import { type IBlock } from './wysiwyg.types.js';

export class WysiwygDragDropHandler {
  private component: any;
  private draggedBlockId: string | null = null;
  private dragOverBlockId: string | null = null;
  private dragOverPosition: 'before' | 'after' | null = null;

  constructor(component: any) {
    this.component = component;
  }

  /**
   * Gets the current drag state
   */
  get dragState() {
    return {
      draggedBlockId: this.draggedBlockId,
      dragOverBlockId: this.dragOverBlockId,
      dragOverPosition: this.dragOverPosition
    };
  }

  /**
   * Handles drag start
   */
  handleDragStart(e: DragEvent, block: IBlock): void {
    if (!e.dataTransfer) return;
    
    this.draggedBlockId = block.id;
    e.dataTransfer.effectAllowed = 'move';
    e.dataTransfer.setData('text/plain', block.id);
    
    // Update component state (for parent drag handler access)
    this.component.draggedBlockId = this.draggedBlockId;
    
    // The parent component already handles adding dragging classes programmatically
  }

  /**
   * Handles drag end
   */
  handleDragEnd(): void {
    this.draggedBlockId = null;
    this.dragOverBlockId = null;
    this.dragOverPosition = null;
    
    // Update component state
    this.component.draggedBlockId = null;
    this.component.dragOverBlockId = null;
    this.component.dragOverPosition = null;
    
    // The parent component already handles removing dragging classes programmatically
  }

  /**
   * Handles drag over
   */
  handleDragOver(e: DragEvent, block: IBlock): void {
    e.preventDefault();
    if (!e.dataTransfer || !this.draggedBlockId || this.draggedBlockId === block.id) return;
    
    e.dataTransfer.dropEffect = 'move';
    
    const rect = (e.currentTarget as HTMLElement).getBoundingClientRect();
    const midpoint = rect.top + rect.height / 2;
    
    this.dragOverBlockId = block.id;
    this.dragOverPosition = e.clientY < midpoint ? 'before' : 'after';
    
    // Update component state
    this.component.dragOverBlockId = this.dragOverBlockId;
    this.component.dragOverPosition = this.dragOverPosition;
    
    // The parent component already handles drag-over classes programmatically
  }

  /**
   * Handles drag leave
   */
  handleDragLeave(block: IBlock): void {
    if (this.dragOverBlockId === block.id) {
      this.dragOverBlockId = null;
      this.dragOverPosition = null;
      
      // Update component state
      this.component.dragOverBlockId = null;
      this.component.dragOverPosition = null;
      
      // The parent component already handles removing drag-over classes programmatically
    }
  }

  /**
   * Handles drop
   */
  handleDrop(e: DragEvent, targetBlock: IBlock): void {
    e.preventDefault();
    
    if (!this.draggedBlockId || this.draggedBlockId === targetBlock.id) return;
    
    // The parent component already has a handleDrop method that handles this programmatically
    // We'll delegate to that to ensure proper programmatic rendering
    this.component.handleDrop(e, targetBlock);
  }


  /**
   * Checks if a block is being dragged
   */
  isDragging(blockId: string): boolean {
    return this.draggedBlockId === blockId;
  }

  /**
   * Checks if a block has drag over state
   */
  isDragOver(blockId: string): boolean {
    return this.dragOverBlockId === blockId;
  }

  /**
   * Gets drag over CSS classes for a block
   */
  getDragOverClasses(blockId: string): string {
    if (!this.isDragOver(blockId)) return '';
    return this.dragOverPosition === 'before' ? 'drag-over-before' : 'drag-over-after';
  }
}