import React, { useState, useEffect, useCallback } from 'react';
import {
  View,
  Text,
  StyleSheet,
  ScrollView,
  TouchableOpacity,
  RefreshControl,
} from 'react-native';
import { useLocalSearchParams, router } from 'expo-router';
import { Ionicons } from '@expo/vector-icons';
import { SafeAreaView } from 'react-native-safe-area-context';
import { api } from '@/services/api';
import { useBeneficiary } from '@/contexts/BeneficiaryContext';
import { LoadingSpinner } from '@/components/ui/LoadingSpinner';
import { FullScreenError } from '@/components/ui/ErrorMessage';
import { Button } from '@/components/ui/Button';
import { AppColors, BorderRadius, FontSizes, Spacing } from '@/constants/theme';
import type { Beneficiary } from '@/types';

export default function BeneficiaryDetailScreen() {
  const { id } = useLocalSearchParams<{ id: string }>();
  const { setCurrentBeneficiary } = useBeneficiary();
  const [beneficiary, setBeneficiary] = useState<Beneficiary | null>(null);
  const [isLoading, setIsLoading] = useState(true);
  const [isRefreshing, setIsRefreshing] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const loadBeneficiary = useCallback(async (showLoading = true) => {
    if (!id) return;

    if (showLoading) setIsLoading(true);
    setError(null);

    try {
      const response = await api.getBeneficiary(parseInt(id, 10));

      if (response.ok && response.data) {
        setBeneficiary(response.data);
      } else {
        setError(response.error?.message || 'Failed to load beneficiary');
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : 'An error occurred');
    } finally {
      setIsLoading(false);
      setIsRefreshing(false);
    }
  }, [id]);

  useEffect(() => {
    loadBeneficiary();
  }, [loadBeneficiary]);

  const handleRefresh = useCallback(() => {
    setIsRefreshing(true);
    loadBeneficiary(false);
  }, [loadBeneficiary]);

  const handleChatPress = () => {
    // Set current beneficiary in context before navigating to chat
    // This allows the chat to include beneficiary context in AI questions
    if (beneficiary) {
      setCurrentBeneficiary(beneficiary);
    }
    router.push('/(tabs)/chat');
  };

  if (isLoading) {
    return <LoadingSpinner fullScreen message="Loading beneficiary data..." />;
  }

  if (error || !beneficiary) {
    return (
      <FullScreenError
        message={error || 'Beneficiary not found'}
        onRetry={() => loadBeneficiary()}
      />
    );
  }

  return (
    <SafeAreaView style={styles.container} edges={['top']}>
      {/* Header */}
      <View style={styles.header}>
        <TouchableOpacity
          style={styles.backButton}
          onPress={() => router.back()}
        >
          <Ionicons name="arrow-back" size={24} color={AppColors.textPrimary} />
        </TouchableOpacity>
        <Text style={styles.headerTitle}>{beneficiary.name}</Text>
        <TouchableOpacity style={styles.menuButton}>
          <Ionicons name="ellipsis-vertical" size={24} color={AppColors.textPrimary} />
        </TouchableOpacity>
      </View>

      <ScrollView
        style={styles.content}
        showsVerticalScrollIndicator={false}
        refreshControl={
          <RefreshControl
            refreshing={isRefreshing}
            onRefresh={handleRefresh}
            tintColor={AppColors.primary}
          />
        }
      >
        {/* Beneficiary Info Card */}
        <View style={styles.infoCard}>
          <View style={styles.avatarContainer}>
            <Text style={styles.avatarText}>
              {beneficiary.name.charAt(0).toUpperCase()}
            </Text>
            <View
              style={[
                styles.statusBadge,
                beneficiary.status === 'online' ? styles.onlineBadge : styles.offlineBadge,
              ]}
            >
              <Text style={styles.statusText}>
                {beneficiary.status === 'online' ? 'Online' : 'Offline'}
              </Text>
            </View>
          </View>

          <Text style={styles.beneficiaryName}>{beneficiary.name}</Text>
          {beneficiary.address && (
            <Text style={styles.relationship}>{beneficiary.address}</Text>
          )}
          <Text style={styles.lastSeen}>
            {beneficiary.last_location ? `📍 ${beneficiary.last_location}` : ''} • {beneficiary.last_activity || 'No recent activity'}
          </Text>
        </View>

        {/* Sensor Stats - using real API data */}
        <View style={styles.section}>
          <Text style={styles.sectionTitle}>Sensor Overview</Text>

