import React, {useEffect, useState, useRef} from "react";
import { useSelector,useDispatch } from "react-redux";
import { useParams, useNavigate } from "react-router-dom";
import { selectAllRoutes, transRoutesSlice, vehicleSlice, selectTomorrowAllRoutes, selectAllActiveDrivers, selectAllActiveVehicles, selectHistoryRoutes } from "./../../store";
import { Modal, Button, Breadcrumb, Tabs, Tab  } from "react-bootstrap";
import RouteCustomerEditor from "./RouteCustomerEditor";
import { AuthService, TransRoutesService, CustomerService } from "../../services";
import TimePicker from 'react-time-picker';
import 'react-time-picker/dist/TimePicker.css';
import moment from 'moment';
import { Archive, GripVertical } from "react-bootstrap-icons";
import { PERSONAL_ROUTE_STATUS } from "../../shared";
import { DndProvider } from 'react-dnd';
import { HTML5Backend } from 'react-dnd-html5-backend';
import { useDrag } from 'react-dnd';

const RouteEdit = () => {
  const params = useParams();
  const allRoutes = useSelector(selectAllRoutes);
  const tomorrowRoutes = useSelector(selectTomorrowAllRoutes);
  const historyRoutes = useSelector(selectHistoryRoutes);
  const drivers = useSelector(selectAllActiveDrivers);
  const vehicles = useSelector(selectAllActiveVehicles);
  // const currentRoute = (allRoutes.find(item => item.id === params.id)) || (tomorrowRoutes.find(item => item.id === params.id)) || (historyRoutes.find(item => item.id === params.id)) || {};
  const currentVehicle = vehicles.find(item => item.id === currentRoute?.vehicle ) || [];
  const navigate = useNavigate();
  const dispatch = useDispatch();
  const { updateRoute} = transRoutesSlice.actions;
  const { updateVehicle} = vehicleSlice.actions;
  const [routeName, setRouteName] = useState('');
  const [newDriver, setNewDriver] = useState('');
  const [newVehicle, setNewVehicle] = useState('');
  const [newRouteType, setNewRouteType] = useState('');
  const [showAddCheckItem, setShowAddCheckItem] = useState(false);
  const [showCopyCheckItem, setShowCopyCheckItem] = useState(false);
  const [newChecklistItems, setNewChecklistItems] = useState([]);
  const [selectedRouteChecklistToCopy, setSelectedRouteChecklistToCopy] = useState({});
  const [newCustomerList, setNewCustomerList] = useState([]);
  const [errorMessage, setErrorMessage] = useState(undefined);
  const [estimatedStartTime, setEstimatedStartTime] = useState(undefined);
  const [currentRoute, setCurrentRoute] = useState(undefined);
  const [allCustomers, setAllCustomers] = useState([]);
  const [unassignedCustomers, setUnassignedCustomers] = useState([]);
  const [addCustomerToRoute, setAddCustomerToRoute] = useState(null);
  const paramsQuery = new URLSearchParams(window.location.search);
  const scheduleDate = paramsQuery.get('dateSchedule');
  const editSection = paramsQuery.get('editSection')
  const redirectToView = () => {
    if (scheduleDate) {
      navigate(`/trans-routes/${params.id}?dateSchedule=${scheduleDate}`);
    } else {
      navigate(`/trans-routes/${params.id}`);
    }
  }

  const redirectToDashboard = () => {
    navigate(`/trans-routes/dashboard`);
  }

  const softDeleteCurrentRoute = () => {
    if (!window.confirm('Are you sure you want to archive this route? This action cannot be undone.')) {
      return;
    }
    const data = Object.assign({}, currentRoute, {status: ['disabled']})
    dispatch(updateRoute({ id: currentRoute?.id, data, callback: redirectToDashboard }));
    // redirectToDashboard();
  }

  const validateRoute = () => {
    const errors = [];
    
