refactor(Post, PostMapper, PostRepository, CreatePostScreen, HomeScreen): update communityId to channelId for improved clarity

- Renamed communityId to channelId across Post entity, PostMapper, and PostRepository for consistency and clarity.
- Updated CreatePostScreen to include channel selection functionality, enhancing user experience when creating posts.
- Adjusted HomeScreen to support filtering posts by channel, improving content organization.
- Refactored related interfaces and services to align with the new channelId terminology, ensuring a cohesive codebase.

src/screens/create/CreatePostScreen.tsx

@@ -19,14 +19,15 @@ import {
   Platform,
   Animated,
   Image,
+  useWindowDimensions,
 } from 'react-native';
 import { SafeAreaView } from 'react-native-safe-area-context';
 import { useRouter, useLocalSearchParams, useNavigation } from 'expo-router';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
 import * as ImagePicker from 'expo-image-picker';
 import { colors, spacing, fontSizes, borderRadius, shadows } from '../../theme';
-import { Text, Button, ResponsiveContainer, AppBackButton } from '../../components/common';
-import { postService, showPrompt, voteService } from '../../services';
+import { Text, ResponsiveContainer } from '../../components/common';
+import { channelService, postService, showPrompt, voteService } from '../../services';
 import { ApiError } from '../../services/api';
 import { uploadService } from '../../services/uploadService';
 import VoteEditor from '../../components/business/VoteEditor';
@@ -40,6 +41,10 @@ interface CreatePostScreenProps {
 
 const MAX_TITLE_LENGTH = 100;
 const MAX_CONTENT_LENGTH = 2000;
+type ChannelOption = {
+  id: string;
+  name: string;
+};
 
 // 表情面板高度
 const EMOJI_PANEL_HEIGHT = 280;
@@ -88,13 +93,14 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
   
   // 响应式布局
   const { isWideScreen, width } = useResponsive();
+  const { height: windowHeight } = useWindowDimensions();
   
   const [title, setTitle] = useState('');
   const [content, setContent] = useState('');
   const [images, setImages] = useState<{ uri: string; uploading?: boolean }[]>([]);
-  const [tags, setTags] = useState<string[]>([]);
-  const [tagInput, setTagInput] = useState('');
-  const [showTagInput, setShowTagInput] = useState(false);
+  const [channelOptions, setChannelOptions] = useState<ChannelOption[]>([]);
+  const [selectedChannelId, setSelectedChannelId] = useState<string | null>(null);
+  const [showChannelPicker, setShowChannelPicker] = useState(false);
   const [showEmojiPanel, setShowEmojiPanel] = useState(false);
   const [posting, setPosting] = useState(false);
   const [loadingPost, setLoadingPost] = useState(false);
@@ -118,6 +124,11 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
     ? Math.min(width, 800) - spacing.lg * 2 
     : width - spacing.lg * 2;
   const imageSize = (availableWidth - imageGap * (imagesPerRow - 1)) / imagesPerRow;
+  const contentInputMinHeight = Math.max(
+    isWideScreen ? 460 : 320,
+    Math.floor(windowHeight * (isWideScreen ? 0.56 : 0.5))
+  );
+  const contentSectionMinHeight = Math.floor(windowHeight * (isWideScreen ? 0.68 : 0.62));
 
   React.useEffect(() => {
     Animated.parallel([
@@ -134,16 +145,19 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
     ]).start();
   }, []);
 
+  React.useEffect(() => {
+    const loadChannels = async () => {
+      const list = await channelService.list();
+      setChannelOptions(list.map(item => ({ id: item.id, name: item.name })));
+    };
+    loadChannels();
+  }, []);
+
   React.useLayoutEffect(() => {
     navigation.setOptions({
-      headerShown: true,
-      title: isEditMode ? '编辑帖子' : '发布帖子',
-      // 当作为 Modal 使用时，显示关闭按钮
-      headerLeft: onClose ? () => (
-        <AppBackButton onPress={onClose} icon="close" />
-      ) : undefined,
+      headerShown: false,
     });
-  }, [navigation, isEditMode, onClose]);
+  }, [navigation]);
 
   React.useEffect(() => {
     if (!isEditMode || !editPostID) {
@@ -264,20 +278,11 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
     setImages(images.filter((_, i) => i !== index));
   };
 
