import { Ionicons } from '@expo/vector-icons';
import { LinearGradient } from 'expo-linear-gradient';
import { useRouter } from 'expo-router';
import { useState } from 'react';
import {
  Alert,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  TextInput,
  View,
} from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useSalaryCalculator } from '../../src/hooks';
import { colors, headerGradientShort } from '../../src/theme';
import type { SalaryCalcInput, SalaryToolLink } from '../../src/types';
import { formatCurrency } from '../../src/utils';


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

function Header({ onBack, onHistory }: { onBack: () => void; onHistory: () => 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}>薪资计算器</Text>
      <Pressable style={styles.headerBtn} onPress={onHistory} hitSlop={8}>
        <Text style={styles.headerAction}>历史记录</Text>
      </Pressable>
    </View>
  );
}

/* ===================== 子组件：数字输入行 ===================== */

function NumberInput({
  label,
  value,
  suffix,
  onChange,
  placeholder,
}: {
  label: string;
  value: number;
  suffix: string;
  onChange: (v: number) => void;
  placeholder?: string;
}) {
  const [text, setText] = useState(String(value));
  return (
    <View style={styles.inputRow}>
      <Text style={styles.inputLabel}>{label}</Text>
      <View style={styles.inputBox}>
        <TextInput
          style={styles.input}
          value={text}
          onChangeText={(t) => {
            setText(t);
            const n = parseFloat(t);
            if (!Number.isNaN(n)) onChange(n);
          }}
          keyboardType="numeric"
          placeholder={placeholder}
          placeholderTextColor={colors.textHint}
        />
        <Text style={styles.inputSuffix}>{suffix}</Text>
      </View>
    </View>
  );
}

function SelectRow({
  label,
  value,
  onPress,
}: {
  label: string;
  value: string;
  onPress: () => void;
}) {
  return (
    <Pressable style={styles.inputRow} onPress={onPress}>
      <Text style={styles.inputLabel}>{label}</Text>
      <View style={styles.selectBox}>
        <Text style={styles.selectValue}>{value}</Text>
        <Ionicons name="chevron-forward" size={18} color={colors.textHint} />
      </View>
    </Pressable>
  );
}

/* ===================== 子组件：五险一金明细 ===================== */

function InsuranceCard({ result }: { result: import('../../src/types').SalaryCalcResult }) {
  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>五险一金明细</Text>
      <View style={styles.cardSubTitleRow}>
        <Text style={styles.cardSubTitle}>个人缴纳</Text>
        <Text style={styles.cardSubTitle}>缴纳比例</Text>
      </View>
      {result.insuranceItems.map((item) => (
        <View key={item.label} style={styles.insuranceRow}>
          <Text style={styles.insuranceLabel}>{item.label}</Text>
          <Text style={styles.insuranceAmount}>{formatCurrency(item.amount)}</Text>
          <Text style={styles.insuranceRate}>{(item.rate * 100).toFixed(1)}%</Text>
        </View>
      ))}
      <View style={styles.divider} />
      <View style={styles.totalRow}>
        <Text style={styles.totalLabel}>合计个人缴纳</Text>
        <Text style={styles.totalAmount}>{formatCurrency(result.monthlySocial)}</Text>
      </View>
    </View>
  );
}

/* ===================== 子组件：个人所得税明细 ===================== */

function TaxCard({ result }: { result: import('../../src/types').SalaryCalcResult }) {
  const taxItems = result.taxItems;
  const monthlyTax = taxItems.find((t) => t.label === '月度个税')?.amount ?? 0;
  const annualTax = taxItems.find((t) => t.label === '年度个税')?.amount ?? 0;
  const taxable = taxItems.find((t) => t.label === '应纳税所得额')?.amount ?? 0;
  const rate = taxItems.find((t) => t.label === '适用税率')?.amount ?? 0;

  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>个人所得税明细</Text>
      <View style={styles.taxGrid}>
        <View style={styles.taxItem}>
          <Text style={styles.taxItemLabel}>应纳税所得额</Text>
          <Text style={styles.taxItemValue}>{formatCurrency(taxable)}</Text>
        </View>
        <View style={styles.taxItem}>
          <Text style={styles.taxItemLabel}>适用税率</Text>
          <Text style={styles.taxItemValue}>{(rate * 100).toFixed(0)}%</Text>
        </View>
      </View>
      <View style={styles.divider} />
      <View style={styles.taxRow}>
        <Text style={styles.taxRowLabel}>月度个税</Text>
        <Text style={styles.taxRowValue}>{formatCurrency(monthlyTax)}/月</Text>
      </View>
      <View style={styles.taxRow}>
        <Text style={styles.taxRowLabel}>年度个税</Text>
        <Text style={styles.taxRowValue}>{formatCurrency(annualTax)}/年</Text>
      </View>
    </View>
  );
}