    // Required fields validation
    if (!routeName || routeName.trim() === '') {
      errors.push('Route Name');
    }
    if (!newRouteType || newRouteType === '') {
      errors.push('Route Type');
    }
    if (!newDriver || newDriver === '') {
      errors.push('Driver');
    }
    if (!newVehicle || newVehicle === '') {
      errors.push('Vehicle');
    }
    
    if (errors.length > 0) {
      window.alert(`Please fill in the following required fields:\n${errors.join('\n')}`);
      return false;
    }
    return true;
  };

  const updateCurrentRoute = () => {
    try {
      if (!validateRoute()) {
        return;
      }
      let data = Object.assign({}, currentRoute, {name: routeName, driver: newDriver, vehicle: newVehicle, type: newRouteType, route_customer_list: newCustomerList});
      if (estimatedStartTime && estimatedStartTime !== '') {
        data = Object.assign({}, data, {estimated_start_time: combineDateAndTime(currentRoute.schedule_date, estimatedStartTime)})
      }
      let payload = { id: currentRoute?.id, data };
      if ((historyRoutes.find(item => item.id === params.id)) || (scheduleDate && new Date(data.schedule_date) > new Date())) {
        payload = Object.assign({}, payload, {dateText: data.schedule_date});
        if (scheduleDate && new Date(data.schedule_date) > new Date()) {
          payload = Object.assign({}, payload, {fromSchedule: true});
        }
      }
      payload.callback = redirectToView;
      dispatch(updateRoute(payload));
      // TransRoutesService.updateInProgress(data);
      // setTimeout(() => {
      //   redirectToView();
      // }, 5000);
    } catch(ex) {

    }
  }

  const addItemToArray = () => {
    const arr = [...newChecklistItems, ''];
    setNewChecklistItems(arr);
  }

  const saveChecklistItems = () => {
    const data = Object.assign({}, currentVehicle, {checklist: newChecklistItems});
    dispatch(updateVehicle({ id: currentVehicle.id, data }));
    setShowAddCheckItem(false);
  }

  const copyChecklistItems = () => {
    const data = Object.assign({}, currentVehicle, {checklist: vehicles.find(vehicle => vehicle.id === selectedRouteChecklistToCopy.vehicle)?.checklist});
    dispatch(updateVehicle({ id: currentVehicle.id, data }));
    setShowCopyCheckItem(false);
  }

  const closeAddCheckItemModal = () => {
    setNewChecklistItems([])
    setShowAddCheckItem(false);
  }

  const showAddCheckItemModal = () => {
    setNewChecklistItems(currentVehicle.checklist || [])
    setShowAddCheckItem(true);
  }

  const closeCopyCheckItemModal = () => {
    setSelectedRouteChecklistToCopy({});
    setShowCopyCheckItem(false);
  }

  const showCopyCheckItemModal = () => {
    setShowCopyCheckItem(true);
  }

  const combineDateAndTime = (date, time) => {
    const dateObj = moment(date);
    const timeObj = moment(time, 'HH:mm');
    dateObj.set({
      hour: timeObj.get('hour'),
      minute: timeObj.get('minute'),
      second: timeObj.get('second')
    })
    return dateObj;
  }

  const calculateUnassignedCustomers = (customers, routes) => {
    if (!customers || !routes) return [];
    
    // Get all customer IDs that are assigned to any route today
    const assignedCustomerIds = new Set();
    routes.forEach(route => {
      route.route_customer_list?.forEach(customer => {
        assignedCustomerIds.add(customer.customer_id);
      });
    });
    
    // Filter out customers that are not assigned to any route
    // Also exclude discharged customers (type is 'discharged' or name contains 'discharged')
    return customers.filter(customer => {
      const isDischarged = customer.type === 'discharged' || 
                          (customer.name && customer.name.toLowerCase().includes('discharged')) ||
                          (customer.status !== 'active');
      return customer.status === 'active' && 
             !assignedCustomerIds.has(customer.id) &&
             !isDischarged;
    });
  }

  useEffect(() => {
    if (!AuthService.canAddOrEditRoutes()) {
      window.alert('You haven\'t login yet OR this user does not have access to this page. Please change an admin account to login.')
      AuthService.logout();
      navigate(`/login`);
    }
    TransRoutesService.getRoute(params.id).then(data => {
      setCurrentRoute(data?.data);
      setRouteName(data?.data?.name);
      setNewDriver(data?.data?.driver);
      setNewVehicle(data?.data?.vehicle);
      setNewRouteType(data?.data?.type);
      setEstimatedStartTime(data?.data?.estimated_start_time && new Date(data?.data?.estimated_start_time));
      setNewCustomerList(data?.data?.route_customer_list);
      setErrorMessage(undefined);
    })
    
    // Fetch all customers
    CustomerService.getAllCustomers().then(data => {
      setAllCustomers(data?.data || []);
    });
  }, []);

  // Calculate unassigned customers when allCustomers or routes change
  useEffect(() => {
    if (!currentRoute?.schedule_date) return;
    
    const routeDate = currentRoute.schedule_date;
    
