added filter and tag for ingredients

database/db.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"fmt"
 	"mealprep/models"
+	"strings"
 	"time"
 
 	_ "github.com/mattn/go-sqlite3"
@@ -71,6 +72,26 @@ func createTables() error {
 
 	CREATE INDEX IF NOT EXISTS idx_ingredients_user_id ON ingredients(user_id);
 
+	-- Tags table (user-isolated)
+	CREATE TABLE IF NOT EXISTS tags (
+		id INTEGER PRIMARY KEY AUTOINCREMENT,
+		user_id INTEGER NOT NULL,
+		name TEXT NOT NULL,
+		FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
+		UNIQUE(user_id, name)
+	);
+
+	CREATE INDEX IF NOT EXISTS idx_tags_user_id ON tags(user_id);
+
+	-- Ingredient tags junction table
+	CREATE TABLE IF NOT EXISTS ingredient_tags (
+		ingredient_id INTEGER NOT NULL,
+		tag_id INTEGER NOT NULL,
+		PRIMARY KEY (ingredient_id, tag_id),
+		FOREIGN KEY (ingredient_id) REFERENCES ingredients(id) ON DELETE CASCADE,
+		FOREIGN KEY (tag_id) REFERENCES tags(id) ON DELETE CASCADE
+	);
+
 	-- Meals table (user-isolated)
 	CREATE TABLE IF NOT EXISTS meals (
 		id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -248,7 +269,14 @@ func DeleteIngredient(userID, ingredientID int) error {
 		"DELETE FROM ingredients WHERE id = ? AND user_id = ?",
 		ingredientID, userID,
 	)
-	return err
+	if err != nil {
+		return err
+	}
+
+	// Clean up unused tags
+	CleanupUnusedTags(userID)
+
+	return nil
 }
 