-  // 添加标签
-  const handleAddTag = useCallback(() => {
-    const tag = tagInput.trim().replace(/^#/, '');
-    if (tag && !tags.includes(tag) && tags.length < 5) {
-      setTags([...tags, tag]);
-      setTagInput('');
-      setShowTagInput(false);
-    }
-  }, [tagInput, tags]);
-
-  // 删除标签
-  const handleRemoveTag = (tag: string) => {
-    setTags(tags.filter(t => t !== tag));
-  };
+   // 选择频道（单选，可再次点击取消）
+  const handleSelectChannel = useCallback((channelId: string) => {
+    setSelectedChannelId(prev => (prev === channelId ? null : channelId));
+    setShowChannelPicker(false);
+  }, []);
 
   // 插入表情
   const handleInsertEmoji = (emoji: string) => {
@@ -290,7 +295,7 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
   // 关闭所有面板
   const closeAllPanels = () => {
     setShowEmojiPanel(false);
-    setShowTagInput(false);
+    setShowChannelPicker(false);
   };
 
   // 切换表情面板
@@ -299,10 +304,10 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
     setShowEmojiPanel(!showEmojiPanel);
   };
 
-  // 切换标签输入
-  const handleToggleTagInput = () => {
+  // 切换频道选择
+  const handleToggleChannelPicker = () => {
     closeAllPanels();
-    setShowTagInput(!showTagInput);
+    setShowChannelPicker(!showChannelPicker);
   };
 
   // 切换投票模式
@@ -373,6 +378,7 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
           title: title.trim(),
           content: content.trim(),
           images: imageUrls,
+          channel_id: selectedChannelId || undefined,
           vote_options: validOptions,
         });
         showPrompt({
@@ -405,6 +411,7 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
             title: title.trim(),
             content: content.trim(),
             images: imageUrls,
+            channel_id: selectedChannelId || undefined,
           });
           showPrompt({
             type: 'info',
@@ -474,66 +481,80 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
     );
   };
 
-  // 渲染标签
-  const renderTags = () => {
-    if (tags.length === 0 && !showTagInput) return null;
+  // 渲染频道（单选）
+  const renderChannelPicker = () => {
+    if (!showChannelPicker) return null;
 
     return (
       <View style={styles.tagsSection}>
         <View style={styles.tagsContainer}>
-          {tags.map((tag, index) => (
-            <View key={index} style={styles.tag}>
-              <MaterialCommunityIcons name="pound" size={12} color={colors.primary.main} />
-              <Text variant="caption" color={colors.primary.main} style={styles.tagText}>{tag}</Text>
-              {/* 独立的删除按钮 */}
+          {channelOptions.map((channel) => {
+            const isSelected = selectedChannelId === channel.id;
+            return (
               <TouchableOpacity
-                style={styles.tagDeleteButton}
-                onPress={() => handleRemoveTag(tag)}
-                hitSlop={{ top: 5, right: 5, bottom: 5, left: 5 }}
+                key={channel.id}
+                style={[styles.tag, isSelected && styles.channelSelected]}
+                onPress={() => handleSelectChannel(channel.id)}
               >
-                <MaterialCommunityIcons name="close-circle" size={14} color={colors.primary.main} />
+                <Text
+                  variant="caption"
+                  color={isSelected ? colors.primary.contrast : colors.text.secondary}
+                  style={styles.tagText}
+                >
+                  {channel.name}
+                </Text>
               </TouchableOpacity>
-            </View>
-          ))}
-          {tags.length < 5 && showTagInput && (
-            <View style={styles.tagInputWrapper}>
-              <MaterialCommunityIcons name="pound" size={14} color={colors.primary.main} />
-              <TextInput
-                style={styles.tagInput}
-                value={tagInput}
-                onChangeText={setTagInput}
-                placeholder="输入话题"
-                placeholderTextColor={colors.text.hint}
-                onSubmitEditing={handleAddTag}
-                returnKeyType="done"
-                autoFocus
-                maxLength={20}
-              />
-              <TouchableOpacity onPress={() => { setTagInput(''); setShowTagInput(false); }} style={styles.tagCancelButton}>
-                <MaterialCommunityIcons name="close" size={16} color={colors.text.secondary} />
-              </TouchableOpacity>
-              <TouchableOpacity onPress={handleAddTag} style={styles.tagConfirmButton}>
-                <MaterialCommunityIcons name="check" size={16} color={colors.primary.main} />
-              </TouchableOpacity>
-            </View>
-          )}
-          {tags.length < 5 && !showTagInput && (
-            <TouchableOpacity style={styles.addTagButton} onPress={() => setShowTagInput(true)}>
-              <MaterialCommunityIcons name="plus" size={14} color={colors.text.secondary} />
-              <Text variant="caption" color={colors.text.secondary} style={styles.addTagText}>话题</Text>
-            </TouchableOpacity>
-          )}
+            );
+          })}
         </View>
+        {channelOptions.length === 0 && (
+          <Text variant="caption" color={colors.text.hint}>暂无可用频道</Text>
+        )}
       </View>
     );
   };
 
