import { View, Text, ScrollView, RefreshControl, ActivityIndicator, TouchableOpacity, Linking, Alert } from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useQueries } from '@tanstack/react-query';
import { router } from 'expo-router';
import { api } from '../../services/api';
import { useAuthStore } from '../../stores/authStore';

const PRIORITY_COLOR: Record<string, string> = { HIGH: '#DC2626', NORMAL: '#0891B2' };
const PRIORITY_BG: Record<string, string>    = { HIGH: '#FEE2E2', NORMAL: '#ECFEFF' };
const TYPE_COLOR: Record<string, string>     = { INSTALLATION: '#0891B2', SUPPORT: '#7C3AED', BILLING: '#D97706' };

function KpiCard({ label, value, color, bg }: { label: string; value: string | number; color: string; bg: string }) {
  return (
    <View style={{ flex: 1, marginHorizontal: 5, borderRadius: 16, padding: 16, backgroundColor: bg }}>
      <Text style={{ fontSize: 11, fontWeight: '700', color, marginBottom: 6, textTransform: 'uppercase', letterSpacing: 0.5 }}>{label}</Text>
      <Text style={{ fontSize: 26, fontWeight: '800', color }}>{value}</Text>
    </View>
  );
}

function TicketRow({ task, onPress }: { task: any; onPress: () => void }) {
  const typeColor = TYPE_COLOR[task.type] ?? '#6B7280';
  return (
    <TouchableOpacity
      onPress={onPress}
      activeOpacity={0.7}
      style={{ backgroundColor: '#FFF', borderRadius: 14, padding: 16, marginBottom: 10, borderWidth: 1, borderColor: '#F1F5F9', borderLeftWidth: 4, borderLeftColor: typeColor }}
    >
      <View style={{ flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center', marginBottom: 6 }}>
        <View style={{ flexDirection: 'row', gap: 6, alignItems: 'center' }}>
          <View style={{ borderRadius: 20, paddingHorizontal: 8, paddingVertical: 3, backgroundColor: `${typeColor}20` }}>
            <Text style={{ fontSize: 11, fontWeight: '700', color: typeColor }}>{task.type}</Text>
          </View>
          {task.priority === 'HIGH' && (
            <View style={{ borderRadius: 20, paddingHorizontal: 8, paddingVertical: 3, backgroundColor: PRIORITY_BG.HIGH }}>
              <Text style={{ fontSize: 11, fontWeight: '700', color: PRIORITY_COLOR.HIGH }}>HIGH</Text>
            </View>
          )}
        </View>
        <Text style={{ fontSize: 12, fontWeight: '600', color: '#64748B' }}>
          {task.status?.replace('_', ' ')}
        </Text>
      </View>
      <Text style={{ fontSize: 15, fontWeight: '700', color: '#0F172A' }} numberOfLines={1}>{task.subject}</Text>
      <Text style={{ fontSize: 13, color: '#64748B', marginTop: 3 }}>
        {task.client?.firstName} {task.client?.lastName}
        {task.assignedTo ? ` · ${task.assignedTo.firstName}` : ' · Unassigned'}
      </Text>
    </TouchableOpacity>
  );
}

function InvoiceRow({ inv }: { inv: any }) {
  const dueDate  = inv.dueDate ? new Date(inv.dueDate) : null;
  const today    = new Date();
  const isOverdue = dueDate && dueDate < today;
  const daysLeft  = dueDate ? Math.ceil((dueDate.getTime() - today.getTime()) / 86400000) : null;

  const navigate = () => {
    const lat = inv.client?.lat;
    const lng = inv.client?.lng;
    if (!lat || !lng) {
      Alert.alert('No Location', 'This client does not have a recorded location yet.');
      return;
    }
    Alert.alert('Navigate', `Open navigation to ${inv.client?.firstName} ${inv.client?.lastName}?`, [
      { text: 'Google Maps', onPress: () => Linking.openURL(`https://www.google.com/maps/dir/?api=1&destination=${lat},${lng}`) },
      { text: 'Waze', onPress: () => Linking.openURL(`waze://?ll=${lat},${lng}&navigate=yes`) },
      { text: 'Cancel', style: 'cancel' },
    ]);
  };

