import { Component, ChangeDetectionStrategy, input, output, computed } from '@angular/core';
import { CommonModule } from '@angular/common';
import { ButtonComponent, IconComponent, TooltipDirective, SkeletonComponent } from '@sda/base-ui';
import { TlGanttRowComponent } from '../tl-gantt-row';
import { TlTimelineToolbarComponent } from '../tl-timeline-toolbar';
import { GanttService } from '../../services/gantt.service';
import type { TlGanttTask, TlGanttDependency, TlDateTick } from '../../types/gantt.types';
import type { TlGanttTaskClickEvent, TlGanttTaskResizeEvent, TlGanttTaskMoveEvent, TlGanttZoomChangeEvent, TlGanttScrollEvent } from '../../types/event.types';
import { calculateDateRange, sortTasksHierarchically, calculateChartWidth } from '../../utils/gantt.utils';

@Component({
  selector: 'tl-gantt-chart',
  standalone: true,
  imports: [
    CommonModule,
    ButtonComponent,
    IconComponent,
    TooltipDirective,
    SkeletonComponent,
    TlGanttRowComponent,
    TlTimelineToolbarComponent,
  ],
  providers: [GanttService],
  templateUrl: './tl-gantt-chart.component.html',
  styleUrl: './tl-gantt-chart.component.scss',
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class TlGanttChartComponent {
  constructor(protected readonly ganttService: GanttService) {}

  readonly tasks = input.required<TlGanttTask[]>();
  readonly dependencies = input<TlGanttDependency[]>([]);
  readonly zoomLevel = input<'day' | 'week' | 'month' | 'quarter' | 'year'>('week');
  readonly rowHeight = input(40);
  readonly showDependencies = input(true);
  readonly showProgress = input(true);
  readonly showTodayLine = input(true);
  readonly loading = input(false);
  readonly emptyMessage = input('No tasks');

  readonly taskClick = output<TlGanttTaskClickEvent>();
  readonly taskResize = output<TlGanttTaskResizeEvent>();
  readonly taskMove = output<TlGanttTaskMoveEvent>();
  readonly zoomChange = output<TlGanttZoomChangeEvent>();
  readonly scroll = output<TlGanttScrollEvent>();

  protected readonly dateRange = computed(() => {
    if (this.tasks().length === 0) {
      return { start: new Date(), end: new Date() };
    }
    return calculateDateRange(this.tasks());
  });

  protected readonly dateAxis = computed(() => {
    const range = this.dateRange();
    return this.ganttService.calculateDateAxis(range.start, range.end);
  });

  protected readonly sortedTasks = computed(() => {
    return sortTasksHierarchically(this.tasks());
  });

  protected readonly taskPositions = computed(() => {
    const range = this.dateRange();
    return this.sortedTasks().map(task =>
      this.ganttService.calculateTaskPosition(task, range.start)
    );
  });

  protected readonly todayPosition = computed(() => {
    if (!this.showTodayLine()) return null;
    const range = this.dateRange();
    return this.ganttService.calculateTodayPosition(range.start);
  });

  protected readonly totalWidth = computed(() => {
    const range = this.dateRange();
    return calculateChartWidth(range.start, range.end, this.ganttService.pixelsPerDay());
  });

  protected onZoomIn(): void {
    this.ganttService.zoomIn();
    this.zoomChange.emit({ level: this.ganttService.zoomLevel() });
  }

  protected onZoomOut(): void {
    this.ganttService.zoomOut();
    this.zoomChange.emit({ level: this.ganttService.zoomLevel() });
  }

  protected onTaskClick(event: TlGanttTaskClickEvent): void {
    this.taskClick.emit(event);
  }

  protected onTaskResize(event: TlGanttTaskResizeEvent): void {
    this.taskResize.emit(event);
  }

  protected getLoadingItems(): number[] {
    return Array.from({ length: 5 }, (_, i) => i);
  }
}