviewVideoURL == "" {
+		result.PreviewVideoURL = extractVideoPreviewURL(html)
+	}
+	return result
+}
+
+func (s *SearchService) enrichArtgrid(result SearchResult) SearchResult {
+	clipID := extractArtgridClipID(result.Link)
+	if clipID == "" {
+		return result
+	}
+
+	apiURL := "https://artgrid.io/api/clip/details?clipId=" + clipID
+	body, err := s.fetchJSONText(apiURL)
+	if err == nil {
+		urls := collectURLs(body)
+		if result.ThumbnailURL == "" {
+			result.ThumbnailURL = pickImageURL(urls)
+		}
+		if result.PreviewVideoURL == "" {
+			result.PreviewVideoURL = pickVideoURL(urls)
+		}
+	}
+
+	if result.ThumbnailURL == "" || result.PreviewVideoURL == "" {
+		html, err := s.fetchText(result.Link)
+		if err == nil {
+			if result.ThumbnailURL == "" {
+				result.ThumbnailURL = firstNonEmpty(
+					extractMetaContent(html, "og:image"),
+					extractMetaContent(html, "twitter:image"),
+				)
+			}
+			if result.PreviewVideoURL == "" {
+				result.PreviewVideoURL = extractVideoPreviewURL(html)
+			}
+		}
+	}
+
+	return result
 }
 
 func (s *SearchService) search(query, categories, engine, source string) ([]SearchResult, error) {
@@ -170,29 +258,40 @@ func (s *SearchService) search(query, categories, engine, source string) ([]Sear
 	results := make([]SearchResult, 0, len(payload.Results))
 	for _, item := range payload.Results {
 		link := strings.TrimSpace(item.URL)
-		thumb := firstNonEmpty(item.Thumbnail, item.ThumbnailSrc, item.ImgSrc, deriveThumbnail(link))
+		if link == "" {
+			continue
+		}
 		results = append(results, SearchResult{
 			Title:        item.Title,
 			Link:         link,
 			DisplayLink:  inferDisplayLink(link, item.ParsedURL),
 			Snippet:      item.Content,
-			ThumbnailURL: thumb,
+			ThumbnailURL: firstNonEmpty(item.Thumbnail, item.ThumbnailSrc, item.ImgSrc, deriveThumbnail(link)),
 			Source:       normalizeSource(source, link, item.Engine),
 		})
 	}
 	return results, nil
 }
 
-func buildGoogleVideoQuery(query string) string {
-	return fmt.Sprintf(`"%s" ("stock footage" OR "b-roll" OR cinematic OR "establishing shot" OR editorial) -tutorial -"how to" -review -reaction -course -podcast -vlog -interview -breakdown -edit -editing`, query)
+func buildGoogleVideoQueries(base string) []string {
+	return []string{
+		fmt.Sprintf(`"%s" ("stock footage" OR "b-roll" OR cinematic OR "establishing shot" OR editorial) -tutorial -"how to" -review -reaction -course -podcast -vlog -interview -breakdown -edit -editing`, base),
+		fmt.Sprintf(`"%s" ("cinematic footage" OR "free stock footage" OR "4k footage") -tutorial -"how to" -review`, base),
+	}
 }
 
-func buildEnvatoQuery(query string) string {
-	return fmt.Sprintf(`"%s" ("stock footage" OR "stock video" OR "motion graphics" OR cinematic OR "b-roll") (site:elements.envato.com OR site:videohive.net/item) -site:elements.envato.com/stock-video -site:elements.envato.com/video-templates -site:elements.envato.com/stock-video/stock-footage`, query)
+func buildEnvatoQueries(base string) []string {
+	return []string{
+		fmt.Sprintf(`"%s" ("stock footage" OR "stock video" OR "b-roll" OR cinematic) site:elements.envato.com`, base),
+		fmt.Sprintf(`"%s" ("stock footage" OR "stock video" OR "b-roll" OR cinematic) site:videohive.net/item`, base),
+	}
 }
 
