import React, { useState } 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 { SettingsSection } from './components/SettingsSection';
import { ToggleField } from './components/ToggleField';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Label } from '@/components/ui/label';
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter } from '@/components/ui/dialog';
import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle } from '@/components/ui/alert-dialog';
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select';
import { SearchableSelect } from '@/components/ui/searchable-select';
import { ExternalLink, RefreshCw, Plus, Pencil, Trash2, Check } from 'lucide-react';
import { toast } from 'sonner';
import { __ } from '@/lib/i18n';

export default function TaxSettings() {
  const queryClient = useQueryClient();
  const wcAdminUrl = (window as any).WNW_CONFIG?.wpAdminUrl || '/wp-admin';

  const [showAddRate, setShowAddRate] = useState(false);
  const [editingRate, setEditingRate] = useState<any | null>(null);
  const [deletingRate, setDeletingRate] = useState<any | null>(null);
  const [dismissedSuggestions, setDismissedSuggestions] = useState<string[]>([]);
  const [selectedTaxClass, setSelectedTaxClass] = useState<string>('standard');

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

  // Fetch suggested rates
  const { data: suggested } = useQuery({
    queryKey: ['tax-suggested'],
    queryFn: () => api.get('/settings/tax/suggested'),
    enabled: settings?.calc_taxes === 'yes',
  });

  // Toggle tax calculation
  const toggleMutation = useMutation({
    mutationFn: async (enabled: boolean) => {
      return api.post('/settings/tax/toggle', { enabled });
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
      toast.success(__('Tax calculation updated'));
    },
    onError: (error: any) => {
      toast.error(error?.message || __('Failed to update tax settings'));
    },
  });

  // Create tax rate
  const createMutation = useMutation({
    mutationFn: async (data: any) => {
      const response = await api.post('/settings/tax/rates', data);
      return response;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
      queryClient.invalidateQueries({ queryKey: ['tax-suggested'] });
      setShowAddRate(false);
      toast.success(__('Tax rate created'));
    },
    onError: (error: any) => {
      console.error('[Tax] Create error:', error);
      toast.error(error?.message || __('Failed to create tax rate'));
    },
  });

  // Update tax rate
  const updateMutation = useMutation({
    mutationFn: async ({ id, data }: any) => {
      return api.put(`/settings/tax/rates/${id}`, data);
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
      setEditingRate(null);
      toast.success(__('Tax rate updated'));
    },
    onError: (error: any) => {
      toast.error(error?.message || __('Failed to update tax rate'));
    },
  });

  // Delete tax rate
  const deleteMutation = useMutation({
    mutationFn: async (id: number) => {
      return api.del(`/settings/tax/rates/${id}`);
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
      setDeletingRate(null);
      toast.success(__('Tax rate deleted'));
    },
    onError: (error: any) => {
      toast.error(error?.message || __('Failed to delete tax rate'));
    },
  });

  // Quick add suggested rate
  const quickAddMutation = useMutation({
    mutationFn: async (suggestedRate: any) => {
      const response = await api.post('/settings/tax/rates', {
        country: suggestedRate.code,
        state: '',
        rate: suggestedRate.rate,
        name: suggestedRate.name,
        tax_class: '',
        priority: 1,
        compound: 0,
        shipping: 1,
      });
      return response;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
      queryClient.invalidateQueries({ queryKey: ['tax-suggested'] });
      toast.success(__('Tax rate added'));
    },
    onError: (error: any) => {
      console.error('[Tax] Quick add error:', error);
      toast.error(error?.message || __('Failed to add tax rate'));
    },
  });

  const handleSubmit = (e: React.FormEvent<HTMLFormElement>) => {
    e.preventDefault();
    const formData = new FormData(e.currentTarget);

    const data = {
      country: formData.get('country') as string,
      state: formData.get('state') as string || '',
      rate: parseFloat(formData.get('rate') as string),
      name: formData.get('name') as string,
      tax_class: selectedTaxClass === 'standard' ? '' : selectedTaxClass,
      priority: 1,
      compound: 0,
      shipping: 1,
    };

    if (editingRate) {
      updateMutation.mutate({ id: editingRate.id, data });
    } else {
      createMutation.mutate(data);
    }
  };

  if (isLoading) {
    return (
      <SettingsLayout
        title={__('Tax')}
        description={__('Configure tax calculation and rates')}
      >
        <div className="flex items-center justify-center py-12">
          <RefreshCw className="h-6 w-6 animate-spin text-muted-foreground" />
        </div>
      </SettingsLayout>
    );
  }

  const allRates = [
    ...(settings?.standard_rates || []),
    ...(settings?.reduced_rates || []),
    ...(settings?.zero_rates || []),
  ];

