import React, { useState, useMemo, useEffect } from 'react';
import { useCustomerDiscountUsageReport } from '../core/_hooks';
import { CustomerDiscountUsageFilters } from '../core/_models';
import { Button } from '@/components/ui/Button';
import { Input } from '@/components/ui/Input';
import { Table } from '@/components/ui/Table';
import { TableColumn } from '@/types';
import { JalaliDateTimePicker } from '@/components/ui/JalaliDateTimePicker';
import { PageContainer, PageTitle } from '@/components/ui/Typography';
import { Pagination } from '@/components/ui/Pagination';
import { Filter, TrendingUp, Users, DollarSign, Hash, X } from 'lucide-react';
import { formatWithThousands, persianToEnglish } from '@/utils/numberUtils';
import { formatCurrency, formatDateTime } from '@/utils/formatters';
import { ReportSkeleton } from '@/components/common/ReportSkeleton';
import { useSearchUsers, useUsers } from '@/pages/users-admin/core/_hooks';
import { UserFilters } from '@/pages/users-admin/core/_models';

const CustomerDiscountUsagePage = () => {
  const [filters, setFilters] = useState<CustomerDiscountUsageFilters>({
    user_id: 0,
    limit: 50,
    offset: 0,
  });

  const [tempFilters, setTempFilters] = useState<CustomerDiscountUsageFilters>({
    user_id: 0,
    limit: 50,
    offset: 0,
  });

  const [refetchKey, setRefetchKey] = useState(0);
  const [userSearchText, setUserSearchText] = useState('');
  const [userSearchDebounced, setUserSearchDebounced] = useState('');
  const [userDropdownOpen, setUserDropdownOpen] = useState(false);

  useEffect(() => {
    const t = setTimeout(() => setUserSearchDebounced(userSearchText), 300);
    return () => clearTimeout(t);
  }, [userSearchText]);

  const { data: usersList } = useUsers({ limit: 20, offset: 0 });
  const userSearchFilters = useMemo<UserFilters>(() =>
    userSearchDebounced ? { search_text: userSearchDebounced, limit: 20, offset: 0 } : {}, [userSearchDebounced]);
  const { data: userSearchData } = useSearchUsers(userSearchFilters);
  const userOptions = userSearchDebounced ? (userSearchData?.users || []) : (usersList || []);

  const filtersWithKey = useMemo(() => ({
    ...filters,
    _refetchKey: refetchKey,
  }), [filters, refetchKey]);

  const { data, isLoading, error } = useCustomerDiscountUsageReport(filtersWithKey as CustomerDiscountUsageFilters & { _refetchKey?: number });

  const handleTempFilterChange = (key: keyof CustomerDiscountUsageFilters, value: any) => {
    setTempFilters(prev => ({
      ...prev,
      [key]: value,
    }));
  };

  const handleDateRangeChange = (from: string | undefined, to: string | undefined) => {
    setTempFilters(prev => ({
      ...prev,
      date_range: {
        from,
        to,
      },
    }));
  };

  const handleNumericFilterChange = (key: 'discount_id', raw: string) => {
    const converted = persianToEnglish(raw).replace(/[^\d]/g, '');
    const numeric = converted ? Number(converted) : undefined;
    handleTempFilterChange(key, numeric);
  };

  const handleSelectUser = (user: { id: number; phone_number?: string; first_name?: string; last_name?: string }) => {
    handleTempFilterChange('user_id', user.id);
    setUserSearchText(user.phone_number || `${user.first_name || ''} ${user.last_name || ''}`.trim() || String(user.id));
    setUserDropdownOpen(false);
  };

  const handleApplyFilters = () => {
    const newFilters = {
      ...tempFilters,
      offset: 0,
    };
    setFilters(newFilters);
    setRefetchKey(prev => prev + 1);
  };

  const handlePageChange = (page: number) => {
    setFilters(prev => ({
      ...prev,
      offset: (page - 1) * prev.limit,
    }));
  };

  const handleClearFilters = () => {
    const clearedFilters = {
      user_id: 0,
      limit: 50,
      offset: 0,
    };
    setTempFilters(clearedFilters);
    setFilters(clearedFilters);
    setUserSearchText('');
  };

  const columns: TableColumn[] = [
    {
      key: 'discount_code',
      label: 'کد تخفیف',
      align: 'right',
    },
    {
      key: 'discount_name',
      label: 'نام کد تخفیف',
      align: 'right',
    },
    {
      key: 'order_number',
      label: 'شماره سفارش',
      align: 'right',
    },
    {
      key: 'amount',
      label: 'مبلغ تخفیف',
      align: 'right',
    },
    {
      key: 'used_at',
      label: 'زمان استفاده',
      align: 'right',
    },
  ];

