import { Ionicons } from '@expo/vector-icons';
import { useRouter } from 'expo-router';
import {
  ActivityIndicator,
  Alert,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  View,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useAIInterview } from '../src/hooks';
import { buildInterviewConfigText } from '../src/api';
import { shareText } from '../src/lib/shareFile';
import { colors, semanticColorTokens } from '../src/theme';
import type {
  InterviewAbilityImprovement,
  InterviewMode,
  InterviewModeOption,
  InterviewQuestionTypeCode,
  InterviewQuestionTypeItem,
  InterviewRecent,
  InterviewSpecial,
} from '../src/types';

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

function Header({ onBack, onShare }: { onBack: () => void; onShare?: () => void }) {
  return (
    <View style={styles.header}>
      <Pressable style={styles.headerBtn} onPress={onBack} hitSlop={8}>
        <Ionicons name="chevron-back" size={24} color={colors.textPrimary} />
      </Pressable>
      <Text style={styles.headerTitle}>AI模拟面试</Text>
      {onShare ? (
        <Pressable style={styles.headerBtn} onPress={onShare} hitSlop={8}>
          <Ionicons name="share-outline" size={22} color={colors.textPrimary} />
        </Pressable>
      ) : (
        <View style={styles.headerBtn} />
      )}
    </View>
  );
}

/* ===================== 子组件：面试模式选择 ===================== */

function ModeCards({
  modes,
  active,
  onSelect,
}: {
  modes: InterviewModeOption[];
  active: InterviewMode;
  onSelect: (mode: InterviewMode) => void;
}) {
  return (
    <View style={styles.section}>
      <Text style={styles.sectionTitle}>面试模式</Text>
      {modes.map((mode) => {
        const selected = mode.id === active;
        return (
          <Pressable
            key={mode.id}
            style={[styles.modeCard, selected && styles.modeCardActive]}
            onPress={() => onSelect(mode.id)}
          >
            <View
              style={[
                styles.modeIcon,
                { backgroundColor: selected ? colors.primary : colors.pageBg },
              ]}
            >
              <Ionicons
                name={mode.icon as keyof typeof Ionicons.glyphMap}
                size={22}
                color={selected ? colors.white : colors.textHint}
              />
            </View>
            <View style={styles.modeBody}>
              <Text style={[styles.modeLabel, selected && styles.modeLabelActive]}>
                {mode.label}
              </Text>
              <Text style={styles.modeDesc}>{mode.desc}</Text>
            </View>
            {selected && <Ionicons name="checkmark-circle" size={22} color={colors.primary} />}
          </Pressable>
        );
      })}
    </View>
  );
}

/* ===================== 子组件：岗位信息（两列网格） ===================== */

function JobInfoGrid({
  items,
}: {
  items: { label: string; value: string }[];
}) {
  return (
    <View style={styles.card}>
      <View style={styles.jobGrid}>
        {items.map((item) => (
          <View key={item.label} style={styles.jobItem}>
            <Text style={styles.jobLabel}>{item.label}</Text>
            <Text style={styles.jobValue}>{item.value}</Text>
          </View>
        ))}
      </View>
    </View>
  );
}

/* ===================== 子组件：题型设置 ===================== */

function QuestionTypeTags({
  types,
  active,
  onToggle,
}: {
  types: InterviewQuestionTypeItem[];
  active: InterviewQuestionTypeCode[];
  onToggle: (id: InterviewQuestionTypeCode) => void;
}) {
  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>题型设置</Text>
      <View style={styles.tagRow}>
        {types.map((t) => {
          const selected = active.includes(t.id);
          const color = semanticColorTokens[t.color] ?? colors.primary;
          return (
            <Pressable
              key={t.id}
              style={[
                styles.typeTag,
                selected && { backgroundColor: color, borderColor: color },
              ]}
              onPress={() => onToggle(t.id)}
            >
              {selected && <Ionicons name="checkmark" size={14} color={colors.white} />}
              <Text style={[styles.typeText, selected && styles.typeTextActive]}>{t.label}</Text>
            </Pressable>
          );
        })}
      </View>
    </View>
  );
}

/* ===================== 子组件：专项突破选项 ===================== */

function SpecialTags({
  specials,
  active,
  onToggle,
}: {
  specials: InterviewSpecial[];
  active: string[];
  onToggle: (id: string) => void;
}) {
  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>专项突破</Text>
      <View style={styles.tagRow}>
        {specials.map((s) => {
          const selected = active.includes(s.id);
          return (
            <Pressable
              key={s.id}
              style={[styles.specialTag, selected && styles.specialTagActive]}
              onPress={() => onToggle(s.id)}
            >
              <Text style={[styles.specialText, selected && styles.specialTextActive]}>
                {s.label}
              </Text>
            </Pressable>
          );
        })}
      </View>
    </View>
  );
}