/* ===================== 子组件：薪资结构 ===================== */

function StructureCard({ result }: { result: import('../../src/types').SalaryCalcResult }) {
  const items = result.structure.filter((s) => s.label !== '税前工资');
  const themeColors: Record<string, string> = {
    primary: colors.primary,
    info: colors.info,
    action: colors.action,
    success: colors.success,
  };
  return (
    <View style={styles.card}>
      <Text style={styles.cardTitle}>薪资结构</Text>
      <View style={styles.structureChart}>
        <View style={styles.pie}>
          {items.map((item, index) => {
            const start = items.slice(0, index).reduce((sum, i) => sum + i.percent, 0);
            return (
              <View
                key={item.label}
                style={[
                  styles.pieSlice,
                  {
                    backgroundColor: themeColors[item.color] ?? colors.primary,
                    transform: [{ rotate: `${(start / 100) * 360}deg` }],
                  },
                ]}
              />
            );
          })}
        </View>
        <View style={styles.structureLegend}>
          {items.map((item) => (
            <View key={item.label} style={styles.legendRow}>
              <View
                style={[
                  styles.legendDot,
                  { backgroundColor: themeColors[item.color] ?? colors.primary },
                ]}
              />
              <Text style={styles.legendLabel}>{item.label}</Text>
              <Text style={styles.legendValue}>{formatCurrency(item.value / 1000, 0)}K</Text>
              <Text style={styles.legendPercent}>{item.percent}%</Text>
            </View>
          ))}
        </View>
      </View>
    </View>
  );
}

/* ===================== 子组件：更多工具 ===================== */

function ToolLink({ tool }: { tool: SalaryToolLink }) {
  return (
    <Pressable style={styles.toolRow}>
      <View style={[styles.toolIcon, { backgroundColor: colors.primaryLight }]}>
        <Ionicons name={tool.icon as keyof typeof Ionicons.glyphMap} size={20} color={colors.primary} />
      </View>
      <View style={styles.toolBody}>
        <Text style={styles.toolTitle}>{tool.title}</Text>
        <Text style={styles.toolDesc}>{tool.desc}</Text>
      </View>
      <Ionicons name="chevron-forward" size={18} color={colors.textHint} />
    </Pressable>
  );
}

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

export default function SalaryCalculatorScreen() {
  const router = useRouter();
  const { inputs, setInputs, result } = useSalaryCalculator();

  const update = <K extends keyof SalaryCalcInput>(key: K, value: SalaryCalcInput[K]) => {
    setInputs({ ...inputs, [key]: value });
  };

  return (
    <SafeAreaView style={styles.container} edges={['top']}>
      <Header onBack={() => router.back()} onHistory={() => Alert.alert('历史记录', '计算历史功能开发中，敬请期待')} />
      <ScrollView contentContainerStyle={styles.body} showsVerticalScrollIndicator={false}>
        {/* 输入卡片 */}
        <View style={styles.card}>
          <Text style={styles.cardTitle}>收入参数</Text>
          <NumberInput
            label="税前月薪"
            value={inputs.monthlyGross}
            suffix="元"
            onChange={(v) => update('monthlyGross', Math.max(0, v))}
          />
          <SelectRow label="所在城市" value={inputs.city} onPress={() => Alert.alert('选择城市', '城市选择功能开发中，敬请期待')} />
          <NumberInput
            label="社保基数"
            value={inputs.socialBase}
            suffix="元"
            onChange={(v) => update('socialBase', Math.max(0, v))}
          />
          <NumberInput
            label="公积金比例"
            value={inputs.providentFundRate * 100}
            suffix="%"
            onChange={(v) => update('providentFundRate', Math.max(0, Math.min(100, v)) / 100)}
          />
          <NumberInput
            label="专项附加扣除"
            value={inputs.specialDeduction}
            suffix="元/月"
            onChange={(v) => update('specialDeduction', Math.max(0, v))}
          />
        </View>

        {/* 结果卡片 */}
        <LinearGradient
          colors={headerGradientShort}
          start={{ x: 0, y: 0 }}
          end={{ x: 1, y: 1 }}
          style={styles.resultCard}
        >
          <Text style={styles.resultLabel}>税后月工资</Text>
          <Text style={styles.resultValue}>{formatCurrency(result.monthlyNet)}</Text>
          <Text style={styles.resultUnit}>/月</Text>
        </LinearGradient>

        {/* 五险一金 */}
        <InsuranceCard result={result} />

        {/* 个税 */}
        <TaxCard result={result} />

        {/* 薪资结构 */}
        <StructureCard result={result} />

        {/* 更多工具 */}
        <View style={styles.card}>
          <Text style={styles.cardTitle}>更多工具</Text>
          {[
            {
              id: 'year-end',
              title: '年终奖个税计算',
              desc: '单独计税 / 并入综合所得对比',
              icon: 'gift-outline',
              route: '/tools/salary-calculator',
            },
            {
              id: 'severance',
              title: '离职补偿金计算',
              desc: 'N+1 补偿金与个税估算',
              icon: 'cash-outline',
              route: '/tools/salary-calculator',
            },
            {
              id: 'proof',
              title: '公积金/社保证明',
              desc: '一键查询缴纳记录',
              icon: 'document-text-outline',
              route: '/tools/salary-calculator',
            },
          ].map((tool) => (
            <ToolLink key={tool.id} tool={tool} />
          ))}
        </View>

