import React, { useCallback, useMemo, useState } from 'react';
import {
  ActivityIndicator,
  FlatList,
  Pressable,
  RefreshControl,
  ScrollView,
  StyleSheet,
  Text,
  View,
} from 'react-native';
import type { NativeStackScreenProps } from '@react-navigation/native-stack';
import { Icon } from '../../../components/Icon';
import DatePicker from 'react-native-date-picker';

import {
  AppModal as Modal,
  Button,
  Card,
  EmptyState,
  Loader,
  ScreenShell,
  SegmentedControl,
} from '../../../components';
import { useTheme } from '../../../theme';
import { formatCurrency, formatDate, formatTime } from '../../../utils/formatters';
import type { HomeStackParamList } from '../../../navigation/types';
import type { ApiError } from '../../../types/api';
import type { BeneficiaryMode, FundTransferHistoryItem, FundTransferStatus } from '../../../types/cbs';
import { describeError } from '../../../services/api/cbsErrors';
import { toStatementDate } from '../../home/utils/statement';
import { useFundTransferHistory, type HistoryFilters } from '../hooks/useFundTransferHistory';
import { humaniseReason, statusCopy, toneColors } from '../utils/transferStatus';

type Props = NativeStackScreenProps<HomeStackParamList, 'TransferHistory'>;

const STATUS_FILTERS: ReadonlyArray<{ value: FundTransferStatus | 'ALL'; label: string }> = [
  { value: 'ALL', label: 'All' },
  { value: 'SUCCESS', label: 'Successful' },
  { value: 'FAILED', label: 'Failed' },
  { value: 'PROCESSING', label: 'In progress' },
  { value: 'PENDING_RECONCILIATION', label: 'Pending' },
  { value: 'MANUAL_REVIEW', label: 'Under review' },
];

const MODE_FILTERS: ReadonlyArray<{ value: BeneficiaryMode | 'ALL'; label: string }> = [
  { value: 'ALL', label: 'All' },
  { value: 'P2A', label: 'Account' },
  { value: 'P2P', label: 'Mobile' },
];

function TransferRow({
  item,
  onPress,
}: {
  item: FundTransferHistoryItem;
  onPress: (item: FundTransferHistoryItem) => void;
}) {
  const theme = useTheme();
  const copy = statusCopy(item.status);
  const colors = toneColors(copy.tone, theme.colors);
  // Shown only for failed and review states, and only when there is one.
  const showReason =
    Boolean(item.failureReason) && (item.status === 'FAILED' || item.status === 'MANUAL_REVIEW');

  return (
    <Pressable
      accessibilityRole="button"
      accessibilityLabel={`${item.payeeName ?? 'Transfer'}, ${formatCurrency(item.amount)}, ${copy.label}`}
      onPress={() => onPress(item)}
    >
      <Card style={styles.card}>
        <View style={styles.row}>
          <View style={[styles.iconWrap, { backgroundColor: colors.surface }]}>
            <Icon name={copy.icon} size={20} color={colors.tone} />
          </View>

          <View style={styles.copy}>
            <Text
              numberOfLines={1}
              style={[theme.text.bodyStrong, { color: theme.colors.textPrimary }]}
            >
              {item.payeeName || 'Payee'}
            </Text>
            {item.payeeDisplay ? (
              <Text style={[theme.text.caption, { color: theme.colors.textSecondary }]}>
                {item.payeeDisplay}
              </Text>
            ) : null}
            <Text style={[theme.text.caption, { color: theme.colors.textMuted }]}>
              {`${formatDate(item.createdAt)} · ${formatTime(item.createdAt)}`}
            </Text>
            {showReason ? (
              <Text style={[theme.text.caption, { color: theme.colors.danger }]}>
                {humaniseReason(item.failureReason as string)}
              </Text>
            ) : null}
          </View>

          <View style={styles.trailing}>
            <Text style={[theme.text.bodyStrong, { color: theme.colors.textPrimary }]}>
              {formatCurrency(item.amount)}
            </Text>
            <View
              style={[
                styles.badge,
                { backgroundColor: colors.surface, borderColor: colors.border },
              ]}
            >
              {/* See TransferDetailScreen: `simple` stops Android clipping the
                  last word of a label drawn in a custom font. */}
              <Text
                textBreakStrategy="simple"
                style={[theme.text.caption, styles.badgeText, { color: colors.tone }]}
              >
                {copy.label}
              </Text>
            </View>
          </View>
        </View>
      </Card>
    </Pressable>
  );
}

