import React, { useState } from 'react';
import { Pressable, StyleSheet, Text, View } from 'react-native';
import * as Haptics from 'expo-haptics';
import { theme } from '../theme';

interface Props {
  title: string;
  error?: string | null;
  onSubmit: (pin: string) => Promise<void> | void;
  onCancel: () => void;
}

const KEYS: (string | null)[] = ['1', '2', '3', '4', '5', '6', '7', '8', '9', null, '0', '⌫'];

export function PinEntry({ title, error, onSubmit, onCancel }: Props) {
  const [pin, setPin] = useState('');

  function press(k: string) {
    if (k === '⌫') {
      setPin((p) => p.slice(0, -1));
      Haptics.selectionAsync().catch(() => {});
      return;
    }
    if (pin.length >= 8) return;
    setPin((p) => p + k);
    Haptics.selectionAsync().catch(() => {});
  }

  return (
    <View style={styles.root}>
      <Text style={styles.title}>{title}</Text>
      {error ? <Text style={styles.error}>{error}</Text> : <View style={{ height: 18 }} />}
      <View style={styles.dots}>
        {Array.from({ length: Math.max(4, pin.length) }).map((_, i) => (
          <View
            key={i}
            style={[styles.dot, i < pin.length && styles.dotFilled]}
          />
        ))}
      </View>

      <View style={styles.pad}>
        {KEYS.map((k, i) =>
          k === null ? (
            <View key={i} style={[styles.key, styles.keyEmpty]} />
          ) : (
            <Pressable
              key={i}
              style={({ pressed }) => [styles.key, pressed && styles.keyPressed]}
              onPress={() => press(k)}
            >
              <Text style={k === '⌫' ? styles.keyBack : styles.keyText}>{k}</Text>
            </Pressable>
          ),
        )}
      </View>

      <View style={styles.actions}>
        <Pressable style={styles.ghostBtn} onPress={onCancel}>
          <Text style={styles.ghostText}>Cancel</Text>
        </Pressable>
        <Pressable
          style={[styles.primaryBtn, pin.length < 4 && styles.primaryBtnDisabled]}
          disabled={pin.length < 4}
          onPress={() => onSubmit(pin)}
        >
          <Text style={styles.primaryText}>Next</Text>
        </Pressable>
      </View>
    </View>
  );
}

const KEY_SIZE = 72;

const styles = StyleSheet.create({
  root: { flex: 1, backgroundColor: theme.bg, alignItems: 'center', paddingTop: 60 },
  title: { color: theme.fg, fontSize: 18, fontWeight: '700' },
  error: { color: theme.bad, fontSize: 13, marginTop: 8 },
  dots: { flexDirection: 'row', gap: 14, marginTop: 14, minHeight: 16 },
  dot: {
    width: 12,
    height: 12,
    borderRadius: 6,
    borderWidth: 1.5,
    borderColor: theme.border,
  },
  dotFilled: { backgroundColor: theme.accent, borderColor: theme.accent },
  pad: {
    marginTop: 24,
    flexDirection: 'row',
    flexWrap: 'wrap',
    width: KEY_SIZE * 3 + 36,
    justifyContent: 'space-between',
    rowGap: 12,
  },
  key: {
    width: KEY_SIZE,
    height: KEY_SIZE,
    borderRadius: KEY_SIZE / 2,
    backgroundColor: theme.card,
    borderWidth: 1,
    borderColor: theme.border,
    alignItems: 'center',
    justifyContent: 'center',
  },
  keyEmpty: { backgroundColor: 'transparent', borderColor: 'transparent' },
  keyPressed: { backgroundColor: theme.bgElevated, borderColor: theme.borderFocus },
  keyText: { color: theme.fg, fontSize: 26, fontWeight: '500' },
  keyBack: { color: theme.muted, fontSize: 22 },
  actions: {
    flexDirection: 'row',
    gap: 12,
    marginTop: 28,
    paddingHorizontal: 24,
  },
  ghostBtn: {
    paddingVertical: 12,
    paddingHorizontal: 22,
    borderRadius: 10,
    borderWidth: 1,
    borderColor: theme.border,
  },
  ghostText: { color: theme.muted, fontSize: 14, fontWeight: '600' },
  primaryBtn: {
    paddingVertical: 12,
    paddingHorizontal: 30,
    borderRadius: 10,
    backgroundColor: theme.accent,
  },
  primaryBtnDisabled: { backgroundColor: theme.border },
  primaryText: { color: '#fff', fontSize: 14, fontWeight: '700' },
});