  const tableData = (data?.usages || []).map(usage => ({
    discount_code: usage.discount_code,
    discount_name: usage.discount_name,
    order_number: usage.order_number || '-',
    amount: formatCurrency(usage.amount),
    used_at: formatDateTime(usage.used_at),
  }));

  const currentPage = Math.floor(filters.offset / filters.limit) + 1;
  const totalPages = data ? Math.ceil(data.total / filters.limit) : 1;

  return (
    <PageContainer>
      <PageTitle>گزارش استفاده کاربر خاص از کدهای تخفیف</PageTitle>

      {/* Filters */}
      <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg p-4 mb-6">
        <div className="flex items-center justify-between mb-4">
          <div className="flex items-center gap-2">
            <Filter className="h-5 w-5 text-gray-500" />
            <h3 className="text-lg font-semibold text-gray-900 dark:text-gray-100">فیلترها</h3>
          </div>
          <div className="flex items-center gap-2">
            <Button
              onClick={handleApplyFilters}
              disabled={!tempFilters.user_id || tempFilters.user_id === 0}
              className="flex items-center gap-2"
            >
              <Filter className="h-4 w-4" />
              اعمال فیلترها
            </Button>
            <Button
              variant="secondary"
              size="sm"
              onClick={handleClearFilters}
              className="flex items-center gap-2"
            >
              <X className="h-4 w-4" />
              پاک کردن فیلترها
            </Button>
          </div>
        </div>

        <div className="mb-4 p-3 bg-blue-50 dark:bg-blue-900/20 border border-blue-200 dark:border-blue-800 rounded-lg">
          <p className="text-sm text-blue-800 dark:text-blue-200">
            <span className="font-semibold">توجه:</span> برای مشاهده گزارش، کاربر را از لیست انتخاب کنید یا با شماره موبایل جستجو کنید. این فیلد الزامی است.
          </p>
        </div>

        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
          <div>
            <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
              شناسه کاربر <span className="text-red-500">*</span>
            </label>
            <div className="relative">
              <Input
                value={userSearchText}
                onChange={(e) => {
                  setUserSearchText(persianToEnglish(e.target.value));
                  setUserDropdownOpen(true);
                  if (tempFilters.user_id) handleTempFilterChange('user_id', 0);
                }}
                onFocus={() => setUserDropdownOpen(true)}
                onBlur={() => setTimeout(() => setUserDropdownOpen(false), 150)}
                placeholder="جستجو با شماره موبایل یا انتخاب از لیست"
              />
              {userDropdownOpen && (
                <div className="absolute z-20 mt-2 w-full rounded-lg border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 shadow-lg max-h-60 overflow-y-auto">
                  {(userSearchDebounced ? (userSearchData?.users ?? []) : (usersList ?? [])).length === 0 && (
                    <div className="p-3 text-sm text-gray-500 dark:text-gray-400">
                      کاربری یافت نشد
                    </div>
                  )}
                  {(userSearchDebounced ? (userSearchData?.users ?? []) : (usersList ?? [])).map((user: { id: number; phone_number?: string; first_name?: string; last_name?: string }) => (
                    <button
                      key={user.id}
                      type="button"
                      onMouseDown={(e) => e.preventDefault()}
                      onClick={() => handleSelectUser(user)}
                      className="w-full text-right px-4 py-2 hover:bg-gray-50 dark:hover:bg-gray-700 transition-colors"
                    >
                      <div className="text-sm text-gray-900 dark:text-gray-100">
                        {user.first_name} {user.last_name}
                      </div>
                      <div className="text-xs text-gray-500 dark:text-gray-400">
                        {user.phone_number}
                      </div>
                    </button>
                  ))}
                </div>
              )}
            </div>
          </div>

          <div>
            <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
              کد تخفیف
            </label>
            <Input
              value={tempFilters.discount_code || ''}
              onChange={(e) => handleTempFilterChange('discount_code', e.target.value || undefined)}
              placeholder="مثلاً SUMMER2025"
            />
          </div>

          <div>
            <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
              شناسه کد تخفیف
            </label>
            <Input
              value={tempFilters.discount_id?.toString() || ''}
              onChange={(e) => handleNumericFilterChange('discount_id', e.target.value)}
              placeholder="مثلاً 123"
              numeric
            />
          </div>

