import { Ionicons } from '@expo/vector-icons';
import { useRouter } from 'expo-router';
import {
  ActivityIndicator,
  Alert,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  TextInput,
  View,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useEnterpriseCommunication } from '../../src/hooks';
import { colors } from '../../src/theme';
import type { EnterpriseChatItem, EnterpriseCommunicationTab, PendingTask } from '../../src/types';

/* ===================== 子组件：顶部导航 ===================== */

function Header({ companyName, onBack }: { companyName: string; onBack: () => void }) {
  const router = useRouter();
  return (
    <View style={styles.header}>
      <Pressable style={styles.headerBtn} onPress={onBack} hitSlop={8}>
        <Ionicons name="chevron-back" size={24} color={colors.textPrimary} />
      </Pressable>
      <View style={styles.headerCenter}>
        <Text style={styles.headerCompany}>{companyName}</Text>
        <Text style={styles.headerTitle}>沟通</Text>
      </View>
      <Pressable
        style={styles.startBtn}
        onPress={() => router.navigate('/talent-recommendation')}
        hitSlop={6}
      >
        <Ionicons name="add" size={16} color={colors.white} />
        <Text style={styles.startBtnText}>发起沟通</Text>
      </Pressable>
    </View>
  );
}

/* ===================== 子组件：Tab 栏 ===================== */

function TabBar({
  tabs,
  active,
  onChange,
}: {
  tabs: EnterpriseCommunicationTab[];
  active: string;
  onChange: (key: string) => void;
}) {
  return (
    <View style={styles.tabBar}>
      {tabs.map((tab) => {
        const isActive = tab.key === active;
        return (
          <Pressable key={tab.key} style={styles.tabItem} onPress={() => onChange(tab.key)}>
            <Text style={[styles.tabLabel, isActive && styles.tabLabelActive]}>
              {tab.label}
              <Text style={[styles.tabCount, isActive && styles.tabCountActive]}>({tab.count})</Text>
            </Text>
            <View style={[styles.tabIndicator, isActive && styles.tabIndicatorActive]} />
          </Pressable>
        );
      })}
    </View>
  );
}

/* ===================== 子组件：待处理任务 ===================== */

function PendingTasks({
  tasks,
  onPressTask,
}: {
  tasks: PendingTask[];
  onPressTask: (task: PendingTask) => void;
}) {
  return (
    <View style={styles.pendingCard}>
      <Text style={styles.pendingTitle}>待处理</Text>
      <View style={styles.pendingGrid}>
        {tasks.map((task) => {
          const token =
            task.color === 'action'
              ? colors.action
              : task.color === 'compareOrange'
                ? colors.compareOrange
                : colors.primary;
          return (
            <Pressable
              key={task.id}
              style={styles.pendingItem}
              onPress={() => onPressTask(task)}
            >
              <View style={[styles.pendingIconWrap, { backgroundColor: token + '15' }]}>
                <Ionicons name={task.icon as keyof typeof Ionicons.glyphMap} size={22} color={token} />
              </View>
              <View style={styles.pendingBody}>
                <View style={styles.pendingLabelRow}>
                  <Text style={styles.pendingLabel}>{task.label}</Text>
                  <View style={styles.pendingBadge}>
                    <Text style={styles.pendingBadgeText}>{task.count}人</Text>
                  </View>
                </View>
                {task.hint ? <Text style={styles.pendingHint}>{task.hint}</Text> : null}
              </View>
              <Ionicons name="chevron-forward" size={16} color={colors.textHint} />
            </Pressable>
          );
        })}
      </View>
    </View>
  );
}

