import React, { useState, useEffect } from 'react';
import { 
  PlusIcon, 
  MapPinIcon,
  BeakerIcon,
  WrenchScrewdriverIcon,
  CalculatorIcon
} from '@heroicons/react/24/outline';
import { propertiesAPI, productsAPI, equipmentAPI } from '../../services/api';
import LoadingSpinner from '../../components/UI/LoadingSpinner';
import toast from 'react-hot-toast';

const Applications = () => {
  const [showPlanForm, setShowPlanForm] = useState(false);
  const [applications, setApplications] = useState([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    fetchApplications();
  }, []);

  const fetchApplications = async () => {
    try {
      setLoading(true);
      // TODO: Implement applications API endpoint
      setApplications([]);
    } catch (error) {
      console.error('Failed to fetch applications:', error);
      toast.error('Failed to load applications');
    } finally {
      setLoading(false);
    }
  };

  if (loading) {
    return (
      <div className="p-6">
        <div className="flex justify-center items-center h-64">
          <LoadingSpinner size="lg" />
        </div>
      </div>
    );
  }

  return (
    <div className="p-6">
      <div className="flex justify-between items-center mb-6">
        <div>
          <h1 className="text-2xl font-bold text-gray-900">Applications</h1>
          <p className="text-gray-600">Plan, track, and log your lawn applications</p>
        </div>
        <button
          onClick={() => setShowPlanForm(true)}
          className="btn-primary flex items-center gap-2"
        >
          <PlusIcon className="h-5 w-5" />
          Plan Application
        </button>
      </div>

      {/* Applications List */}
      {applications.length === 0 ? (
        <div className="card text-center py-12">
          <CalculatorIcon className="h-16 w-16 text-gray-300 mx-auto mb-4" />
          <h3 className="text-lg font-medium text-gray-900 mb-2">No Applications Yet</h3>
          <p className="text-gray-600 mb-6">
            Start by planning your first lawn application
          </p>
          <button
            onClick={() => setShowPlanForm(true)}
            className="btn-primary"
          >
            Plan Your First Application
          </button>
        </div>
      ) : (
        <div className="space-y-4">
          {applications.map((application) => (
            <div key={application.id} className="card">
              {/* Application card content will go here */}
              <p>Application: {application.id}</p>
            </div>
          ))}
        </div>
      )}

      {/* Plan Application Modal */}
      {showPlanForm && (
        <ApplicationPlanModal
          onClose={() => setShowPlanForm(false)}
          onSubmit={(planData) => {
            console.log('Plan submitted:', planData);
            setShowPlanForm(false);
            fetchApplications();
          }}
        />
      )}
    </div>
  );
};

// Application Planning Modal Component
const ApplicationPlanModal = ({ onClose, onSubmit }) => {
  const [properties, setProperties] = useState([]);
  const [products, setProducts] = useState([]);
  const [equipment, setEquipment] = useState([]);
  const [selectedPropertyDetails, setSelectedPropertyDetails] = useState(null);
  const [loading, setLoading] = useState(true);
  const [loadingProperty, setLoadingProperty] = useState(false);
  
  const [planData, setPlanData] = useState({
    propertyId: '',
    selectedAreas: [],
    productId: '',
    applicationType: '', // 'liquid' or 'granular'
    equipmentId: '',
    notes: ''
  });

  useEffect(() => {
    fetchPlanningData();
  }, []);

  const fetchPlanningData = async () => {
    try {
      setLoading(true);
      const [propertiesResponse, productsResponse, equipmentResponse] = await Promise.all([
        propertiesAPI.getAll(),
        productsAPI.getAll(),
        equipmentAPI.getAll()
      ]);
      
      console.log('Properties response:', propertiesResponse.data);
      console.log('Products response:', productsResponse.data);
      console.log('Equipment response:', equipmentResponse.data);
      
