import React, { useCallback, useEffect, useRef } from 'react';
import {
  View,
  Text,
  ScrollView,
  TouchableOpacity,
  Alert,
  Switch,
  InteractionManager,
} from 'react-native';
import { useAppTheme, borderRadius, spacing, shadow, typography } from '@theme';
import { PrimaryButton } from '@components';
import { BellIcon, PersonIcon, WalletIcon, ClipboardIcon } from '@icons';
import { useAppDispatch, useAppSelector } from '@store';
import { setOnlineStatus } from '@store/commonReducers/auth';
import { useNavigation } from '@react-navigation/native';
import { NativeStackNavigationProp } from '@react-navigation/native-stack';
import { AppStackParamList } from '@navigation/navigationTypes';
import { RouteNames, JobStatus } from '@utils/constants';
import { formatCurrency } from '@utils/formatters';
import { getStyles } from './dashboardScreen.styles';
import { toggleStatus, updateDeliveryPartnerLocation } from './thunk';
import {
  getCurrentLocationWithAddress,
  showPermissionDeniedAlert,
  socketService,
} from '@services';

export const DashboardScreen: React.FC = () => {
  const { colors } = useAppTheme();
  const styles = getStyles(colors);
  const dispatch = useAppDispatch();
  const navigation =
    useNavigation<NativeStackNavigationProp<AppStackParamList>>();

  // Derive online status from API response stored in dashboard slice.
  // Falls back to auth.isOnline during the initial load before any toggle API call.
  const { availabiltyStatus, loading: toggleLoading } = useAppSelector(
    state => state.dashboard,
  );
  const { user } = useAppSelector(state => state.auth);
  const authIsOnline = useAppSelector(state => state.auth.isOnline);
  const isOnline = availabiltyStatus
    ? availabiltyStatus.availabilityStatus === 'ONLINE'
    : authIsOnline;
  const { todayEarnings, completedCount, onlineMinutes, weeklyData } =
    useAppSelector(state => state.earnings);
  const { jobStatus, activeJob } = useAppSelector(state => state.job);

  const locationIntervalRef = useRef<ReturnType<typeof setInterval> | null>(
    null,
  );

  const sendLocationUpdate = useCallback(async () => {
    try {
      const result = await getCurrentLocationWithAddress();
      const coords = result.coords;

      dispatch(
        updateDeliveryPartnerLocation({
          latitude: coords.latitude,
          longitude: coords.longitude,
          accuracyMeters: coords.accuracy ?? 0,
          speedKph: coords.speed ? coords.speed * 3.6 : 0, // convert m/s -> km/h if needed
          heading: coords.heading ?? 0,
        }),
      );
    } catch (err) {
      console.log('--------location update error------', err);
    }
  }, [dispatch]);

  useEffect(() => {
    if (isOnline) {
      // Fire one immediately on going online, then every 15s
      sendLocationUpdate();
      locationIntervalRef.current = setInterval(sendLocationUpdate, 15000);
    } else {
      if (locationIntervalRef.current) {
        clearInterval(locationIntervalRef.current);
        locationIntervalRef.current = null;
      }
    }

    return () => {
      if (locationIntervalRef.current) {
        clearInterval(locationIntervalRef.current);
        locationIntervalRef.current = null;
      }
    };
  }, [isOnline, sendLocationUpdate]);

  // Notify the socket server when online/offline status changes
  useEffect(() => {
    if (isOnline) {
      socketService.goOnline();
    } else {
      socketService.goOffline();
    }
  }, [isOnline]);

  const handleToggleOnline = () => {
    const newStatus = isOnline ? 'OFFLINE' : 'ONLINE';

    // Optimistically update the auth flag so the timer and UI react immediately
    dispatch(setOnlineStatus(!isOnline));

    dispatch(toggleStatus({ availabilityStatus: newStatus }))
      .unwrap()
      .then(response => {
        // Confirm state from server — setOnlineStatus stays in sync
        const isNowOnline = response.availabilityStatus === 'ONLINE';
        dispatch(setOnlineStatus(isNowOnline));
      })
      .catch(() => {
        // Revert the optimistic update on API failure
        dispatch(setOnlineStatus(isOnline));
        Alert.alert(
          'Status Update Failed',
          'Could not update your availability. Please try again.',
        );
      });
  };

  const handleActiveJobBannerPress = () => {
    // Navigate back to the screen corresponding to the current job step
    switch (jobStatus) {
      case JobStatus.NewRequest:
        navigation.navigate(RouteNames.NewJobRequest);
        break;
      case JobStatus.Accepted:
        navigation.navigate(RouteNames.OrderAccepted);
        break;
      case JobStatus.ArrivedAtStore:
        navigation.navigate(RouteNames.ConfirmPickup);
        break;
      case JobStatus.PickedUp:
        navigation.navigate(RouteNames.OrderPickedUp);
        break;
      case JobStatus.EnRoute:
        navigation.navigate(RouteNames.LiveTracking);
        break;
      case JobStatus.ArrivedAtCustomer:
        navigation.navigate(RouteNames.DeliverOrder);
        break;
      default:
        Alert.alert('Status Error', 'Unknown active delivery state.');
    }
  };

  const formatOnlineTime = (mins: number) => {
    const hours = Math.floor(mins / 60);
    const remainingMins = mins % 60;
    return `${hours}h ${
      remainingMins < 10 ? `0${remainingMins}` : remainingMins
    }m`;
  };