/* ===================== 子组件：聊天列表项 ===================== */

function ChatRow({ chat }: { chat: EnterpriseChatItem }) {
  const router = useRouter();
  return (
    <Pressable style={styles.chatRow} onPress={() => router.push('/chat/' + chat.id)}>
      <View style={styles.chatAvatar}>
        <Text style={styles.chatAvatarText}>{chat.avatar}</Text>
      </View>
      <View style={styles.chatBody}>
        <View style={styles.chatHeader}>
          <View style={styles.chatNameWrap}>
            <Text style={styles.chatName}>{chat.name}</Text>
            {chat.labels.length > 0 ? (
              <View style={styles.chatLabelTag}>
                <Text style={styles.chatLabelTagText}>{chat.labels[0]}</Text>
              </View>
            ) : null}
          </View>
          <Text style={styles.chatTime}>{chat.time}</Text>
        </View>
        <Text style={styles.chatTitle}>{chat.title}</Text>
        <View style={styles.chatFooter}>
          <Text style={styles.chatLastMessage} numberOfLines={1}>
            {chat.lastMessage}
          </Text>
          {chat.unreadCount > 0 ? (
            <View style={styles.unreadBadge}>
              <Text style={styles.unreadBadgeText}>{chat.unreadCount}</Text>
            </View>
          ) : null}
        </View>
      </View>
    </Pressable>
  );
}

/* ===================== 子组件：搜索栏 ===================== */

function SearchBar({
  value,
  onChange,
  onClear,
}: {
  value: string;
  onChange: (text: string) => void;
  onClear: () => void;
}) {
  return (
    <View style={styles.searchBar}>
      <Ionicons name="search-outline" size={18} color={colors.textHint} />
      <TextInput
        style={styles.searchInput}
        value={value}
        onChangeText={onChange}
        placeholder="搜索候选人姓名 / 职位 / 消息"
        placeholderTextColor={colors.textHint}
        returnKeyType="search"
      />
      {value !== '' && (
        <Pressable onPress={onClear} hitSlop={8}>
          <Ionicons name="close-circle" size={16} color={colors.textHint} />
        </Pressable>
      )}
    </View>
  );
}

/* ===================== 子组件：快捷操作栏 ===================== */

/** 单个快捷操作：有 route 则跳转，无对应页面时由页面层给出「功能开发中」提示 */
type QuickActionItem = { icon: string; label: string; route?: string };

function QuickActions({
  actions,
  onPressAction,
}: {
  actions: QuickActionItem[];
  onPressAction: (action: QuickActionItem) => void;
}) {
  return (
    <View style={styles.quickActionsCard}>
      {actions.map((action) => (
        <Pressable key={action.label} style={styles.quickAction} onPress={() => onPressAction(action)}>
          <Ionicons name={action.icon as keyof typeof Ionicons.glyphMap} size={20} color={colors.textSecondary} />
          <Text style={styles.quickActionText}>{action.label}</Text>
        </Pressable>
      ))}
    </View>
  );
}

/* ===================== 子组件：空状态 ===================== */

function EmptyState({
  dataReference,
  onDiscover,
}: {
  dataReference: { label: string; value: string }[];
  onDiscover: () => void;
}) {
  return (
    <View style={styles.emptyCard}>
      <View style={styles.emptyIconWrap}>
        <Ionicons name="chatbubbles-outline" size={48} color={colors.primary} />
      </View>
      <Text style={styles.emptyTitle}>还没有沟通记录</Text>
      <Text style={styles.emptySubtitle}>从人才推荐中发现合适的候选人，主动发起沟通吧</Text>
      <Pressable style={styles.emptyBtn} onPress={onDiscover} hitSlop={6}>
        <Text style={styles.emptyBtnText}>去发现人才</Text>
      </Pressable>

      <View style={styles.dataCard}>
        <Text style={styles.dataTitle}>数据参考</Text>
        {dataReference.map((item, index) => (
          <View key={index} style={styles.dataRow}>
            <Ionicons name="trending-up-outline" size={16} color={colors.success} />
            <Text style={styles.dataText}>
              {item.label}
              <Text style={styles.dataValue}> {item.value}</Text>
            </Text>
          </View>
        ))}
      </View>
    </View>
  );
}

