import Ionicons from '@expo/vector-icons/Ionicons';
import { useRouter } from 'expo-router';
import React, { useCallback, useMemo, useState } from 'react';
import type { ListRenderItem } from 'react-native';
import {
  ActivityIndicator,
  FlatList,
  RefreshControl,
  StatusBar,
  StyleSheet,
  Text,
  TouchableOpacity,
  View,
} from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { useBalance } from '@/hooks/use-balance';
import { useTransactions } from '@/hooks/use-transactions';
import type { Transaction, TransactionKind } from '@/lib/api/transactions';

type FilterKey = 'all' | TransactionKind;

const screenPalette = {
  background: '#080808',
  surface: '#101010',
  surfaceActive: '#1C1C1C',
  surfaceOutline: '#1D1D1D',
  divider: '#161616',
  primaryText: '#F5F5F5',
  secondaryText: '#6C6C6C',
  accent: '#FEB840',
  accentHalo: 'rgba(254, 184, 64, 0.22)',
  negative: '#8F8F8F',
};

const FILTERS: { key: FilterKey; label: string }[] = [
  { key: 'all', label: 'All records' },
  { key: 'consumed', label: 'Consumed' },
  { key: 'obtained', label: 'Obtained' },
];

export default function PointsDetailsScreen() {
  const insets = useSafeAreaInsets();
  const router = useRouter();
  const [activeFilter, setActiveFilter] = useState<FilterKey>('all');

  const { balance, isLoading: isBalanceLoading, refresh: refreshBalance } = useBalance();
  const {
    transactions,
    isLoading: isTransactionsLoading,
    refresh: refreshTransactions,
  } = useTransactions();

  const [refreshing, setRefreshing] = useState(false);

  const onRefresh = useCallback(async () => {
    setRefreshing(true);
    await Promise.all([refreshBalance(), refreshTransactions()]);
    setRefreshing(false);
  }, [refreshBalance, refreshTransactions]);

  const filteredEntries = useMemo(() => {
    if (activeFilter === 'all') {
      return transactions;
    }

    return transactions.filter(entry => entry.kind === activeFilter);
  }, [activeFilter, transactions]);

  const listContentStyle = useMemo(
    () => ({
      paddingBottom: Math.max(insets.bottom + 36, 72),
      paddingTop: 4,
    }),
    [insets.bottom],
  );

  const keyExtractor = useCallback((entry: Transaction) => entry.id, []);

  const renderSeparator = useCallback(() => <View style={styles.listDivider} />, []);

  const renderLedgerEntry: ListRenderItem<Transaction> = useCallback(({ item }) => {
    const amount = Math.abs(item.amount);
    const isPositive = item.amount > 0;
    const displayDate = new Date(item.happenedAt).toLocaleString('zh-CN', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      hour: '2-digit',
      minute: '2-digit',
    });

    return (
      <View style={styles.recordRow}>
        <View>
          <Text style={styles.recordTitle}>{item.title}</Text>
          <Text style={styles.recordTimestamp}>{displayDate}</Text>
        </View>
        <Text
          style={[
            styles.recordValue,
            isPositive ? styles.valuePositive : styles.valueNegative,
          ]}
        >
          {isPositive ? `+ ${amount}` : `- ${amount}`}
        </Text>
      </View>
    );
  }, []);

  const isLoading = isBalanceLoading || isTransactionsLoading;

  return (
    <View style={[styles.screen, { paddingTop: insets.top + 12 }]}>
      <StatusBar barStyle="light-content" />

      {isLoading && !refreshing ? (
        <View style={styles.loadingContainer}>
          <ActivityIndicator size="large" color={screenPalette.accent} />
        </View>
      ) : (
        <>
          <View style={styles.balanceCluster}>
            <View style={styles.energyOrb}>
              <Ionicons name="flash" size={22} color={screenPalette.accent} />
            </View>
            <Text style={styles.balanceValue}>{balance.remainingTokenBalance}</Text>
          </View>