+  const selectedChannelName = React.useMemo(() => {
+    if (!selectedChannelId) return '';
+    return channelOptions.find(c => c.id === selectedChannelId)?.name || '';
+  }, [selectedChannelId, channelOptions]);
+
+  const renderChannelEntryRow = () => (
+    <TouchableOpacity
+      style={styles.channelEntryRow}
+      onPress={handleToggleChannelPicker}
+      activeOpacity={0.8}
+    >
+      <Text variant="body" color={colors.text.secondary} style={styles.channelEntryLabel}>
+        发表至：
+      </Text>
+      <View style={styles.channelEntryValueWrap}>
+        <Text
+          variant="body"
+          color={selectedChannelName ? colors.text.primary : colors.text.hint}
+          style={styles.channelEntryValue}
+        >
+          {selectedChannelName || '选择频道'}
+        </Text>
+        <MaterialCommunityIcons name="chevron-right" size={18} color={colors.text.hint} />
+      </View>
+    </TouchableOpacity>
+  );
+
   // 渲染投票编辑器
   const renderVoteEditor = () => {
     if (!isVotePost) return null;
 
     return (
       <View style={isWideScreen && styles.voteEditorWide}>
+        <View style={styles.voteEditorHeaderRow}>
+          <Text variant="caption" color={colors.text.secondary}>
+            已插入投票
+          </Text>
+          <TouchableOpacity onPress={() => setIsVotePost(false)} activeOpacity={0.7}>
+            <Text variant="caption" color={colors.primary.main}>移除投票</Text>
+          </TouchableOpacity>
+        </View>
         <VoteEditor
           options={voteOptions}
           onAddOption={handleAddVoteOption}
@@ -549,7 +570,12 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
 
   // 渲染内容输入区
   const renderContentSection = () => (
-    <View style={styles.contentSection}>
+    <View
+      style={[
+        styles.contentSection,
+        contentSectionMinHeight ? { minHeight: contentSectionMinHeight } : null,
+      ]}
+    >
       {/* 标题输入 */}
       <TextInput
         style={[
@@ -569,6 +595,7 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
         style={[
           styles.contentInput,
           isWideScreen && styles.contentInputWide,
+          { minHeight: contentInputMinHeight },
         ]}
         value={content}
         onChangeText={setContent}
@@ -579,6 +606,10 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
         maxLength={MAX_CONTENT_LENGTH}
         onSelectionChange={(e) => setSelection(e.nativeEvent.selection)}
       />
+
+      {/* 作为正文容器的子模块，追加在文本后面 */}
+      {renderImageGrid()}
+      {renderVoteEditor()}
     </View>
   );
 
@@ -642,25 +673,6 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
           </View>
         </TouchableOpacity>
 
-        <TouchableOpacity
-          style={styles.toolbarButton}
-          onPress={handleToggleTagInput}
-          disabled={tags.length >= 5 || posting}
-        >
-          <View style={styles.toolbarButtonInner}>
-            <MaterialCommunityIcons
-              name="pound"
-              size={24}
-              color={tags.length >= 5 ? colors.text.disabled : (showTagInput ? colors.primary.main : colors.text.secondary)}
-            />
-            {tags.length > 0 && (
-              <View style={styles.tagBadge}>
-                <Text style={styles.tagBadgeText}>{tags.length}</Text>
-              </View>
-            )}
-          </View>
-        </TouchableOpacity>
-
         <TouchableOpacity
           style={styles.toolbarButton}
           onPress={handleToggleEmojiPanel}
@@ -690,36 +702,54 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
           </View>
         </TouchableOpacity>
       </View>
+    </View>
+  );
 