 // Meal operations (user-isolated)
@@ -454,3 +482,240 @@ func GetGroceryList(userID int) ([]models.GroceryItem, error) {
 	}
 	return items, nil
 }
+
+// Tag operations (user-isolated)
+
+func GetAllTags(userID int) ([]models.Tag, error) {
+	rows, err := DB.Query(
+		"SELECT id, user_id, name FROM tags WHERE user_id = ? ORDER BY name",
+		userID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var tags []models.Tag
+	for rows.Next() {
+		var tag models.Tag
+		if err := rows.Scan(&tag.ID, &tag.UserID, &tag.Name); err != nil {
+			return nil, err
+		}
+		tags = append(tags, tag)
+	}
+	return tags, nil
+}
+
+func GetUsedTags(userID int) ([]models.Tag, error) {
+	query := `
+		SELECT DISTINCT t.id, t.user_id, t.name
+		FROM tags t
+		JOIN ingredient_tags it ON t.id = it.tag_id
+		WHERE t.user_id = ?
+		ORDER BY t.name
+	`
+	rows, err := DB.Query(query, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var tags []models.Tag
+	for rows.Next() {
+		var tag models.Tag
+		if err := rows.Scan(&tag.ID, &tag.UserID, &tag.Name); err != nil {
+			return nil, err
+		}
+		tags = append(tags, tag)
+	}
+	return tags, nil
+}
+
+func CleanupUnusedTags(userID int) error {
+	// Delete tags that have no ingredient associations
+	_, err := DB.Exec(`
+		DELETE FROM tags
+		WHERE user_id = ?
+		AND id NOT IN (
+			SELECT DISTINCT tag_id FROM ingredient_tags
+		)
+	`, userID)
+	return err
+}
+
+func AddTag(userID int, name string) (int64, error) {
+	result, err := DB.Exec(
+		"INSERT INTO tags (user_id, name) VALUES (?, ?)",
+		userID, name,
+	)
+	if err != nil {
+		return 0, err
+	}
+	return result.LastInsertId()
+}
+
+func GetOrCreateTag(userID int, name string) (int64, error) {
+	// Try to get existing tag
+	var tagID int64
+	err := DB.QueryRow(
+		"SELECT id FROM tags WHERE user_id = ? AND name = ?",
+		userID, name,
+	).Scan(&tagID)
+
+	if err == sql.ErrNoRows {
+		// Tag doesn't exist, create it
+		return AddTag(userID, name)
+	}
+	if err != nil {
+		return 0, err
+	}
+	return tagID, nil
+}
+
+func DeleteTag(userID, tagID int) error {
+	_, err := DB.Exec(
+		"DELETE FROM tags WHERE id = ? AND user_id = ?",
+		tagID, userID,
+	)
+	return err
+}
+
+// Ingredient tag operations
+
+func GetIngredientTags(userID, ingredientID int) ([]models.Tag, error) {
+	query := `
+		SELECT t.id, t.user_id, t.name
+		FROM tags t
+		JOIN ingredient_tags it ON t.id = it.tag_id
+		JOIN ingredients i ON it.ingredient_id = i.id
+		WHERE it.ingredient_id = ? AND i.user_id = ? AND t.user_id = ?
+		ORDER BY t.name
+	`
+	rows, err := DB.Query(query, ingredientID, userID, userID)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var tags []models.Tag
+	for rows.Next() {
+		var tag models.Tag
+		if err := rows.Scan(&tag.ID, &tag.UserID, &tag.Name); err != nil {
+			return nil, err
+		}
+		tags = append(tags, tag)
+	}
+	return tags, nil
+}
+
+func AddIngredientTag(userID, ingredientID, tagID int) error {
+	// Verify ingredient and tag belong to user
+	var count int
+	err := DB.QueryRow(
+		"SELECT COUNT(*) FROM ingredients i, tags t WHERE i.id = ? AND t.id = ? AND i.user_id = ? AND t.user_id = ?",
+		ingredientID, tagID, userID, userID,
+	).Scan(&count)
+	if err != nil || count == 0 {
+		return fmt.Errorf("ingredient or tag not found or doesn't belong to user")
+	}
+
+	_, err = DB.Exec(
+		"INSERT OR IGNORE INTO ingredient_tags (ingredient_id, tag_id) VALUES (?, ?)",
+		ingredientID, tagID,
+	)
+	return err
+}
+
+func RemoveIngredientTag(userID, ingredientID, tagID int) error {
+	// Verify ownership
+	var count int
+	err := DB.QueryRow(
+		"SELECT COUNT(*) FROM ingredients WHERE id = ? AND user_id = ?",
+		ingredientID, userID,
+	).Scan(&count)
+	if err != nil || count == 0 {
+		return fmt.Errorf("ingredient not found or doesn't belong to user")
+	}
+
+	_, err = DB.Exec(
+		"DELETE FROM ingredient_tags WHERE ingredient_id = ? AND tag_id = ?",
+		ingredientID, tagID,
+	)
+	if err != nil {
+		return err
+	}
+
+	// Clean up unused tags
+	CleanupUnusedTags(userID)
+
+	return nil
+}
+
+func GetIngredientsWithTags(userID int) ([]models.Ingredient, error) {
+	rows, err := DB.Query(
+		"SELECT id, user_id, name, unit FROM ingredients WHERE user_id = ? ORDER BY name",
+		userID,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var ingredients []models.Ingredient
+	for rows.Next() {
+		var ing models.Ingredient
+		if err := rows.Scan(&ing.ID, &ing.UserID, &ing.Name, &ing.Unit); err != nil {
+			return nil, err
+		}
+
+		// Get tags for this ingredient
+		ing.Tags, _ = GetIngredientTags(userID, ing.ID)
+		ingredients = append(ingredients, ing)
+	}
+	return ingredients, nil
+}
+
+func SearchIngredientsByTags(userID int, tagNames []string) ([]models.Ingredient, error) {
+	if len(tagNames) == 0 {
+		return GetIngredientsWithTags(userID)
+	}
+
+	// Build query with placeholders for tag names
+	placeholders := make([]string, len(tagNames))
+	args := []interface{}{userID}
+	for i, name := range tagNames {
+		placeholders[i] = "?"
+		args = append(args, name)
+	}
+	args = append(args, len(tagNames))
+
+	query := fmt.Sprintf(`
+		SELECT DISTINCT i.id, i.user_id, i.name, i.unit
+		FROM ingredients i
+		JOIN ingredient_tags it ON i.id = it.ingredient_id
+		JOIN tags t ON it.tag_id = t.id
+		WHERE i.user_id = ? AND t.name IN (%s)
+		GROUP BY i.id
+		HAVING COUNT(DISTINCT t.id) = ?
+		ORDER BY i.name
+	`, strings.Join(placeholders, ","))
+
+	rows, err := DB.Query(query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var ingredients []models.Ingredient
+	for rows.Next() {
+		var ing models.Ingredient
+		if err := rows.Scan(&ing.ID, &ing.UserID, &ing.Name, &ing.Unit); err != nil {
+			return nil, err
+		}
+
+		// Get tags for this ingredient
+		ing.Tags, _ = GetIngredientTags(userID, ing.ID)
+		ingredients = append(ingredients, ing)
+	}
+	return ingredients, nil
+}