  return (
    <View style={{ backgroundColor: '#FFF', borderRadius: 14, padding: 16, marginBottom: 10, borderWidth: 1, borderColor: isOverdue ? '#FCA5A5' : '#F1F5F9', borderLeftWidth: 4, borderLeftColor: isOverdue ? '#DC2626' : '#F59E0B' }}>
      <View style={{ flexDirection: 'row', justifyContent: 'space-between', alignItems: 'flex-start' }}>
        <View style={{ flex: 1 }}>
          <Text style={{ fontSize: 15, fontWeight: '700', color: '#0F172A' }}>
            {inv.client?.firstName} {inv.client?.lastName}
          </Text>
          <Text style={{ fontSize: 13, color: '#64748B', marginTop: 2 }}>{inv.invoiceNumber}</Text>
          <Text style={{ fontSize: 13, color: isOverdue ? '#DC2626' : '#D97706', fontWeight: '600', marginTop: 3 }}>
            {isOverdue
              ? `Overdue by ${Math.abs(daysLeft ?? 0)} day${Math.abs(daysLeft ?? 0) !== 1 ? 's' : ''}`
              : daysLeft !== null
                ? `Due in ${daysLeft} day${daysLeft !== 1 ? 's' : ''}`
                : 'No due date'}
          </Text>
        </View>
        <View style={{ alignItems: 'flex-end' }}>
          <Text style={{ fontSize: 16, fontWeight: '800', color: '#991B1B' }}>₱{Number(inv.balance).toLocaleString()}</Text>
          <TouchableOpacity onPress={navigate} style={{ marginTop: 8, backgroundColor: '#ECFEFF', borderRadius: 10, paddingHorizontal: 10, paddingVertical: 6 }} activeOpacity={0.7}>
            <Text style={{ fontSize: 12, fontWeight: '700', color: '#0891B2' }}>📍 Navigate</Text>
          </TouchableOpacity>
        </View>
      </View>
    </View>
  );
}

export default function DashboardScreen() {
  const { user } = useAuthStore();
  const role  = user?.roles?.[0] ?? user?.role ?? '';
  const isAdminOrStaff = role === 'ADMIN' || role === 'STAFF';

  const hour = new Date().getHours();
  const greeting = hour < 12 ? 'Good morning' : hour < 18 ? 'Good afternoon' : 'Good evening';

  const [summaryQ, ticketsQ, invoicesQ] = useQueries({
    queries: [
      {
        queryKey: ['dashboard'],
        queryFn: () => api.get('/api/v1/dashboard/summary').then(r => r.data),
      },
      {
        queryKey: ['dashboard-tickets'],
        queryFn: async () => {
          const res = await api.get('/api/v1/tickets?limit=50');
          const all: any[] = res.data?.data ?? res.data ?? [];
          return all.filter((t: any) => t.status === 'OPEN' || t.status === 'IN_PROGRESS');
        },
      },
      {
        queryKey: ['dashboard-invoices'],
        queryFn: async () => {
          const res = await api.get('/api/v1/invoices?limit=50');
          const all: any[] = res.data?.data ?? res.data ?? [];
          const unpaid = all.filter((inv: any) => ['SENT', 'PARTIAL', 'OVERDUE'].includes(inv.status) && Number(inv.balance) > 0);
          unpaid.sort((a: any, b: any) => {
            const da = a.dueDate ? new Date(a.dueDate).getTime() : Infinity;
            const db = b.dueDate ? new Date(b.dueDate).getTime() : Infinity;
            return da - db;
          });
          return unpaid.slice(0, 10);
        },
      },
    ],
  });

  const isLoading = summaryQ.isLoading || ticketsQ.isLoading || invoicesQ.isLoading;
  const isRefetching = summaryQ.isRefetching || ticketsQ.isRefetching || invoicesQ.isRefetching;

  const summary = summaryQ.data ?? {};
  const allActiveTickets: any[] = ticketsQ.data ?? [];
  const unpaidInvoices: any[]   = invoicesQ.data ?? [];

  const unassigned   = allActiveTickets.filter((t: any) => !t.assignedToId);
  const assignedToMe = allActiveTickets.filter((t: any) => t.assignedToId === user?.id);
  // Merge: assigned-to-me first, then unassigned, deduped, max 10
  const seen = new Set<string>();
  const mergedTickets = [...assignedToMe, ...unassigned].filter((t: any) => {
    if (seen.has(t.id)) return false;
    seen.add(t.id);
    return true;
  }).slice(0, 10);
  const byPrio = (a: any, b: any) => (a.priority === 'HIGH' ? -1 : 1) - (b.priority === 'HIGH' ? -1 : 1);

  const refetchAll = () => { summaryQ.refetch(); ticketsQ.refetch(); invoicesQ.refetch(); };

  return (
    <SafeAreaView style={{ flex: 1, backgroundColor: '#0891B2' }} edges={['top']}>
      <ScrollView
        style={{ flex: 1, backgroundColor: '#F8FAFC' }}
        refreshControl={<RefreshControl refreshing={isRefetching} onRefresh={refetchAll} tintColor="#0891B2" />}
      >
        {/* Header */}
        <View style={{ backgroundColor: '#0891B2', paddingHorizontal: 20, paddingTop: 16, paddingBottom: 24 }}>
          <Text style={{ color: '#A5F3FC', fontSize: 15, fontWeight: '500' }}>{greeting},</Text>
          <Text style={{ color: '#FFF', fontSize: 28, fontWeight: '800', marginTop: 2 }}>{user?.firstName ?? 'Field Staff'}</Text>
        </View>

        {isLoading ? (
          <View style={{ paddingVertical: 80, alignItems: 'center' }}>
            <ActivityIndicator color="#0891B2" size="large" />
          </View>
        ) : (
          <View style={{ padding: 16 }}>

