import { useState } from 'react';
import { View, Text, FlatList, TextInput, TouchableOpacity, ActivityIndicator, RefreshControl } from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useQuery } from '@tanstack/react-query';
import { router } from 'expo-router';
import { api } from '../../../services/api';

const STATUS_CONFIG: Record<string, { label: string; color: string; bg: string; accent: string }> = {
  ACTIVE:    { label: 'Active',    color: '#166534', bg: '#DCFCE7', accent: '#16A34A' },
  SUSPENDED: { label: 'Suspended', color: '#92400E', bg: '#FEF3C7', accent: '#D97706' },
  CANCELLED: { label: 'Cancelled', color: '#991B1B', bg: '#FEE2E2', accent: '#DC2626' },
  PENDING:   { label: 'Pending',   color: '#475569', bg: '#F1F5F9', accent: '#94A3B8' },
  NO_SUB:    { label: 'No Sub',    color: '#6B7280', bg: '#F1F5F9', accent: '#CBD5E1' },
};

// Client.status is null in API — derive from subscription status instead
function getClientStatus(client: any) {
  const sub = client?.subscriptions?.[0];
  if (!sub) return 'NO_SUB';
  return sub.status ?? 'PENDING';
}

export default function ClientsScreen() {
  const [search, setSearch] = useState('');
  const { data, isLoading, refetch, isRefetching } = useQuery({
    queryKey: ['clients'],
    queryFn: () => api.get('/api/v1/clients?limit=100').then(r => r.data?.data ?? r.data),
  });

  const clients = (data ?? []).filter((c: any) =>
    `${c.firstName} ${c.lastName} ${c.accountNumber}`.toLowerCase().includes(search.toLowerCase())
  );

  return (
    <SafeAreaView style={{ flex: 1, backgroundColor: '#0891B2' }} edges={['top']}>
      <View style={{ flex: 1, backgroundColor: '#F8FAFC' }}>
        {/* Header */}
        <View style={{ backgroundColor: '#0891B2', paddingHorizontal: 20, paddingTop: 16, paddingBottom: 20, flexDirection: 'row', alignItems: 'flex-end', justifyContent: 'space-between' }}>
          <View>
            <Text style={{ color: '#FFF', fontSize: 28, fontWeight: '800' }}>Clients</Text>
            <Text style={{ color: '#A5F3FC', fontSize: 15, marginTop: 2 }}>{data?.length ?? 0} subscribers</Text>
          </View>
          <TouchableOpacity
            onPress={() => router.push('/(app)/clients/new')}
            style={{ backgroundColor: '#fff', borderRadius: 20, paddingHorizontal: 14, paddingVertical: 8, flexDirection: 'row', alignItems: 'center', gap: 6 }}
          >
            <Text style={{ fontSize: 18, color: '#0891B2', fontWeight: '800', lineHeight: 20 }}>+</Text>
            <Text style={{ fontSize: 14, fontWeight: '700', color: '#0891B2' }}>New Client</Text>
          </TouchableOpacity>
        </View>

        {/* Search */}
        <View style={{ backgroundColor: '#FFF', paddingHorizontal: 16, paddingVertical: 12, borderBottomWidth: 1, borderBottomColor: '#F1F5F9' }}>
          <View style={{ backgroundColor: '#F8FAFC', borderWidth: 1.5, borderColor: '#E2E8F0', borderRadius: 12, flexDirection: 'row', alignItems: 'center', paddingHorizontal: 14 }}>
            <TextInput
              style={{ flex: 1, paddingVertical: 13, fontSize: 16, color: '#0F172A' }}
              placeholder="Search by name or account #"
              placeholderTextColor="#94A3B8"
              value={search}
              onChangeText={setSearch}
            />
            {search.length > 0 && (
              <TouchableOpacity onPress={() => setSearch('')} hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}>
                <View style={{ width: 20, height: 20, borderRadius: 10, backgroundColor: '#CBD5E1', alignItems: 'center', justifyContent: 'center' }}>
                  <Text style={{ color: '#FFF', fontSize: 12, fontWeight: '800', lineHeight: 14 }}>×</Text>
                </View>
              </TouchableOpacity>
            )}
          </View>
        </View>

        {isLoading ? (
          <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
            <ActivityIndicator color="#0891B2" size="large" />
          </View>
        ) : (
          <FlatList
            data={clients}
            keyExtractor={(item) => item.id}
            refreshControl={<RefreshControl refreshing={isRefetching} onRefresh={refetch} tintColor="#0891B2" />}
            contentContainerStyle={{ padding: 16, paddingBottom: 32 }}
            renderItem={({ item }) => {
              const statusKey = getClientStatus(item);
              const st = STATUS_CONFIG[statusKey] ?? { label: statusKey, color: '#475569', bg: '#F1F5F9', accent: '#94A3B8' };
              const plan = item.subscriptions?.[0]?.plan?.name;
              return (
                <TouchableOpacity
                  style={{ backgroundColor: '#FFF', borderRadius: 16, padding: 18, marginBottom: 12, borderWidth: 1, borderColor: '#F1F5F9', borderLeftWidth: 4, borderLeftColor: st.accent }}
                  onPress={() => router.push(`/(app)/clients/${item.id}`)}
                  activeOpacity={0.7}
                >
                  <View style={{ flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center' }}>
                    <View style={{ flex: 1, marginRight: 12 }}>
                      <Text style={{ fontSize: 17, fontWeight: '700', color: '#0F172A' }}>{item.firstName} {item.lastName}</Text>
                      <Text style={{ fontSize: 14, color: '#64748B', marginTop: 3 }}>{item.accountNumber}{plan ? ` · ${plan}` : ''}</Text>
                      {item.phone && <Text style={{ fontSize: 14, color: '#94A3B8', marginTop: 2 }}>{item.phone}</Text>}
                    </View>
                    <View style={{ borderRadius: 20, paddingHorizontal: 12, paddingVertical: 6, backgroundColor: st.bg }}>
                      <Text style={{ fontSize: 13, fontWeight: '800', color: st.color }}>{st.label}</Text>
                    </View>
                  </View>
                </TouchableOpacity>
              );
            }}
            ListEmptyComponent={
              <View style={{ alignItems: 'center', paddingVertical: 60 }}>
                <Text style={{ fontSize: 17, color: '#94A3B8' }}>No clients found</Text>
              </View>
            }
          />
        )}
      </View>
    </SafeAreaView>
  );
}