handlers/ingredients.go

@@ -12,7 +12,38 @@ import (
 // IngredientsHandler handles the ingredients page
 func IngredientsHandler(w http.ResponseWriter, r *http.Request) {
 	userID := auth.GetUserID(r)
-	ingredients, err := database.GetAllIngredients(userID)
+
+	// Check if there's a search query
+	searchTags := r.URL.Query().Get("tags")
+	var ingredients []interface{}
+	var err error
+
+	if searchTags != "" {
+		tagNames := strings.Split(searchTags, ",")
+		for i := range tagNames {
+			tagNames[i] = strings.TrimSpace(tagNames[i])
+		}
+		ings, err := database.SearchIngredientsByTags(userID, tagNames)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		for _, ing := range ings {
+			ingredients = append(ingredients, ing)
+		}
+	} else {
+		ings, err := database.GetIngredientsWithTags(userID)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		for _, ing := range ings {
+			ingredients = append(ingredients, ing)
+		}
+	}
+
+	// Get all available tags for the filter UI (only tags that are in use)
+	allTags, err := database.GetUsedTags(userID)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -25,30 +56,136 @@ func IngredientsHandler(w http.ResponseWriter, r *http.Request) {
 			<form hx-post="/ingredients" hx-target="#ingredients-list" hx-swap="beforeend" class="add-form">
 				<input type="text" name="name" placeholder="Ingredient name" required />
 				<input type="text" name="unit" placeholder="Unit (e.g., grams, cups)" required />
+				<input type="text" name="tags" placeholder="Tags (comma-separated)" />
 				<button type="submit">Add Ingredient</button>
 			</form>
 