-      {/* 右侧发布按钮 */}
-      <View style={styles.toolbarRight}>
-        <Text variant="caption" color={colors.text.hint} style={styles.charCount}>
+  const renderTopActionBar = () => (
+    <View style={styles.topActionBar}>
+      <TouchableOpacity
+        onPress={() => (onClose ? onClose() : router.back())}
+        style={styles.topActionButton}
+        activeOpacity={0.7}
+      >
+        <Text variant="body" color={colors.text.secondary}>取消</Text>
+      </TouchableOpacity>
+
+      <View style={styles.topActionCenter}>
+        <Text variant="body" color={colors.text.primary} style={styles.topActionTitle}>
+          {isEditMode ? '编辑帖子' : '发布帖子'}
+        </Text>
+        <Text variant="caption" color={colors.text.hint} style={styles.topActionCount}>
           {content.length}/{MAX_CONTENT_LENGTH}
         </Text>
-        <TouchableOpacity
-          style={[
-            styles.postButton,
-            (!content.trim() || posting) && styles.postButtonDisabled
-          ]}
-          onPress={handlePost}
-          disabled={!content.trim() || posting}
-          activeOpacity={0.8}
-        >
-          {posting ? (
-            <MaterialCommunityIcons name="loading" size={18} color={colors.primary.contrast} />
-          ) : (
-            <Text variant="body" color={colors.primary.contrast} style={styles.postButtonText}>
-              {isEditMode ? '保存' : '发布'}
-            </Text>
-          )}
-        </TouchableOpacity>
       </View>
+
+      <TouchableOpacity
+        onPress={handlePost}
+        disabled={!content.trim() || posting}
+        style={[
+          styles.topActionButton,
+          styles.topActionButtonRight,
+          (!content.trim() || posting) && styles.topActionButtonDisabled,
+        ]}
+        activeOpacity={0.8}
+      >
+        <Text
+          variant="body"
+          color={!content.trim() || posting ? colors.text.hint : colors.primary.main}
+          style={styles.topActionPublishText}
+        >
+          {posting ? '发布中' : '发布'}
+        </Text>
+      </TouchableOpacity>
     </View>
   );
 
   // 渲染主内容
   const renderMainContent = () => (
     <>
+      {renderTopActionBar()}
+
       <ScrollView
         contentContainerStyle={styles.scrollContent}
         showsVerticalScrollIndicator={false}
@@ -727,17 +757,13 @@ export const CreatePostScreen: React.FC<CreatePostScreenProps> = (props) => {
       >
         {/* 内容输入区 */}
         {renderContentSection()}
-
-        {/* 投票编辑器 */}
-        {renderVoteEditor()}
-
-        {/* 图片网格 */}
-        {renderImageGrid()}
-
-        {/* 标签 */}
-        {renderTags()}
       </ScrollView>
 
+      {renderChannelEntryRow()}
+
+      {/* 频道选择面板 */}
+      {renderChannelPicker()}
+
       {/* 表情面板 - 位于底部工具栏上方 */}
       {renderEmojiPanel()}
 