/* ===================== 页面 ===================== */

const QUICK_ACTIONS: QuickActionItem[] = [
  { icon: 'mail-outline', label: '批量发邀请', route: '/talent-recommendation' },
  { icon: 'document-text-outline', label: '批量发Offer' },
  { icon: 'calendar-outline', label: '面试评分', route: '/interview-score' },
  { icon: 'notifications-outline', label: '群发通知' },
];

export default function EnterpriseChatScreen() {
  const router = useRouter();
  const {
    communication,
    activeTab,
    setActiveTab,
    keyword,
    setKeyword,
    chats,
    isEmptySearch,
    loading,
    error,
    refresh,
  } = useEnterpriseCommunication();

  // 快捷操作分发：有目标路由则跳转，无对应页面则提示「功能开发中」
  const handleQuickAction = (action: QuickActionItem) => {
    if (action.route) {
      router.push(action.route);
    } else {
      Alert.alert('提示', `${action.label}功能开发中，敬请期待`);
    }
  };

  // 待办卡片：优先跳页面，其次切 Tab（接口层给的目标，页面不写死映射）
  const handlePressTask = (task: PendingTask) => {
    if (task.route) {
      router.push(task.route as never);
      return;
    }
    if (task.tabKey) {
      setActiveTab(task.tabKey);
      setKeyword('');
      return;
    }
    Alert.alert('提示', `${task.label}功能开发中，敬请期待`);
  };

  if (loading) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <Header companyName="智联科技" onBack={() => router.back()} />
        <View style={styles.center}>
          <ActivityIndicator size="large" color={colors.primary} />
        </View>
      </SafeAreaView>
    );
  }

  if (error || !communication) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <Header companyName="智联科技" onBack={() => router.back()} />
        <View style={styles.center}>
          <Ionicons name="alert-circle-outline" size={40} color={colors.danger} />
          <Text style={styles.tip}>加载失败</Text>
          <Pressable style={styles.retryBtn} onPress={refresh}>
            <Text style={styles.retryText}>重试</Text>
          </Pressable>
        </View>
      </SafeAreaView>
    );
  }

