endpoints to add tags

backend/internal/handler/files.go

@@ -137,9 +137,36 @@ func (h *FileHandler) Delete(c *gin.Context) {
 }
 
 func (h *FileHandler) AddTags(c *gin.Context) {
-	api.Error(c, http.StatusNotImplemented, "NOT_IMPLEMENTED", "Tags not yet implemented")
+	id := c.Param("id")
+
+	var body struct {
+		Tags []string `json:"tags" binding:"required"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil {
+		api.Error(c, http.StatusBadRequest, "INVALID_BODY", "Body must contain a 'tags' array")
+		return
+	}
+
+	if err := h.files.AddTags(id, body.Tags); err != nil {
+		api.Error(c, http.StatusInternalServerError, "DB_ERROR", "Failed to add tags")
+		return
+	}
+
+	tags, err := h.files.GetTagsByFileID(id)
+	if err != nil {
+		api.Error(c, http.StatusInternalServerError, "DB_ERROR", "Failed to fetch tags")
+		return
+	}
+
+	api.Success(c, tags)
 }
 
 func (h *FileHandler) GetTags(c *gin.Context) {
-	api.Success(c, []interface{}{})
+	id := c.Param("id")
+	tags, err := h.files.GetTagsByFileID(id)
+	if err != nil {
+		api.Error(c, http.StatusInternalServerError, "DB_ERROR", "Failed to fetch tags")
+		return
+	}
+	api.Success(c, tags)
 }

backend/internal/model/file.go

@@ -1,5 +1,11 @@
 package model
 
+type Tag struct {
+	ID       string `json:"id"`
+	Name     string `json:"name"`
+	TagType  string `json:"tagType"`
+}
+
 type File struct {
 	ID         string `json:"id"`
 	Name       string `json:"name"`
@@ -8,6 +14,7 @@ type File struct {
 	StorageKey string `json:"-"`
 	Checksum   string `json:"-"`
 	OcrText    string `json:"ocrText,omitempty"`
+	Tags       []Tag  `json:"tags"`
 	CreatedAt  string `json:"createdAt"`
 	UpdatedAt  string `json:"updatedAt"`
 }

backend/internal/model/tag.go

@@ -1,6 +1 @@
 package model
-
-type Tag struct {
-	ID   string `json:"id"`
-	Name string `json:"name"`
-}

backend/internal/service/file.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"database/sql"
 	"encoding/hex"
 	"fmt"
 	"mime/multipart"
@@ -74,7 +75,11 @@ func (s *FileService) List() ([]model.File, error) {
 
 	files := make([]model.File, len(dbFiles))
 	for i, f := range dbFiles {
-		files[i] = dbToModel(f)
+		tags, err := s.queries.GetTagsByFileID(context.Background(), sql.NullString{String: f.ID, Valid: true})
+		if err != nil {
+			return nil, fmt.Errorf("get tags for file %s: %w", f.ID, err)
+		}
+		files[i] = dbToModel(f, tags)
 	}
 	return files, nil
 }
@@ -84,7 +89,11 @@ func (s *FileService) Get(id string) (*model.File, error) {
 	if err != nil {
 		return nil, fmt.Errorf("get file: %w", err)
 	}
-	m := dbToModel(f)
+	tags, err := s.queries.GetTagsByFileID(context.Background(), sql.NullString{String: f.ID, Valid: true})
+	if err != nil {
+		return nil, fmt.Errorf("get tags: %w", err)
+	}
+	m := dbToModel(f, tags)
 	return &m, nil
 }
 
@@ -113,7 +122,51 @@ func (s *FileService) UpdateOCRText(id, text string) error {
 	})
 }
 
