import React, { useState, useMemo } from 'react';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { api } from '@/lib/api';
import { SettingsLayout } from './components/SettingsLayout';
import { SettingsCard } from './components/SettingsCard';
import { Switch } from '@/components/ui/switch';
import { Badge } from '@/components/ui/badge';
import { Input } from '@/components/ui/input';
import { Button } from '@/components/ui/button';
import { RefreshCw, Mail, Heart, Users, RefreshCcw, Key, Search, Settings, Truck, CreditCard, BarChart3, Puzzle } from 'lucide-react';
import { toast } from 'sonner';
import { __ } from '@/lib/i18n';
import { useNavigate } from 'react-router-dom';

interface Module {
  id: string;
  label: string;
  description: string;
  category: string;
  icon: string;
  enabled: boolean;
  features: string[];
  is_addon?: boolean;
  version?: string;
  author?: string;
  has_settings?: boolean;
}

interface ModulesData {
  modules: Record<string, Module>;
  grouped: Record<string, Module[]>;
  categories: Record<string, string>;
}

export default function Modules() {
  const queryClient = useQueryClient();
  const navigate = useNavigate();
  const [searchQuery, setSearchQuery] = useState('');
  const [selectedCategory, setSelectedCategory] = useState<string | null>(null);

  const { data: modulesData, isLoading } = useQuery<ModulesData>({
    queryKey: ['modules'],
    queryFn: async () => {
      const response = await api.get('/modules');
      // api.get returns JSON directly, not wrapped in .data
      return response as ModulesData;
    },
  });

  const toggleModule = useMutation({
    mutationFn: async ({ moduleId, enabled }: { moduleId: string; enabled: boolean }) => {
      return api.post('/modules/toggle', { module_id: moduleId, enabled });
    },
    onSuccess: (data, variables) => {
      queryClient.invalidateQueries({ queryKey: ['modules'] });
      toast.success(
        variables.enabled
          ? __('Module enabled successfully')
          : __('Module disabled successfully')
      );
    },
    onError: (error: any) => {
      toast.error(error?.message || __('Failed to toggle module'));
    },
  });

  const getIcon = (iconName: string) => {
    const icons: Record<string, any> = {
      mail: Mail,
      heart: Heart,
      users: Users,
      'refresh-cw': RefreshCcw,
      key: Key,
      truck: Truck,
      'credit-card': CreditCard,
      'bar-chart-3': BarChart3,
      puzzle: Puzzle,
    };
    const Icon = icons[iconName] || Puzzle;
    return <Icon className="h-5 w-5" />;
  };

  // Filter modules based on search and category
  const filteredGrouped = useMemo(() => {
    if (!modulesData?.grouped) return {};
    
    const filtered: Record<string, Module[]> = {};
    
    Object.entries(modulesData.grouped).forEach(([category, modules]) => {
      // Filter by category if selected
      if (selectedCategory && category !== selectedCategory) return;
      
      // Filter by search query
      const matchingModules = modules.filter((module) => {
        if (!searchQuery) return true;
        const query = searchQuery.toLowerCase();
        return (
          module.label.toLowerCase().includes(query) ||
          module.description.toLowerCase().includes(query) ||
          module.features.some((f) => f.toLowerCase().includes(query))
        );
      });
      
      if (matchingModules.length > 0) {
        filtered[category] = matchingModules;
      }
    });
    
    return filtered;
  }, [modulesData, searchQuery, selectedCategory]);

  const categories = Object.keys(modulesData?.categories || {});

  return (
    <SettingsLayout
      title={__('Module Management')}
      description={__('Enable or disable features to customize your store')}
      isLoading={isLoading}
    >
      {/* Search and Filters */}
      <div className="mb-6 space-y-4">
        {/* Search Input */}
        <div className="relative">
          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
          <Input
            placeholder={__('Search modules...')}
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            className="!pl-9"
          />
        </div>
        