          <View style={styles.segmentRail}>
            {FILTERS.map(filter => {
              const isActive = filter.key === activeFilter;

              return (
                <TouchableOpacity
                  key={filter.key}
                  style={[styles.segmentChip, isActive && styles.segmentChipActive]}
                  onPress={() => setActiveFilter(filter.key)}
                  accessibilityRole="button"
                >
                  <Text style={[styles.segmentLabel, isActive && styles.segmentLabelActive]}>
                    {filter.label}
                  </Text>
                </TouchableOpacity>
              );
            })}
          </View>

          <FlatList
            data={filteredEntries}
            keyExtractor={keyExtractor}
            style={styles.list}
            contentContainerStyle={listContentStyle}
            showsVerticalScrollIndicator={false}
            ItemSeparatorComponent={renderSeparator}
            renderItem={renderLedgerEntry}
            refreshControl={
              <RefreshControl
                refreshing={refreshing}
                onRefresh={onRefresh}
                tintColor={screenPalette.accent}
              />
            }
          />
        </>
      )}
    </View>
  );
}

const styles = StyleSheet.create({
  screen: {
    flex: 1,
    backgroundColor: screenPalette.background,
    paddingHorizontal: 24,
  },
  loadingContainer: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
  headerRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    minHeight: 48,
  },
  iconButton: {
    width: 40,
    height: 40,
    borderRadius: 20,
    alignItems: 'center',
    justifyContent: 'center',
  },
  headerTitle: {
    fontSize: 17,
    lineHeight: 24,
    fontWeight: '600',
    color: screenPalette.primaryText,
    letterSpacing: 0.2,
  },
  balanceCluster: {
    alignItems: 'center',
    marginTop: 32,
    marginBottom: 28,
    gap: 10,
  },
  energyOrb: {
    width: 60,
    height: 60,
    borderRadius: 30,
    backgroundColor: screenPalette.accentHalo,
    alignItems: 'center',
    justifyContent: 'center',
    shadowColor: screenPalette.accent,
    shadowOpacity: 0.3,
    shadowRadius: 16,
    shadowOffset: { width: 0, height: 8 },
    elevation: 8,
  },
  balanceValue: {
    fontSize: 46,
    lineHeight: 52,
    fontWeight: '700',
    color: screenPalette.primaryText,
    letterSpacing: 0.5,
    fontVariant: ['tabular-nums'],
  },
  segmentRail: {
    flexDirection: 'row',
    backgroundColor: screenPalette.surface,
    padding: 4,
    borderRadius: 28,
    borderWidth: StyleSheet.hairlineWidth,
    borderColor: screenPalette.surfaceOutline,
    gap: 4,
  },
  segmentChip: {
    flex: 1,
    borderRadius: 24,
    alignItems: 'center',
    justifyContent: 'center',
    paddingVertical: 11,
  },
  segmentChipActive: {
    backgroundColor: screenPalette.surfaceActive,
  },
  segmentLabel: {
    fontSize: 14,
    lineHeight: 20,
    color: screenPalette.secondaryText,
    fontWeight: '500',
    letterSpacing: 0.2,
  },
  segmentLabelActive: {
    color: screenPalette.primaryText,
  },
  list: {
    flex: 1,
    marginTop: 28,
  },
  listDivider: {
    height: StyleSheet.hairlineWidth,
    backgroundColor: screenPalette.divider,
    marginVertical: 0,
  },
  recordRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingVertical: 14,
  },
  recordTitle: {
    fontSize: 15,
    lineHeight: 22,
    fontWeight: '600',
    color: screenPalette.primaryText,
  },
  recordTimestamp: {
    marginTop: 6,
    fontSize: 12,
    lineHeight: 18,
    color: screenPalette.secondaryText,
    letterSpacing: 0.2,
  },
  recordValue: {
    fontSize: 16,
    lineHeight: 22,
    fontWeight: '600',
    fontVariant: ['tabular-nums'],
  },
  valuePositive: {
    color: screenPalette.accent,
  },
  valueNegative: {
    color: screenPalette.negative,
  },
});