-func buildArtgridQuery(query string) string {
-	return fmt.Sprintf(`"%s" ("stock footage" OR "b-roll" OR cinematic OR editorial) site:artgrid.io/clip/`, query)
+func buildArtgridQueries(base string) []string {
+	return []string{
+		fmt.Sprintf(`"%s" ("stock footage" OR "b-roll" OR cinematic OR editorial) site:artgrid.io/clip/`, base),
+		fmt.Sprintf(`"%s" ("footage" OR "cinematic" OR "establishing shot") site:artgrid.io/clip/`, base),
+	}
 }
 
 func isUsefulGoogleVideoResult(result SearchResult) bool {
@@ -200,21 +299,13 @@ func isUsefulGoogleVideoResult(result SearchResult) bool {
 	for _, banned := range []string{
 		"tutorial", "how to", "review", "reaction", "podcast", "interview", "walkthrough",
 		"course", "lesson", "edit tutorial", "editing tutorial", "premiere pro", "after effects",
-		"breakdown", "explained", "vlog",
+		"breakdown", "explained", "vlog", "tips", "guide", "learn", "free download",
 	} {
 		if strings.Contains(text, banned) {
 			return false
 		}
 	}
-	for _, desired := range []string{
-		"b-roll", "stock footage", "cinematic", "footage", "establishing shot", "4k",
-	} {
-		if strings.Contains(text, desired) {
-			return true
-		}
-	}
-	lowerLink := strings.ToLower(result.Link)
-	return strings.Contains(lowerLink, "youtube.com/watch") || strings.Contains(lowerLink, "youtu.be/")
+	return true
 }
 
 func isRenderableEnvatoResult(result SearchResult) bool {
@@ -225,7 +316,7 @@ func isRenderableEnvatoResult(result SearchResult) bool {
 	host := strings.ToLower(parsed.Host)
 	path := strings.Trim(parsed.Path, "/")
 	if strings.Contains(host, "videohive.net") {
-		return strings.HasPrefix(path, "item/")
+		return strings.HasPrefix(path, "item/") && len(strings.Split(path, "/")) >= 2
 	}
 	if strings.Contains(host, "elements.envato.com") {
 		if path == "" || strings.Contains(path, "/") {
@@ -244,17 +335,7 @@ func isRenderableArtgridResult(result SearchResult) bool {
 	if !strings.Contains(strings.ToLower(parsed.Host), "artgrid.io") {
 		return false
 	}
-	path := strings.Trim(parsed.Path, "/")
-	return regexp.MustCompile(`^clip/[0-9]+/`).MatchString(path)
-}
-
-func firstNonEmpty(values ...string) string {
-	for _, value := range values {
-		if strings.TrimSpace(value) != "" {
-			return value
-		}
-	}
-	return ""
+	return regexp.MustCompile(`^/clip/[0-9]+/`).MatchString(parsed.Path)
 }
 
 func normalizeSource(source, link, engine string) string {
@@ -305,6 +386,150 @@ func extractYouTubeID(link string) string {
 	return ""
 }
 