-			<div id="ingredients-list" class="items-list">
+			<div class="search-section">
-				{{range .}}
+				<h3>Filter by Tags</h3>
-				<div class="item" id="ingredient-{{.ID}}">
+				<div class="tag-filter">
-					<span class="item-name">{{.Name}}</span>
+					{{range .AllTags}}
-					<span class="item-unit">({{.Unit}})</span>
+					<button class="tag-filter-btn"
-					<button
+							onclick="toggleTagFilter('{{.Name}}')">
-						hx-delete="/ingredients/{{.ID}}"
+						{{.Name}}
-						hx-target="#ingredient-{{.ID}}"
-						hx-swap="outerHTML"
-						hx-confirm="Are you sure you want to delete this ingredient?"
-						class="delete-btn">
-						Delete
 					</button>
+					{{end}}
+				</div>
+				<div id="active-filters" class="active-filters"></div>
+				<button onclick="clearFilters()" class="clear-filters-btn">Clear Filters</button>
+			</div>
+
+			<div id="ingredients-list" class="items-list">
+				{{range .Ingredients}}
+				<div class="item" id="ingredient-{{.ID}}">
+					<div class="item-content">
+						<span class="item-name">{{.Name}}</span>
+						<span class="item-unit">({{.Unit}})</span>
+						<div class="item-tags">
+							{{range .Tags}}
+							<span class="tag">{{.Name}}</span>
+							{{end}}
+						</div>
+					</div>
+					<div class="item-actions">
+						<button
+							hx-get="/ingredients/{{.ID}}/tags"
+							hx-target="#tag-modal-content"
+							hx-swap="innerHTML"
+							onclick="document.getElementById('tag-modal').style.display='block'"
+							class="edit-tags-btn">
+							Edit Tags
+						</button>
+						<button
+							hx-delete="/ingredients/{{.ID}}"
+							hx-target="#ingredient-{{.ID}}"
+							hx-swap="outerHTML"
+							hx-confirm="Are you sure you want to delete this ingredient?"
+							class="delete-btn">
+							Delete
+						</button>
+					</div>
 				</div>
 				{{end}}
 			</div>
 		</div>
+
+		<!-- Tag Edit Modal -->
+		<div id="tag-modal" class="modal">
+			<div class="modal-content">
+				<span class="close" onclick="document.getElementById('tag-modal').style.display='none'">&times;</span>
+				<div id="tag-modal-content">
+					<!-- Content loaded via HTMX -->
+				</div>
+			</div>
+		</div>
+
+		<script>
+			let activeFilters = new Set();
+
+			// Listen for tag changes and refresh ingredients
+			document.body.addEventListener('refreshIngredients', function() {
+				// Close the modal first
+				document.getElementById('tag-modal').style.display='none';
+				// Then refresh the page
+				htmx.ajax('GET', '/ingredients', {target: '#ingredients-content', swap: 'innerHTML'});
+			});
+
+			function toggleTagFilter(tagName) {
+				if (activeFilters.has(tagName)) {
+					activeFilters.delete(tagName);
+				} else {
+					activeFilters.add(tagName);
+				}
+				updateFilters();
+			}
+
+			function clearFilters() {
+				activeFilters.clear();
+				updateFilters();
+			}
+
+			function updateFilters() {
+				// Update active filters display
+				const activeFiltersDiv = document.getElementById('active-filters');
+				if (activeFilters.size > 0) {
+					activeFiltersDiv.innerHTML = 'Active filters: ' + Array.from(activeFilters).join(', ');
+				} else {
+					activeFiltersDiv.innerHTML = '';
+				}
+
+				// Update filter button states
+				document.querySelectorAll('.tag-filter-btn').forEach(btn => {
+					if (activeFilters.has(btn.textContent.trim())) {
+						btn.classList.add('active');
+					} else {
+						btn.classList.remove('active');
+					}
+				});
+
+				// Reload ingredients with filters
+				const url = activeFilters.size > 0
+					? '/ingredients?tags=' + Array.from(activeFilters).join(',')
+					: '/ingredients';
+
+				htmx.ajax('GET', url, {target: '#ingredients-content', swap: 'innerHTML'});
+			}
+		</script>
 	`
 
+	data := struct {
+		Ingredients []interface{}
+		AllTags     []interface{}
+	}{
+		Ingredients: ingredients,
+		AllTags:     []interface{}{},
+	}
+
+	for _, tag := range allTags {
+		data.AllTags = append(data.AllTags, tag)
+	}
+
 	t := template.Must(template.New("ingredients").Parse(tmpl))
-	t.Execute(w, ingredients)
+	t.Execute(w, data)
 }
 
