'use client';

import { useState, useEffect } from 'react';
import { vehicleRequestsApi, carmodooApi, VehicleRequest, VehicleRequestWithVehicles, CarmodooSearchResult } from '@/lib/api';

const ITEMS_PER_PAGE = 12;

export default function AdminVehicleRequestsPage() {
  const [requests, setRequests] = useState<VehicleRequest[]>([]);
  const [selectedRequest, setSelectedRequest] = useState<VehicleRequestWithVehicles | null>(null);
  const [isLoading, setIsLoading] = useState(true);
  const [statusFilter, setStatusFilter] = useState<string>('');
  const [showAddModal, setShowAddModal] = useState(false);
  const [searchResults, setSearchResults] = useState<CarmodooSearchResult[]>([]);
  const [isSearching, setIsSearching] = useState(false);
  const [deletingVehicleId, setDeletingVehicleId] = useState<number | null>(null);

  // Pagination state
  const [currentPage, setCurrentPage] = useState(1);
  const [totalResults, setTotalResults] = useState(0);

  // Load requests
  useEffect(() => {
    loadRequests();
  }, [statusFilter]);

  const loadRequests = async () => {
    try {
      setIsLoading(true);
      const data = await vehicleRequestsApi.adminGetAllRequests(statusFilter || undefined);
      setRequests(data);
    } catch (error) {
      console.error('Failed to load requests:', error);
    } finally {
      setIsLoading(false);
    }
  };

  // Load request detail
  const loadRequestDetail = async (requestId: number) => {
    try {
      const data = await vehicleRequestsApi.adminGetRequestDetail(requestId);
      setSelectedRequest(data);
    } catch (error) {
      console.error('Failed to load request detail:', error);
    }
  };

  // Search for vehicles based on request criteria
  const searchVehicles = async (page: number = 1) => {
    if (!selectedRequest) return;

    try {
      setIsSearching(true);
      const params: any = {
        page: page,
        page_size: 50, // Fetch more results
      };

      if (selectedRequest.request.maker_code) params.maker_code = selectedRequest.request.maker_code;
      if (selectedRequest.request.model_code) params.model_code = selectedRequest.request.model_code;
      if (selectedRequest.request.grade_code) params.grade = selectedRequest.request.grade_code;
      if (selectedRequest.request.year_from) params.year_min = selectedRequest.request.year_from;
      if (selectedRequest.request.year_to) params.year_max = selectedRequest.request.year_to;
      if (selectedRequest.request.mileage_min) params.mileage_min = selectedRequest.request.mileage_min;
      if (selectedRequest.request.mileage_max) params.mileage_max = selectedRequest.request.mileage_max;
      if (selectedRequest.request.fuel) params.fuel = selectedRequest.request.fuel;

      const result = await carmodooApi.requestSearch(params);
      setSearchResults(result.cars);
      setTotalResults(result.cars.length);
      setCurrentPage(page);
    } catch (error) {
      console.error('Failed to search vehicles:', error);
    } finally {
      setIsSearching(false);
    }
  };

  // Get paginated results
  const getPaginatedResults = () => {
    const startIndex = (currentPage - 1) * ITEMS_PER_PAGE;
    const endIndex = startIndex + ITEMS_PER_PAGE;
    return searchResults.slice(startIndex, endIndex);
  };

  const totalPages = Math.ceil(searchResults.length / ITEMS_PER_PAGE);

  // Add vehicle to request
  const addVehicleToRequest = async (car: CarmodooSearchResult) => {
    if (!selectedRequest) return;

    try {
      await vehicleRequestsApi.adminAddVehicle(selectedRequest.request.id, {
        request_id: selectedRequest.request.id,
        car_data: car,
        is_approved: true, // Auto-approve when adding
      });

      // Reload request detail
      await loadRequestDetail(selectedRequest.request.id);

      // Remove from search results
      setSearchResults(prev => prev.filter(c => c.id !== car.id));
    } catch (error) {
      console.error('Failed to add vehicle:', error);
    }
  };

  // Delete vehicle from request
  const deleteVehicleFromRequest = async (vehicleId: number) => {
    if (!selectedRequest) return;

    if (!confirm('Are you sure you want to remove this vehicle from the recommendation list?')) {
      return;
    }

    try {
      setDeletingVehicleId(vehicleId);
      await vehicleRequestsApi.adminDeleteVehicle(selectedRequest.request.id, vehicleId);

      // Reload request detail
      await loadRequestDetail(selectedRequest.request.id);
    } catch (error) {
      console.error('Failed to delete vehicle:', error);
    } finally {
      setDeletingVehicleId(null);
    }
  };