          <div>
            <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
              تاریخ شروع
            </label>
            <JalaliDateTimePicker
              value={tempFilters.date_range?.from}
              onChange={(value) => handleDateRangeChange(value, tempFilters.date_range?.to)}
              placeholder="انتخاب تاریخ شروع"
            />
          </div>

          <div>
            <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
              تاریخ پایان
            </label>
            <JalaliDateTimePicker
              value={tempFilters.date_range?.to}
              onChange={(value) => handleDateRangeChange(tempFilters.date_range?.from, value)}
              placeholder="انتخاب تاریخ پایان"
            />
          </div>
        </div>
      </div>

      {/* Summary Cards */}
      {data?.summary && (
        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4 mb-6">
          <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg p-4">
            <div className="flex items-center gap-3">
              <div className="p-2 bg-blue-100 dark:bg-blue-900 rounded-lg">
                <Hash className="h-5 w-5 text-blue-600 dark:text-blue-400" />
              </div>
              <div>
                <p className="text-sm text-gray-600 dark:text-gray-400">کل استفاده‌ها</p>
                <p className="text-xl font-bold text-gray-900 dark:text-gray-100">
                  {formatWithThousands(data.summary.total_usages)}
                </p>
              </div>
            </div>
          </div>

          <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg p-4">
            <div className="flex items-center gap-3">
              <div className="p-2 bg-green-100 dark:bg-green-900 rounded-lg">
                <DollarSign className="h-5 w-5 text-green-600 dark:text-green-400" />
              </div>
              <div>
                <p className="text-sm text-gray-600 dark:text-gray-400">مجموع تخفیف دریافتی</p>
                <p className="text-xl font-bold text-gray-900 dark:text-gray-100">
                  {formatCurrency(data.summary.total_discount_amount)}
                </p>
              </div>
            </div>
          </div>

          <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg p-4">
            <div className="flex items-center gap-3">
              <div className="p-2 bg-purple-100 dark:bg-purple-900 rounded-lg">
                <Hash className="h-5 w-5 text-purple-600 dark:text-purple-400" />
              </div>
              <div>
                <p className="text-sm text-gray-600 dark:text-gray-400">کدهای متفاوت</p>
                <p className="text-xl font-bold text-gray-900 dark:text-gray-100">
                  {formatWithThousands(data.summary.unique_codes)}
                </p>
              </div>
            </div>
          </div>

          <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg p-4">
            <div className="flex items-center gap-3">
              <div className="p-2 bg-yellow-100 dark:bg-yellow-900 rounded-lg">
                <TrendingUp className="h-5 w-5 text-yellow-600 dark:text-yellow-400" />
              </div>
              <div>
                <p className="text-sm text-gray-600 dark:text-gray-400">میانگین تخفیف هر سفارش</p>
                <p className="text-xl font-bold text-gray-900 dark:text-gray-100">
                  {formatCurrency(data.summary.average_discount_per_order)}
                </p>
              </div>
            </div>
          </div>
        </div>
      )}

      {/* Table */}
      {isLoading ? (
        <ReportSkeleton summaryCardCount={4} tableColumnCount={7} />
      ) : error ? (
        <div className="bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-lg p-4">
          <p className="text-red-600 dark:text-red-400">خطا در دریافت داده‌ها</p>
        </div>
      ) : filters.user_id === 0 ? (
        <div className="bg-yellow-50 dark:bg-yellow-900/20 border border-yellow-200 dark:border-yellow-800 rounded-lg p-4">
          <p className="text-yellow-600 dark:text-yellow-400">لطفاً شناسه کاربر را وارد کنید</p>
        </div>
      ) : (
        <>
          <div className="bg-white dark:bg-gray-800 shadow-sm border border-gray-200 dark:border-gray-700 rounded-lg overflow-hidden">
            <Table columns={columns} data={tableData} loading={isLoading} />
          </div>

          {data && data.total > 0 && totalPages > 1 && (
            <div className="mt-4 flex justify-center">
              <Pagination
                currentPage={currentPage}
                totalPages={totalPages}
                onPageChange={handlePageChange}
                itemsPerPage={filters.limit}
                totalItems={data.total}
              />
            </div>
          )}

          {data && data.total === 0 && (
            <div className="bg-gray-50 dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg p-8 text-center">
              <p className="text-gray-600 dark:text-gray-400">داده‌ای یافت نشد</p>
            </div>
          )}
        </>
      )}
    </PageContainer>
  );
};

export default CustomerDiscountUsagePage;