 // AddIngredientHandler handles adding a new ingredient
@@ -62,6 +199,7 @@ func AddIngredientHandler(w http.ResponseWriter, r *http.Request) {
 
 	name := strings.TrimSpace(r.FormValue("name"))
 	unit := strings.TrimSpace(r.FormValue("unit"))
+	tagsStr := strings.TrimSpace(r.FormValue("tags"))
 
 	if name == "" || unit == "" {
 		http.Error(w, "Name and unit are required", http.StatusBadRequest)
@@ -74,18 +212,54 @@ func AddIngredientHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Process tags if provided
+	var tags []string
+	if tagsStr != "" {
+		tagNames := strings.Split(tagsStr, ",")
+		for _, tagName := range tagNames {
+			tagName = strings.TrimSpace(tagName)
+			if tagName != "" {
+				// Get or create tag
+				tagID, err := database.GetOrCreateTag(userID, tagName)
+				if err != nil {
+					continue // Skip this tag on error
+				}
+				// Link tag to ingredient
+				database.AddIngredientTag(userID, int(id), int(tagID))
+				tags = append(tags, tagName)
+			}
+		}
+	}
+
 	tmpl := `
 		<div class="item" id="ingredient-{{.ID}}">
-			<span class="item-name">{{.Name}}</span>
+			<div class="item-content">
-			<span class="item-unit">({{.Unit}})</span>
+				<span class="item-name">{{.Name}}</span>
-			<button
+				<span class="item-unit">({{.Unit}})</span>
-				hx-delete="/ingredients/{{.ID}}"
+				<div class="item-tags">
-				hx-target="#ingredient-{{.ID}}"
+					{{range .Tags}}
-				hx-swap="outerHTML"
+					<span class="tag">{{.}}</span>
-				hx-confirm="Are you sure you want to delete this ingredient?"
+					{{end}}
-				class="delete-btn">
+				</div>
-				Delete
+			</div>
-			</button>
+			<div class="item-actions">
+				<button
+					hx-get="/ingredients/{{.ID}}/tags"
+					hx-target="#tag-modal-content"
+					hx-swap="innerHTML"
+					onclick="document.getElementById('tag-modal').style.display='block'"
+					class="edit-tags-btn">
+					Edit Tags
+				</button>
+				<button
+					hx-delete="/ingredients/{{.ID}}"
+					hx-target="#ingredient-{{.ID}}"
+					hx-swap="outerHTML"
+					hx-confirm="Are you sure you want to delete this ingredient?"
+					class="delete-btn">
+					Delete
+				</button>
+			</div>
 		</div>
 	`
 
@@ -93,7 +267,8 @@ func AddIngredientHandler(w http.ResponseWriter, r *http.Request) {
 		ID   int64
 		Name string
 		Unit string
-	}{id, name, unit}
+		Tags []string
+	}{id, name, unit, tags}
 
 	t := template.Must(template.New("ingredient").Parse(tmpl))
 	t.Execute(w, data)
@@ -117,3 +292,224 @@ func DeleteIngredientHandler(w http.ResponseWriter, r *http.Request) {
 