        <Pressable style={styles.saveBtn} onPress={() => Alert.alert('保存计算记录', '保存功能开发中，敬请期待')}>
          <Text style={styles.saveBtnText}>保存计算记录</Text>
        </Pressable>
      </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: 60, justifyContent: 'center' },
  headerTitle: { fontSize: 17, fontWeight: '700', color: colors.textPrimary },
  headerAction: { fontSize: 14, color: colors.primary, textAlign: 'right' },
  body: { padding: 16, paddingBottom: 32 },
  card: {
    backgroundColor: colors.white,
    borderRadius: 14,
    padding: 16,
    marginBottom: 12,
    borderWidth: 1,
    borderColor: colors.borderLight,
  },
  cardTitle: { fontSize: 15, fontWeight: '700', color: colors.textPrimary, marginBottom: 14 },
  inputRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingVertical: 12,
    borderTopWidth: 1,
    borderTopColor: colors.borderLight,
  },
  inputLabel: { fontSize: 14, color: colors.textPrimary },
  inputBox: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: colors.pageBg,
    borderRadius: 10,
    paddingHorizontal: 12,
    paddingVertical: 8,
  },
  input: {
    minWidth: 80,
    fontSize: 15,
    fontWeight: '700',
    color: colors.textPrimary,
    textAlign: 'right',
  },
  inputSuffix: { fontSize: 13, color: colors.textSecondary, marginLeft: 4 },
  selectBox: { flexDirection: 'row', alignItems: 'center' },
  selectValue: { fontSize: 15, fontWeight: '600', color: colors.textPrimary, marginRight: 4 },
  resultCard: {
    borderRadius: 16,
    padding: 24,
    alignItems: 'center',
    marginBottom: 12,
  },
  resultLabel: { fontSize: 14, color: colors.textInverse, opacity: 0.9 },
  resultValue: { fontSize: 42, fontWeight: '800', color: colors.textInverse, marginTop: 8 },
  resultUnit: { fontSize: 14, color: colors.textInverse, opacity: 0.9, marginTop: 2 },
  cardSubTitleRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    marginBottom: 10,
  },
  cardSubTitle: { fontSize: 12, color: colors.textHint },
  insuranceRow: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingVertical: 10,
  },
  insuranceLabel: { flex: 1, fontSize: 14, color: colors.textPrimary },
  insuranceAmount: { width: 80, fontSize: 14, fontWeight: '700', color: colors.textPrimary, textAlign: 'right' },
  insuranceRate: { width: 60, fontSize: 13, color: colors.textSecondary, textAlign: 'right' },
  divider: { height: 1, backgroundColor: colors.borderLight, marginVertical: 10 },
  totalRow: { flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center' },
  totalLabel: { fontSize: 15, fontWeight: '700', color: colors.textPrimary },
  totalAmount: { fontSize: 18, fontWeight: '800', color: colors.primary },
  taxGrid: { flexDirection: 'row', gap: 12, marginBottom: 10 },
  taxItem: {
    flex: 1,
    backgroundColor: colors.pageBg,
    borderRadius: 10,
    padding: 12,
  },
  taxItemLabel: { fontSize: 12, color: colors.textSecondary, marginBottom: 6 },
  taxItemValue: { fontSize: 18, fontWeight: '800', color: colors.textPrimary },
  taxRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    paddingVertical: 8,
  },
  taxRowLabel: { fontSize: 14, color: colors.textPrimary },
  taxRowValue: { fontSize: 15, fontWeight: '700', color: colors.textPrimary },
  structureChart: { flexDirection: 'row', alignItems: 'center' },
  pie: {
    width: 100,
    height: 100,
    borderRadius: 50,
    backgroundColor: colors.borderLight,
    overflow: 'hidden',
  },
  pieSlice: {
    position: 'absolute',
    width: 100,
    height: 100,
    borderRadius: 50,
  },
  structureLegend: { flex: 1, marginLeft: 20 },
  legendRow: { flexDirection: 'row', alignItems: 'center', marginBottom: 10 },
  legendDot: { width: 10, height: 10, borderRadius: 5 },
  legendLabel: { flex: 1, fontSize: 13, color: colors.textPrimary, marginLeft: 8 },
  legendValue: { fontSize: 13, fontWeight: '700', color: colors.textPrimary, marginRight: 8 },
  legendPercent: { width: 40, fontSize: 12, color: colors.textSecondary, textAlign: 'right' },
  toolRow: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingVertical: 12,
    borderTopWidth: 1,
    borderTopColor: colors.borderLight,
  },
  toolIcon: {
    width: 36,
    height: 36,
    borderRadius: 18,
    alignItems: 'center',
    justifyContent: 'center',
  },
  toolBody: { flex: 1, marginLeft: 12 },
  toolTitle: { fontSize: 14, fontWeight: '700', color: colors.textPrimary },
  toolDesc: { fontSize: 12, color: colors.textSecondary, marginTop: 2 },
  saveBtn: {
    backgroundColor: colors.primaryBtn,
    borderRadius: 24,
    paddingVertical: 14,
    alignItems: 'center',
    marginTop: 8,
  },
  saveBtnText: { fontSize: 16, fontWeight: '700', color: colors.white },
});