    // Get routes from the same date as the current route (excluding current route which we'll handle separately)
    const sameDateRoutes = [
      ...allRoutes.filter(route => route.schedule_date === routeDate && route.id !== currentRoute.id),
      ...tomorrowRoutes.filter(route => route.schedule_date === routeDate && route.id !== currentRoute.id),
      ...historyRoutes.filter(route => route.schedule_date === routeDate && route.id !== currentRoute.id)
    ];
    
    // Add a virtual route with the current newCustomerList (to include customers being added in the editor)
    const routesWithCurrentEdits = [
      ...sameDateRoutes,
      { route_customer_list: newCustomerList || [] }
    ];
    
    const unassigned = calculateUnassignedCustomers(allCustomers, routesWithCurrentEdits);
    setUnassignedCustomers(unassigned);
  }, [allCustomers, allRoutes, tomorrowRoutes, historyRoutes, currentRoute, newCustomerList]);

  // useEffect(() => {
  //   if (currentRoute) {
  //     setRouteName(currentRoute.name);
  //     setNewDriver(currentRoute.driver);
  //     setNewVehicle(currentRoute.vehicle);
  //     setNewRouteType(currentRoute.type);
  //     setEstimatedStartTime(currentRoute.estimated_start_time && new Date(currentRoute.estimated_start_time));
  //     setNewCustomerList(currentRoute.route_customer_list);
  //   }
  //   setErrorMessage(undefined);
  // }, [currentRoute])

  // Draggable component for unassigned customers
  const DraggableUnassignedCustomer = ({ customer }) => {
    const [{ isDragging }, drag] = useDrag({
      type: 'UNASSIGNED_CUSTOMER',
      item: () => customer,
      collect: (monitor) => ({
        isDragging: monitor.isDragging(),
      }),
    });

    const opacity = isDragging ? 0.5 : 1;

    return (
      <div ref={drag} style={{ opacity }} className="customers-dnd-item-container-absent">
        <GripVertical className="me-4" size={14}></GripVertical>
        <div className="customer-dnd-item">
          <span>{customer.name} </span>
          <small className="me-2">{customer.address1}</small>
          <small className="me-2">{customer.type}</small>
        </div>
      </div>
    );
  };

  return (
    <>
      <div className="list row mb-4">
        <Breadcrumb>
          <Breadcrumb.Item href="/">Transportation</Breadcrumb.Item>
          <Breadcrumb.Item href="/trans-routes/dashboard">
            Transportation Routes
          </Breadcrumb.Item>
          <Breadcrumb.Item active>
            Edit Route
          </Breadcrumb.Item>
        </Breadcrumb>
        <div className="col-md-12 text-primary">
           <h4>
             Edit Route Information <button className="btn btn-link btn-sm" onClick={() => {redirectToView()}}>Back</button>
           </h4> 
        </div>
      </div>