  // Update request status
  const updateStatus = async (requestId: number, newStatus: string) => {
    try {
      await vehicleRequestsApi.adminUpdateRequestStatus(requestId, newStatus);
      loadRequests();
      if (selectedRequest?.request.id === requestId) {
        loadRequestDetail(requestId);
      }
    } catch (error) {
      console.error('Failed to update status:', error);
    }
  };

  // Format date
  const formatDate = (dateString: string) => {
    return new Date(dateString).toLocaleDateString('ko-KR', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      hour: '2-digit',
      minute: '2-digit',
    });
  };

  // Get status badge
  const getStatusBadge = (status: string) => {
    const colors: Record<string, string> = {
      pending: 'bg-yellow-100 text-yellow-800',
      reviewed: 'bg-blue-100 text-blue-800',
      completed: 'bg-green-100 text-green-800',
    };
    const labels: Record<string, string> = {
      pending: 'Pending',
      reviewed: 'Reviewed',
      completed: 'Completed',
    };
    return (
      <span className={`px-2 py-1 rounded-full text-xs font-medium ${colors[status] || 'bg-gray-100 text-gray-800'}`}>
        {labels[status] || status}
      </span>
    );
  };

  return (
    <div className="space-y-6">
      <div className="flex justify-between items-center">
        <h1 className="text-2xl font-bold text-gray-800">Vehicle Requests</h1>
        <select
          value={statusFilter}
          onChange={(e) => setStatusFilter(e.target.value)}
          className="border border-gray-300 rounded-lg px-4 py-2"
        >
          <option value="">All Status</option>
          <option value="pending">Pending</option>
          <option value="reviewed">Reviewed</option>
          <option value="completed">Completed</option>
        </select>
      </div>

      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Requests List */}
        <div className="bg-white rounded-lg shadow">
          <div className="p-4 border-b">
            <h2 className="font-semibold text-gray-700">Requests ({requests.length})</h2>
          </div>

          {isLoading ? (
            <div className="p-8 text-center">
              <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-primary-600 mx-auto"></div>
            </div>
          ) : requests.length === 0 ? (
            <div className="p-8 text-center text-gray-500">No requests found</div>
          ) : (
            <div className="divide-y max-h-[600px] overflow-y-auto">
              {requests.map((request) => (
                <div
                  key={request.id}
                  onClick={() => loadRequestDetail(request.id)}
                  className={`p-4 cursor-pointer hover:bg-gray-50 transition ${
                    selectedRequest?.request.id === request.id ? 'bg-primary-50' : ''
                  }`}
                >
                  <div className="flex items-start justify-between mb-2">
                    <div>
                      <h3 className="font-medium text-gray-800">
                        {request.maker_name} - {request.model_name}
                      </h3>
                      <p className="text-sm text-gray-500">
                        User ID: {request.user_id}
                      </p>
                    </div>
                    {getStatusBadge(request.status)}
                  </div>
                  <div className="text-sm text-gray-500">
                    {request.year_from && request.year_to && (
                      <span className="mr-4">Year: {request.year_from}-{request.year_to}</span>
                    )}
                    {request.mileage_max && (
                      <span>Max Mileage: {Math.round(request.mileage_max / 10000)}만km</span>
                    )}
                  </div>
                  <p className="text-xs text-gray-400 mt-1">
                    {formatDate(request.created_at)}
                  </p>
                </div>
              ))}
            </div>
          )}
        </div>

        {/* Request Detail */}
        <div className="bg-white rounded-lg shadow">
          <div className="p-4 border-b">
            <h2 className="font-semibold text-gray-700">Request Detail</h2>
          </div>

          {!selectedRequest ? (
            <div className="p-8 text-center text-gray-500">
              Select a request to view details
            </div>
          ) : (
            <div className="p-4 space-y-4">
              {/* Request Info */}
              <div className="bg-gray-50 rounded-lg p-4">
                <h3 className="font-semibold text-gray-700 mb-3">Search Criteria</h3>
                <div className="grid grid-cols-2 gap-2 text-sm">
                  <div>
                    <span className="text-gray-500">Maker:</span>
                    <span className="ml-2 font-medium">{selectedRequest.request.maker_name}</span>
                  </div>
                  <div>
                    <span className="text-gray-500">Model:</span>
                    <span className="ml-2 font-medium">{selectedRequest.request.model_name}</span>
                  </div>
                  {selectedRequest.request.grade_name && (
                    <div>
                      <span className="text-gray-500">Grade:</span>
                      <span className="ml-2 font-medium">{selectedRequest.request.grade_name}</span>
                    </div>
                  )}
                  {(selectedRequest.request.year_from || selectedRequest.request.year_to) && (
                    <div>
                      <span className="text-gray-500">Year:</span>
                      <span className="ml-2 font-medium">
                        {selectedRequest.request.year_from || '-'} ~ {selectedRequest.request.year_to || '-'}
                      </span>
                    </div>
                  )}
                  {(selectedRequest.request.mileage_min || selectedRequest.request.mileage_max) && (
                    <div>
                      <span className="text-gray-500">Mileage:</span>
                      <span className="ml-2 font-medium">
                        {selectedRequest.request.mileage_min ? Math.round(selectedRequest.request.mileage_min / 10000) : '-'} ~{' '}
                        {selectedRequest.request.mileage_max ? Math.round(selectedRequest.request.mileage_max / 10000) : '-'} 만km
                      </span>
                    </div>
                  )}
                  {selectedRequest.request.fuel && (
                    <div>
                      <span className="text-gray-500">Fuel:</span>
                      <span className="ml-2 font-medium">{selectedRequest.request.fuel}</span>
                    </div>
                  )}
                </div>
              </div>