+func extractMetaContent(html, property string) string {
+	patterns := []*regexp.Regexp{
+		regexp.MustCompile(`(?i)<meta[^>]+property=["']` + regexp.QuoteMeta(property) + `["'][^>]+content=["']([^"']+)`),
+		regexp.MustCompile(`(?i)<meta[^>]+name=["']` + regexp.QuoteMeta(property) + `["'][^>]+content=["']([^"']+)`),
+	}
+	for _, pattern := range patterns {
+		matches := pattern.FindStringSubmatch(html)
+		if len(matches) == 2 {
+			return htmlUnescape(matches[1])
+		}
+	}
+	return ""
+}
+
+func extractVideoPreviewURL(html string) string {
+	pattern := regexp.MustCompile(`https?:\\?/\\?/[^"'\\s>]+(?:mp4|m3u8)`)
+	matches := pattern.FindAllString(html, -1)
+	for _, match := range matches {
+		candidate := strings.ReplaceAll(match, `\/`, `/`)
+		candidate = strings.ReplaceAll(candidate, `\u002F`, `/`)
+		candidate = strings.ReplaceAll(candidate, `\\`, "")
+		if strings.Contains(strings.ToLower(candidate), "preview") || strings.Contains(strings.ToLower(candidate), "video") {
+			return candidate
+		}
+	}
+	return ""
+}
+
+func extractArtgridClipID(link string) string {
+	matches := regexp.MustCompile(`/clip/([0-9]+)/`).FindStringSubmatch(link)
+	if len(matches) == 2 {
+		return matches[1]
+	}
+	return ""
+}
+
+func collectURLs(body string) []string {
+	pattern := regexp.MustCompile(`https?:\/\/[^"'\\\s]+`)
+	matches := pattern.FindAllString(body, -1)
+	seen := map[string]bool{}
+	results := make([]string, 0, len(matches))
+	for _, match := range matches {
+		candidate := strings.TrimSpace(strings.Trim(match, `"'`))
+		if candidate == "" || seen[candidate] {
+			continue
+		}
+		seen[candidate] = true
+		results = append(results, candidate)
+	}
+	return results
+}
+
+func pickImageURL(urls []string) string {
+	for _, item := range urls {
+		lower := strings.ToLower(item)
+		if strings.Contains(lower, ".jpg") || strings.Contains(lower, ".jpeg") || strings.Contains(lower, ".png") || strings.Contains(lower, ".webp") {
+			return item
+		}
+	}
+	return ""
+}
+
+func pickVideoURL(urls []string) string {
+	for _, item := range urls {
+		lower := strings.ToLower(item)
+		if strings.Contains(lower, ".mp4") || strings.Contains(lower, ".m3u8") {
+			return item
+		}
+	}
+	return ""
+}
+
+func (s *SearchService) fetchText(target string) (string, error) {
+	resp, err := s.Client.Get(target)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 300 {
+		return "", fmt.Errorf("fetch returned status %d", resp.StatusCode)
+	}
+	data, err := io.ReadAll(io.LimitReader(resp.Body, 1024*1024))
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
+func (s *SearchService) fetchJSONText(target string) (string, error) {
+	req, err := http.NewRequest(http.MethodGet, target, nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/json, text/json")
+	resp, err := s.Client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 300 {
+		return "", fmt.Errorf("json fetch returned status %d", resp.StatusCode)
+	}
+	data, err := io.ReadAll(io.LimitReader(resp.Body, 1024*1024))
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
+func firstNonEmpty(values ...string) string {
+	for _, value := range values {
+		if strings.TrimSpace(value) != "" {
+			return value
+		}
+	}
+	return ""
+}
+
+func limitQueries(queries []string, limit int) []string {
+	seen := map[string]bool{}
+	filtered := make([]string, 0, minInt(len(queries), limit))
+	for _, item := range queries {
+		trimmed := strings.TrimSpace(item)
+		if trimmed == "" {
+			continue
+		}
+		key := strings.ToLower(trimmed)
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		filtered = append(filtered, trimmed)
+		if len(filtered) >= limit {
+			break
+		}
+	}
+	return filtered
+}
+
+func htmlUnescape(text string) string {
+	replacer := strings.NewReplacer("&amp;", "&", "&quot;", `"`, "&#39;", "'", "&lt;", "<", "&gt;", ">")
+	return replacer.Replace(text)
+}
+
 func sourceWeight(source string) int {
 	switch source {
 	case "Envato":
@@ -317,3 +542,10 @@ func sourceWeight(source string) int {
 		return 0
 	}
 }
+
+func minInt(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

backend/services/gemini.go

@@ -9,6 +9,9 @@ import (
 	"mime"
 	"net/http"
 	neturl "net/url"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"strings"
 	"time"
 )
@@ -19,12 +22,13 @@ type GeminiService struct {
 }
 
 type AIRecommendation struct {
-	Title        string `json:"title"`
-	Link         string `json:"link"`
-	ThumbnailURL string `json:"thumbnailUrl"`
-	Source       string `json:"source"`
-	Reason       string `json:"reason"`
-	Recommended  bool   `json:"recommended"`
+	Title           string `json:"title"`
+	Link            string `json:"link"`
+	ThumbnailURL    string `json:"thumbnailUrl"`
+	PreviewVideoURL string `json:"previewVideoUrl"`
+	Source          string `json:"source"`
+	Reason          string `json:"reason"`
+	Recommended     bool   `json:"recommended"`
 }
 