@@ -788,10 +814,48 @@ const styles = StyleSheet.create({
     backgroundColor: colors.background.paper,
   },
   scrollContent: {
+    flexGrow: 1,
     paddingBottom: spacing.xl,
   },
+  topActionBar: {
+    height: 52,
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'space-between',
+    paddingHorizontal: spacing.lg,
+    borderBottomWidth: StyleSheet.hairlineWidth,
+    borderBottomColor: colors.divider,
+    backgroundColor: colors.background.paper,
+  },
+  topActionButton: {
+    minWidth: 44,
+    height: 36,
+    justifyContent: 'center',
+  },
+  topActionButtonRight: {
+    alignItems: 'flex-end',
+  },
+  topActionButtonDisabled: {
+    opacity: 0.7,
+  },
+  topActionTitle: {
+    fontSize: fontSizes.lg,
+    fontWeight: '600',
+  },
+  topActionCenter: {
+    alignItems: 'center',
+    justifyContent: 'center',
+  },
+  topActionCount: {
+    marginTop: 2,
+    fontSize: fontSizes.xs,
+  },
+  topActionPublishText: {
+    fontWeight: '600',
+  },
   // 内容输入区
   contentSection: {
+    flexGrow: 1,
     paddingHorizontal: spacing.lg,
     paddingTop: spacing.md,
   },
@@ -806,22 +870,21 @@ const styles = StyleSheet.create({
     fontSize: fontSizes.xl,
   },
   contentInput: {
+    flexGrow: 1,
     fontSize: fontSizes.md,
     color: colors.text.primary,
-    minHeight: 120,
     lineHeight: 22,
     paddingVertical: spacing.sm,
   },
   contentInputWide: {
     fontSize: fontSizes.lg,
     lineHeight: 26,
-    minHeight: 150,
   },
   // 图片网格
   imageGrid: {
     flexDirection: 'row',
     flexWrap: 'wrap',
-    paddingHorizontal: spacing.lg,
+    paddingHorizontal: 0,
     paddingTop: spacing.md,
     gap: 8,
   },
@@ -866,7 +929,11 @@ const styles = StyleSheet.create({
   // 标签
   tagsSection: {
     paddingHorizontal: spacing.lg,
-    paddingTop: spacing.lg,
+    paddingTop: spacing.md,
+    paddingBottom: spacing.sm,
+    borderTopWidth: StyleSheet.hairlineWidth,
+    borderTopColor: colors.divider,
+    backgroundColor: colors.background.paper,
   },
   tagsContainer: {
     flexDirection: 'row',
@@ -874,60 +941,19 @@ const styles = StyleSheet.create({
     gap: spacing.sm,
   },
   tag: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    backgroundColor: colors.primary.light + '15',
-    borderRadius: borderRadius.full,
-    paddingLeft: spacing.sm,
-    paddingRight: spacing.xs,
-    paddingVertical: spacing.xs,
-  },
-  tagText: {
-    marginLeft: spacing.xs,
-    fontWeight: '500',
-  },
-  tagDeleteButton: {
-    marginLeft: spacing.xs,
-    padding: 2,
-  },
-  tagInputWrapper: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    backgroundColor: colors.background.default,
-    borderRadius: borderRadius.full,
-    paddingLeft: spacing.sm,
-    paddingRight: spacing.xs,
-    paddingVertical: spacing.xs,
-    borderWidth: 1,
-    borderColor: colors.primary.main,
-  },
-  tagInput: {
-    fontSize: fontSizes.sm,
-    color: colors.text.primary,
-    minWidth: 80,
-    marginLeft: spacing.xs,
-    padding: 0,
-  },
-  tagCancelButton: {
-    padding: spacing.xs,
-    marginRight: spacing.xs,
-  },
-  tagConfirmButton: {
-    padding: spacing.xs,
-  },
-  addTagButton: {
-    flexDirection: 'row',
-    alignItems: 'center',
     backgroundColor: colors.background.default,
     borderRadius: borderRadius.full,
     paddingHorizontal: spacing.md,
     paddingVertical: spacing.xs,
     borderWidth: 1,
     borderColor: colors.divider,
-    borderStyle: 'dashed',
   },
-  addTagText: {
-    marginLeft: spacing.xs,
+  channelSelected: {
+    backgroundColor: colors.primary.main,
+    borderColor: colors.primary.main,
+  },
+  tagText: {
+    fontWeight: '500',
   },
   // 投票编辑器宽屏样式
   voteEditorWide: {
@@ -935,7 +961,36 @@ const styles = StyleSheet.create({
     alignSelf: 'center',
     width: '100%',
   },
+  voteEditorHeaderRow: {
+    marginHorizontal: spacing.lg,
+    marginTop: spacing.md,
+    marginBottom: -spacing.sm,
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'space-between',
+  },
   // 底部工具栏
+  channelEntryRow: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'space-between',
+    paddingHorizontal: spacing.lg,
+    paddingVertical: spacing.sm,
+    borderTopWidth: StyleSheet.hairlineWidth,
+    borderTopColor: colors.divider,
+    backgroundColor: colors.background.paper,
+  },
+  channelEntryLabel: {
+    fontSize: fontSizes.md,
+  },
+  channelEntryValueWrap: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    gap: spacing.xs,
+  },
+  channelEntryValue: {
+    fontSize: fontSizes.md,
+  },
   toolbar: {
     flexDirection: 'row',
     justifyContent: 'space-between',
@@ -951,11 +1006,6 @@ const styles = StyleSheet.create({
     alignItems: 'center',
     gap: spacing.xs,
   },
-  toolbarRight: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    gap: spacing.md,
-  },
   toolbarButton: {
     position: 'relative',
   },
@@ -966,41 +1016,6 @@ const styles = StyleSheet.create({
     justifyContent: 'center',
     alignItems: 'center',
   },
-  tagBadge: {
-    position: 'absolute',
-    top: 4,
-    right: 4,
-    minWidth: 16,
-    height: 16,
-    borderRadius: 8,
-    backgroundColor: colors.primary.main,
-    justifyContent: 'center',
-    alignItems: 'center',
-  },
-  tagBadgeText: {
-    color: colors.primary.contrast,
-    fontSize: fontSizes.xs,
-    fontWeight: '600',
-  },
-  charCount: {
-    fontSize: fontSizes.xs,
-  },
-  postButton: {
-    backgroundColor: colors.primary.main,
-    paddingHorizontal: spacing.lg,
-    paddingVertical: spacing.sm,
-    borderRadius: borderRadius.full,
-    minWidth: 64,
-    alignItems: 'center',
-    justifyContent: 'center',
-  },
-  postButtonDisabled: {
-    backgroundColor: colors.text.disabled,
-  },
-  postButtonText: {
-    fontWeight: '600',
-    fontSize: fontSizes.sm,
-  },
   // 表情面板
   emojiPanel: {
     height: EMOJI_PANEL_HEIGHT,