/**
 * Copyright since 2025 Mifos Initiative
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/** Angular Imports */
import { Component, OnInit, inject } from '@angular/core';
import {
  UntypedFormGroup,
  UntypedFormBuilder,
  UntypedFormArray,
  Validators,
  ReactiveFormsModule
} from '@angular/forms';
import { Router, ActivatedRoute, RouterLink } from '@angular/router';
import { MatDialog } from '@angular/material/dialog';
import { CdkDragDrop, moveItemInArray, CdkDropList, CdkDrag } from '@angular/cdk/drag-drop';

/** Custom Services */
import { SystemService } from '../../system.service';

/** Custom Components */
import { CancelDialogComponent } from '../../../shared/cancel-dialog/cancel-dialog.component';
import { CdkTextareaAutosize } from '@angular/cdk/text-field';
import { MatButton, MatIconButton } from '@angular/material/button';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import { MatDivider } from '@angular/material/divider';
import { MatTooltip } from '@angular/material/tooltip';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';
import { AlertService } from 'app/core/alert/alert.service';

/**
 * Create survey component.
 */
@Component({
  selector: 'mifosx-create-survey',
  templateUrl: './create-survey.component.html',
  styleUrls: ['./create-survey.component.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    CdkTextareaAutosize,
    CdkDropList,
    CdkDrag,
    FaIconComponent,
    MatDivider,
    MatIconButton,
    MatTooltip
  ]
})
export class CreateSurveyComponent implements OnInit {
  private formBuilder = inject(UntypedFormBuilder);
  private systemService = inject(SystemService);
  private route = inject(ActivatedRoute);
  private router = inject(Router);
  dialog = inject(MatDialog);
  private alertService = inject(AlertService);

  /** Survey form. */
  surveyForm: UntypedFormGroup;

  /**
   * Creates the survey form.
   */
  ngOnInit() {
    this.createSurveyForm();
  }

  /**
   * Creates the survey form.
   */
  createSurveyForm() {
    this.surveyForm = this.formBuilder.group({
      key: [
        '',
        Validators.required
      ],
      name: [
        '',
        Validators.required
      ],
      countryCode: [
        '',
        [
          Validators.required,
          Validators.pattern('^\\s*([A-Za-z]{2})?\\s*$')
        ]
      ],
      description: [''],
      questionDatas: this.formBuilder.array([])
    });
  }

  /**
   * Gets the questions form array.
   * @returns {FormArray} Questions form array.
   */
  get questionDatas(): UntypedFormArray {
    return this.surveyForm.get('questionDatas') as UntypedFormArray;
  }

  /**
   * Gets the responses form array.
   * @param {number} questionIndex Index of question to retrieve responses from.
   * @returns {FormArray} Responses form array.
   */
  getResponseDatas(questionIndex: number): UntypedFormArray {
    return this.surveyForm.get([
      'questionDatas',
      questionIndex,
      'responseDatas'
    ]) as UntypedFormArray;
  }

  /**
   * Creates a question form group
   * @returns {FormGroup} Question form group.
   */
  createQuestionForm(): UntypedFormGroup {
    return this.formBuilder.group({
      key: [
        '',
        Validators.required
      ],
      text: [
        '',
        Validators.required
      ],
      description: [''],
      responseDatas: this.formBuilder.array([this.createResponseForm()]),
      sequenceNo: ['']
    });
  }

  /**
   * Adds a question to the questions form array
   */
  addQuestion() {
    this.questionDatas.push(this.createQuestionForm());
    this.updateSequenceNumber();
  }

  /**
   * Removes the particular question form from the questions form array at given index.
   * @param {number} index Array index from where question form needs to be removed.
   */
  removeQuestion(index: number) {
    this.questionDatas.removeAt(index);
    this.updateSequenceNumber();
  }

  /**
   * Creates a response form group
   * @returns {FormGroup} Response form group.
   */
  createResponseForm(): UntypedFormGroup {
    return this.formBuilder.group({
      text: [
        '',
        Validators.required
      ],
      value: [
        '',
        [
          Validators.required,
          Validators.pattern('^\\s*[-]?\\d{0,4}\\s*$')
        ]
      ],
      sequenceNo: ['']
    });
  }

  /**
   * Adds a response to the responses form array of the question with the given Index
   * @param {number} questionIndex Index of question to add response to.
   */
  addResponse(questionIndex: number) {
    this.getResponseDatas(questionIndex).push(this.createResponseForm());
    this.updateSequenceNumber();
  }

  /**
   * Removes the particular response form from the given responses form array at given index.
   * @param {FormArray} responseFormArray Given responses form array.
   * @param {number} index Array index from where response form needs to be removed.
   */
  removeResponse(responseFormArray: UntypedFormArray, index: number) {
    responseFormArray.removeAt(index);
    this.updateSequenceNumber();
  }

  /**
   * Updates the sequence numbers of questions and responses
   */
  updateSequenceNumber() {
    for (let questionIndex = 0; questionIndex < this.questionDatas.length; questionIndex++) {
      this.questionDatas
        .at(questionIndex)
        .get('sequenceNo')
        .setValue(questionIndex + 1);
      for (let responseIndex = 0; responseIndex < this.getResponseDatas(questionIndex).length; responseIndex++) {
        this.getResponseDatas(questionIndex)
          .at(responseIndex)
          .get('sequenceNo')
          .setValue(responseIndex + 1);
      }
    }
  }

  /**
   * Cancels the survey and redirects to surveys.
   */
  cancelSurvey() {
    const cancelSurveyDialogRef = this.dialog.open(CancelDialogComponent);
    cancelSurveyDialogRef.afterClosed().subscribe((response: any) => {
      if (response.cancel) {
        this.router.navigate(['../'], { relativeTo: this.route });
      }
    });
  }

  /**
   * Reorders the question order according to the user drop
   */
  dropQuestion(event: CdkDragDrop<string[]>) {
    moveItemInArray(this.questionDatas.controls, event.previousIndex, event.currentIndex);
    this.updateSequenceNumber();
  }

  /**
   * Reorders the response order according to the user drop
   */
  dropResponse(event: CdkDragDrop<string[]>, questionIndex: number) {
    moveItemInArray(this.getResponseDatas(questionIndex).controls, event.previousIndex, event.currentIndex);
    this.updateSequenceNumber();
  }

  /**
   * Submits the survey form and creates survey,
   * if successful redirects to surveys.
   */
  submit() {
    this.surveyForm.patchValue({
      countryCode: this.surveyForm.value.countryCode.toUpperCase()
    });
    this.systemService.createSurvey(this.surveyForm.value).subscribe((response: any) => {
      if (response?.rollbackTransaction) {
        this.alertService.alert({
          type: 'Success',
          message: 'Survey creation has been submitted for approval.'
        });
      }
      this.router.navigate(['../'], { relativeTo: this.route });
    });
  }
}