            {/* KPI Row 1 */}
            <View style={{ flexDirection: 'row', marginBottom: 10 }}>
              <KpiCard label="Subscribers" value={summary?.subscribers?.total ?? '—'} color="#0E7490" bg="#ECFEFF" />
              <KpiCard label="Active" value={summary?.subscribers?.active ?? '—'} color="#166534" bg="#F0FDF4" />
            </View>

            {/* KPI Row 2 */}
            <View style={{ flexDirection: 'row', marginBottom: 16 }}>
              <KpiCard label="Unpaid Invoices" value={summary?.billing?.unpaidInvoices ?? '—'} color="#991B1B" bg="#FEF2F2" />
              <KpiCard label="Open Tickets" value={summary?.support?.openTickets ?? '—'} color="#92400E" bg="#FFFBEB" />
            </View>

            {/* Revenue — ADMIN/STAFF only */}
            {isAdminOrStaff && summary?.revenue?.thisMonth != null && (
              <View style={{ backgroundColor: '#FFF', borderRadius: 16, padding: 18, marginBottom: 16, borderWidth: 1, borderColor: '#F1F5F9', flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center' }}>
                <View>
                  <Text style={{ fontSize: 12, fontWeight: '700', color: '#94A3B8', textTransform: 'uppercase', letterSpacing: 0.4, marginBottom: 4 }}>This Month's Revenue</Text>
                  <Text style={{ fontSize: 24, fontWeight: '800', color: '#166534' }}>₱{Number(summary.revenue.thisMonth).toLocaleString()}</Text>
                </View>
                {summary.revenue.growth !== undefined && (
                  <View style={{ backgroundColor: '#F0FDF4', borderRadius: 12, paddingHorizontal: 12, paddingVertical: 6 }}>
                    <Text style={{ fontSize: 15, fontWeight: '800', color: '#16A34A' }}>+{summary.revenue.growth}%</Text>
                  </View>
                )}
              </View>
            )}

            {/* ── Active Tickets ── */}
            <View style={{ flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center', marginBottom: 10 }}>
              <View style={{ flexDirection: 'row', alignItems: 'center' }}>
                <Text style={{ fontSize: 17, fontWeight: '800', color: '#0F172A' }}>Tickets</Text>
                {mergedTickets.length > 0 && (
                  <View style={{ backgroundColor: '#ECFEFF', borderRadius: 20, paddingHorizontal: 8, paddingVertical: 2, marginLeft: 8 }}>
                    <Text style={{ fontSize: 12, fontWeight: '700', color: '#0891B2' }}>{mergedTickets.length}</Text>
                  </View>
                )}
              </View>
              <TouchableOpacity onPress={() => router.push('/(app)/tasks')} hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}>
                <Text style={{ fontSize: 14, fontWeight: '600', color: '#0891B2' }}>View all</Text>
              </TouchableOpacity>
            </View>

            {mergedTickets.length === 0 ? (
              <View style={{ backgroundColor: '#FFF', borderRadius: 14, padding: 20, alignItems: 'center', marginBottom: 20, borderWidth: 1, borderColor: '#F1F5F9' }}>
                <Text style={{ fontSize: 15, color: '#94A3B8' }}>No active tickets 🎉</Text>
              </View>
            ) : (
              <View style={{ marginBottom: 20 }}>
                {[...mergedTickets].sort(byPrio).map((t: any) => (
                  <TicketRow key={t.id} task={t} onPress={() => router.push(`/(app)/tasks/${t.id}`)} />
                ))}
              </View>
            )}

            {/* ── Unpaid Invoices ── */}
            <View style={{ flexDirection: 'row', justifyContent: 'space-between', alignItems: 'center', marginBottom: 10 }}>
              <Text style={{ fontSize: 17, fontWeight: '800', color: '#0F172A' }}>Unpaid Invoices</Text>
              <TouchableOpacity onPress={() => router.push('/(app)/payments')} hitSlop={{ top: 10, bottom: 10, left: 10, right: 10 }}>
                <Text style={{ fontSize: 14, fontWeight: '600', color: '#0891B2' }}>View all</Text>
              </TouchableOpacity>
            </View>

            {unpaidInvoices.length === 0 ? (
              <View style={{ backgroundColor: '#FFF', borderRadius: 14, padding: 20, alignItems: 'center', marginBottom: 20, borderWidth: 1, borderColor: '#F1F5F9' }}>
                <Text style={{ fontSize: 15, color: '#94A3B8' }}>No unpaid invoices 🎉</Text>
              </View>
            ) : (
              <View style={{ marginBottom: 20 }}>
                {unpaidInvoices.map((inv: any) => (
                  <InvoiceRow key={inv.id} inv={inv} />
                ))}
              </View>
            )}

            <View style={{ height: 24 }} />
          </View>
        )}
      </ScrollView>
    </SafeAreaView>
  );
}