 	w.WriteHeader(http.StatusOK)
 }
+
+// GetIngredientTagsHandler returns the tag editing UI for an ingredient
+func GetIngredientTagsHandler(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r)
+
+	// Extract ingredient ID from path /ingredients/{id}/tags
+	pathParts := strings.Split(strings.TrimPrefix(r.URL.Path, "/ingredients/"), "/")
+	if len(pathParts) < 1 {
+		http.Error(w, "Invalid path", http.StatusBadRequest)
+		return
+	}
+
+	ingredientID, err := strconv.Atoi(pathParts[0])
+	if err != nil {
+		http.Error(w, "Invalid ingredient ID", http.StatusBadRequest)
+		return
+	}
+
+	// Get current tags for ingredient
+	currentTags, err := database.GetIngredientTags(userID, ingredientID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Get all available tags
+	allTags, err := database.GetAllTags(userID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Build a set of current tag IDs for easy lookup
+	currentTagIDs := make(map[int]bool)
+	for _, tag := range currentTags {
+		currentTagIDs[tag.ID] = true
+	}
+
+	tmpl := `
+		<h3>Edit Tags</h3>
+		<div class="tag-edit-section">
+			<h4>Current Tags</h4>
+			<div id="current-tags-{{.IngredientID}}">
+				{{range .CurrentTags}}
+				<span class="tag">
+					{{.Name}}
+					<button
+						hx-delete="/ingredients/{{$.IngredientID}}/tags/{{.ID}}"
+						hx-target="#current-tags-{{$.IngredientID}}"
+						hx-swap="innerHTML"
+						class="tag-remove">
+						×
+					</button>
+				</span>
+				{{end}}
+			</div>
+
+			<h4>Add Tags</h4>
+			<form hx-post="/ingredients/{{.IngredientID}}/tags"
+				  hx-target="#current-tags-{{.IngredientID}}"
+				  hx-swap="innerHTML"
+				  class="add-tag-form">
+				<input type="text" name="tag_name" placeholder="New tag name" list="existing-tags" required />
+				<datalist id="existing-tags">
+					{{range .AllTags}}
+					{{if not (index $.CurrentTagIDs .ID)}}
+					<option value="{{.Name}}">
+					{{end}}
+					{{end}}
+				</datalist>
+				<button type="submit">Add Tag</button>
+			</form>
+		</div>
+	`
+
+	data := struct {
+		IngredientID  int
+		CurrentTags   []interface{}
+		AllTags       []interface{}
+		CurrentTagIDs map[int]bool
+	}{
+		IngredientID:  ingredientID,
+		CurrentTags:   []interface{}{},
+		AllTags:       []interface{}{},
+		CurrentTagIDs: currentTagIDs,
+	}
+
+	for _, tag := range currentTags {
+		data.CurrentTags = append(data.CurrentTags, tag)
+	}
+	for _, tag := range allTags {
+		data.AllTags = append(data.AllTags, tag)
+	}
+
+	t := template.Must(template.New("ingredient-tags").Parse(tmpl))
+	t.Execute(w, data)
+}
+
+// AddIngredientTagHandler adds a tag to an ingredient
+func AddIngredientTagHandler(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r)
+
+	// Extract ingredient ID from path
+	pathParts := strings.Split(strings.TrimPrefix(r.URL.Path, "/ingredients/"), "/")
+	if len(pathParts) < 1 {
+		http.Error(w, "Invalid path", http.StatusBadRequest)
+		return
+	}
+
+	ingredientID, err := strconv.Atoi(pathParts[0])
+	if err != nil {
+		http.Error(w, "Invalid ingredient ID", http.StatusBadRequest)
+		return
+	}
+
+	if err := r.ParseForm(); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	tagName := strings.TrimSpace(r.FormValue("tag_name"))
+	if tagName == "" {
+		http.Error(w, "Tag name is required", http.StatusBadRequest)
+		return
+	}
+
+	// Get or create the tag
+	tagID, err := database.GetOrCreateTag(userID, tagName)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Add tag to ingredient
+	if err := database.AddIngredientTag(userID, ingredientID, int(tagID)); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Return updated tag list with trigger to refresh page
+	w.Header().Set("HX-Trigger", "refreshIngredients")
+	renderCurrentTags(w, userID, ingredientID)
+}
+
+// RemoveIngredientTagHandler removes a tag from an ingredient
+func RemoveIngredientTagHandler(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r)
+
+	// Extract ingredient ID and tag ID from path /ingredients/{ingredient_id}/tags/{tag_id}
+	pathParts := strings.Split(strings.TrimPrefix(r.URL.Path, "/ingredients/"), "/")
+	if len(pathParts) < 3 {
+		http.Error(w, "Invalid path", http.StatusBadRequest)
+		return
+	}
+
+	ingredientID, err := strconv.Atoi(pathParts[0])
+	if err != nil {
+		http.Error(w, "Invalid ingredient ID", http.StatusBadRequest)
+		return
+	}
+
+	tagID, err := strconv.Atoi(pathParts[2])
+	if err != nil {
+		http.Error(w, "Invalid tag ID", http.StatusBadRequest)
+		return
+	}
+
+	// Remove tag from ingredient
+	if err := database.RemoveIngredientTag(userID, ingredientID, tagID); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// Return updated tag list with trigger to refresh page
+	w.Header().Set("HX-Trigger", "refreshIngredients")
+	renderCurrentTags(w, userID, ingredientID)
+}
+
+// Helper function to render current tags
+func renderCurrentTags(w http.ResponseWriter, userID, ingredientID int) {
+	currentTags, err := database.GetIngredientTags(userID, ingredientID)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	tmpl := `
+		{{range .Tags}}
+		<span class="tag">
+			{{.Name}}
+			<button
+				hx-delete="/ingredients/{{$.IngredientID}}/tags/{{.ID}}"
+				hx-target="#current-tags-{{$.IngredientID}}"
+				hx-swap="innerHTML"
+				class="tag-remove">
+				×
+			</button>
+		</span>
+		{{end}}
+	`
+
+	type TagWithID struct {
+		ID   int
+		Name string
+	}
+
+	data := struct {
+		Tags         []TagWithID
+		IngredientID int
+	}{
+		Tags:         []TagWithID{},
+		IngredientID: ingredientID,
+	}
+
+	for _, tag := range currentTags {
+		data.Tags = append(data.Tags, TagWithID{ID: tag.ID, Name: tag.Name})
+	}
+
+	t := template.Must(template.New("current-tags").Parse(tmpl))
+	t.Execute(w, data)
+}