export default function TransferHistoryScreen({ navigation }: Props) {
  const theme = useTheme();
  const [filters, setFilters] = useState<HistoryFilters>({ status: 'ALL', mode: 'ALL' });

  const [rangeOpen, setRangeOpen] = useState(false);
  const [pickerOpen, setPickerOpen] = useState<'from' | 'to' | null>(null);
  const [tempFrom, setTempFrom] = useState(() => {
    const date = new Date();
    date.setDate(date.getDate() - 30);
    return date;
  });
  const [tempTo, setTempTo] = useState(() => new Date());
  const [rangeError, setRangeError] = useState<string | null>(null);

  const { transfers, totalElements, hasMore, isLoading, isLoadingMore, isRefreshing, error, loadMore, reload } =
    useFundTransferHistory(filters);

  const apiError = error as ApiError | undefined;

  const hasRange = Boolean(filters.fromDate && filters.toDate);

  const openDetail = useCallback(
    (item: FundTransferHistoryItem) => navigation.navigate('TransferDetail', { transferId: item.transferId }),
    [navigation],
  );

  const applyRange = useCallback(() => {
    if (tempFrom.getTime() > tempTo.getTime()) {
      setRangeError('The start date cannot be after the end date.');
      return;
    }

    setRangeError(null);
    setRangeOpen(false);
    setFilters((current) => ({
      ...current,
      fromDate: toStatementDate(tempFrom),
      toDate: toStatementDate(tempTo),
    }));
  }, [tempFrom, tempTo]);

  const clearRange = useCallback(() => {
    setRangeOpen(false);
    setRangeError(null);
    setFilters((current) => ({ ...current, fromDate: undefined, toDate: undefined }));
  }, []);

  const subtitle = useMemo(() => {
    if (isLoading) return 'Loading your transfers';
    return `${totalElements} ${totalElements === 1 ? 'transfer' : 'transfers'}`;
  }, [isLoading, totalElements]);

  const listHeader = (
    <View style={styles.filters}>
      <ScrollView horizontal showsHorizontalScrollIndicator={false} contentContainerStyle={styles.chips}>
        {STATUS_FILTERS.map((option) => {
          const active = filters.status === option.value;

          return (
            <Pressable
              key={option.value}
              accessibilityRole="button"
              accessibilityState={{ selected: active }}
              onPress={() => setFilters((current) => ({ ...current, status: option.value }))}
              style={[
                styles.chip,
                {
                  borderRadius: theme.radius.pill,
                  backgroundColor: active ? theme.colors.primary : theme.colors.surface,
                  borderColor: active ? theme.colors.primary : theme.colors.cardBorder,
                },
              ]}
            >
              <Text
                style={[
                  theme.text.bodySmall,
                  { color: active ? theme.colors.textOnBrand : theme.colors.textPrimary },
                ]}
              >
                {option.label}
              </Text>
            </Pressable>
          );
        })}
      </ScrollView>

      <SegmentedControl
        options={MODE_FILTERS}
        value={filters.mode}
        onChange={(mode) => setFilters((current) => ({ ...current, mode }))}
        accessibilityLabel="Transfer type"
      />

      <Pressable
        accessibilityRole="button"
        onPress={() => setRangeOpen(true)}
        style={[
          styles.rangeButton,
          {
            backgroundColor: theme.colors.surface,
            borderColor: hasRange ? theme.colors.primary : theme.colors.cardBorder,
            borderRadius: theme.radius.md,
          },
        ]}
      >
        <Icon name="calendar-outline" size={18} color={theme.colors.primary} />
        <Text style={[theme.text.body, styles.rangeText, { color: theme.colors.textPrimary }]}>
          {hasRange
            ? `${formatDate(filters.fromDate as string)} – ${formatDate(filters.toDate as string)}`
            : 'Any date'}
        </Text>
        <Icon name="chevron-down" size={16} color={theme.colors.textMuted} />
      </Pressable>
    </View>
  );

  const renderEmpty = () => {
    if (isLoading) {
      return <Loader />;
    }

    if (apiError) {
      const copy = describeError(apiError.code);

      return (
        <EmptyState
          title={copy.title}
          description={apiError.message || copy.description}
          actionLabel="Try again"
          onAction={reload}
        />
      );
    }

    return (
      <EmptyState
        title="No transfers found"
        description={
          filters.status === 'ALL' && filters.mode === 'ALL' && !hasRange
            ? 'Transfers you make from the app will appear here.'
            : 'Nothing matches these filters. Try widening them.'
        }
      />
    );
  };