 type QueryExpansion struct {
@@ -39,141 +43,8 @@ func NewGeminiService(apiKey string) *GeminiService {
 }
 
 func (g *GeminiService) ExpandQuery(query string) ([]string, error) {
-	if g.APIKey == "" {
-		return fallbackQueryExpansion(query, query), nil
-	}
-
 	englishBase := g.TranslateQuery(query)
-
-	body := map[string]any{
-		"systemInstruction": map[string]any{
-			"parts": []map[string]string{
-				{
-					"text": "You are a JSON-only API. Output valid JSON only. Never add prose, labels, markdown, or explanations before or after the JSON.",
-				},
-			},
-		},
-		"contents": []map[string]any{
-			{
-				"parts": []map[string]string{
-					{
-						"text": `Return JSON only in this shape: {"querywords":["..."]}.
-Generate at most 10 concise English search variations for media discovery across Google Video, Envato, and Artgrid.
-The queries must be usable directly in English search engines for stock footage discovery.
-Prioritize media, video footage, stock footage, cinematic b-roll, editorial footage, and scene-based search terms.
-Avoid celebrity gossip, reaction-style phrasing, clickbait phrasing, and generic web search wording.
-Do not output Korean unless it is part of a proper noun.
-Original user query: ` + query + `
-English base translation: ` + englishBase,
-					},
-				},
-			},
-		},
-		"generationConfig": map[string]any{
-			"responseMimeType": "application/json",
-			"temperature":      0.2,
-			"maxOutputTokens":  220,
-			"responseSchema": map[string]any{
-				"type": "OBJECT",
-				"properties": map[string]any{
-					"querywords": map[string]any{
-						"type": "ARRAY",
-						"items": map[string]any{
-							"type": "STRING",
-						},
-					},
-				},
-				"required": []string{"querywords"},
-			},
-		},
-	}
-
-	rawText, err := g.generateText(body)
-	if err != nil {
-		return fallbackQueryExpansion(query, englishBase), nil
-	}
-
-	jsonText, err := extractJSONObject(rawText)
-	if err != nil {
-		strictBody := map[string]any{
-			"systemInstruction": map[string]any{
-				"parts": []map[string]string{
-					{
-						"text": "You are a strict JSON emitter. Output one valid JSON object only. Do not write any other text.",
-					},
-				},
-			},
-			"contents": []map[string]any{
-				{
-					"parts": []map[string]string{
-						{
-							"text": `STRICT JSON ONLY.
-Output must start with { and end with }.
-Do not add prose, explanations, markdown, code fences, or labels.
-Return exactly this shape: {"querywords":["..."]}.
-Generate up to 10 search queries for media discovery across Google Video, Envato, and Artgrid.
-Every query must be in natural English and suitable for stock-footage search.
-Original user query: ` + query + `
-English base translation: ` + englishBase,
-						},
-					},
-				},
-			},
-			"generationConfig": map[string]any{
-				"responseMimeType": "application/json",
-				"temperature":      0.1,
-				"maxOutputTokens":  220,
-				"responseSchema": map[string]any{
-					"type": "OBJECT",
-					"properties": map[string]any{
-						"querywords": map[string]any{
-							"type": "ARRAY",
-							"items": map[string]any{
-								"type": "STRING",
-							},
-						},
-					},
-					"required": []string{"querywords"},
-				},
-			},
-		}
-		rawText, retryErr := g.generateText(strictBody)
-		if retryErr != nil {
-			return fallbackQueryExpansion(query, englishBase), nil
-		}
-		jsonText, err = extractJSONObject(rawText)
-		if err != nil {
-			return fallbackQueryExpansion(query, englishBase), nil
-		}
-	}
-
-	var parsed QueryExpansion
-	if err := json.Unmarshal([]byte(jsonText), &parsed); err != nil {
-		return fallbackQueryExpansion(query, englishBase), nil
-	}
-
-	queries := fallbackQueryExpansion(query, englishBase)
-	seen := map[string]bool{}
-	englishOnly := !strings.EqualFold(strings.TrimSpace(englishBase), strings.TrimSpace(query))
-	for _, existing := range queries {
-		seen[strings.ToLower(strings.TrimSpace(existing))] = true
-	}
-	for _, item := range parsed.Querywords {
-		trimmed := strings.TrimSpace(item)
-		if trimmed == "" {
-			continue
-		}
-		if englishOnly && !isLikelyEnglishQuery(trimmed) {
-			continue
-		}
-		key := strings.ToLower(trimmed)
-		if seen[key] {
-			continue
-		}
-		seen[key] = true
-		queries = append(queries, trimmed)
-	}
-	return queries, nil
+	return buildSearchQueries(query, englishBase), nil
 }
 
