add icon for documents without thumbnails

backend/internal/handler/files.go

@@ -118,6 +118,10 @@ func (h *FileHandler) Get(c *gin.Context) {
 		"name":      file.Name,
 		"url":       h.urls.GenerateDownloadURL(file.ID),
 		"size":      file.Size,
+		"mimeType":  file.MimeType,
+		"createdAt": file.CreatedAt,
+		"updatedAt": file.UpdatedAt,
+		"ocrText":   file.OcrText,
 	})
 }
 

mobile/app/file-detail.tsx

@@ -12,6 +12,7 @@ import {
 import { RouteProp, useRoute } from '@react-navigation/native';
 import { useFile, useFileImage } from '../hooks/useFiles';
 import { TagChip } from '../components/TagChip';
+import { FileThumbnail } from '../components/FileThumbnail';
 
 const SCREEN_WIDTH = Dimensions.get('window').width;
 
@@ -30,14 +31,17 @@ function DetailItem({ fileId }: { fileId: string }) {
   return (
     <ScrollView style={styles.page} contentContainerStyle={styles.pageContent}>
       <View style={styles.imageContainer}>
-        {imageLoading ? (
-          <ActivityIndicator size="large" color="#1976D2" />
-        ) : uri ? (
+        {uri ? (
           <Image source={{ uri }} style={styles.image} resizeMode="contain" />
+        ) : file ? (
+          <FileThumbnail
+            mimeType={file.mimeType ?? 'application/pdf'}
+            fileName={file.name ?? fileId}
+            size={SCREEN_WIDTH * 0.6}
+            isLoading={imageLoading}
+          />
         ) : (
-          <View style={styles.placeholder}>
-            <Text style={styles.placeholderText}>PDF</Text>
-          </View>
+          <ActivityIndicator size="large" color="#1976D2" />
         )}
       </View>
 

mobile/app/index.tsx

@@ -1,5 +1,5 @@
 import React, { useState, useMemo, useEffect } from 'react';
-import { View, FlatList, StyleSheet, TouchableOpacity, Text, Dimensions, Image, ActivityIndicator, KeyboardAvoidingView, Platform, Keyboard } from 'react-native';
+import { View, FlatList, StyleSheet, TouchableOpacity, Text, Dimensions, KeyboardAvoidingView, Platform, Keyboard } from 'react-native';
 import { useNavigation } from '@react-navigation/native';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 import { NativeStackNavigationProp } from '@react-navigation/native-stack';
@@ -7,6 +7,7 @@ import { MaterialIcons } from '@expo/vector-icons';
 import { useFiles, useFileImage } from '../hooks/useFiles';
 import { FileItem } from '../types';
 import { SearchBar, SearchFilters } from '../components/SearchBar';
+import { FileThumbnail } from '../components/FileThumbnail';
 
 const NUM_COLUMNS = 3;
 const SCREEN_WIDTH = Dimensions.get('window').width;
@@ -57,21 +58,15 @@ function formatDateLabel(key: string): string {
 function FileGridItem({ file, onPress }: { file: FileItem; onPress?: () => void }) {
   const { data, isLoading } = useFileImage(file.id);
 
-  const uri = data?.data?.url;
-
   return (
     <TouchableOpacity style={styles.gridItem} onPress={onPress} activeOpacity={0.7}>
-      {isLoading ? (
-        <View style={styles.placeholder}>
-          <ActivityIndicator size="small" color="#1976D2" />
-        </View>
-      ) : uri ? (
-        <Image source={{ uri }} style={styles.thumb} />
-      ) : (
-        <View style={styles.placeholder}>
-          <Text style={styles.placeholderText}>PDF</Text>
-        </View>
-      )}
+      <FileThumbnail
+        uri={data?.data?.url}
+        mimeType={file.mimeType}
+        fileName={file.name}
+        size={ITEM_SIZE}
+        isLoading={isLoading}
+      />
       <Text style={styles.fileName} numberOfLines={1}>{file.name}</Text>
     </TouchableOpacity>
   );
@@ -264,25 +259,6 @@ const styles = StyleSheet.create({
   gridItem: {
     width: ITEM_SIZE,
   },
-  thumb: {
-    width: ITEM_SIZE,
-    height: ITEM_SIZE,
-    borderRadius: 6,
-    backgroundColor: '#e0e0e0',
-  },
-  placeholder: {
-    width: ITEM_SIZE,
-    height: ITEM_SIZE,
-    borderRadius: 6,
-    backgroundColor: '#e3f2fd',
-    justifyContent: 'center',
-    alignItems: 'center',
-  },
-  placeholderText: {
-    fontSize: 12,
-    color: '#1976D2',
-    fontWeight: '600',
-  },
   fileName: {
     fontSize: 11,
     color: '#666',