      setProperties(propertiesResponse.data.data.properties || []);
      // Combine shared and user products
      const allProducts = [
        ...(productsResponse.data.data.sharedProducts || []),
        ...(productsResponse.data.data.userProducts || [])
      ];
      setProducts(allProducts);
      setEquipment(equipmentResponse.data.data.equipment || []);
    } catch (error) {
      console.error('Failed to fetch planning data:', error);
      toast.error('Failed to load planning data');
    } finally {
      setLoading(false);
    }
  };

  const fetchPropertyDetails = async (propertyId) => {
    try {
      setLoadingProperty(true);
      const response = await propertiesAPI.getById(parseInt(propertyId));
      console.log('Property details response:', response.data);
      setSelectedPropertyDetails(response.data.data.property);
    } catch (error) {
      console.error('Failed to fetch property details:', error);
      toast.error('Failed to load property details');
      setSelectedPropertyDetails(null);
    } finally {
      setLoadingProperty(false);
    }
  };

  const handlePropertyChange = (propertyId) => {
    setPlanData({ ...planData, propertyId, selectedAreas: [] });
    setSelectedPropertyDetails(null);
    if (propertyId) {
      fetchPropertyDetails(propertyId);
    }
  };
  
  // Filter equipment based on application type
  const availableEquipment = equipment.filter(eq => {
    if (planData.applicationType === 'liquid') {
      return eq.categoryName === 'Sprayer';
    } else if (planData.applicationType === 'granular') {
      return eq.categoryName === 'Spreader';
    }
    return false;
  });

  const handleSubmit = (e) => {
    e.preventDefault();
    
    if (!planData.propertyId || planData.selectedAreas.length === 0) {
      toast.error('Please select a property and at least one area');
      return;
    }
    
    if (!planData.productId) {
      toast.error('Please select a product');
      return;
    }
    
    if (!planData.equipmentId) {
      toast.error('Please select equipment');
      return;
    }

    onSubmit(planData);
  };

  const handleAreaToggle = (areaId) => {
    setPlanData(prev => ({
      ...prev,
      selectedAreas: prev.selectedAreas.includes(areaId)
        ? prev.selectedAreas.filter(id => id !== areaId)
        : [...prev.selectedAreas, areaId]
    }));
  };

  return (
    <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
      <div className="bg-white rounded-lg p-6 w-full max-w-4xl max-h-[90vh] overflow-y-auto">
        <h3 className="text-lg font-semibold mb-4">Plan Application</h3>
        
        {loading ? (
          <LoadingSpinner />
        ) : (
          <form onSubmit={handleSubmit} className="space-y-6">
            {/* Property Selection */}
            <div>
              <label className="label flex items-center gap-2">
                <MapPinIcon className="h-5 w-5" />
                Property *
              </label>
              <select
                className="input"
                value={planData.propertyId}
                onChange={(e) => handlePropertyChange(e.target.value)}
                required
              >
                <option value="">Select a property...</option>
                {properties.map((property) => (
                  <option key={property.id} value={property.id}>
                    {property.name} - {property.address}
                  </option>
                ))}
              </select>
            </div>

            {/* Area Selection */}
            {loadingProperty && (
              <div className="flex items-center gap-2 text-gray-600">
                <LoadingSpinner size="sm" />
                <span>Loading property details...</span>
              </div>
            )}
            
            {selectedPropertyDetails && selectedPropertyDetails.sections && selectedPropertyDetails.sections.length > 0 && (
              <div>
                <label className="label">Application Areas *</label>
                <div className="grid grid-cols-2 md:grid-cols-3 gap-3">
                  {selectedPropertyDetails.sections.map((section) => (
                    <label key={section.id} className="flex items-center">
                      <input
                        type="checkbox"
                        checked={planData.selectedAreas.includes(section.id)}
                        onChange={() => handleAreaToggle(section.id)}
                        className="rounded border-gray-300 text-blue-600 focus:ring-blue-500"
                      />
                      <span className="ml-2 text-sm">
                        {section.name} ({section.area ? `${Math.round(section.area)} sq ft` : 'No size'})
                      </span>
                    </label>
                  ))}
                </div>
                {planData.selectedAreas.length > 0 && (
                  <p className="text-sm text-gray-600 mt-2">
                    Total area: {selectedPropertyDetails.sections
                      .filter(s => planData.selectedAreas.includes(s.id))
                      .reduce((total, s) => total + (s.area || 0), 0).toFixed(0)} sq ft
                  </p>
                )}
              </div>
            )}
            