  return (
    <SafeAreaView style={styles.container} edges={['top', 'bottom']}>
      <Header companyName={communication.companyName} onBack={() => router.back()} />
      <TabBar tabs={communication.tabs} active={activeTab} onChange={setActiveTab} />
      <ScrollView contentContainerStyle={styles.body} showsVerticalScrollIndicator={false}>
        {communication.hasData ? (
          <View>
            <PendingTasks tasks={communication.pendingTasks} onPressTask={handlePressTask} />
            <SearchBar value={keyword} onChange={setKeyword} onClear={() => setKeyword('')} />
            {chats.length === 0 ? (
              <View style={styles.emptyList}>
                <Ionicons name="chatbubbles-outline" size={32} color={colors.textHint} />
                <Text style={styles.emptyListText}>
                  {isEmptySearch ? `没有匹配「${keyword.trim()}」的会话` : '这个分类下暂时没有会话'}
                </Text>
              </View>
            ) : (
              <View style={styles.chatListCard}>
                {chats.map((chat, index) => {
                  const isLast = index === chats.length - 1;
                  return (
                    <View key={chat.id} style={isLast ? undefined : styles.chatBorder}>
                      <ChatRow chat={chat} />
                    </View>
                  );
                })}
              </View>
            )}
            <QuickActions actions={QUICK_ACTIONS} onPressAction={handleQuickAction} />
          </View>
        ) : (
          <EmptyState
            dataReference={communication.dataReference}
            onDiscover={() => router.navigate('/talent-recommendation')}
          />
        )}
      </ScrollView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: colors.pageBg },
  header: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: 12,
    paddingVertical: 12,
    backgroundColor: colors.white,
  },
  headerBtn: { width: 40, alignItems: 'center' },
  headerCenter: { alignItems: 'center' },
  headerCompany: { fontSize: 12, color: colors.textSecondary },
  headerTitle: { fontSize: 17, fontWeight: '700', color: colors.textPrimary, marginTop: 2 },
  startBtn: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: colors.primaryBtn,
    paddingHorizontal: 10,
    paddingVertical: 6,
    borderRadius: 16,
  },
  startBtnText: {
    color: colors.white,
    fontSize: 12,
    fontWeight: '600',
    marginLeft: 2,
  },
  tabBar: {
    flexDirection: 'row',
    backgroundColor: colors.white,
    borderBottomWidth: 1,
    borderBottomColor: colors.borderLight,
  },
  tabItem: {
    flex: 1,
    alignItems: 'center',
    paddingTop: 8,
  },
  tabLabel: {
    fontSize: 13,
    color: colors.textSecondary,
    paddingBottom: 8,
  },
  tabLabelActive: {
    color: colors.textPrimary,
    fontWeight: '600',
  },
  tabCount: {
    fontSize: 12,
    color: colors.textHint,
    marginLeft: 2,
  },
  tabCountActive: {
    color: colors.primary,
  },
  tabIndicator: {
    height: 2,
    width: 20,
    borderRadius: 1,
    backgroundColor: 'transparent',
    marginBottom: -1,
  },
  tabIndicatorActive: {
    backgroundColor: colors.primary,
  },
  body: {
    padding: 16,
    paddingBottom: 24,
  },
  center: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    gap: 12,
  },
  tip: { fontSize: 14, color: colors.textSecondary },
  retryBtn: {
    marginTop: 8,
    paddingHorizontal: 24,
    paddingVertical: 8,
    borderRadius: 18,
    backgroundColor: colors.primaryBtn,
  },
  retryText: { color: colors.white, fontSize: 13, fontWeight: '600' },
  pendingCard: {
    backgroundColor: colors.white,
    borderRadius: 12,
    padding: 16,
    marginBottom: 12,
  },
  pendingTitle: {
    fontSize: 15,
    fontWeight: '700',
    color: colors.textPrimary,
    marginBottom: 12,
  },
  pendingGrid: {
    gap: 12,
  },
  pendingItem: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: colors.pageBg,
    borderRadius: 10,
    padding: 12,
  },
  pendingIconWrap: {
    width: 40,
    height: 40,
    borderRadius: 10,
    alignItems: 'center',
    justifyContent: 'center',
    marginRight: 12,
  },
  pendingBody: {
    flex: 1,
  },
  pendingLabelRow: {
    flexDirection: 'row',
    alignItems: 'center',
  },
  pendingLabel: {
    fontSize: 14,
    fontWeight: '600',