mobile/components/FileThumbnail.tsx

@@ -0,0 +1,79 @@
+import React from 'react';
+import { View, Text, Image, ActivityIndicator, StyleSheet } from 'react-native';
+import { MaterialIcons } from '@expo/vector-icons';
+import type { ComponentProps } from 'react';
+
+type IconName = ComponentProps<typeof MaterialIcons>['name'];
+
+interface FileTypeInfo {
+  icon: IconName;
+  color: string;
+  bg: string;
+}
+
+function getFileInfo(mimeType: string, fileName: string): FileTypeInfo {
+  if (mimeType.startsWith('image/')) return { icon: 'image', color: '#4CAF50', bg: '#E8F5E9' };
+  if (mimeType === 'application/pdf') return { icon: 'picture-as-pdf', color: '#E53935', bg: '#FFEBEE' };
+  if (mimeType.includes('word') || mimeType.includes('document')) return { icon: 'description', color: '#1565C0', bg: '#E3F2FD' };
+  if (mimeType.includes('spreadsheet') || mimeType.includes('excel') || mimeType.includes('csv')) return { icon: 'table-chart', color: '#2E7D32', bg: '#E8F5E9' };
+  if (mimeType.includes('presentation') || mimeType.includes('powerpoint')) return { icon: 'slideshow', color: '#E65100', bg: '#FFF3E0' };
+  if (mimeType.startsWith('text/')) return { icon: 'article', color: '#546E7A', bg: '#ECEFF1' };
+  if (mimeType.startsWith('video/')) return { icon: 'movie', color: '#6A1B9A', bg: '#F3E5F5' };
+  if (mimeType.startsWith('audio/')) return { icon: 'audiotrack', color: '#AD1457', bg: '#FCE4EC' };
+  return { icon: 'insert-drive-file', color: '#757575', bg: '#F5F5F5' };
+}
+
+function getExtension(fileName: string): string {
+  const ext = fileName.split('.').pop();
+  return ext ? ext.toUpperCase() : '';
+}
+
+interface FileThumbnailProps {
+  uri?: string;
+  mimeType: string;
+  fileName: string;
+  size: number;
+  isLoading?: boolean;
+}
+
+export function FileThumbnail({ uri, mimeType, fileName, size, isLoading }: FileThumbnailProps) {
+  const info = getFileInfo(mimeType, fileName);
+  const ext = getExtension(fileName);
+
+  if (isLoading) {
+    return (
+      <View style={[styles.container, { width: size, height: size, backgroundColor: info.bg }]}>
+        <ActivityIndicator size="small" color={info.color} />
+      </View>
+    );
+  }
+
+  if (uri && mimeType.startsWith('image/')) {
+    return <Image source={{ uri }} style={[styles.image, { width: size, height: size }]} />;
+  }
+
+  return (
+    <View style={[styles.container, { width: size, height: size, backgroundColor: info.bg }]}>
+      <MaterialIcons name={info.icon} size={size * 0.35} color={info.color} />
+      {ext.length <= 4 && (
+        <Text style={[styles.ext, { color: info.color }]}>{ext}</Text>
+      )}
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    borderRadius: 6,
+    justifyContent: 'center',
+    alignItems: 'center',
+    gap: 2,
+  },
+  image: {
+    borderRadius: 6,
+  },
+  ext: {
+    fontSize: 11,
+    fontWeight: '700',
+  },
+});