import React from 'react';
import {
  View,
  StyleSheet,
  ScrollView,
  RefreshControl,
} from 'react-native';
import { Card, Text, FAB } from 'react-native-paper';
import { useQuery } from '@tanstack/react-query';
import { useNavigation } from '@react-navigation/native';
import type { NativeStackNavigationProp } from '@react-navigation/native-stack';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useAuth } from '../../hooks/useAuth';
import { proposalsApi } from '../../lib/api/proposals';
import { ProposalCard } from '../../components/ProposalCard';
import { EmptyState } from '../../components/EmptyState';
import { QUERY_KEYS } from '../../constants/queryKeys';
import type { ProposalsStackParamList } from '../../navigation/types';

type Nav = NativeStackNavigationProp<ProposalsStackParamList>;

export function DashboardScreen() {
  const { user } = useAuth();
  const navigation = useNavigation<Nav>();

  const statsQuery = useQuery({
    queryKey: [QUERY_KEYS.dashboard, 'stats'],
    queryFn: () => proposalsApi.getStats(),
  });

  const proposalsQuery = useQuery({
    queryKey: [QUERY_KEYS.proposals, 'recent'],
    queryFn: () => proposalsApi.getAll({ pageSize: 5 }),
  });

  const refreshing = statsQuery.isRefetching || proposalsQuery.isRefetching;

  const onRefresh = () => {
    statsQuery.refetch();
    proposalsQuery.refetch();
  };

  const stats = statsQuery.data;
  const proposals = proposalsQuery.data?.items ?? [];

  return (
    <SafeAreaView style={styles.container} edges={['bottom']}>
      <ScrollView
        contentContainerStyle={styles.scroll}
        refreshControl={
          <RefreshControl refreshing={refreshing} onRefresh={onRefresh} />
        }
      >
        <Text variant="headlineSmall" style={styles.welcome}>
          Welcome, {user?.displayName?.includes('@') ? user.displayName.split('@')[0] : user?.displayName?.split(' ')[0] || 'there'}
        </Text>

        {stats && (
          <View style={styles.statsRow}>
            <StatCard label="Total" value={stats.totalCount} color="#1565C0" />
            <StatCard
              label="In Review"
              value={stats.inReviewCount}
              color="#E65100"
            />
            <StatCard
              label="Approved"
              value={stats.approvedCount}
              color="#2E7D32"
            />
            <StatCard label="Sent" value={stats.sentCount} color="#7B1FA2" />
          </View>
        )}

        <Text variant="titleMedium" style={styles.sectionTitle}>
          Recent Proposals
        </Text>

        {proposals.length === 0 && !proposalsQuery.isLoading ? (
          <EmptyState
            icon="file-document-outline"
            title="No proposals yet"
            message="Tap + to submit your first proposal"
          />
        ) : (
          proposals.map((p) => (
            <ProposalCard
              key={p.id}
              proposal={p}
              onPress={() =>
                navigation.navigate('ProposalDetail', { proposalId: p.id })
              }
            />
          ))
        )}
      </ScrollView>

      <FAB
        icon="plus"
        style={styles.fab}
        onPress={() => navigation.navigate('NewProposal')}
      />
    </SafeAreaView>
  );
}

function StatCard({
  label,
  value,
  color,
}: {
  label: string;
  value: number;
  color: string;
}) {
  return (
    <Card style={styles.statCard} mode="elevated">
      <Card.Content style={styles.statContent}>
        <Text variant="headlineMedium" style={[styles.statValue, { color }]}>
          {value}
        </Text>
        <Text variant="bodySmall" style={styles.statLabel}>
          {label}
        </Text>
      </Card.Content>
    </Card>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#FAFAFA',
  },
  scroll: {
    paddingBottom: 80,
  },
  welcome: {
    fontWeight: '700',
    paddingHorizontal: 16,
    paddingTop: 16,
    paddingBottom: 12,
  },
  statsRow: {
    flexDirection: 'row',
    paddingHorizontal: 12,
    gap: 8,
    marginBottom: 16,
  },
  statCard: {
    flex: 1,
  },
  statContent: {
    alignItems: 'center',
    paddingVertical: 8,
  },
  statValue: {
    fontWeight: '700',
  },
  statLabel: {
    color: '#757575',
    marginTop: 2,
  },
  sectionTitle: {
    fontWeight: '600',
    paddingHorizontal: 16,
    paddingVertical: 8,
  },
  fab: {
    position: 'absolute',
    right: 16,
    bottom: 16,
    backgroundColor: '#1565C0',
  },
});