import { ChangeDetectorRef, Component, Input, OnChanges, OnInit, ViewChild } from '@angular/core';

import { BehaviorSubject, Subscription } from 'rxjs';
import { filter, mergeMap, take } from 'rxjs/operators';
import { DynamicFormControlModel, } from '@ng-dynamic-forms/core';
import { NgbModal } from '@ng-bootstrap/ng-bootstrap';

import { SectionUploadService } from '../section-upload.service';
import { isNotEmpty, isNotNull, isNotUndefined } from '../../../../shared/empty.util';
import { FormService } from '../../../../shared/form/form.service';
import { JsonPatchOperationsBuilder } from '../../../../core/json-patch/builder/json-patch-operations-builder';
import { JsonPatchOperationPathCombiner } from '../../../../core/json-patch/builder/json-patch-operation-path-combiner';
import { WorkspaceitemSectionUploadFileObject } from '../../../../core/submission/models/workspaceitem-section-upload-file.model';
import { SubmissionFormsModel } from '../../../../core/config/models/config-submission-forms.model';
import { dateToISOFormat } from '../../../../shared/date.util';
import { SubmissionService } from '../../../submission.service';
import { HALEndpointService } from '../../../../core/shared/hal-endpoint.service';
import { SubmissionJsonPatchOperationsService } from '../../../../core/submission/submission-json-patch-operations.service';
import { SubmissionObject } from '../../../../core/submission/models/submission-object.model';
import { WorkspaceitemSectionUploadObject } from '../../../../core/submission/models/workspaceitem-section-upload.model';
import { SubmissionSectionUploadFileEditComponent } from './edit/section-upload-file-edit.component';
import { Bitstream } from '../../../../core/shared/bitstream.model';

/**
 * This component represents a single bitstream contained in the submission
 */
@Component({
  selector: 'ds-submission-upload-section-file',
  styleUrls: ['./section-upload-file.component.scss'],
  templateUrl: './section-upload-file.component.html',
})
export class SubmissionSectionUploadFileComponent implements OnChanges, OnInit {

  /**
   * The list of available access condition
   * @type {Array}
   */
  @Input() availableAccessConditionOptions: any[];

  /**
   * The submission id
   * @type {string}
   */
  @Input() collectionId: string;

  /**
   * Define if collection access conditions policy type :
   * POLICY_DEFAULT_NO_LIST : is not possible to define additional access group/s for the single file
   * POLICY_DEFAULT_WITH_LIST : is possible to define additional access group/s for the single file
   * @type {number}
   */
  @Input() collectionPolicyType: number;

  /**
   * The configuration for the bitstream's metadata form
   * @type {SubmissionFormsModel}
   */
  @Input() configMetadataForm: SubmissionFormsModel;

  /**
   * The bitstream id
   * @type {string}
   */
  @Input() fileId: string;

  /**
   * The bitstream array key
   * @type {string}
   */
  @Input() fileIndex: string;

  /**
   * The bitstream id
   * @type {string}
   */
  @Input() fileName: string;

  /**
   * The section id
   * @type {string}
   */
  @Input() sectionId: string;

  /**
   * The submission id
   * @type {string}
   */
  @Input() submissionId: string;

  /**
   * The bitstream's metadata data
   * @type {WorkspaceitemSectionUploadFileObject}
   */
  public fileData: WorkspaceitemSectionUploadFileObject;

  /**
   * The form id
   * @type {string}
   */
  public formId: string;

  /**
   * A boolean representing if to show bitstream edit form
   * @type {boolean}
   */
  public readMode: boolean;

  /**
   * The form model
   * @type {DynamicFormControlModel[]}
   */
  public formModel: DynamicFormControlModel[];

  /**
   * A boolean representing if a submission delete operation is pending
   * @type {BehaviorSubject<boolean>}
   */
  public processingDelete$ = new BehaviorSubject<boolean>(false);

  /**
   * The [JsonPatchOperationPathCombiner] object
   * @type {JsonPatchOperationPathCombiner}
   */
  protected pathCombiner: JsonPatchOperationPathCombiner;

  /**
   * Array to track all subscriptions and unsubscribe them onDestroy
   * @type {Array}
   */
  protected subscriptions: Subscription[] = [];

  /**
   * The [[SubmissionSectionUploadFileEditComponent]] reference
   * @type {SubmissionSectionUploadFileEditComponent}
   */
  @ViewChild(SubmissionSectionUploadFileEditComponent) fileEditComp: SubmissionSectionUploadFileEditComponent;

  /**
   * Initialize instance variables
   *
   * @param {ChangeDetectorRef} cdr
   * @param {FormService} formService
   * @param {HALEndpointService} halService
   * @param {NgbModal} modalService
   * @param {JsonPatchOperationsBuilder} operationsBuilder
   * @param {SubmissionJsonPatchOperationsService} operationsService
   * @param {SubmissionService} submissionService
   * @param {SectionUploadService} uploadService
   */
  constructor(private cdr: ChangeDetectorRef,
              private formService: FormService,
              private halService: HALEndpointService,
              private modalService: NgbModal,
              private operationsBuilder: JsonPatchOperationsBuilder,
              private operationsService: SubmissionJsonPatchOperationsService,
              private submissionService: SubmissionService,
              private uploadService: SectionUploadService) {
    this.readMode = true;
  }