          <View style={styles.statsGrid}>
            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: beneficiary.status === 'online' ? '#D1FAE5' : '#F3F4F6' }]}>
                <Ionicons
                  name={beneficiary.status === 'online' ? "walk" : "walk-outline"}
                  size={24}
                  color={beneficiary.status === 'online' ? AppColors.success : AppColors.textMuted}
                />
              </View>
              <Text style={styles.statValue}>
                {beneficiary.status === 'online' ? 'Active' : 'Inactive'}
              </Text>
              <Text style={styles.statLabel}>Status</Text>
              <Text style={styles.statUnit}>{beneficiary.last_activity || '--'}</Text>
            </View>

            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: '#DBEAFE' }]}>
                <Ionicons
                  name="location-outline"
                  size={24}
                  color={AppColors.primary}
                />
              </View>
              <Text style={styles.statValue} numberOfLines={1}>
                {beneficiary.last_location || '--'}
              </Text>
              <Text style={styles.statLabel}>Location</Text>
              <Text style={styles.statUnit} numberOfLines={1}>{beneficiary.before_last_location || '--'}</Text>
            </View>

            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: '#E0E7FF' }]}>
                <Ionicons name="thermometer-outline" size={24} color={AppColors.primaryDark} />
              </View>
              <Text style={styles.statValue}>
                {beneficiary.temperature?.toFixed(1) || '--'}{beneficiary.units || '°F'}
              </Text>
              <Text style={styles.statLabel}>Temperature</Text>
              <Text style={styles.statUnit}>Bedroom: {beneficiary.bedroom_temperature?.toFixed(1) || '--'}{beneficiary.units || '°F'}</Text>
            </View>
          </View>

          {/* Additional stats row */}
          <View style={[styles.statsGrid, { marginTop: Spacing.md }]}>
            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: '#F3E8FF' }]}>
                <Ionicons name="moon-outline" size={24} color="#9333EA" />
              </View>
              <Text style={styles.statValue}>
                {beneficiary.sleep_hours?.toFixed(1) || '--'}h
              </Text>
              <Text style={styles.statLabel}>Sleep</Text>
            </View>

            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: beneficiary.wellness_score && beneficiary.wellness_score >= 70 ? '#D1FAE5' : '#FEF3C7' }]}>
                <Ionicons
                  name="heart-outline"
                  size={24}
                  color={beneficiary.wellness_score && beneficiary.wellness_score >= 70 ? AppColors.success : AppColors.warning}
                />
              </View>
              <Text style={styles.statValue}>
                {beneficiary.wellness_score || '--'}%
              </Text>
              <Text style={styles.statLabel}>Wellness</Text>
              <Text style={styles.statUnit}>{beneficiary.wellness_descriptor || '--'}</Text>
            </View>

            <View style={styles.statCard}>
              <View style={[styles.statIcon, { backgroundColor: '#DBEAFE' }]}>
                <Ionicons name="home-outline" size={24} color={AppColors.primary} />
              </View>
              <Text style={styles.statValue} numberOfLines={1}>
                {beneficiary.address?.split(',')[0] || '--'}
              </Text>
              <Text style={styles.statLabel}>Address</Text>
            </View>
          </View>
        </View>

        {/* Quick Actions */}
        <View style={styles.section}>
          <Text style={styles.sectionTitle}>Quick Actions</Text>

          <View style={styles.actionsGrid}>
            <TouchableOpacity style={styles.actionCard} onPress={handleChatPress}>
              <View style={[styles.actionIcon, { backgroundColor: '#D1FAE5' }]}>
                <Ionicons name="chatbubble-ellipses" size={24} color={AppColors.success} />
              </View>
              <Text style={styles.actionLabel}>Chat with Julia</Text>
            </TouchableOpacity>

            <TouchableOpacity style={styles.actionCard}>
              <View style={[styles.actionIcon, { backgroundColor: '#FEF3C7' }]}>
                <Ionicons name="notifications" size={24} color={AppColors.warning} />
              </View>
              <Text style={styles.actionLabel}>Set Reminder</Text>
            </TouchableOpacity>

            <TouchableOpacity style={styles.actionCard}>
              <View style={[styles.actionIcon, { backgroundColor: '#DBEAFE' }]}>
                <Ionicons name="call" size={24} color={AppColors.primary} />
              </View>
              <Text style={styles.actionLabel}>Video Call</Text>
            </TouchableOpacity>

