import { Ionicons } from '@expo/vector-icons';
import { useRouter } from 'expo-router';
import { useEffect, useState } from 'react';
import {
  ActivityIndicator,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  TextInput,
  View,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { colors } from '../src/theme';
import { useAuth } from '../src/context/AuthContext';
import { useJobPreference } from '../src/hooks';
import {
  EXPECTED_CITY_OPTIONS,
  EXPECTED_SALARY_OPTIONS,
  JOB_STATUS_OPTIONS,
  WORK_TYPE_OPTIONS,
} from '../src/constants';
import { withCurrentOption } from '../src/utils';
import type { JobPreference } from '../src/types';

/* ===================== 子组件：单选项 chips ===================== */

function ChipGroup({
  title,
  options,
  value,
  onSelect,
}: {
  title: string;
  options: string[];
  value: string;
  onSelect: (v: string) => void;
}) {
  return (
    <View style={styles.section}>
      <Text style={styles.sectionTitle}>{title}</Text>
      <View style={styles.chips}>
        {options.map((opt) => {
          const selected = opt === value;
          return (
            <Pressable
              key={opt}
              style={[styles.chip, selected && styles.chipSelected]}
              onPress={() => onSelect(opt)}
            >
              <Text style={[styles.chipText, selected && styles.chipTextSelected]}>{opt}</Text>
            </Pressable>
          );
        })}
      </View>
    </View>
  );
}

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

function Loading() {
  return (
    <View style={styles.center}>
      <ActivityIndicator size="large" color={colors.primary} />
      <Text style={styles.tip}>正在加载求职意向…</Text>
    </View>
  );
}

function ErrorState({ onRetry }: { onRetry: () => void }) {
  return (
    <View style={styles.center}>
      <Ionicons name="alert-circle-outline" size={40} color={colors.textHint} />
      <Text style={styles.tip}>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 JobPreferenceScreen() {
  const router = useRouter();
  const { completeCandidateSetup } = useAuth();
  const { preference, loading, error, refresh, save } = useJobPreference();
  const [form, setForm] = useState<JobPreference | null>(null);
  const [saving, setSaving] = useState(false);

  useEffect(() => {
    if (preference && !form) setForm(preference);
  }, [preference, form]);

  if (loading || !form) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <Loading />
      </SafeAreaView>
    );
  }

  if (error) {
    return (
      <SafeAreaView style={styles.container} edges={['top']}>
        <ErrorState onRetry={refresh} />
      </SafeAreaView>
    );
  }

  const canSave = form.position.trim().length > 0;

  const update = <K extends keyof JobPreference>(field: K, value: JobPreference[K]) => {
    setForm((prev) => (prev ? { ...prev, [field]: value } : prev));
  };

  const handleSave = async () => {
    if (!canSave || saving) return;
    setSaving(true);
    try {
      await save(form);
      completeCandidateSetup();
      router.replace('/(tabs)/jobs');
    } finally {
      setSaving(false);
    }
  };

  const handleSkip = () => {
    router.replace('/(tabs)/jobs');
  };

  return (
    <SafeAreaView style={styles.container} edges={['top']}>
      <ScrollView contentContainerStyle={styles.body} showsVerticalScrollIndicator={false}>
        <View style={styles.header}>
          <Text style={styles.headerTitle}>设置求职意向</Text>
          <Text style={styles.headerDesc}>告诉我们你的期望，才能推荐更匹配的岗位</Text>
        </View>

        <View style={styles.section}>
          <Text style={styles.sectionTitle}>期望职位</Text>
          <TextInput
            style={styles.input}
            value={form.position}
            onChangeText={(v) => update('position', v)}
            placeholder="如：前端开发工程师"
            placeholderTextColor={colors.textHint}
          />
        </View>

        <ChipGroup
          title="期望城市"
          options={EXPECTED_CITY_OPTIONS}
          value={form.city}
          onSelect={(v) => update('city', v)}
        />
        <ChipGroup
          title="期望薪资"
          // 引导 P7 的两个阶梯能拼出快捷档覆盖不到的组合，补进当前值避免「一个都没选中」
          options={withCurrentOption(EXPECTED_SALARY_OPTIONS, form.salary)}
          value={form.salary}
          onSelect={(v) => update('salary', v)}
        />
        <ChipGroup
          title="工作类型"
          options={WORK_TYPE_OPTIONS}
          value={form.workType}
          onSelect={(v) => update('workType', v)}
        />
        <ChipGroup
          title="求职状态"
          options={JOB_STATUS_OPTIONS}
          value={form.status}
          onSelect={(v) => update('status', v)}
        />
      </ScrollView>

      <View style={styles.footer}>
        <Pressable
          style={[styles.saveBtn, (!canSave || saving) && styles.saveBtnDisabled]}
          onPress={handleSave}
          disabled={!canSave || saving}
        >
          <Text style={styles.saveText}>{saving ? '保存中…' : '保存并进入求职端'}</Text>
        </Pressable>
        <Pressable style={styles.skipBtn} onPress={handleSkip} hitSlop={6}>
          <Text style={styles.skipText}>稍后设置</Text>
        </Pressable>
      </View>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: colors.pageBg },
  body: { padding: 20, paddingBottom: 24 },
  center: { flex: 1, alignItems: 'center', justifyContent: 'center', 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 },
  header: { marginBottom: 20 },
  headerTitle: { fontSize: 22, fontWeight: '800', color: colors.textPrimary },
  headerDesc: { fontSize: 13, color: colors.textSecondary, marginTop: 6 },
  section: { marginBottom: 20 },
  sectionTitle: { fontSize: 15, fontWeight: '700', color: colors.textPrimary, marginBottom: 10 },
  input: {
    height: 50,
    borderRadius: 12,
    borderWidth: 1,
    borderColor: colors.border,
    backgroundColor: colors.white,
    paddingHorizontal: 14,
    fontSize: 16,
    color: colors.textPrimary,
  },
  chips: { flexDirection: 'row', flexWrap: 'wrap', gap: 10 },
  chip: {
    paddingHorizontal: 14,
    paddingVertical: 9,
    borderRadius: 18,
    backgroundColor: colors.white,
    borderWidth: 1,
    borderColor: colors.border,
  },
  chipSelected: { backgroundColor: colors.primaryLight, borderColor: colors.primary },
  chipText: { fontSize: 13, color: colors.textSecondary },
  chipTextSelected: { color: colors.primaryText, fontWeight: '600' },
  footer: {
    paddingHorizontal: 20,
    paddingVertical: 14,
    backgroundColor: colors.white,
    borderTopWidth: 1,
    borderTopColor: colors.borderLight,
  },
  saveBtn: {
    height: 50,
    borderRadius: 25,
    backgroundColor: colors.primaryBtn,
    alignItems: 'center',
    justifyContent: 'center',
  },
  saveBtnDisabled: { backgroundColor: colors.border, opacity: 0.7 },
  saveText: { fontSize: 16, fontWeight: '700', color: colors.textInverse },
  skipBtn: { alignItems: 'center', paddingVertical: 14 },
  skipText: { fontSize: 14, color: colors.textHint },
});