            {selectedPropertyDetails && (!selectedPropertyDetails.sections || selectedPropertyDetails.sections.length === 0) && (
              <div className="p-4 bg-yellow-50 border border-yellow-200 rounded-lg">
                <p className="text-yellow-800 text-sm">
                  This property has no lawn sections defined. Please add lawn sections to the property first.
                </p>
              </div>
            )}

            {/* Product Selection */}
            <div>
              <label className="label flex items-center gap-2">
                <BeakerIcon className="h-5 w-5" />
                Product *
              </label>
              <select
                className="input"
                value={planData.productId}
                onChange={(e) => {
                  const selectedProduct = products.find(p => p.id === parseInt(e.target.value));
                  console.log('Selected product:', selectedProduct);
                  
                  // Determine application type from product type
                  let applicationType = '';
                  if (selectedProduct) {
                    const productType = selectedProduct.productType || selectedProduct.customProductType;
                    // Map product types to application types
                    if (productType && (productType.toLowerCase().includes('liquid') || productType.toLowerCase().includes('concentrate'))) {
                      applicationType = 'liquid';
                    } else if (productType && (productType.toLowerCase().includes('granular') || productType.toLowerCase().includes('granule'))) {
                      applicationType = 'granular';
                    }
                  }
                  
                  setPlanData({ 
                    ...planData, 
                    productId: e.target.value,
                    applicationType: applicationType
                  });
                }}
                required
              >
                <option value="">Select a product...</option>
                {products.map((product) => {
                  const displayName = product.customName || product.name;
                  const productType = product.productType || product.customProductType;
                  const brand = product.brand || product.customBrand;
                  const rateInfo = product.customRateAmount && product.customRateUnit 
                    ? ` (${product.customRateAmount} ${product.customRateUnit})`
                    : '';
                  
                  return (
                    <option key={product.id} value={product.id}>
                      {displayName}{brand ? ` - ${brand}` : ''}{productType ? ` (${productType})` : ''}{rateInfo}
                    </option>
                  );
                })}
              </select>
            </div>

            {/* Equipment Selection */}
            {planData.applicationType && (
              <div>
                <label className="label flex items-center gap-2">
                  <WrenchScrewdriverIcon className="h-5 w-5" />
                  Equipment * ({planData.applicationType})
                </label>
                <select
                  className="input"
                  value={planData.equipmentId}
                  onChange={(e) => setPlanData({ ...planData, equipmentId: e.target.value })}
                  required
                >
                  <option value="">Select equipment...</option>
                  {availableEquipment.map((eq) => (
                    <option key={eq.id} value={eq.id}>
                      {eq.customName || eq.typeName} 
                      {eq.manufacturer && ` - ${eq.manufacturer}`}
                      {eq.tankSizeGallons && ` (${eq.tankSizeGallons} gal)`}
                      {eq.capacityLbs && ` (${eq.capacityLbs} lbs)`}
                    </option>
                  ))}
                </select>
                {availableEquipment.length === 0 && (
                  <p className="text-sm text-orange-600 mt-1">
                    No {planData.applicationType === 'liquid' ? 'sprayers' : 'spreaders'} found. 
                    Please add equipment first.
                  </p>
                )}
              </div>
            )}

            {/* Notes */}
            <div>
              <label className="label">Notes</label>
              <textarea
                className="input"
                rows="3"
                value={planData.notes}
                onChange={(e) => setPlanData({ ...planData, notes: e.target.value })}
                placeholder="Application notes, weather conditions, etc."
              />
            </div>

            <div className="flex gap-3 pt-4">
              <button type="submit" className="btn-primary flex-1">
                Create Application Plan
              </button>
              <button
                type="button"
                onClick={onClose}
                className="btn-secondary flex-1"
              >
                Cancel
              </button>
            </div>
          </form>
        )}
      </div>
    </div>
  );
};

export default Applications;