/* ===================== 子组件：预估可提升能力 ===================== */

function ImprovementCard({
  improvements,
}: {
  improvements: InterviewAbilityImprovement[];
}) {
  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>本次预估可提升能力</Text>
      {improvements.map((imp) => {
        const color = semanticColorTokens[imp.color] ?? colors.primary;
        return (
          <View key={imp.id} style={styles.improvementRow}>
            <Text style={styles.improvementLabel}>{imp.label}</Text>
            <View style={styles.improvementTrack}>
              <View
                style={[
                  styles.improvementFill,
                  { width: `${imp.percent * 5}%`, backgroundColor: color },
                ]}
              />
            </View>
            <Text style={[styles.improvementValue, { color }]}>+{imp.percent}%</Text>
          </View>
        );
      })}
    </View>
  );
}

/* ===================== 子组件：最近练习 ===================== */

function RecentCard({ recent }: { recent: InterviewRecent[] }) {
  return (
    <View style={styles.card}>
      {/* 原先这里挂着「全部记录 >」：项目内没有面试练习记录页，先摘掉 */}
      <View style={styles.cardHeaderRow}>
        <Text style={styles.cardTitle}>最近练习</Text>
      </View>
      {recent.map((item) => {
        const color = semanticColorTokens[item.resultColor] ?? colors.primary;
        return (
          <View key={item.id} style={styles.recentRow}>
            <Text style={styles.recentDate}>{item.date}</Text>
            <Text style={styles.recentTitle}>{item.title}</Text>
            <View style={[styles.recentTag, { backgroundColor: `${color}20` }]}>
              <Text style={[styles.recentResult, { color }]}>{item.result}</Text>
            </View>
          </View>
        );
      })}
    </View>
  );
}

/* ===================== 子组件：四态 ===================== */

function Loading() {
  return (
    <View style={styles.center}>
      <ActivityIndicator size="large" color={colors.primary} />
      <Text style={styles.tip}>正在加载面试配置…</Text>
    </View>
  );
}

function ErrorState({ onRetry }: { onRetry: () => void }) {
  return (
    <View style={styles.center}>
      <Ionicons name="videocam-outline" size={40} color={colors.textHint} />
      <Text style={styles.tip}>配置加载失败</Text>
      <Pressable style={styles.retryBtn} onPress={onRetry} hitSlop={6}>
        <Text style={styles.retryText}>点击重试</Text>
      </Pressable>
    </View>
  );
}

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

export default function InterviewScreen() {
  const router = useRouter();
  const {
    data,
    loading,
    error,
    refresh,
    mode,
    setMode,
    questionTypes,
    toggleQuestionType,
    specials,
    toggleSpecial,
    start,
    starting,
  } = useAIInterview();

  const handleStart = async () => {
    await start();
  };

  /**
   * 分享面试配置：拼成文本经系统分享面板发出。
   * 传入的是**页面上的当前选择**（模式 / 题型 / 专项），不是接口默认值 —— 用户改过之后两者不同。
   * `ok` 只代表面板已拉起，不能据此提示「分享成功」，只在失败时说明原因（见 lib/shareFile）。
   */
  const handleShare = async () => {
    if (!data) return;
    const outcome = await shareText(
      buildInterviewConfigText(data, mode, questionTypes, specials),
      'AI 模拟面试配置',
    );
    if (!outcome.ok) Alert.alert('无法分享', outcome.message);
  };

  if (loading) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <Header onBack={() => router.back()} />
        <Loading />
      </SafeAreaView>
    );
  }

  if (error || !data) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <Header onBack={() => router.back()} />
        <ErrorState onRetry={refresh} />
      </SafeAreaView>
    );
  }

  return (
    <SafeAreaView style={styles.container} edges={['top']}>
      <Header onBack={() => router.back()} onShare={handleShare} />
      <ScrollView contentContainerStyle={styles.body} showsVerticalScrollIndicator={false}>
        <ModeCards modes={data.modes} active={mode} onSelect={setMode} />

        <JobInfoGrid
          items={[
            { label: '面试岗位', value: data.jobInfo.position },
            { label: '面试公司', value: data.jobInfo.company },
            { label: '面试难度', value: data.jobInfo.difficulty },
            { label: '面试时长', value: `${data.jobInfo.duration}分钟` },
          ]}
        />

        <QuestionTypeTags
          types={data.questionTypes}
          active={questionTypes}
          onToggle={toggleQuestionType}
        />

        {mode === 'special' && (
          <SpecialTags specials={data.specials} active={specials} onToggle={toggleSpecial} />
        )}

