import { Component, EventEmitter, inject, Input, Output, SimpleChanges } from '@angular/core';
import { FormBuilder, FormGroup, ReactiveFormsModule, Validators } from '@angular/forms';
import { finalize, forkJoin } from 'rxjs';
import { TravelPlanService } from '../../core/services/carnet/travel-plan.service';
import { ApiErrorHandlerService } from '../../core/services/common/api-error-handler.service';
import { NotificationService } from '../../core/services/common/notification.service';
import { Country, TravelEntry, TravelPlan } from '../../core/models/carnet/travel-plan';
import { AngularMaterialModule } from '../../shared/module/angular-material.module';
import { CommonModule } from '@angular/common';
import { MatListModule } from '@angular/material/list';
import { MatDialog } from '@angular/material/dialog';
import { ConfirmDialogComponent } from '../../shared/components/confirm-dialog/confirm-dialog.component';

@Component({
  selector: 'app-travel-plan',
  imports: [AngularMaterialModule, ReactiveFormsModule, CommonModule, MatListModule],
  templateUrl: './travel-plan.component.html',
  styleUrl: './travel-plan.component.scss'
})
export class TravelPlanComponent {
  @Input() headerid: number = 0;
  @Input() isViewMode = false;
  @Input() applicationType: 'new' | 'edit' | 'additional' | 'duplicate' | 'extend' | null = 'edit';

  @Output() completed = new EventEmitter<boolean>();
  @Output() needsInsurance = new EventEmitter<boolean>();

  private fb = inject(FormBuilder);
  private dialog = inject(MatDialog);

  private travelPlanService = inject(TravelPlanService);
  private notificationService = inject(NotificationService);
  private errorHandler = inject(ApiErrorHandlerService);

  travelForm: FormGroup;
  isLoading = false;
  changeInProgress = false;
  showAdditionalSetsValidationMessage: boolean = false;
  visitsCount = 1;
  transitsCount = 1;

  countries: Country[] = [];
  selectedVisitCountries: TravelEntry[] = [];
  selectedTransitCountries: TravelEntry[] = [];

  // Currently selected country in the listbox
  selectedAvailableVisitCountry: Country | null = null;
  selectedAvailableTransitCountry: Country | null = null;
  selectedVisitCountry: Country | null = null;
  selectedTransitCountry: Country | null = null;

  constructor() {
    this.travelForm = this.fb.group({
      usaEntries: ['', [Validators.required, Validators.min(1), Validators.max(99)]],
      visitsInput: ['', [Validators.min(1), Validators.max(99)]],
      transitsInput: ['', [Validators.min(1), Validators.max(99)]],
    });
  }

  ngOnInit(): void {
    if (this.headerid) {
      this.loadTravelPlan();
    }
  }

  ngOnChanges(changes: SimpleChanges) {
    if (changes['headerid'] && this.headerid > 0) {
      this.loadTravelPlan();
    }
  }

  onAvailableVisitCountrySelection(event: any) {
    this.selectedAvailableVisitCountry = event.value;
  }

  onVisitCountrySelection(event: any) {
    this.selectedVisitCountry = event.value;
  }

  onAvailableTransitCountrySelection(event: any) {
    this.selectedAvailableTransitCountry = event.value;
  }

  onTransitCountrySelection(event: any) {
    this.selectedTransitCountry = event.value;
  }

  // Add selected country to visits
  addVisitCountry(): void {
    if (!this.selectedAvailableVisitCountry) return;

    if (this.selectedAvailableVisitCountry.actionType === 'FYI') {
      this.fyiAction(this.selectedAvailableVisitCountry);
    } else if (this.selectedAvailableVisitCountry.actionType === 'WARNING') {
      this.warningAction(this.selectedAvailableVisitCountry);
    } else if (this.selectedAvailableVisitCountry.actionType === 'ACTION') {
      this.takeAction(this.selectedAvailableVisitCountry);
    } else {
      this.addVisitCountryToCollection();
    }
  }

  addVisitCountryToCollection(): void {
    if (!this.selectedAvailableVisitCountry) return;

    const existingIndex = this.selectedVisitCountries.findIndex(
      c => c.value === this.selectedAvailableVisitCountry!.value
    );

    if (existingIndex === -1) {
      this.selectedVisitCountries.push({
        ...this.selectedAvailableVisitCountry,
        visits: this.visitsCount
      });

      if (this.applicationType === 'additional') {
        this.needsInsurance.emit(this.selectedVisitCountries.length > 0);
      }
    }

    this.visitsCount = 1;
  }

  fyiAction(country: Country): void {

    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '560px',
      data: {
        title: 'For your information',
        message: country.actionMessage,
        confirmText: 'Ok',
        cancelText: 'Cancel'
      }
    });

    dialogRef.afterClosed().subscribe(result => {
      if (result) {
        this.addVisitCountryToCollection();
      }
    });
  }

  warningAction(country: Country): void {

    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '560px',
      data: {
        title: 'Warning',
        message: country.actionMessage,
        confirmText: 'Ok',
        cancelText: 'Cancel'
      }
    });

    dialogRef.afterClosed().subscribe(result => {
      if (result) {
        this.addVisitCountryToCollection();
      }
    });
  }

  takeAction(country: Country): void {

    if (this.IsCountryExists('transit', country)) {
      this.addVisitCountryToCollection();
      return;
    }