            <TouchableOpacity style={styles.actionCard}>
              <View style={[styles.actionIcon, { backgroundColor: '#F3E8FF' }]}>
                <Ionicons name="analytics" size={24} color="#9333EA" />
              </View>
              <Text style={styles.actionLabel}>Activity Report</Text>
            </TouchableOpacity>
          </View>
        </View>

        {/* Chat with Julia Button */}
        <View style={styles.chatButtonContainer}>
          <Button
            title="Chat with Julia AI"
            onPress={handleChatPress}
            fullWidth
            size="lg"
          />
        </View>
      </ScrollView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: AppColors.surface,
  },
  header: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: Spacing.md,
    paddingVertical: Spacing.sm,
    backgroundColor: AppColors.background,
    borderBottomWidth: 1,
    borderBottomColor: AppColors.border,
  },
  backButton: {
    padding: Spacing.xs,
  },
  headerTitle: {
    fontSize: FontSizes.lg,
    fontWeight: '600',
    color: AppColors.textPrimary,
  },
  menuButton: {
    padding: Spacing.xs,
  },
  content: {
    flex: 1,
  },
  infoCard: {
    backgroundColor: AppColors.background,
    padding: Spacing.xl,
    alignItems: 'center',
    marginBottom: Spacing.md,
  },
  avatarContainer: {
    width: 100,
    height: 100,
    borderRadius: BorderRadius.full,
    backgroundColor: AppColors.primaryLight,
    justifyContent: 'center',
    alignItems: 'center',
    marginBottom: Spacing.md,
  },
  avatarText: {
    fontSize: FontSizes['3xl'],
    fontWeight: '600',
    color: AppColors.white,
  },
  statusBadge: {
    position: 'absolute',
    bottom: 0,
    paddingHorizontal: Spacing.sm,
    paddingVertical: Spacing.xs,
    borderRadius: BorderRadius.full,
  },
  onlineBadge: {
    backgroundColor: AppColors.success,
  },
  offlineBadge: {
    backgroundColor: AppColors.offline,
  },
  statusText: {
    fontSize: FontSizes.xs,
    fontWeight: '500',
    color: AppColors.white,
  },
  beneficiaryName: {
    fontSize: FontSizes['2xl'],
    fontWeight: '700',
    color: AppColors.textPrimary,
  },
  relationship: {
    fontSize: FontSizes.base,
    color: AppColors.textSecondary,
    marginTop: Spacing.xs,
  },
  lastSeen: {
    fontSize: FontSizes.sm,
    color: AppColors.textMuted,
    marginTop: Spacing.sm,
  },
  section: {
    backgroundColor: AppColors.background,
    padding: Spacing.lg,
    marginBottom: Spacing.md,
  },
  sectionTitle: {
    fontSize: FontSizes.lg,
    fontWeight: '600',
    color: AppColors.textPrimary,
    marginBottom: Spacing.md,
  },
  statsGrid: {
    flexDirection: 'row',
    justifyContent: 'space-between',
  },
  statCard: {
    flex: 1,
    alignItems: 'center',
    padding: Spacing.sm,
  },
  statIcon: {
    width: 48,
    height: 48,
    borderRadius: BorderRadius.lg,
    justifyContent: 'center',
    alignItems: 'center',
    marginBottom: Spacing.sm,
  },
  statValue: {
    fontSize: FontSizes.xl,
    fontWeight: '700',
    color: AppColors.textPrimary,
  },
  statLabel: {
    fontSize: FontSizes.xs,
    color: AppColors.textSecondary,
    marginTop: Spacing.xs,
  },
  statUnit: {
    fontSize: FontSizes.xs,
    color: AppColors.textMuted,
  },
  actionsGrid: {
    flexDirection: 'row',
    flexWrap: 'wrap',
    justifyContent: 'space-between',
  },
  actionCard: {
    width: '48%',
    backgroundColor: AppColors.surface,
    borderRadius: BorderRadius.lg,
    padding: Spacing.md,
    alignItems: 'center',
    marginBottom: Spacing.md,
  },
  actionIcon: {
    width: 48,
    height: 48,
    borderRadius: BorderRadius.lg,
    justifyContent: 'center',
    alignItems: 'center',
    marginBottom: Spacing.sm,
  },
  actionLabel: {
    fontSize: FontSizes.sm,
    fontWeight: '500',
    color: AppColors.textPrimary,
    textAlign: 'center',
  },
  chatButtonContainer: {
    padding: Spacing.lg,
    paddingBottom: Spacing.xxl,
  },
});