        <ImprovementCard improvements={data.improvements} />

        <RecentCard recent={data.recent} />
      </ScrollView>

      <View style={styles.footer}>
        <Pressable
          style={[styles.startBtn, starting && styles.startBtnDisabled]}
          onPress={handleStart}
          disabled={starting}
        >
          {starting ? (
            <ActivityIndicator size="small" color={colors.white} />
          ) : (
            <Text style={styles.startBtnText}>开始面试</Text>
          )}
        </Pressable>
      </View>
    </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' },
  headerTitle: { fontSize: 17, fontWeight: '700', color: colors.textPrimary },
  body: { paddingHorizontal: 8, paddingBottom: 100, paddingTop: 12 },
  center: { flex: 1, alignItems: 'center', justifyContent: 'center', paddingHorizontal: 40, gap: 12 },
  tip: { fontSize: 14, color: colors.textSecondary },
  retryBtn: {
    paddingHorizontal: 18,
    paddingVertical: 8,
    borderRadius: 16,
    backgroundColor: colors.primaryLight,
  },
  retryText: { fontSize: 13, fontWeight: '600', color: colors.primaryText },
  section: { marginBottom: 16 },
  sectionTitle: { fontSize: 16, fontWeight: '700', color: colors.textPrimary, marginBottom: 12 },
  modeCard: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: colors.white,
    borderRadius: 8,
    padding: 8,
    marginBottom: 8,
    borderWidth: 1,
    borderColor: colors.borderLight,
  },
  modeCardActive: { borderColor: colors.primary, backgroundColor: colors.primaryLight },
  modeIcon: {
    width: 44,
    height: 44,
    borderRadius: 22,
    alignItems: 'center',
    justifyContent: 'center',
  },
  modeBody: { flex: 1, marginLeft: 12 },
  modeLabel: { fontSize: 15, fontWeight: '700', color: colors.textPrimary },
  modeLabelActive: { color: colors.primaryText },
  modeDesc: { fontSize: 12, color: colors.textSecondary, marginTop: 2 },
  card: {
    backgroundColor: colors.white,
    borderRadius: 8,
    padding: 8,
    marginBottom: 8,
    borderWidth: 1,
    borderColor: colors.borderLight,
  },
  cardHeaderRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    marginBottom: 12,
  },
  cardTitle: { fontSize: 15, fontWeight: '700', color: colors.textPrimary },
  moreLink: { fontSize: 13, color: colors.primary },
  jobGrid: { flexDirection: 'row', flexWrap: 'wrap' },
  jobItem: { width: '50%', marginBottom: 14 },
  jobLabel: { fontSize: 12, color: colors.textHint, marginBottom: 4 },
  jobValue: { fontSize: 14, fontWeight: '700', color: colors.textPrimary },
  tagRow: { flexDirection: 'row', flexWrap: 'wrap', gap: 10 },
  typeTag: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingHorizontal: 14,
    paddingVertical: 8,
    borderRadius: 18,
    backgroundColor: colors.white,
    borderWidth: 1,
    borderColor: colors.border,
  },
  typeText: { fontSize: 13, color: colors.textSecondary, marginLeft: 4 },
  typeTextActive: { color: colors.white, fontWeight: '600' },
  specialTag: {
    paddingHorizontal: 14,
    paddingVertical: 8,
    borderRadius: 18,
    backgroundColor: colors.pageBg,
    borderWidth: 1,
    borderColor: colors.borderLight,
  },
  specialTagActive: { backgroundColor: colors.primaryLight, borderColor: colors.primary },
  specialText: { fontSize: 13, color: colors.textSecondary },
  specialTextActive: { color: colors.primaryText, fontWeight: '600' },
  improvementRow: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingVertical: 8,
  },
  improvementLabel: { width: 70, fontSize: 13, color: colors.textPrimary },
  improvementTrack: {
    flex: 1,
    height: 8,
    borderRadius: 4,
    backgroundColor: colors.borderLight,
    overflow: 'hidden',
  },
  improvementFill: { height: 8, borderRadius: 4 },
  improvementValue: {
    width: 50,
    fontSize: 13,
    fontWeight: '700',
    textAlign: 'right',
  },
  recentRow: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingVertical: 10,
    borderTopWidth: 1,
    borderTopColor: colors.borderLight,
  },
  recentDate: { width: 60, fontSize: 12, color: colors.textHint },
  recentTitle: { flex: 1, fontSize: 14, color: colors.textPrimary },
  recentTag: { borderRadius: 10, paddingHorizontal: 8, paddingVertical: 2 },
  recentResult: { fontSize: 12, fontWeight: '600' },
  footer: {
    position: 'absolute',
    left: 0,
    right: 0,
    bottom: 0,
    paddingHorizontal: 16,
    paddingVertical: 12,
    backgroundColor: colors.white,
    borderTopWidth: 1,
    borderTopColor: colors.borderLight,
  },
  startBtn: {
    backgroundColor: colors.primaryBtn,
    borderRadius: 24,
    paddingVertical: 14,
    alignItems: 'center',
  },
  startBtnDisabled: { backgroundColor: colors.textDisabled },
  startBtnText: { fontSize: 16, fontWeight: '700', color: colors.white },
});