    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '560px',
      data: {
        title: 'Act',
        message: country.actionMessage,
        confirmText: 'Ok',
        cancelText: 'Cancel'
      }
    });

    dialogRef.afterClosed().subscribe(result => {
      if (result) {
        this.transitsCount = this.visitsCount;
        this.selectedAvailableTransitCountry = this.selectedAvailableVisitCountry;
        this.addVisitCountryToCollection();
        this.addTransitCountryToCollection();
      }
    });
  }

  // Add selected country to transits
  addTransitCountry(): void {
    if (!this.selectedAvailableTransitCountry) return;
    this.addTransitCountryToCollection();
  }

  addTransitCountryToCollection(): void {
    if (!this.selectedAvailableTransitCountry) return;

    const existingIndex = this.selectedTransitCountries.findIndex(
      c => c.value === this.selectedAvailableTransitCountry!.value
    );

    if (existingIndex === -1) {
      this.selectedTransitCountries.push({
        ...this.selectedAvailableTransitCountry,
        visits: this.transitsCount
      });
    }
    this.transitsCount = 1;
  }

  IsCountryExists(countryType: string, country: Country): boolean {

    const existingIndex = countryType === 'transit' ? this.selectedTransitCountries.findIndex(
      c => c.value === country!.value
    ) : this.selectedVisitCountries.findIndex(
      c => c.value === country!.value
    );

    return existingIndex > -1;
  }

  // Remove country from visits
  removeVisitCountry(): void {
    if (!this.selectedVisitCountry) return;

    this.selectedVisitCountries = this.selectedVisitCountries.filter(
      c => c.value !== this.selectedVisitCountry!.value
    );

    if (this.applicationType === 'additional') {
      this.needsInsurance.emit(this.selectedVisitCountries.length > 0);
    }
  }

  // Remove country from transits
  removeTransitCountry(): void {
    if (!this.selectedTransitCountry) return;

    this.selectedTransitCountries = this.selectedTransitCountries.filter(
      c => c.value !== this.selectedTransitCountry!.value
    );
  }

  // Calculate total visits
  get totalVisits(): number {
    return this.selectedVisitCountries.reduce((sum, country) => sum + country.visits, 0);
  }

  // Calculate total transits
  get totalTransits(): number {
    return this.selectedTransitCountries.reduce((sum, country) => sum + country.visits, 0);
  }

  // Check if a country is already selected (visit)
  isVisitCountrySelected(country: Country): boolean {
    return this.selectedVisitCountries.some(c => c.value === country.value)
  }

  // Check if a country is already selected (transit)
  isTransitCountrySelected(country: Country): boolean {
    return this.selectedTransitCountries.some(c => c.value === country.value);
  }

  loadTravelPlan(): void {
    this.isLoading = true;

    forkJoin({
      countries: this.travelPlanService.getCountriesAndMessages(),
      travelPlanData: this.travelPlanService.getTravelPlan(this.headerid)
    }).pipe(finalize(() => {
      this.isLoading = false;
    })).subscribe({
      next: (results) => {
        this.countries = results.countries as Country[];
        this.patchTravelPlanData(results.travelPlanData);
      },
      error: (error) => {
        console.error('Error loading travel plan data', error);
        let errorMessage = this.errorHandler.handleApiError(error, 'Failed to load travel plan data');
        this.notificationService.showError(errorMessage);
      }
    });
  }

  private patchTravelPlanData(plan: TravelPlan): void {

    this.selectedVisitCountries = plan?.entries;
    this.selectedTransitCountries = plan?.transits;

    if (this.applicationType === 'additional') {
      this.needsInsurance.emit(this.selectedVisitCountries.length > 0)
    }

    // Patch form values
    this.travelForm.patchValue({
      usaEntries: plan?.usSets === 0 ? '' : plan?.usSets,
      visitsInput: 1,
      transitsInput: 1 // Reset to default
    });

    if (this.isViewMode) {
      this.travelForm.disable();
    }

    if (this.applicationType === 'additional') {
      const usentriesControl = this.travelForm.get('usaEntries');
      usentriesControl?.setValidators([Validators.min(1), Validators.max(99)]);
      usentriesControl?.updateValueAndValidity();
    }

    this.completed.emit(this.travelForm.valid || this.travelForm.disabled
      || (this.applicationType === 'additional' && (this.travelForm.value.usaEntries
        || this.selectedVisitCountries.length > 0 || this.selectedTransitCountries.length > 0)));
  }

  onSubmit(): void {
    if (this.travelForm.invalid) {
      this.travelForm.markAllAsTouched();
      return;
    }

    this.showAdditionalSetsValidationMessage = false;
    if (this.applicationType === 'additional' && (!this.travelForm.value.usaEntries &&
      this.selectedVisitCountries.length === 0 &&
      this.selectedTransitCountries.length === 0
    )) {
      this.showAdditionalSetsValidationMessage = true;
      return;
    }

    const travelPlan: TravelPlan = {
      usSets: this.travelForm.value.usaEntries,
      entries: this.selectedVisitCountries,
      transits: this.selectedTransitCountries
    };

    this.changeInProgress = true;

    this.travelPlanService.saveTravelPlan(this.headerid, travelPlan).pipe(finalize(() => {
      this.changeInProgress = false;
    })).subscribe({
      next: () => {
        this.notificationService.showSuccess('Travel plan saved successfully');
        this.completed.emit(true);
      },
      error: (error) => {
        let errorMessage = this.errorHandler.handleApiError(error, 'Failed to save travel plan');
        this.notificationService.showError(errorMessage);
        console.error('Error saving travel plan data : ', error);
      }
    });
  }
}