              {/* Status Controls */}
              <div className="flex items-center gap-2">
                <span className="text-sm text-gray-500">Status:</span>
                {getStatusBadge(selectedRequest.request.status)}
                <select
                  value={selectedRequest.request.status}
                  onChange={(e) => updateStatus(selectedRequest.request.id, e.target.value)}
                  className="ml-auto border border-gray-300 rounded px-3 py-1 text-sm"
                >
                  <option value="pending">Pending</option>
                  <option value="reviewed">Reviewed</option>
                  <option value="completed">Completed</option>
                </select>
              </div>

              {/* Approved Vehicles */}
              <div>
                <div className="flex items-center justify-between mb-3">
                  <h3 className="font-semibold text-gray-700">
                    Recommended Vehicles ({selectedRequest.approved_vehicles.length})
                  </h3>
                  <button
                    onClick={() => {
                      setShowAddModal(true);
                      setCurrentPage(1);
                      searchVehicles(1);
                    }}
                    className="bg-primary-600 text-white px-3 py-1 rounded text-sm hover:bg-primary-700"
                  >
                    + Add Vehicle
                  </button>
                </div>

                {selectedRequest.approved_vehicles.length === 0 ? (
                  <div className="bg-gray-50 rounded-lg p-4 text-center text-gray-500 text-sm">
                    No vehicles added yet
                  </div>
                ) : (
                  <div className="space-y-2 max-h-[300px] overflow-y-auto">
                    {selectedRequest.approved_vehicles.map((vehicle) => (
                      <div key={vehicle.id} className="bg-gray-50 rounded-lg p-3 flex items-center gap-3">
                        {vehicle.car_data.main_image && (
                          <img
                            src={vehicle.car_data.main_image}
                            alt=""
                            className="w-16 h-12 object-cover rounded"
                          />
                        )}
                        <div className="flex-1 min-w-0">
                          <p className="font-medium text-sm truncate">{vehicle.car_data.car_name}</p>
                          <p className="text-xs text-gray-500">
                            {vehicle.car_data.year} | {vehicle.car_data.mileage?.toLocaleString()}km
                          </p>
                        </div>
                        <div className="text-right flex items-center gap-2">
                          <p className="text-sm font-medium text-primary-600">
                            {vehicle.car_data.final_price?.toLocaleString()}만원
                          </p>
                          <button
                            onClick={() => deleteVehicleFromRequest(vehicle.id)}
                            disabled={deletingVehicleId === vehicle.id}
                            className="text-red-500 hover:text-red-700 p-1 disabled:opacity-50"
                            title="Remove from list"
                          >
                            {deletingVehicleId === vehicle.id ? (
                              <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-red-500"></div>
                            ) : (
                              <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth="2" d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
                              </svg>
                            )}
                          </button>
                        </div>
                      </div>
                    ))}
                  </div>
                )}
              </div>
            </div>
          )}
        </div>
      </div>

      {/* Add Vehicle Modal */}
      {showAddModal && selectedRequest && (
        <div className="fixed inset-0 bg-black bg-opacity-50 z-50 flex items-center justify-center p-4">
          <div className="bg-white rounded-lg max-w-5xl w-full max-h-[90vh] overflow-hidden flex flex-col">
            <div className="p-4 border-b flex items-center justify-between shrink-0">
              <h3 className="font-semibold text-gray-800">Search & Add Vehicles</h3>
              <button
                onClick={() => {
                  setShowAddModal(false);
                  setSearchResults([]);
                  setCurrentPage(1);
                }}
                className="text-gray-500 hover:text-gray-700 text-2xl"
              >
                &times;
              </button>
            </div>