        {/* Category Pills */}
        <div className="flex flex-wrap gap-2">
          <Button
            variant={selectedCategory === null ? 'default' : 'outline'}
            size="sm"
            onClick={() => setSelectedCategory(null)}
          >
            {__('All Categories')}
          </Button>
          {categories.map((category) => (
            <Button
              key={category}
              variant={selectedCategory === category ? 'default' : 'outline'}
              size="sm"
              onClick={() => setSelectedCategory(category)}
            >
              {modulesData?.categories[category] || category}
            </Button>
          ))}
        </div>
      </div>

      {/* Info Card */}
      <div className="bg-blue-50 dark:bg-blue-950/20 border border-blue-200 dark:border-blue-900 rounded-lg p-4 mb-6">
        <div className="text-sm space-y-2">
          <p className="text-blue-900 dark:text-blue-100">
            {__(
              'Modules allow you to enable only the features you need. Disabling unused modules improves performance and reduces clutter in your admin panel.'
            )}
          </p>
          <p className="text-xs text-blue-700 dark:text-blue-300">
            💡 {__('Tip: When you disable a module, its menu items and settings will be hidden from the admin panel, and its features will be disabled on the frontend.')}
          </p>
        </div>
      </div>

      {/* Module Categories */}
      {Object.keys(filteredGrouped).length === 0 && (
        <div className="text-center py-12 text-muted-foreground">
          <Search className="h-12 w-12 mx-auto mb-3 opacity-50" />
          <p>{__('No modules found matching your search')}</p>
        </div>
      )}
      
      {Object.entries(filteredGrouped).map(([category, modules]) => {
        
        if (modules.length === 0) return null;

        return (
          <SettingsCard
            key={category}
            title={modulesData?.categories[category] || category}
            description={__('Manage modules in this category')}
          >
            <div className="space-y-4">
              {modules.map((module) => (
                <div
                  key={module.id}
                  className="flex items-start gap-4 p-4 border rounded-lg bg-card hover:bg-accent/5 transition-colors"
                >
                  {/* Icon */}
                  <div
                    className={`p-3 rounded-lg ${
                      module.enabled
                        ? 'bg-primary/10 text-primary'
                        : 'bg-muted text-muted-foreground'
                    }`}
                  >
                    {getIcon(module.icon)}
                  </div>

                  {/* Content */}
                  <div className="flex-1 min-w-0">
                    <div className="flex items-center gap-2 mb-1">
                      <h3 className="font-medium text-sm">{module.label}</h3>
                      {module.enabled && (
                        <Badge variant="secondary" className="text-xs">
                          {__('Active')}
                        </Badge>
                      )}
                      {module.is_addon && (
                        <Badge variant="outline" className="text-xs">
                          {__('Addon')}
                        </Badge>
                      )}
                    </div>
                    <p className="text-xs text-muted-foreground mb-3">
                      {module.description}
                    </p>

                    {/* Features List */}
                    {module.features && module.features.length > 0 && (
                      <ul className="space-y-1">
                        {module.features.map((feature, index) => (
                          <li
                            key={index}
                            className="text-xs text-muted-foreground flex items-center gap-2"
                          >
                            <span className="text-primary">•</span>
                            {feature}
                          </li>
                        ))}
                      </ul>
                    )}
                  </div>

                  {/* Actions */}
                  <div className="flex items-center gap-2">
                    {/* Settings Gear Icon */}
                    {module.has_settings && module.enabled && (
                      <Button
                        variant="ghost"
                        size="icon"
                        onClick={() => navigate(`/settings/modules/${module.id}`)}
                        title={__('Module Settings')}
                      >
                        <Settings className="h-4 w-4" />
                      </Button>
                    )}
                    
                    {/* Toggle Switch */}
                    <Switch
                      checked={module.enabled}
                      onCheckedChange={(enabled) =>
                        toggleModule.mutate({ moduleId: module.id, enabled })
                      }
                      disabled={toggleModule.isPending}
                    />
                  </div>
                </div>
              ))}
            </div>
          </SettingsCard>
        );
      })}
    </SettingsLayout>
  );
}