 func (g *GeminiService) TranslateQuery(query string) string {
@@ -277,7 +148,7 @@ User query: ` + query,
 
 	maxImages := min(len(candidates), 10)
 	for idx := 0; idx < maxImages; idx++ {
-		img, mimeType, err := fetchImageAsInlineData(g.Client, candidates[idx].ThumbnailURL)
+		img, mimeType, err := fetchCandidateVisualInlineData(g.Client, candidates[idx])
 		if err != nil {
 			continue
 		}
@@ -348,24 +219,26 @@ User query: ` + query,
 		}
 		src := candidates[rec.Index]
 		recommendations = append(recommendations, AIRecommendation{
-			Title:        src.Title,
-			Link:         src.Link,
-			ThumbnailURL: src.ThumbnailURL,
-			Source:       src.Source,
-			Reason:       rec.Reason,
-			Recommended:  true,
+			Title:           src.Title,
+			Link:            src.Link,
+			ThumbnailURL:    src.ThumbnailURL,
+			PreviewVideoURL: src.PreviewVideoURL,
+			Source:          src.Source,
+			Reason:          rec.Reason,
+			Recommended:     true,
 		})
 	}
 
 	if len(recommendations) == 0 {
 		for _, candidate := range candidates[:min(4, len(candidates))] {
 			recommendations = append(recommendations, AIRecommendation{
-				Title:        candidate.Title,
-				Link:         candidate.Link,
-				ThumbnailURL: candidate.ThumbnailURL,
-				Source:       candidate.Source,
-				Reason:       "Fallback result because Gemini returned no recommended items.",
-				Recommended:  true,
+				Title:           candidate.Title,
+				Link:            candidate.Link,
+				ThumbnailURL:    candidate.ThumbnailURL,
+				PreviewVideoURL: candidate.PreviewVideoURL,
+				Source:          candidate.Source,
+				Reason:          "Fallback result because Gemini returned no recommended items.",
+				Recommended:     true,
 			})
 		}
 	}
@@ -374,6 +247,9 @@ User query: ` + query,
 }
 
 func fetchImageAsInlineData(client *http.Client, imageURL string) (string, string, error) {
+	if strings.TrimSpace(imageURL) == "" {
+		return "", "", fmt.Errorf("image url is empty")
+	}
 	resp, err := client.Get(imageURL)
 	if err != nil {
 		return "", "", err
@@ -397,6 +273,40 @@ func fetchImageAsInlineData(client *http.Client, imageURL string) (string, strin
 	return base64.StdEncoding.EncodeToString(data), mimeType, nil
 }
 
+func fetchCandidateVisualInlineData(client *http.Client, candidate SearchResult) (string, string, error) {
+	if candidate.ThumbnailURL != "" {
+		data, mimeType, err := fetchImageAsInlineData(client, candidate.ThumbnailURL)
+		if err == nil {
+			return data, mimeType, nil
+		}
+	}
+	if candidate.PreviewVideoURL != "" {
+		return extractFrameFromVideo(candidate.PreviewVideoURL)
+	}
+	return "", "", fmt.Errorf("candidate has no thumbnail or preview video")
+}
+
+func extractFrameFromVideo(videoURL string) (string, string, error) {
+	tempDir, err := os.MkdirTemp("", "gemini-frame-*")
+	if err != nil {
+		return "", "", err
+	}
+	defer os.RemoveAll(tempDir)
+
+	framePath := filepath.Join(tempDir, "frame.jpg")
+	cmd := exec.Command("ffmpeg", "-y", "-ss", "00:00:00.500", "-i", videoURL, "-frames:v", "1", "-q:v", "2", framePath)
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return "", "", fmt.Errorf("ffmpeg frame extraction failed: %s", strings.TrimSpace(string(output)))
+	}
+
+	data, err := os.ReadFile(framePath)
+	if err != nil {
+		return "", "", err
+	}
+	return base64.StdEncoding.EncodeToString(data), "image/jpeg", nil
+}
+
 func min(a, b int) int {
 	if a < b {
 		return a
@@ -457,27 +367,24 @@ func truncateForError(text string, limit int) string {
 	return trimmed[:limit] + "..."
 }
 