  /**
   * Retrieve bitstream's metadata
   */
  ngOnChanges() {
    if (this.availableAccessConditionOptions) {
      // Retrieve file state
      this.subscriptions.push(
        this.uploadService
          .getFileData(this.submissionId, this.sectionId, this.fileId).pipe(
          filter((bitstream) => isNotUndefined(bitstream)))
          .subscribe((bitstream) => {
              this.fileData = bitstream;
            }
          )
      );
    }
  }

  /**
   * Initialize instance variables
   */
  ngOnInit() {
    this.formId = this.formService.getUniqueId(this.fileId);
    this.pathCombiner = new JsonPatchOperationPathCombiner('sections', this.sectionId, 'files', this.fileIndex);
  }

  /**
   * Delete bitstream from submission
   */
  protected deleteFile() {
    this.operationsBuilder.remove(this.pathCombiner.getPath());
    this.subscriptions.push(this.operationsService.jsonPatchByResourceID(
      this.submissionService.getSubmissionObjectLinkName(),
      this.submissionId,
      this.pathCombiner.rootElement,
      this.pathCombiner.subRootElement)
      .subscribe(() => {
        this.uploadService.removeUploadedFile(this.submissionId, this.sectionId, this.fileId);
        this.processingDelete$.next(false);
      }));
  }

  /**
   * Show confirmation dialog for delete
   */
  public confirmDelete(content) {
    this.modalService.open(content).result.then(
      (result) => {
        if (result === 'ok') {
          this.processingDelete$.next(true);
          this.deleteFile();
        }
      }
    );
  }

  /**
   * Build a Bitstream object by the current file uuid
   *
   * @return Bitstream object
   */
  public getBitstream(): Bitstream {
    return Object.assign(new Bitstream(), {
      uuid: this.fileData.uuid
    });
  }

  /**
   * Save bitstream metadata
   *
   * @param event
   *    the click event emitted
   */
  public saveBitstreamData(event) {
    event.preventDefault();

    // validate form
    this.formService.validateAllFormFields(this.fileEditComp.formRef.formGroup);
    this.subscriptions.push(this.formService.isValid(this.formId).pipe(
      take(1),
      filter((isValid) => isValid),
      mergeMap(() => this.formService.getFormData(this.formId)),
      take(1),
      mergeMap((formData: any) => {
        // collect bitstream metadata
        Object.keys((formData.metadata))
          .filter((key) => isNotEmpty(formData.metadata[key]))
          .forEach((key) => {
            const metadataKey = key.replace(/_/g, '.');
            const path = `metadata/${metadataKey}`;
            this.operationsBuilder.add(this.pathCombiner.getPath(path), formData.metadata[key], true);
          });
        const accessConditionsToSave = [];
        formData.accessConditions
          .map((accessConditions) => accessConditions.accessConditionGroup)
          .filter((accessCondition) => isNotEmpty(accessCondition))
          .forEach((accessCondition) => {
            let accessConditionOpt;

            this.availableAccessConditionOptions
              .filter((element) => isNotNull(accessCondition.name) && element.name === accessCondition.name[0].value)
              .forEach((element) => accessConditionOpt = element);

            if (accessConditionOpt) {
                accessConditionOpt = Object.assign({}, accessCondition);
                accessConditionOpt.name = this.retrieveValueFromField(accessCondition.name);
                if (accessCondition.startDate) {
                  const startDate = this.retrieveValueFromField(accessCondition.startDate);
                  accessConditionOpt.startDate = dateToISOFormat(startDate);
                }
                if (accessCondition.endDate) {
                  const endDate = this.retrieveValueFromField(accessCondition.endDate);
                  accessConditionOpt.endDate = dateToISOFormat(endDate);
                }
                accessConditionsToSave.push(accessConditionOpt);
            }
          });

        if (isNotEmpty(accessConditionsToSave)) {
          this.operationsBuilder.add(this.pathCombiner.getPath('accessConditions'), accessConditionsToSave, true);
        }

        // dispatch a PATCH request to save metadata
        return this.operationsService.jsonPatchByResourceID(
          this.submissionService.getSubmissionObjectLinkName(),
          this.submissionId,
          this.pathCombiner.rootElement,
          this.pathCombiner.subRootElement);
      })
    ).subscribe((result: SubmissionObject[]) => {
      if (result[0].sections.upload) {
        Object.keys((result[0].sections.upload as WorkspaceitemSectionUploadObject).files)
          .filter((key) => (result[0].sections.upload as WorkspaceitemSectionUploadObject).files[key].uuid === this.fileId)
          .forEach((key) => this.uploadService.updateFileData(
            this.submissionId,
            this.sectionId,
            this.fileId,
            (result[0].sections.upload as WorkspaceitemSectionUploadObject).files[key]));
      }
      this.switchMode();
    }));
  }

  /**
   * Retrieve field value
   *
   * @param field
   *    the specified field object
   */
  private retrieveValueFromField(field: any) {
    const temp = Array.isArray(field) ? field[0] : field;
    return (temp) ? temp.value : undefined;
  }

  /**
   * Switch from edit form to metadata view
   */
  public switchMode() {
    this.readMode = !this.readMode;
    this.cdr.detectChanges();
  }

}