import React from 'react';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { api } from '@/lib/api';
import { SettingsCard } from '../components/SettingsCard';
import { Switch } from '@/components/ui/switch';
import { Button } from '@/components/ui/button';
import { Badge } from '@/components/ui/badge';
import { RefreshCw, Mail, MessageCircle, Send, Bell } from 'lucide-react';
import { toast } from 'sonner';
import { __ } from '@/lib/i18n';

interface NotificationEvent {
  id: string;
  label: string;
  description: string;
  category: string;
  enabled: boolean;
  channels: {
    [channelId: string]: {
      enabled: boolean;
      recipient: 'admin' | 'customer' | 'both';
    };
  };
}

interface NotificationChannel {
  id: string;
  label: string;
  icon: string;
  enabled: boolean;
  builtin?: boolean;
  addon?: string;
}

export default function NotificationEvents() {
  const queryClient = useQueryClient();

  // Fetch events
  const { data: eventsData, isLoading: eventsLoading } = useQuery({
    queryKey: ['notification-events'],
    queryFn: () => api.get('/notifications/events'),
  });

  // Fetch channels
  const { data: channels, isLoading: channelsLoading } = useQuery({
    queryKey: ['notification-channels'],
    queryFn: () => api.get('/notifications/channels'),
  });

  // Update event mutation
  const updateMutation = useMutation({
    mutationFn: async ({ eventId, channelId, enabled, recipient }: any) => {
      return api.post('/notifications/events/update', {
        eventId,
        channelId,
        enabled,
        recipient,
      });
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['notification-events'] });
      toast.success(__('Event settings updated'));
    },
    onError: (error: any) => {
      toast.error(error?.message || __('Failed to update event'));
    },
  });

  const getChannelIcon = (channelId: string) => {
    switch (channelId) {
      case 'email':
        return <Mail className="h-4 w-4" />;
      case 'whatsapp':
        return <MessageCircle className="h-4 w-4" />;
      case 'telegram':
        return <Send className="h-4 w-4" />;
      default:
        return <Bell className="h-4 w-4" />;
    }
  };

  const toggleChannel = (eventId: string, channelId: string, currentlyEnabled: boolean) => {
    updateMutation.mutate({
      eventId,
      channelId,
      enabled: !currentlyEnabled,
      recipient: 'admin', // Default recipient
    });
  };

  if (eventsLoading || channelsLoading) {
    return (
      <div className="flex items-center justify-center py-12">
        <RefreshCw className="h-6 w-6 animate-spin text-muted-foreground" />
      </div>
    );
  }

  const orderEvents = eventsData?.orders || [];
  const productEvents = eventsData?.products || [];
  const customerEvents = eventsData?.customers || [];

  return (
    <div className="space-y-6">
      {/* Info Card */}
      <SettingsCard
        title={__('Notification Events')}
        description={__('Configure which channels to use for each notification event')}
      >
        <div className="text-sm space-y-3">
          <p className="text-muted-foreground">
            {__(
              'Choose which notification channels (Email, WhatsApp, Telegram, etc.) should be used for each event. Enable multiple channels to send notifications through different mediums.'
            )}
          </p>
          <div className="bg-muted/50 rounded-lg p-4">
            <p className="text-xs text-muted-foreground">
              💡 {__('Tip: Email is always available. Install addons to enable WhatsApp, Telegram, SMS, and other channels.')}
            </p>
          </div>
        </div>
      </SettingsCard>

      {/* Order Events */}
      {orderEvents.length > 0 && (
        <SettingsCard
          title={__('Order Events')}
          description={__('Notifications triggered by order status changes')}
        >
          <div className="space-y-6">
            {orderEvents.map((event: NotificationEvent) => (
              <div key={event.id} className="pb-6 border-b last:border-0">
                <div className="mb-4">
                  <h3 className="font-medium text-sm">{event.label}</h3>
                  <p className="text-xs text-muted-foreground mt-1">{event.description}</p>
                </div>

                {/* Channel Selection */}
                <div className="space-y-3">
                  {channels?.map((channel: NotificationChannel) => {
                    const channelEnabled = event.channels?.[channel.id]?.enabled || false;
                    const recipient = event.channels?.[channel.id]?.recipient || 'admin';

                    return (
                      <div
                        key={channel.id}
                        className="flex items-center justify-between p-3 rounded-lg border bg-card"
                      >
                        <div className="flex items-center gap-3">
                          <div className={`p-2 rounded-lg ${channelEnabled ? 'bg-green-500/20 text-green-600' : 'bg-muted text-muted-foreground'}`}>
                            {getChannelIcon(channel.id)}
                          </div>
                          <div>
                            <div className="flex items-center gap-2">
                              <span className="text-sm font-medium">{channel.label}</span>
                              {channel.builtin && (
                                <Badge variant="secondary" className="text-xs">
                                  {__('Built-in')}
                                </Badge>
                              )}
                            </div>
                            {channelEnabled && (
                              <span className="text-xs text-muted-foreground">
                                {__('Send to')}: {recipient === 'admin' ? __('Admin') : recipient === 'customer' ? __('Customer') : __('Both')}
                              </span>
                            )}
                          </div>
                        </div>
                        <Switch
                          checked={channelEnabled}
                          onCheckedChange={() => toggleChannel(event.id, channel.id, channelEnabled)}
                          disabled={!channel.enabled || updateMutation.isPending}
                        />
                      </div>
                    );
                  })}
                </div>
              </div>
            ))}
          </div>
        </SettingsCard>
      )}