main.go

@@ -63,10 +63,25 @@ func main() {
 		}
 	}))
 	http.HandleFunc("/ingredients/", auth.RequireAuth(func(w http.ResponseWriter, r *http.Request) {
-		if r.Method == "DELETE" {
+		path := r.URL.Path
-			handlers.DeleteIngredientHandler(w, r)
+		if strings.Contains(path, "/tags") {
+			// Ingredient tag routes
+			if r.Method == "GET" {
+				handlers.GetIngredientTagsHandler(w, r)
+			} else if r.Method == "POST" {
+				handlers.AddIngredientTagHandler(w, r)
+			} else if r.Method == "DELETE" {
+				handlers.RemoveIngredientTagHandler(w, r)
+			} else {
+				http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+			}
 		} else {
-			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+			// Ingredient delete route
+			if r.Method == "DELETE" {
+				handlers.DeleteIngredientHandler(w, r)
+			} else {
+				http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+			}
 		}
 	}))
 

models/models.go

@@ -24,6 +24,20 @@ type Ingredient struct {
 	UserID int    `json:"user_id"`
 	Name   string `json:"name"`
 	Unit   string `json:"unit"` // e.g., "grams", "ml", "cups", "pieces", "tbsp"
+	Tags   []Tag  `json:"tags,omitempty"`
+}
+
+// Tag represents a tag for categorizing ingredients
+type Tag struct {
+	ID     int    `json:"id"`
+	UserID int    `json:"user_id"`
+	Name   string `json:"name"`
+}
+
+// IngredientTag represents the many-to-many relationship between ingredients and tags
+type IngredientTag struct {
+	IngredientID int `json:"ingredient_id"`
+	TagID        int `json:"tag_id"`
 }
 