            <div className="p-4 border-b shrink-0">
              <div className="flex items-center justify-between">
                <div>
                  <p className="text-sm text-gray-600">
                    Searching for: <span className="font-medium">{selectedRequest.request.maker_name} {selectedRequest.request.model_name}</span>
                  </p>
                  {searchResults.length > 0 && (
                    <p className="text-sm text-gray-500 mt-1">
                      Found {searchResults.length} vehicles (showing {Math.min((currentPage - 1) * ITEMS_PER_PAGE + 1, searchResults.length)}-{Math.min(currentPage * ITEMS_PER_PAGE, searchResults.length)})
                    </p>
                  )}
                </div>
                <button
                  onClick={() => searchVehicles(1)}
                  disabled={isSearching}
                  className="bg-primary-600 text-white px-4 py-2 rounded hover:bg-primary-700 disabled:opacity-50"
                >
                  {isSearching ? 'Searching...' : 'Refresh'}
                </button>
              </div>
            </div>

            <div className="flex-1 overflow-y-auto p-4">
              {isSearching ? (
                <div className="p-8 text-center">
                  <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-primary-600 mx-auto"></div>
                  <p className="mt-2 text-gray-500">Searching from Carmodoo...</p>
                </div>
              ) : searchResults.length === 0 ? (
                <div className="p-8 text-center text-gray-500">No vehicles found</div>
              ) : (
                <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
                  {getPaginatedResults().map((car) => (
                    <div key={car.id} className="border rounded-lg p-3 hover:shadow-md transition">
                      {car.main_image && (
                        <img
                          src={car.main_image}
                          alt=""
                          className="w-full h-32 object-cover rounded mb-2"
                        />
                      )}
                      <div className="space-y-1">
                        <p className="font-medium text-sm truncate" title={car.car_name}>{car.car_name}</p>
                        <div className="text-xs text-gray-500 space-y-0.5">
                          <p>{car.year}년 | {car.mileage?.toLocaleString()}km</p>
                          <p>{car.fuel} | {car.transmission}</p>
                          {car.color && <p>Color: {car.color}</p>}
                        </div>
                        <p className="text-sm font-bold text-primary-600">
                          {car.final_price?.toLocaleString()}만원
                        </p>
                        <button
                          onClick={() => addVehicleToRequest(car)}
                          className="w-full bg-green-600 text-white px-3 py-1.5 rounded text-sm hover:bg-green-700 mt-2"
                        >
                          + Add to List
                        </button>
                      </div>
                    </div>
                  ))}
                </div>
              )}
            </div>

            {/* Pagination */}
            {searchResults.length > ITEMS_PER_PAGE && (
              <div className="p-4 border-t shrink-0 flex items-center justify-center gap-2">
                <button
                  onClick={() => setCurrentPage(1)}
                  disabled={currentPage === 1}
                  className="px-3 py-1 border rounded disabled:opacity-50 disabled:cursor-not-allowed hover:bg-gray-50"
                >
                  &laquo;
                </button>
                <button
                  onClick={() => setCurrentPage(prev => Math.max(1, prev - 1))}
                  disabled={currentPage === 1}
                  className="px-3 py-1 border rounded disabled:opacity-50 disabled:cursor-not-allowed hover:bg-gray-50"
                >
                  &lsaquo;
                </button>

                {/* Page numbers */}
                {Array.from({ length: totalPages }, (_, i) => i + 1)
                  .filter(page => {
                    // Show first, last, current, and pages near current
                    return page === 1 || page === totalPages || Math.abs(page - currentPage) <= 2;
                  })
                  .map((page, index, array) => (
                    <span key={page}>
                      {index > 0 && array[index - 1] !== page - 1 && (
                        <span className="px-2 text-gray-400">...</span>
                      )}
                      <button
                        onClick={() => setCurrentPage(page)}
                        className={`px-3 py-1 border rounded ${
                          currentPage === page
                            ? 'bg-primary-600 text-white border-primary-600'
                            : 'hover:bg-gray-50'
                        }`}
                      >
                        {page}
                      </button>
                    </span>
                  ))}

                <button
                  onClick={() => setCurrentPage(prev => Math.min(totalPages, prev + 1))}
                  disabled={currentPage === totalPages}
                  className="px-3 py-1 border rounded disabled:opacity-50 disabled:cursor-not-allowed hover:bg-gray-50"
                >
                  &rsaquo;
                </button>
                <button
                  onClick={() => setCurrentPage(totalPages)}
                  disabled={currentPage === totalPages}
                  className="px-3 py-1 border rounded disabled:opacity-50 disabled:cursor-not-allowed hover:bg-gray-50"
                >
                  &raquo;
                </button>
              </div>
            )}
          </div>
        </div>
      )}
    </div>
  );
}