      {/* Product Events */}
      {productEvents.length > 0 && (
        <SettingsCard
          title={__('Product Events')}
          description={__('Notifications about product stock levels')}
        >
          <div className="space-y-6">
            {productEvents.map((event: NotificationEvent) => (
              <div key={event.id} className="pb-6 border-b last:border-0">
                <div className="mb-4">
                  <h3 className="font-medium text-sm">{event.label}</h3>
                  <p className="text-xs text-muted-foreground mt-1">{event.description}</p>
                </div>

                <div className="space-y-3">
                  {channels?.map((channel: NotificationChannel) => {
                    const channelEnabled = event.channels?.[channel.id]?.enabled || false;
                    const recipient = event.channels?.[channel.id]?.recipient || 'admin';

                    return (
                      <div
                        key={channel.id}
                        className="flex items-center justify-between p-3 rounded-lg border bg-card"
                      >
                        <div className="flex items-center gap-3">
                          <div className={`p-2 rounded-lg ${channelEnabled ? 'bg-green-500/20 text-green-600' : 'bg-muted text-muted-foreground'}`}>
                            {getChannelIcon(channel.id)}
                          </div>
                          <div>
                            <div className="flex items-center gap-2">
                              <span className="text-sm font-medium">{channel.label}</span>
                              {channel.builtin && (
                                <Badge variant="secondary" className="text-xs">
                                  {__('Built-in')}
                                </Badge>
                              )}
                            </div>
                            {channelEnabled && (
                              <span className="text-xs text-muted-foreground">
                                {__('Send to')}: {recipient === 'admin' ? __('Admin') : recipient === 'customer' ? __('Customer') : __('Both')}
                              </span>
                            )}
                          </div>
                        </div>
                        <Switch
                          checked={channelEnabled}
                          onCheckedChange={() => toggleChannel(event.id, channel.id, channelEnabled)}
                          disabled={!channel.enabled || updateMutation.isPending}
                        />
                      </div>
                    );
                  })}
                </div>
              </div>
            ))}
          </div>
        </SettingsCard>
      )}

      {/* Customer Events */}
      {customerEvents.length > 0 && (
        <SettingsCard
          title={__('Customer Events')}
          description={__('Notifications about customer activities')}
        >
          <div className="space-y-6">
            {customerEvents.map((event: NotificationEvent) => (
              <div key={event.id} className="pb-6 border-b last:border-0">
                <div className="mb-4">
                  <h3 className="font-medium text-sm">{event.label}</h3>
                  <p className="text-xs text-muted-foreground mt-1">{event.description}</p>
                </div>

                <div className="space-y-3">
                  {channels?.map((channel: NotificationChannel) => {
                    const channelEnabled = event.channels?.[channel.id]?.enabled || false;
                    const recipient = event.channels?.[channel.id]?.recipient || 'admin';

                    return (
                      <div
                        key={channel.id}
                        className="flex items-center justify-between p-3 rounded-lg border bg-card"
                      >
                        <div className="flex items-center gap-3">
                          <div className={`p-2 rounded-lg ${channelEnabled ? 'bg-green-500/20 text-green-600' : 'bg-muted text-muted-foreground'}`}>
                            {getChannelIcon(channel.id)}
                          </div>
                          <div>
                            <div className="flex items-center gap-2">
                              <span className="text-sm font-medium">{channel.label}</span>
                              {channel.builtin && (
                                <Badge variant="secondary" className="text-xs">
                                  {__('Built-in')}
                                </Badge>
                              )}
                            </div>
                            {channelEnabled && (
                              <span className="text-xs text-muted-foreground">
                                {__('Send to')}: {recipient === 'admin' ? __('Admin') : recipient === 'customer' ? __('Customer') : __('Both')}
                              </span>
                            )}
                          </div>
                        </div>
                        <Switch
                          checked={channelEnabled}
                          onCheckedChange={() => toggleChannel(event.id, channel.id, channelEnabled)}
                          disabled={!channel.enabled || updateMutation.isPending}
                        />
                      </div>
                    );
                  })}
                </div>
              </div>
            ))}
          </div>
        </SettingsCard>
      )}
    </div>
  );
}
