// SPDX-FileCopyrightText: 2025-2026 Lucio Lelii <lucio.lelii@isti.cnr.it> - ISTI-CNR
// SPDX-License-Identifier: AGPL-3.0-or-later
// Attribution term under AGPL-3.0 section 7(b): see LICENSE-ADDENDUM.

import { AfterViewInit, Directive, ElementRef, Input, OnChanges, OnDestroy, SimpleChanges, inject } from '@angular/core';
import { MatTooltip } from '@angular/material/tooltip';

/**
 * Shows a title preview only when its host has actually been ellipsized. Measuring after render
 * and observing size changes avoids the stale first-row-only result a template expression gives
 * while a list is still laying itself out.
 */
@Directive({
  selector: '[appTruncatedTooltip]',
  standalone: true,
  hostDirectives: [MatTooltip]
})
export class TruncatedTooltipDirective implements AfterViewInit, OnChanges, OnDestroy {
  @Input({ required: true }) appTruncatedTooltip = '';

  private readonly element = inject(ElementRef<HTMLElement>);
  private readonly tooltip = inject(MatTooltip);
  private resizeObserver: ResizeObserver | null = null;

  ngAfterViewInit() {
    this.tooltip.position = 'above';
    this.tooltip.tooltipClass = 'title-preview-tooltip';
    this.scheduleRefresh();

    if (typeof ResizeObserver !== 'undefined') {
      this.resizeObserver = new ResizeObserver(() => this.refresh());
      this.resizeObserver.observe(this.element.nativeElement);
    }
  }

  ngOnChanges(_changes: SimpleChanges) {
    this.tooltip.message = this.appTruncatedTooltip;
    this.scheduleRefresh();
  }

  ngOnDestroy() {
    this.resizeObserver?.disconnect();
  }

  private scheduleRefresh() {
    queueMicrotask(() => this.refresh());
  }

  private refresh() {
    const host = this.element.nativeElement;
    this.tooltip.message = this.appTruncatedTooltip;
    this.tooltip.disabled = host.scrollWidth <= host.clientWidth;
  }
}