import React, { useState, useCallback } from 'react';
import { View, Text, StyleSheet, FlatList, ActivityIndicator, TouchableOpacity, RefreshControl, SafeAreaView, Alert } from 'react-native';
import { Ionicons } from '@expo/vector-icons';
import { useNavigation, useFocusEffect } from '@react-navigation/native';
import apiService from '../../services/apiService';
import { COLORS } from '../../constants/colors';
import { StatusBar } from 'expo-status-bar';

const CARD_BG = '#F1F9F1';
const CIRCLE_BG = '#A2E4A4';

const LoanOrdersScreen = () => {
  const navigation = useNavigation();
  const [orders, setOrders] = useState([]);
  const [loading, setLoading] = useState(true);
  const [refreshing, setRefreshing] = useState(false);

  const fetchOrders = async () => {
    try {
      const res = await apiService.getLoanOrders();
      if (res.success) {
        setOrders(Array.isArray(res.data) ? res.data : []);
      } else {
        console.warn(res.error);
      }
    } catch (e) {
      console.warn(e.message);
    } finally {
      setLoading(false);
      setRefreshing(false);
    }
  };

  useFocusEffect(
    useCallback(() => {
      fetchOrders();
    }, [])
  );

  const onRefresh = () => {
    setRefreshing(true);
    fetchOrders();
  };

  const renderItem = ({ item }) => {
    const amountLine = `Karz mukdary: `;
    const amount = (item.loan_amount + ' TMT') || '-';
    const created = item.created_at ? new Date(item.created_at).toLocaleDateString() : '';

    const handleDelete = async (orderId) => {
      Alert.alert(
        "Sargyty pozmak",
        "Siz hakykatdanam bu sargyty pozmak isleýärsiňizmi?",
        [
          { text: "Ýok", style: "cancel" },
          {
            text: "Hawa",
            onPress: async () => {
              try {
                const res = await apiService.deleteLoanOrder(orderId);
                if (res.success) {
                  setOrders(prevOrders => prevOrders.filter(order => order.id !== orderId));
                } else {
                  console.warn('Failed to delete order:', res.error);
                }
              } catch (e) {
                console.error('Error deleting order:', e.message);
              }
            },
          },
        ],
        { cancelable: true }
      );
    };

    return (
      <TouchableOpacity style={styles.card} onPress={() => navigation.navigate('LoanOrderDetails', { orderId: item.id })}>
        <View style={styles.circle}>
          <Text style={styles.circleText}>{item.id}</Text>
        </View>
        <View style={styles.cardContent}>
          <Text style={styles.passportText}>{item.loan_type}</Text>
          <Text style={styles.accountLabel}>{amountLine}
            <Text style={{ color: COLORS.textPrimary }}>{amount}</Text>
          </Text>
          
          <Text style={styles.dateText}>Döredilen senesi: {created}</Text>
        </View>
        <TouchableOpacity onPress={() => handleDelete(item.id)} style={styles.deleteButton}>
          <Ionicons name="trash" size={24} color={COLORS.error} />
        </TouchableOpacity>
      </TouchableOpacity>
    );
  };

  if (loading) {
    return (
      <View style={styles.centered}>
        <ActivityIndicator size="large" color={COLORS.primary} />
      </View>
    );
  }

  return (
    <SafeAreaView style={styles.container}>
      <StatusBar style="dark" />
      {/* Header */}
      <View style={styles.header}>
        <TouchableOpacity onPress={() => navigation.goBack()} style={{ paddingRight: 12 }}>
          <Ionicons name="arrow-back" size={24} color={COLORS.textPrimary} />
        </TouchableOpacity>
        <Text style={styles.headerTitle}>Karz sargytlar</Text>
      </View>

      <FlatList
        data={orders}
        keyExtractor={(it) => it.id?.toString()}
        renderItem={renderItem}
        contentContainerStyle={orders.length === 0 && styles.emptyContainer}
        refreshControl={<RefreshControl refreshing={refreshing} onRefresh={onRefresh} />}
        ListEmptyComponent={<Text style={styles.emptyText}>Maglumat ýok</Text>}
      />

      <TouchableOpacity style={styles.fab} onPress={() => navigation.navigate('CreateLoanOrder')}>
        <Ionicons name="add" size={28} color={COLORS.white} />
      </TouchableOpacity>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: COLORS.backgroundSecondary },
  centered: { flex: 1, alignItems: 'center', justifyContent: 'center' },
  header: { flexDirection: 'row', alignItems: 'center', padding: 16 },
  headerTitle: { fontSize: 18, fontWeight: 'bold', color: COLORS.textPrimary, marginLeft: 12 },
  card: {
    flexDirection: 'row',
    backgroundColor: CARD_BG,
    marginHorizontal: 24,
    marginTop: 16,
    borderRadius: 12,
    padding: 16,
    alignItems: 'center',
    justifyContent: 'space-between',
  },
  circle: {
    width: 40,
    height: 40,
    borderRadius: 20,
    backgroundColor: CIRCLE_BG,
    alignItems: 'center',
    justifyContent: 'center',
    marginRight: 16,
  },
  circleText: { color: COLORS.white, fontWeight: '600' },
  cardContent: { flex: 1 },
  passportText: { fontWeight: '700', color: COLORS.textPrimary, marginBottom: 4 },
  accountLabel: { color: COLORS.textSecondary, fontSize: 14 },
  accountValue: { color: COLORS.textPrimary, marginBottom: 4 },
  dateText: { color: COLORS.textSecondary, fontSize: 12, textAlign: 'left' },
  emptyContainer: { flex: 1, justifyContent: 'center', alignItems: 'center' },
  emptyText: { fontSize: 16, color: COLORS.textSecondary },
  fab: {
    position: 'absolute',
    right: 24,
    bottom: 40,
    width: 56,
    height: 56,
    borderRadius: 28,
    backgroundColor: COLORS.primary,
    alignItems: 'center',
    justifyContent: 'center',
    elevation: 4,
  },
  deleteButton: {
    padding: 8,
  },
});

export default LoanOrdersScreen;