  // Check if a suggested rate is already added
  const isRateAdded = (countryCode: string) => {
    return allRates.some((rate: any) => rate.country === countryCode);
  };

  return (
    <SettingsLayout
      title={__('Tax')}
      description={__('Configure tax calculation and rates for your store')}
      action={
        <Button
          variant="outline"
          size="sm"
          onClick={() => {
            queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
            queryClient.invalidateQueries({ queryKey: ['tax-suggested'] });
          }}
        >
          <RefreshCw className="h-4 w-4 mr-2" />
          {__('Refresh')}
        </Button>
      }
    >
      <div className="space-y-6">
        {/* Enable Tax Calculation */}
        <SettingsCard
          title={__('Tax Calculation')}
          description={__('Enable or disable tax calculation for your store')}
        >
          <ToggleField
            id="calc_taxes"
            label={__('Enable tax rates and calculations')}
            description={__('Calculate and display taxes at checkout based on customer location')}
            checked={settings?.calc_taxes === 'yes'}
            onCheckedChange={(checked: boolean) => toggleMutation.mutate(checked)}
            disabled={toggleMutation.isPending}
          />
        </SettingsCard>

        {/* Tax Rates */}
        {settings?.calc_taxes === 'yes' && (
          <SettingsCard
            title={__('Tax Rates')}
            description={__('Manage tax rates for different locations')}
            action={
              <Button
                size="sm"
                onClick={() => {
                  setSelectedTaxClass('standard');
                  setShowAddRate(true);
                }}
              >
                <Plus className="h-4 w-4 mr-2" />
                {__('Add Tax Rate')}
              </Button>
            }
          >
            {/* Suggested Rates Notice */}
            {suggested?.suggested && suggested.suggested.length > 0 && suggested.suggested.some((r: any) => !isRateAdded(r.code)) && (
              <div className="mb-4 p-4 bg-blue-50 border border-blue-200 rounded-lg">
                <div className="flex items-start justify-between gap-4">
                  <div className="flex-1">
                    <h4 className="font-medium text-sm text-blue-900 mb-2">
                      {__('Suggested tax rates based on your selling locations')}
                    </h4>
                    <div className="space-y-2">
                      {suggested.suggested.filter((r: any) => !isRateAdded(r.code)).map((rate: any) => (
                        <div key={rate.code} className="flex items-center justify-between">
                          <span className="text-sm text-blue-800">
                            {rate.country}: {rate.rate}% ({rate.name})
                          </span>
                          <Button
                            size="sm"
                            variant="outline"
                            className="h-7 text-xs"
                            onClick={() => quickAddMutation.mutate(rate)}
                            disabled={quickAddMutation.isPending}
                          >
                            {__('Add')}
                          </Button>
                        </div>
                      ))}
                    </div>
                  </div>
                </div>
              </div>
            )}

            {/* Tax Rates List */}
            {allRates.length === 0 ? (
              <div className="text-center py-8 text-muted-foreground">
                <p>{__('No tax rates configured yet')}</p>
                <p className="text-sm mt-1">{__('Add a tax rate to get started')}</p>
              </div>
            ) : (
              <div className="space-y-2">
                {allRates.map((rate: any) => (
                  <div key={rate.id} className="flex items-center justify-between p-3 border rounded-lg hover:bg-accent/50 transition-colors">
                    <div className="flex-1">
                      <div className="flex items-center gap-2">
                        <span className="font-medium">{rate.name}</span>
                        <span className="text-sm text-muted-foreground">
                          {rate.country} {rate.state && `- ${rate.state}`}
                        </span>
                      </div>
                      <p className="text-sm text-muted-foreground mt-0.5">
                        {rate.rate}% tax rate
                      </p>
                    </div>
                    <div className="flex items-center gap-2">
                      <Button
                        variant="ghost"
                        size="sm"
                        onClick={() => setEditingRate(rate)}
                      >
                        <Pencil className="h-4 w-4" />
                      </Button>
                      <Button
                        variant="ghost"
                        size="sm"
                        onClick={() => setDeletingRate(rate)}
                      >
                        <Trash2 className="h-4 w-4" />
                      </Button>
                    </div>
                  </div>
                ))}
              </div>
            )}
          </SettingsCard>
        )}

        {/* Display Settings */}
        {settings?.calc_taxes === 'yes' && (
          <SettingsCard
            title={__('Display Settings')}
            description={__('Configure how taxes are displayed to customers')}
          >
            <div className="space-y-4">
              <SettingsSection
                label={__('Prices are entered')}
                description={__('How you enter product prices in the admin')}
              >
                <Select
                  value={settings?.prices_include_tax || 'no'}
                  onValueChange={(value) => {
                    // Update setting
                  }}
                >
                  <SelectTrigger className="w-full">
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="no">{__('Excluding tax')}</SelectItem>
                    <SelectItem value="yes">{__('Including tax')}</SelectItem>
                  </SelectContent>
                </Select>
              </SettingsSection>

