/**
 * 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, OnDestroy, inject } from '@angular/core';
import {
  MatDialogRef,
  MAT_DIALOG_DATA,
  MatDialogTitle,
  MatDialogContent,
  MatDialogActions,
  MatDialogClose
} from '@angular/material/dialog';
import { DomSanitizer, SafeResourceUrl } from '@angular/platform-browser';
import { CdkScrollable } from '@angular/cdk/scrolling';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';

export interface DocumentPreviewDialogData {
  blob: Blob;
  title?: string;
  fileName?: string;
}

/**
 * Generic in-app document preview dialog — shows an image inline or a PDF in an embedded
 * viewer, with a Download fallback for anything else. Used in place of window.open() for
 * saved KYC/address/senior-citizen/PWD documents: opening a new browser tab is subject to
 * popup blockers (fires only after the async download resolves) and, for images, Chrome/Edge
 * frequently fail to paint a huge base64 data: URL until the tab is manually refreshed.
 */
@Component({
  selector: 'mifosx-document-preview-dialog',
  templateUrl: './document-preview-dialog.component.html',
  styleUrls: ['./document-preview-dialog.component.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    MatDialogTitle,
    CdkScrollable,
    MatDialogContent,
    MatDialogActions,
    MatDialogClose
  ]
})
export class DocumentPreviewDialogComponent implements OnDestroy {
  dialogRef = inject<MatDialogRef<DocumentPreviewDialogComponent>>(MatDialogRef);
  private sanitizer = inject(DomSanitizer);
  data = inject<DocumentPreviewDialogData>(MAT_DIALOG_DATA);

  private readonly objectUrl: string;
  readonly safeUrl: SafeResourceUrl;
  readonly isImage: boolean;
  readonly isPdf: boolean;

  constructor() {
    this.objectUrl = URL.createObjectURL(this.data.blob);
    this.safeUrl = this.sanitizer.bypassSecurityTrustResourceUrl(this.objectUrl);
    const type = this.data.blob.type || '';
    this.isImage = type.startsWith('image/');
    this.isPdf = type === 'application/pdf';
  }

  ngOnDestroy(): void {
    URL.revokeObjectURL(this.objectUrl);
  }

  get previewUrl(): string {
    return this.objectUrl;
  }

  download(): void {
    const a = document.createElement('a');
    a.href = this.objectUrl;
    a.download = this.data.fileName || 'document';
    a.click();
  }
}