      <div className="app-main-content-list-container form-page">
				<div className="app-main-content-list-func-container">
					<Tabs defaultActiveKey="routeOverview" id="route-view-tab">
						<Tab eventKey="routeOverview" title="Route Information">
              { editSection === 'info' && <div className="multi-columns-container">
                <div className="column-container">
                  <div className="column-card">
                    <h6 className="text-primary">Route Details</h6>
                    <div className="app-main-content-fields-section">
                      <div className="me-4">
                        <div className="field-label">Route Name
                          <span className="required">*</span>
                        </div>
                        <input type="text" value={routeName || ''} onChange={e => setRouteName(e.target.value)}/>
                      </div>
                      <div className="me-4">
                        <div className="field-label">Vechile
                          <span className="required">*</span>
                        </div>
                        <select value={newVehicle} onChange={e => setNewVehicle(e.target.value)}>
                          {vehicles.map((vehicle) => (<option key={vehicle.id} value={vehicle.id}>{vehicle.vehicle_number}</option>))}
                        </select>
                      </div>
                    </div>
                    <div className="app-main-content-fields-section">
                      <div className="me-4">
                        <div className="field-label">Driver
                          <span className="required">*</span>
                        </div>
                        <select value={newDriver} onChange={e => setNewDriver(e.target.value)}>
                          {drivers.map((driver) => <option key={driver.id} value={driver.id}>{driver.name}</option>)}
                        </select>
                      </div>
                      <div className="me-4">
                        <div className="field-label">Route Type
                          <span className="required">*</span>
                        </div>
                        <select value={newRouteType} onChange={e => setNewRouteType(e.target.value)}>
                          <option value="inbound">Inbound</option>
                          <option value="outbound">Outbound</option>
                        </select>
                      </div>
                    </div>
                    { newRouteType === 'outbound' && <div className="app-main-content-fields-section">
                      <div className="me-4">
                        <div className="field-label">Estimated Start Time
                        </div>
                        <TimePicker disableClock={true} format={'HH:mm'} value={estimatedStartTime} onChange={setEstimatedStartTime} />
                      </div>
                    </div>}
                    <div className="app-main-content-fields-section">
                      <div className="me-4">
                        <div className="field-label">Vehicle Checklist
                        </div>
                        { currentVehicle?.checklist?.length > 0 && (<table className="mb-4">
                          <tbody>
                            {currentVehicle.checklist.map((item, index) => (<tr key={index}><td>{item}</td></tr>))}
                          </tbody>
                        </table>) }
                        <div className="mb-4"><button className="btn btn-link btn-sm" onClick={() => showAddCheckItemModal()}>+Add Check Items</button></div>
                        <div className="mb-4"><button className="btn btn-link btn-sm" onClick={() => showCopyCheckItemModal()}>Copy Checklist From Other Route</button></div>
                      </div>
                    </div>
                    <div className="list row mb-5">
                      <div className="col-md-12 col-sm-12 col-xs-12">
                        <button className="btn btn-default btn-sm float-right" onClick={() => redirectToView()}> Cancel </button>
                        <button className="btn btn-primary btn-sm float-right" onClick={() => updateCurrentRoute()}> Save </button>
                      </div>
                      {errorMessage && <div className="col-md-12 col-sm-12 col-xs-12 alert alert-danger mt-4">{errorMessage}</div>}
                    </div>
                  </div>
                </div>
                <div className="column-container">
                  { newVehicle && newVehicle !== '' && <div className="column-card mb-4">
                    <h6 className="text-primary">Vehicle Information</h6>
                    <div className="app-main-content-fields-section short">
                      <div className="field-body">
                        <div className="field-label">Vehicle Number</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.vehicle_number}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Seating Capacity</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.capacity}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Mileage</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.mileage}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Make</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.make}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Model</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.model}</div>
                      </div>
                    </div>
                    <div className="app-main-content-fields-section short">
                      <div className="field-body">
                        <div className="field-label">License Plate</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.tag}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Year</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.year}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">GPS ID</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.gps_tag}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">EZPass</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.ezpass}</div>
                      </div>
                      <div className="field-body">
                        <div className="field-label">Vin</div>
                        <div className="field-value">{vehicles.find(item => item.id === newVehicle)?.vin || ''}</div>
                      </div>
                    </div>
                  </div>}
                  {
                    newDriver && newDriver !== '' && <div className="column-card">
                      <h6 className="text-primary">Driver Information</h6>
                      <small className="text-primary">Personal Details</small>
                      <div className="app-main-content-fields-section short">
                        <div className="field-body">
                          <div className="field-label">Driver Name</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.name}</div>
                        </div>
                        <div className="field-body">
                          <div className="field-label">Preferred Name</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.name_cn}</div>
                        </div>
                        <div className="field-body">
                          <div className="field-label">Job Title</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.title}</div>
                        </div>
                        <div className="field-body">
                          <div className="field-label">Job Type</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.employment_status}</div>
                        </div>
                        <div className="field-body">
                          <div className="field-label">License Type</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.license_type}</div>
                        </div>
                      </div>
                      <div className="app-main-content-fields-section short">
                        <div className="field-body">
                          <div className="field-label">Phone Number</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.phone}</div>
                        </div>
                        <div className="field-body">
                          <div className="field-label">Email</div>
                          <div className="field-value">{drivers.find(item => item.id === newDriver)?.email}</div>
                        </div>
                        <div className="field-body"></div>
                        <div className="field-body"></div>
                        <div className="field-body"></div>
                      </div>
                    </div>
                  }
                </div>
              </div> }