              <SettingsSection
                label={__('Display prices in shop')}
                description={__('How prices are displayed on product pages')}
              >
                <Select
                  value={settings?.tax_display_shop || 'excl'}
                  onValueChange={(value) => {
                    // Update setting
                  }}
                >
                  <SelectTrigger className="w-full">
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="excl">{__('Excluding tax')}</SelectItem>
                    <SelectItem value="incl">{__('Including tax')}</SelectItem>
                  </SelectContent>
                </Select>
              </SettingsSection>

              <SettingsSection
                label={__('Display prices in cart')}
                description={__('How prices are displayed in cart and checkout')}
              >
                <Select
                  value={settings?.tax_display_cart || 'excl'}
                  onValueChange={(value) => {
                    // Update setting
                  }}
                >
                  <SelectTrigger className="w-full">
                    <SelectValue />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="excl">{__('Excluding tax')}</SelectItem>
                    <SelectItem value="incl">{__('Including tax')}</SelectItem>
                  </SelectContent>
                </Select>
              </SettingsSection>
            </div>
          </SettingsCard>
        )}

        {/* Advanced Settings Link */}
        <SettingsCard
          title={__('Advanced Tax Settings')}
          description={__('Configure advanced tax options in WooCommerce')}
        >
          <Button
            variant="outline"
            onClick={() => window.location.href = `${wcAdminUrl}/admin.php?page=wc-settings&tab=tax`}
          >
            <ExternalLink className="h-4 w-4 mr-2" />
            {__('Open WooCommerce Tax Settings')}
          </Button>
        </SettingsCard>
      </div>

      {/* Add/Edit Tax Rate Dialog */}
      <Dialog open={showAddRate || !!editingRate} onOpenChange={(open) => {
        if (!open) {
          setShowAddRate(false);
          setEditingRate(null);
          setSelectedTaxClass('standard');
        } else {
          // Initialize tax class when opening (convert empty to 'standard')
          setSelectedTaxClass(editingRate?.tax_class || 'standard');
        }
      }}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>
              {editingRate ? __('Edit Tax Rate') : __('Add Tax Rate')}
            </DialogTitle>
          </DialogHeader>
          <form onSubmit={handleSubmit}>
            <div className="space-y-4 px-6 py-4">
              <div>
                <Label>{__('Country')}</Label>
                <Input
                  name="country"
                  type="text"
                  placeholder="ID"
                  defaultValue={editingRate?.country || ''}
                  required
                />
                <p className="text-xs text-muted-foreground mt-1">
                  {__('2-letter country code (e.g., ID, MY, SG)')}
                </p>
              </div>

              <div>
                <Label>{__('State/Province (Optional)')}</Label>
                <Input
                  name="state"
                  type="text"
                  placeholder="CA"
                  defaultValue={editingRate?.state || ''}
                />
                <p className="text-xs text-muted-foreground mt-1">
                  {__('Leave empty for country-wide rate')}
                </p>
              </div>

              <div>
                <Label>{__('Tax Rate (%)')}</Label>
                <Input
                  name="rate"
                  type="number"
                  step="0.01"
                  min="0"
                  max="100"
                  placeholder="11"
                  defaultValue={editingRate?.rate || ''}
                  required
                />
              </div>

              <div>
                <Label>{__('Tax Name')}</Label>
                <Input
                  name="name"
                  type="text"
                  placeholder="PPN (VAT)"
                  defaultValue={editingRate?.name || ''}
                  required
                />
              </div>

              <div>
                <Label>{__('Tax Class (Optional)')}</Label>
                <Select value={selectedTaxClass || 'standard'} onValueChange={setSelectedTaxClass}>
                  <SelectTrigger>
                    <SelectValue placeholder={__('Standard')} />
                  </SelectTrigger>
                  <SelectContent>
                    <SelectItem value="standard">{__('Standard')}</SelectItem>
                    <SelectItem value="reduced-rate">{__('Reduced Rate')}</SelectItem>
                    <SelectItem value="zero-rate">{__('Zero Rate')}</SelectItem>
                  </SelectContent>
                </Select>
              </div>
            </div>

            <DialogFooter>
              <Button
                type="button"
                variant="outline"
                onClick={() => {
                  setShowAddRate(false);
                  setEditingRate(null);
                }}
              >
                {__('Cancel')}
              </Button>
              <Button
                type="submit"
                disabled={createMutation.isPending || updateMutation.isPending}
              >
                {editingRate ? __('Update Rate') : __('Add Rate')}
              </Button>
            </DialogFooter>
          </form>
        </DialogContent>
      </Dialog>

      {/* Delete Confirmation */}
      <AlertDialog open={!!deletingRate} onOpenChange={(open) => !open && setDeletingRate(null)}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>{__('Delete Tax Rate?')}</AlertDialogTitle>
            <AlertDialogDescription>
              {__('Are you sure you want to delete this tax rate? This action cannot be undone.')}
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>{__('Cancel')}</AlertDialogCancel>
            <AlertDialogAction
              onClick={() => deletingRate && deleteMutation.mutate(deletingRate.id)}
              className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
            >
              {__('Delete')}
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </SettingsLayout>
  );
}