  return (
    <ScreenShell title="History" subtitle={subtitle} scrollable={false}>
      <FlatList
        data={transfers}
        keyExtractor={(item) => item.transferId}
        renderItem={({ item }) => <TransferRow item={item} onPress={openDetail} />}
        ListHeaderComponent={listHeader}
        ListEmptyComponent={renderEmpty}
        ListFooterComponent={
          isLoadingMore ? (
            <ActivityIndicator style={styles.footer} color={theme.colors.primary} />
          ) : null
        }
        ItemSeparatorComponent={Separator}
        onEndReached={hasMore ? loadMore : undefined}
        onEndReachedThreshold={0.4}
        refreshControl={
          <RefreshControl
            refreshing={isRefreshing}
            onRefresh={reload}
            tintColor={theme.colors.primary}
            colors={[theme.colors.primary]}
          />
        }
        showsVerticalScrollIndicator={false}
        contentContainerStyle={styles.listContent}
      />

      <Modal visible={rangeOpen} onClose={() => setRangeOpen(false)} title="Filter by date">
        <View style={styles.modalBody}>
          {(['from', 'to'] as const).map((which) => (
            <View key={which} style={styles.dateField}>
              <Text style={[theme.text.eyebrow, { color: theme.colors.textSecondary }]}>
                {which === 'from' ? 'From' : 'To'}
              </Text>
              <Pressable
                accessibilityRole="button"
                onPress={() => setPickerOpen(which)}
                style={[
                  styles.rangeButton,
                  {
                    backgroundColor: theme.colors.surfaceMuted,
                    borderColor: theme.colors.cardBorder,
                    borderRadius: theme.radius.md,
                  },
                ]}
              >
                <Icon name="calendar-outline" size={18} color={theme.colors.primary} />
                <Text style={[theme.text.body, styles.rangeText, { color: theme.colors.textPrimary }]}>
                  {formatDate(toStatementDate(which === 'from' ? tempFrom : tempTo))}
                </Text>
              </Pressable>
            </View>
          ))}

          {rangeError ? (
            <Text style={[theme.text.caption, { color: theme.colors.danger }]}>{rangeError}</Text>
          ) : null}

          <View style={styles.modalActions}>
            <Button title="Apply" onPress={applyRange} style={styles.modalButton} />
            <Button
              title={hasRange ? 'Clear dates' : 'Cancel'}
              variant="secondary"
              onPress={hasRange ? clearRange : () => setRangeOpen(false)}
              style={styles.modalButton}
            />
          </View>
        </View>

        <DatePicker
          modal
          open={pickerOpen !== null}
          date={pickerOpen === 'to' ? tempTo : tempFrom}
          maximumDate={new Date()}
          mode="date"
          title={pickerOpen === 'to' ? 'Select end date' : 'Select start date'}
          onConfirm={(date) => {
            if (pickerOpen === 'to') setTempTo(date);
            else setTempFrom(date);
            setPickerOpen(null);
            setRangeError(null);
          }}
          onCancel={() => setPickerOpen(null)}
        />
      </Modal>
    </ScreenShell>
  );
}

const Separator = () => <View style={styles.separator} />;

const styles = StyleSheet.create({
  listContent: {
    paddingBottom: 24,
    flexGrow: 1,
  },
  filters: {
    gap: 12,
    marginBottom: 16,
  },
  chips: {
    gap: 8,
  },
  chip: {
    paddingHorizontal: 14,
    paddingVertical: 8,
    borderWidth: 1,
  },
  rangeButton: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 10,
    paddingHorizontal: 14,
    paddingVertical: 12,
    borderWidth: 1,
  },
  rangeText: {
    flex: 1,
  },
  separator: {
    height: 10,
  },
  card: {
    padding: 14,
  },
  row: {
    flexDirection: 'row',
    alignItems: 'flex-start',
    gap: 12,
  },
  iconWrap: {
    width: 40,
    height: 40,
    borderRadius: 20,
    alignItems: 'center',
    justifyContent: 'center',
  },
  copy: {
    flex: 1,
    gap: 2,
  },
  trailing: {
    alignItems: 'flex-end',
    gap: 6,
  },
  badgeText: {
    textAlign: 'right',
  },
  badge: {
    maxWidth: 150,
    paddingHorizontal: 8,
    paddingVertical: 2,
    borderRadius: 999,
    borderWidth: 1,
  },
  footer: {
    marginVertical: 16,
  },
  modalBody: {
    gap: 14,
  },
  dateField: {
    gap: 6,
  },
  modalActions: {
    flexDirection: 'row',
    gap: 10,
    marginTop: 6,
  },
  modalButton: {
    flex: 1,
  },
});