  // Helper to render chart bar heights dynamically based on amounts
  const maxWeeklyAmount = Math.max(...weeklyData.map(d => d.amount), 1);

  return (
    <View style={styles.container}>
      <ScrollView
        contentContainerStyle={styles.scrollContainer}
        showsVerticalScrollIndicator={false}
      >
        {/* Header Section */}
        <View style={styles.header}>
          <View>
            <Text style={styles.greetingText}>Good Morning ☀️</Text>
            <Text style={styles.nameText}>{user?.name}</Text>
          </View>

          <View style={styles.toggleWrapper}>
            <View
              style={[
                styles.statusDot,
                {
                  backgroundColor: isOnline
                    ? colors.statusOnline
                    : colors.statusOffline,
                },
              ]}
            />
            <Text
              style={[
                styles.statusText,
                {
                  color: isOnline ? colors.statusOnline : colors.statusOffline,
                },
              ]}
            >
              {isOnline ? 'Online' : 'Offline'}
            </Text>
            <Switch
              value={isOnline}
              onValueChange={handleToggleOnline}
              trackColor={{ false: colors.border, true: colors.primaryLight }}
              thumbColor={isOnline ? colors.primary : colors.placeholder}
              disabled={toggleLoading}
              style={{ marginLeft: 8, opacity: toggleLoading ? 0.5 : 1 }}
            />
          </View>
        </View>

        {/* Offline Warning Banner */}
        {!isOnline && (
          <View style={styles.offlineBanner}>
            <Text style={styles.offlineBannerText}>
              You are offline. Go online to start receiving orders.
            </Text>
          </View>
        )}

        {/* Today's Summary Card */}
        <View style={styles.summaryCard}>
          <Text style={styles.summaryTitle}>Today's Summary</Text>
          <View style={styles.statsRow}>
            <View style={styles.statBox}>
              <Text style={styles.statVal}>
                {formatCurrency(isOnline ? todayEarnings : 0)}
              </Text>
              <Text style={styles.statLabel}>Earnings</Text>
            </View>

            <View style={styles.statDivider} />

            <View style={styles.statBox}>
              <Text style={styles.statVal}>
                {isOnline ? completedCount : 0}
              </Text>
              <Text style={styles.statLabel}>Completed</Text>
            </View>

            <View style={styles.statDivider} />

            <View style={styles.statBox}>
              <Text style={styles.statVal}>
                {formatOnlineTime(isOnline ? onlineMinutes : 0)}
              </Text>
              <Text style={styles.statLabel}>Online Time</Text>
            </View>
          </View>
        </View>

        {/* Conditional Layout for Online vs Offline */}
        {isOnline ? (
          <>
            {/* Performance Stats */}
            <View style={styles.performanceCard}>
              <Text style={styles.perfTitle}>Your Performance</Text>
              <View style={styles.perfRow}>
                <View style={styles.perfBox}>
                  <Text style={[styles.perfVal, { color: colors.warning }]}>
                    4.8 ★
                  </Text>
                  <Text style={styles.perfLabel}>Rating</Text>
                </View>
                <View style={styles.perfBox}>
                  <Text style={styles.perfVal}>95%</Text>
                  <Text style={styles.perfLabel}>Acceptance</Text>
                </View>
                <View style={styles.perfBox}>
                  <Text style={styles.perfVal}>98%</Text>
                  <Text style={styles.perfLabel}>Completion</Text>
                </View>
              </View>
            </View>

            {/* Weekly Earnings Chart (Styled SVG/Flex columns) */}
            <View style={styles.chartCard}>
              <Text style={styles.chartTitle}>Weekly Overview</Text>
              <View style={styles.chartRow}>
                {weeklyData.map((data, index) => {
                  // Bar height percent
                  const heightPercent = `${
                    (data.amount / maxWeeklyAmount) * 85
                  }%`;
                  return (
                    <View key={index} style={styles.barContainer}>
                      <Text style={styles.barVal}>₹{data.amount}</Text>
                      <View
                        style={[
                          styles.bar,
                          {
                            height: heightPercent as any,
                            backgroundColor:
                              index === weeklyData.length - 1
                                ? colors.primary
                                : colors.placeholder,
                          },
                        ]}
                      />
                      <Text style={styles.barLabel}>{data.day}</Text>
                    </View>
                  );
                })}
              </View>
            </View>