-func dbToModel(f db.File) model.File {
+func (s *FileService) AddTags(fileID string, tagNames []string) error {
+	for _, name := range tagNames {
+		tag, err := s.queries.GetTagByName(context.Background(), name)
+		if err == sql.ErrNoRows {
+			tag, err = s.queries.CreateTag(context.Background(), db.CreateTagParams{
+				ID:      uuid.New().String(),
+				TagName: name,
+				TagType: "none",
+			})
+			if err != nil {
+				return fmt.Errorf("create tag %q: %w", name, err)
+			}
+		} else if err != nil {
+			return fmt.Errorf("get tag %q: %w", name, err)
+		}
+
+		err = s.queries.AddTagToFile(context.Background(), db.AddTagToFileParams{
+			ID:     uuid.New().String(),
+			TagID:  sql.NullString{String: tag.ID, Valid: true},
+			FileID: sql.NullString{String: fileID, Valid: true},
+		})
+		if err != nil {
+			return fmt.Errorf("link tag %q to file: %w", name, err)
+		}
+	}
+	return nil
+}
+
+func (s *FileService) GetTagsByFileID(fileID string) ([]model.Tag, error) {
+	dbTags, err := s.queries.GetTagsByFileID(context.Background(), sql.NullString{String: fileID, Valid: true})
+	if err != nil {
+		return nil, fmt.Errorf("get tags: %w", err)
+	}
+	tags := make([]model.Tag, len(dbTags))
+	for i, t := range dbTags {
+		tags[i] = model.Tag{ID: t.ID, Name: t.TagName, TagType: t.TagType}
+	}
+	return tags, nil
+}
+
+func dbToModel(f db.File, dbTags []db.Tag) model.File {
+	tags := make([]model.Tag, len(dbTags))
+	for i, t := range dbTags {
+		tags[i] = model.Tag{ID: t.ID, Name: t.TagName, TagType: t.TagType}
+	}
 	return model.File{
 		ID:         f.ID,
 		Name:       f.Name,
@@ -122,6 +175,7 @@ func dbToModel(f db.File) model.File {
 		StorageKey: f.StorageKey,
 		Checksum:   f.Checksum,
 		OcrText:    f.OcrText,
+		Tags:       tags,
 		CreatedAt:  f.CreatedAt.String(),
 		UpdatedAt:  f.UpdatedAt.String(),
 	}

mobile/app/index.tsx

@@ -46,6 +46,25 @@ function groupByDate(files: FileItem[]): GroupedFiles {
   return groups;
 }
 
+function groupByTag(files: FileItem[]): GroupedFiles {
+  const groups: GroupedFiles = {};
+  for (const file of files) {
+    const tags = file.tags ?? [];
+    if (tags.length === 0) {
+      if (!groups['Sans tag']) groups['Sans tag'] = [];
+      groups['Sans tag'].push(file);
+    } else {
+      for (const tag of tags) {
+        const name = typeof tag === 'string' ? tag : tag.name;
+        if (!name) continue;
+        if (!groups[name]) groups[name] = [];
+        groups[name].push(file);
+      }
+    }
+  }
+  return groups;
+}
+
 function formatDateLabel(key: string): string {
   const d = new Date();
   const today = d.toLocaleDateString('fr-FR', { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' });
@@ -115,6 +134,7 @@ export function HomeScreen() {
   const [filters, setFilters] = useState<SearchFilters>({ name: true, ocrText: true, tags: true });
   const [keyboardOpen, setKeyboardOpen] = useState(false);
   const [selectedIds, setSelectedIds] = useState<Set<string>>(new Set());
+  const [groupByTags, setGroupByTags] = useState(false);
 
   useEffect(() => {
     const show = Keyboard.addListener('keyboardDidShow', () => setKeyboardOpen(true));
@@ -131,7 +151,7 @@ export function HomeScreen() {
     [files, searchQuery, filters]
   );
 