-func fallbackQueryExpansion(originalQuery, englishQuery string) []string {
+func buildSearchQueries(originalQuery, englishQuery string) []string {
 	base := strings.TrimSpace(englishQuery)
 	if base == "" {
 		base = strings.TrimSpace(originalQuery)
 	}
 	candidates := []string{
 		base,
-		base + " b-roll",
+		strings.ReplaceAll(base, "pov", "point of view"),
 		base + " stock footage",
+		base + " b-roll",
 		base + " cinematic footage",
-		base + " establishing shot",
 		base + " editorial footage",
-		base + " urban scene",
-		base + " ambient footage",
-		base + " 4k footage",
-		base + " cinematic b-roll",
+		base + " establishing shot",
 	}
 	seen := map[string]bool{}
 	queries := make([]string, 0, len(candidates))
 	for _, item := range candidates {
-		trimmed := strings.TrimSpace(item)
+		trimmed := strings.TrimSpace(strings.Join(strings.Fields(item), " "))
 		if trimmed == "" {
 			continue
 		}

frontend/app.js

@@ -133,12 +133,27 @@ function renderResults(results) {
   }
   for (const item of results) {
     const node = cardTemplate.content.firstElementChild.cloneNode(true);
+    const image = node.querySelector("img");
+    const previewVideo = node.querySelector(".preview-hover");
     node.href = item.link;
-    node.querySelector("img").src = item.thumbnailUrl || "https://placehold.co/1280x720/0a0a0a/ffffff?text=No+Preview";
-    node.querySelector("img").alt = item.title;
+    image.src = item.thumbnailUrl || "https://placehold.co/1280x720/0a0a0a/ffffff?text=Preview";
+    image.alt = item.title;
     node.querySelector("h3").textContent = item.title;
     node.querySelector("p").textContent = item.reason;
     node.querySelector(".source-badge").textContent = item.source;
+    if (item.previewVideoUrl) {
+      previewVideo.src = item.previewVideoUrl;
+      previewVideo.poster = item.thumbnailUrl || "";
+      node.addEventListener("mouseenter", () => {
+        previewVideo.classList.remove("hidden");
+        previewVideo.play().catch(() => {});
+      });
+      node.addEventListener("mouseleave", () => {
+        previewVideo.pause();
+        previewVideo.currentTime = 0;
+        previewVideo.classList.add("hidden");
+      });
+    }
     searchResults.appendChild(node);
   }
 }

frontend/index.html

@@ -128,6 +128,7 @@
       <a target="_blank" rel="noreferrer" class="group overflow-hidden rounded-3xl border border-white/10 bg-black/30 transition hover:border-white/30">
         <div class="relative aspect-video overflow-hidden bg-zinc-900">
           <img class="h-full w-full object-cover transition duration-500 group-hover:scale-105" alt="" />
+          <video class="preview-hover absolute inset-0 hidden h-full w-full object-cover" muted loop playsinline preload="none"></video>
           <div class="absolute left-3 top-3 rounded-full border border-white/20 bg-black/60 px-3 py-1 text-[11px] uppercase tracking-[0.25em] text-white">AI Recommended</div>
           <div class="source-badge absolute bottom-3 left-3 rounded-full bg-white px-3 py-1 text-[11px] font-medium uppercase tracking-[0.2em] text-black"></div>
         </div>
@@ -138,6 +139,6 @@
       </a>
     </template>
 
-    <script src="/app.js?v=20260313d" defer></script>
+    <script src="/app.js?v=20260313e" defer></script>
   </body>
 </html>