    color: colors.textPrimary,
  },
  pendingBadge: {
    backgroundColor: colors.actionLight,
    borderRadius: 10,
    paddingHorizontal: 8,
    paddingVertical: 2,
    marginLeft: 8,
  },
  pendingBadgeText: {
    fontSize: 12,
    fontWeight: '700',
    color: colors.actionText,
  },
  pendingHint: {
    fontSize: 12,
    color: colors.textSecondary,
    marginTop: 2,
  },
  searchBar: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: colors.white,
    borderRadius: 10,
    paddingHorizontal: 12,
    paddingVertical: 10,
    marginBottom: 12,
  },
  searchInput: {
    flex: 1,
    marginLeft: 8,
    fontSize: 14,
    color: colors.textPrimary,
    padding: 0,
  },
  emptyList: {
    alignItems: 'center',
    gap: 10,
    paddingVertical: 32,
    backgroundColor: colors.white,
    borderRadius: 14,
  },
  emptyListText: { fontSize: 13, color: colors.textSecondary },
  chatListCard: {
    backgroundColor: colors.white,
    borderRadius: 12,
    overflow: 'hidden',
    marginBottom: 12,
  },
  chatBorder: {
    borderBottomWidth: 1,
    borderBottomColor: colors.borderLight,
  },
  chatRow: {
    flexDirection: 'row',
    alignItems: 'center',
    padding: 14,
  },
  chatAvatar: {
    width: 48,
    height: 48,
    borderRadius: 24,
    backgroundColor: colors.primaryLight,
    alignItems: 'center',
    justifyContent: 'center',
    marginRight: 12,
  },
  chatAvatarText: {
    fontSize: 18,
    fontWeight: '700',
    color: colors.primary,
  },
  chatBody: {
    flex: 1,
  },
  chatHeader: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
  },
  chatNameWrap: {
    flexDirection: 'row',
    alignItems: 'center',
  },
  chatName: {
    fontSize: 15,
    fontWeight: '700',
    color: colors.textPrimary,
  },
  chatLabelTag: {
    backgroundColor: colors.compareOrange + '20',
    borderRadius: 8,
    paddingHorizontal: 6,
    paddingVertical: 2,
    marginLeft: 8,
  },
  chatLabelTagText: {
    fontSize: 11,
    color: colors.compareOrange,
    fontWeight: '600',
  },
  chatTime: {
    fontSize: 12,
    color: colors.textHint,
  },
  chatTitle: {
    fontSize: 13,
    color: colors.textSecondary,
    marginTop: 2,
  },
  chatFooter: {
    flexDirection: 'row',
    alignItems: 'center',
    marginTop: 4,
  },
  chatLastMessage: {
    flex: 1,
    fontSize: 13,
    color: colors.textHint,
  },
  unreadBadge: {
    minWidth: 18,
    height: 18,
    borderRadius: 9,
    backgroundColor: colors.danger,
    alignItems: 'center',
    justifyContent: 'center',
    marginLeft: 8,
  },
  unreadBadgeText: {
    fontSize: 11,
    color: colors.white,
    fontWeight: '700',
  },
  quickActionsCard: {
    flexDirection: 'row',
    backgroundColor: colors.white,
    borderRadius: 12,
    paddingVertical: 14,
  },
  quickAction: {
    flex: 1,
    alignItems: 'center',
  },
  quickActionText: {
    fontSize: 11,
    color: colors.textSecondary,
    marginTop: 4,
  },
  emptyCard: {
    backgroundColor: colors.white,
    borderRadius: 16,
    padding: 28,
    alignItems: 'center',
  },
  emptyIconWrap: {
    width: 88,
    height: 88,
    borderRadius: 44,
    backgroundColor: colors.primaryLight,
    alignItems: 'center',
    justifyContent: 'center',
    marginBottom: 16,
  },
  emptyTitle: {
    fontSize: 18,
    fontWeight: '700',
    color: colors.textPrimary,
    marginBottom: 8,
  },
  emptySubtitle: {
    fontSize: 13,
    color: colors.textSecondary,
    textAlign: 'center',
    marginBottom: 20,
  },
  emptyBtn: {
    backgroundColor: colors.primaryBtn,
    paddingHorizontal: 32,
    paddingVertical: 12,
    borderRadius: 24,
    marginBottom: 24,
  },
  emptyBtnText: {
    color: colors.white,
    fontSize: 15,
    fontWeight: '600',
  },
  dataCard: {
    width: '100%',
    backgroundColor: colors.primaryLight,
    borderRadius: 12,
    padding: 16,
    alignItems: 'flex-start',
  },
  dataTitle: {
    fontSize: 14,
    fontWeight: '700',
    color: colors.primaryText,
    marginBottom: 12,
  },
  dataRow: {
    flexDirection: 'row',
    alignItems: 'flex-start',
    marginBottom: 10,
  },
  dataText: {
    flex: 1,
    fontSize: 13,
    color: colors.textPrimary,
    marginLeft: 10,
    lineHeight: 18,
  },
  dataValue: {
    color: colors.success,
    fontWeight: '700',
  },
});