            <PrimaryButton
              title="Go Offline"
              onPress={handleToggleOnline}
              style={[styles.offlineBtn, { backgroundColor: colors.error }]}
            />
          </>
        ) : (
          <View style={styles.promptCard}>
            <Text style={styles.promptTitle}>
              Go Online to start receiving delivery requests
            </Text>
            <Text style={styles.promptDesc}>
              Make sure you are in a high-demand delivery zone to maximize your
              earnings.
            </Text>
            <PrimaryButton
              title="Go Online"
              onPress={handleToggleOnline}
              style={styles.onlineBtn}
            />
          </View>
        )}

        {/* Help & Support Cards at bottom */}
        <View style={styles.helpSection}>
          <Text style={styles.helpTitle}>Help & Support</Text>
          <View style={styles.helpRow}>
            <TouchableOpacity
              style={styles.helpItem}
              onPress={() =>
                Alert.alert(
                  'Emergency SOS',
                  'Calling nearest security/emergency dispatch...',
                )
              }
            >
              <BellIcon size={24} color={colors.error} />
              <Text style={styles.helpLabel}>Emergency SOS</Text>
              <Text style={styles.helpSub}>Immediate Assistance</Text>
            </TouchableOpacity>

            <TouchableOpacity
              style={styles.helpItem}
              onPress={() =>
                navigation.navigate(RouteNames.BottomTabs, {
                  screen: RouteNames.Profile,
                })
              }
            >
              <ClipboardIcon size={24} color={colors.primary} />
              <Text style={styles.helpLabel}>FAQ Center</Text>
              <Text style={styles.helpSub}>Help & Guides</Text>
            </TouchableOpacity>

            <TouchableOpacity
              style={styles.helpItem}
              onPress={() =>
                Alert.alert(
                  'Support Chat',
                  'Initiating live helpdesk agent chat...',
                )
              }
            >
              <PersonIcon size={24} color={colors.statusOnDelivery} />
              <Text style={styles.helpLabel}>Live Support</Text>
              <Text style={styles.helpSub}>24/7 Chat Help</Text>
            </TouchableOpacity>
          </View>
        </View>
      </ScrollView>

      {/* Active Job Floating Bottom Banner */}
      {jobStatus !== JobStatus.Idle &&
        jobStatus !== JobStatus.NewRequest &&
        activeJob && (
          <TouchableOpacity
            style={{
              position: 'absolute',
              bottom: spacing.xs,
              left: spacing.md,
              right: spacing.md,
              backgroundColor: colors.primary,
              borderRadius: borderRadius.md,
              paddingVertical: spacing.md,
              paddingHorizontal: spacing.lg,
              flexDirection: 'row',
              alignItems: 'center',
              justifyContent: 'space-between',
              ...shadow.lg,
            }}
            activeOpacity={0.9}
            onPress={handleActiveJobBannerPress}
          >
            <View
              style={{ flexDirection: 'row', alignItems: 'center', flex: 1 }}
            >
              <ClipboardIcon size={20} color={colors.white} />
              <View style={{ marginLeft: spacing.sm, flex: 1 }}>
                <Text
                  style={{
                    color: colors.white,
                    fontWeight: 'bold',
                    fontSize: typography.fontSize.sm,
                  }}
                >
                  Order {activeJob.orderId}
                </Text>
                <Text
                  style={{
                    color: colors.primaryLight,
                    fontSize: typography.fontSize.xs,
                  }}
                  numberOfLines={1}
                >
                  {jobStatus === JobStatus.Accepted &&
                    'Heading to pickup store...'}
                  {jobStatus === JobStatus.ArrivedAtStore &&
                    'At pickup store, check items...'}
                  {jobStatus === JobStatus.PickedUp &&
                    'Order picked up, routing to customer...'}
                  {jobStatus === JobStatus.EnRoute &&
                    'On the way to customer...'}
                  {jobStatus === JobStatus.ArrivedAtCustomer &&
                    'Arrived at customer location...'}
                </Text>
              </View>
            </View>
            <View
              style={{
                backgroundColor: colors.white,
                paddingHorizontal: spacing.md,
                paddingVertical: 6,
                borderRadius: borderRadius.sm,
              }}
            >
              <Text
                style={{
                  color: colors.primary,
                  fontWeight: 'bold',
                  fontSize: typography.fontSize.xs,
                }}
              >
                View
              </Text>
            </View>
          </TouchableOpacity>
        )}
    </View>
  );
};

// export default DashboardScreen;