 // Meal represents a meal recipe

static/styles.css

@@ -460,6 +460,201 @@ button:hover {
     font-style: italic;
 }
 
+/* Tags */
+.tag {
+    display: inline-block;
+    padding: 4px 10px;
+    background-color: #3498db;
+    color: white;
+    border-radius: 12px;
+    font-size: 12px;
+    font-weight: 500;
+    margin-right: 5px;
+    margin-bottom: 5px;
+}
+
+.item-tags {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 5px;
+    margin-top: 8px;
+}
+
+.item-content {
+    flex: 1;
+}
+
+.item-actions {
+    display: flex;
+    gap: 8px;
+    flex-shrink: 0;
+}
+
+.edit-tags-btn {
+    background-color: #9b59b6;
+    padding: 8px 15px;
+    font-size: 13px;
+}
+
+.edit-tags-btn:hover {
+    background-color: #8e44ad;
+}
+
+/* Tag Filter Section */
+.search-section {
+    margin-bottom: 25px;
+    padding: 20px;
+    background-color: #f8f9fa;
+    border-radius: 8px;
+    border: 1px solid #e0e0e0;
+}
+
+.search-section h3 {
+    margin-bottom: 15px;
+    color: #2c3e50;
+    font-size: 1.1em;
+}
+
+.tag-filter {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 15px;
+}
+
+.tag-filter-btn {
+    padding: 8px 16px;
+    background-color: #ecf0f1;
+    color: #2c3e50;
+    border: 2px solid #bdc3c7;
+    border-radius: 20px;
+    font-size: 13px;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.3s ease;
+}
+
+.tag-filter-btn:hover {
+    background-color: #bdc3c7;
+    border-color: #95a5a6;
+}
+
+.tag-filter-btn.active {
+    background-color: #3498db;
+    color: white;
+    border-color: #3498db;
+}
+
+.active-filters {
+    color: #7f8c8d;
+    font-size: 14px;
+    font-style: italic;
+    min-height: 20px;
+    margin-bottom: 10px;
+}
+
+.clear-filters-btn {
+    padding: 8px 16px;
+    background-color: #e74c3c;
+    color: white;
+    font-size: 13px;
+}
+
+.clear-filters-btn:hover {
+    background-color: #c0392b;
+}
+
+/* Tag Edit Modal */
+.modal {
+    display: none;
+    position: fixed;
+    z-index: 1000;
+    left: 0;
+    top: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.5);
+}
+
+.modal .modal-content {
+    background-color: white;
+    margin: 10% auto;
+    padding: 30px;
+    border-radius: 10px;
+    width: 90%;
+    max-width: 500px;
+    position: relative;
+    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
+}
+
+.close {
+    color: #aaa;
+    float: right;
+    font-size: 28px;
+    font-weight: bold;
+    cursor: pointer;
+    line-height: 20px;
+}
+
+.close:hover,
+.close:focus {
+    color: #000;
+}
+
+.tag-edit-section {
+    margin-top: 20px;
+}
+
+.tag-edit-section h4 {
+    margin-top: 20px;
+    margin-bottom: 10px;
+    color: #2c3e50;
+}
+
+#current-tags-{{.IngredientID}},
+[id^="current-tags-"] {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 20px;
+    min-height: 40px;
+    padding: 10px;
+    background-color: #f8f9fa;
+    border-radius: 6px;
+}
+
+.tag-remove {
+    background-color: transparent;
+    color: white;
+    padding: 0 5px;
+    margin-left: 5px;
+    font-size: 16px;
+    font-weight: bold;
+    border: none;
+    cursor: pointer;
+    border-radius: 50%;
+}
+
+.tag-remove:hover {
+    background-color: rgba(0, 0, 0, 0.2);
+}
+
+.add-tag-form {
+    display: flex;
+    gap: 10px;
+    padding: 15px;
+    background-color: #f8f9fa;
+    border-radius: 6px;
+}
+
+.add-tag-form input {
+    flex: 1;
+}
+
+.add-tag-form button {
+    flex-shrink: 0;
+}
+
 /* Authentication Pages */
 .auth-container {
     min-height: 100vh;