              {
                editSection === 'assignment' && <DndProvider backend={HTML5Backend}>
                  <div className="multi-columns-container">
                    <div className="column-container">
                      <div className="column-card adjust" style={{paddingRight: '30px'}}>
                        <div className="col-md-12 mb-4">
                          <RouteCustomerEditor 
                            currentRoute={currentRoute ? {
                              ...currentRoute,
                              route_customer_list: currentRoute.route_customer_list?.filter(
                                customer => customer?.customer_route_status !== PERSONAL_ROUTE_STATUS.SCHEDULED_ABSENT
                              ) || []
                            } : undefined} 
                            setNewCustomerList={setNewCustomerList}
                            onAddCustomer={(addFn) => setAddCustomerToRoute(() => addFn)}
                          />
                        </div>
                      </div>
                    </div>
                    <div className="column-container">
                      <div className="column-card adjust">
                        <h6 className="text-primary">Scheduled Absences ({currentRoute?.route_customer_list?.filter(item => item?.customer_route_status === PERSONAL_ROUTE_STATUS.SCHEDULED_ABSENT)?.length || 0})</h6>
                        <div className="customers-container mb-4">
                          {
                            currentRoute?.route_customer_list.filter(customer => customer?.customer_route_status === PERSONAL_ROUTE_STATUS.SCHEDULED_ABSENT)?.map((abItem) => {
                              return <div key={abItem.customer_id} className="customers-dnd-item-container-absent">
                                <GripVertical className="me-4" size={14}></GripVertical>
                                <div className="customer-dnd-item">
                                  <span>{abItem.customer_name} </span>
                                    <small className="me-2">{abItem.customer_address}</small>
                                    <small className="me-2">{abItem.customer_pickup_status}</small>
                                </div>
                                
                              </div>
                            })
                          }
                        </div>
                      </div>
                    </div>
                    <div className="column-container">
                      <div className="column-card adjust">
                        <h6 className="text-primary">Unassigned Customers ({unassignedCustomers?.length || 0})</h6>
                        <div className="customers-container mb-4">
                          {
                            unassignedCustomers?.map((customer) => {
                              return <DraggableUnassignedCustomer key={customer.id} customer={customer} />
                            })
                          }
                        </div>
                      </div>
                    </div>
                  </div>
                </DndProvider>
              }
            </Tab>
          </Tabs>
          <div className="list-func-panel">
            <button className="btn btn-primary" onClick={() => softDeleteCurrentRoute()}><Archive size={16} className="me-2"></Archive>Delete</button>
          </div>
        </div>
      </div>

    
      <Modal show={showAddCheckItem} onHide={() => closeAddCheckItemModal()}>
        <Modal.Header closeButton>
          <Modal.Title>Add New Checklist Item</Modal.Title>
        </Modal.Header>
        <Modal.Body>
          <>
            {newChecklistItems?.map((item, index) => (<div className="mb-4" key={index}><input type="text" value={item} onChange={(e) => setNewChecklistItems([...newChecklistItems].map((a, index1) => {if (index1 === index) {return e.target.value;} return a;}))}/>
              <button className="btn btn-link btn-sm" onClick={(e) => setNewChecklistItems([...newChecklistItems].filter((value, index1) => index1 != index))}>Remove</button>
            </div>))}
            <button className="btn btn-link" onClick={() => addItemToArray()}>+Add New Item</button>
          </>
        </Modal.Body>
        <Modal.Footer>
          <Button variant="secondary" onClick={() => closeAddCheckItemModal()}>
            Close
          </Button>
          <Button variant="primary" onClick={() => saveChecklistItems()}>
            Save Checklist Items
          </Button>
        </Modal.Footer>
      </Modal>
      <Modal show={showCopyCheckItem} onHide={() => closeCopyCheckItemModal()}>
        <Modal.Header closeButton>
          <Modal.Title> Click on Route to Select</Modal.Title>
        </Modal.Header>
        <Modal.Body>
          <>
           {[...allRoutes, ...tomorrowRoutes].filter(r => r.id !== currentRoute?.id).map((route) => {
             return (<div className={`card-container ${route.id === selectedRouteChecklistToCopy.id ? 'selected': ''}`} key={route.id} onClick={() => setSelectedRouteChecklistToCopy(route)}>
               <div>{route.name}</div>
               <div>
                  {vehicles.find((a) => a.id === route.vehicle)?.checklist?.map((item, index) => <small key={index} className="me-2">{item}</small>)}
               </div>
             </div>);
           })}
          </>
        </Modal.Body>
        <Modal.Footer>
          <Button variant="secondary" onClick={() => closeCopyCheckItemModal()}>
            Close
          </Button>
          <Button variant="primary" onClick={() => copyChecklistItems()}>
            Copy Checklist Items
          </Button>
        </Modal.Footer>
      </Modal>
    </>
    
  );
};

export default RouteEdit;