-  const groups = groupByDate(filteredFiles);
+  const groups = groupByTags ? groupByTag(filteredFiles) : groupByDate(filteredFiles);
   const groupKeys = Object.keys(groups);
 
   const fileIdToIndex = useMemo(() => {
@@ -236,11 +256,16 @@ export function HomeScreen() {
             </Text>
           </View>
         }
-        renderItem={({ item: dateKey }) => {
+        renderItem={({ item: groupKey }) => {
-          const groupFiles = groups[dateKey];
+          const groupFiles = groups[groupKey];
+          const label = groupByTags ? groupKey : formatDateLabel(groupKey);
           return (
             <View style={styles.section}>
-              <Text style={styles.sectionTitle}>{formatDateLabel(dateKey)}</Text>
+              <View style={styles.sectionHeader}>
+                {groupByTags && <MaterialIcons name="label" size={16} color="#1976D2" style={styles.sectionIcon} />}
+                <Text style={styles.sectionTitle}>{label}</Text>
+                <Text style={styles.sectionCount}>{groupFiles.length}</Text>
+              </View>
               <View style={styles.grid}>
                 {groupFiles.map((file) => (
                   <FileGridItem
@@ -264,6 +289,8 @@ export function HomeScreen() {
           onClear={() => setSearchQuery('')}
           filters={filters}
           onFiltersChange={setFilters}
+          groupByTags={groupByTags}
+          onGroupToggle={() => setGroupByTags(!groupByTags)}
           bottomPadding={keyboardOpen ? insets.bottom+8 : 0}
         />
       )}
@@ -358,9 +385,22 @@ const styles = StyleSheet.create({
   sectionTitle: {
     fontSize: 18,
     fontWeight: '700',
-    marginBottom: 12,
     color: '#333',
   },
+  sectionHeader: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    marginBottom: 12,
+    gap: 6,
+  },
+  sectionIcon: {
+    marginTop: 2,
+  },
+  sectionCount: {
+    fontSize: 14,
+    color: '#999',
+    fontWeight: '400',
+  },
   grid: {
     flexDirection: 'row',
     flexWrap: 'wrap',

mobile/components/SearchBar.tsx

@@ -17,6 +17,8 @@ interface SearchBarProps {
   onClear: () => void;
   filters: SearchFilters;
   onFiltersChange: (f: SearchFilters) => void;
+  groupByTags: boolean;
+  onGroupToggle: () => void;
   bottomPadding?: number;
 }
 
@@ -26,7 +28,7 @@ const FILTER_OPTIONS: { key: keyof SearchFilters; label: string; icon: IconName
   { key: 'tags', label: 'Tags', icon: 'label-outline' },
 ];
 
-export function SearchBar({ query, onQueryChange, onClear, filters, onFiltersChange, bottomPadding = 0 }: SearchBarProps) {
+export function SearchBar({ query, onQueryChange, onClear, filters, onFiltersChange, groupByTags, onGroupToggle, bottomPadding = 0 }: SearchBarProps) {
   const animatedHeight = useRef(new Animated.Value(0)).current;
   const [panelOpen, setPanelOpen] = React.useState(false);
 
@@ -81,6 +83,17 @@ export function SearchBar({ query, onQueryChange, onClear, filters, onFiltersCha
             color={hasActiveFilter ? '#fff' : '#1976D2'}
           />
         </TouchableOpacity>
+
+        <TouchableOpacity
+          style={[styles.groupBtn, groupByTags && styles.groupBtnActive]}
+          onPress={onGroupToggle}
+        >
+          <MaterialIcons
+            name="folder-special"
+            size={22}
+            color={groupByTags ? '#fff' : '#1976D2'}
+          />
+        </TouchableOpacity>
       </View>
 
       <Animated.View style={[styles.filterPanel, { maxHeight: panelMaxHeight, opacity: animatedHeight }]}>
@@ -151,6 +164,19 @@ const styles = StyleSheet.create({
   filterBtnActive: {
     backgroundColor: '#1976D2',
   },
+  groupBtn: {
+    width: 40,
+    height: 40,
+    borderRadius: 10,
+    borderWidth: 1,
+    borderColor: '#1976D2',
+    justifyContent: 'center',
+    alignItems: 'center',
+    backgroundColor: '#fff',
+  },
+  groupBtnActive: {
+    backgroundColor: '#1976D2',
+  },
   filterPanel: {
     flexDirection: 'row',
     paddingHorizontal: 12,