/**
 * ColumnDetector - Bare detect hvilken kolonne musen er over
 */

import { ALL_DAY_CONSTANTS } from '../core/CalendarConfig';
import { eventBus } from '../core/EventBus';

export class ColumnDetector {
  private currentColumn: string | null = null;
  private isMouseDown = false;
  private lastMousePosition = { x: 0, y: 0 };
  private lastLoggedPosition = { x: 0, y: 0 };
  private draggedClone: HTMLElement | null = null;
  private originalEvent: HTMLElement | null = null;
  private mouseOffset = { x: 0, y: 0 };
  
  // Konfiguration for snap interval
  private snapIntervalMinutes = 15; // 15 minutter
  private hourHeightPx = 60; // Fra CSS --hour-height
  private get snapDistancePx(): number {
    return (this.snapIntervalMinutes / 60) * this.hourHeightPx; // 15/60 * 60 = 15px
  }
  
  constructor() {
    this.init();
  }
  
  /**
   * Konfigurer snap interval
   */
  public setSnapInterval(minutes: number): void {
    this.snapIntervalMinutes = minutes;
    console.log(`Snap interval set to ${minutes} minutes (${this.snapDistancePx}px)`);
  }

  /**
   * Fade out og fjern element fra DOM
   */
  private fadeOutAndRemove(element: HTMLElement): void {
    element.style.transition = 'opacity 0.3s ease-out';
    element.style.opacity = '0';
    
    setTimeout(() => {
      element.remove();
    }, 300);
  }

  /**
   * Fjern "clone-" prefix fra event ID og gendan pointer events
   */
  private removeClonePrefix(clone: HTMLElement): void {
    const cloneId = clone.dataset.eventId;
    if (cloneId && cloneId.startsWith('clone-')) {
      const originalId = cloneId.replace('clone-', '');
      clone.dataset.eventId = originalId;
      console.log(`Removed clone prefix: ${cloneId} -> ${originalId}`);
    }
    
    // Gendan pointer events så klonen kan dragges igen
    clone.style.pointerEvents = '';
  }

  private init(): void {
    // Lyt til mouse move på hele body
    document.body.addEventListener('mousemove', this.handleMouseMove.bind(this));
    
    // Lyt til click på hele body
    document.body.addEventListener('click', this.handleClick.bind(this));
    
    // Lyt til mouse down og up
    document.body.addEventListener('mousedown', this.handleMouseDown.bind(this));
    document.body.addEventListener('mouseup', this.handleMouseUp.bind(this));
    
    // Listen for header mouseover events
    eventBus.on('header:mouseover', (event) => {
      const { dayHeader, headerRenderer } = (event as CustomEvent).detail;
      if (this.isMouseDown && this.draggedClone) {
        console.log('Dragging clone over header - calling addToAllDay');
        headerRenderer.addToAllDay(dayHeader);
      }
    });
  }


  private handleMouseMove(event: MouseEvent): void {
    // Hvis musen er holdt nede, tjek for snap interval vertikal bevægelse
    if (this.isMouseDown) {
      const deltaY = Math.abs(event.clientY - this.lastLoggedPosition.y);
      
      if (deltaY >= this.snapDistancePx) {
        console.log(`Mouse dragged ${this.snapIntervalMinutes} minutes (${this.snapDistancePx}px) vertically:`, {
          from: this.lastLoggedPosition,
          to: { x: event.clientX, y: event.clientY },
          verticalDistance: Math.round(deltaY),
          snapInterval: `${this.snapIntervalMinutes} minutes`
        });
        this.lastLoggedPosition = { x: event.clientX, y: event.clientY };
        
        // Opdater klonens Y-position ved snap interval (relativt til kolonne)
        if (this.draggedClone && this.draggedClone.parentElement) {
          const columnRect = this.draggedClone.parentElement.getBoundingClientRect();
          const relativeY = event.clientY - columnRect.top - this.mouseOffset.y;
          this.draggedClone.style.top = relativeY + 'px';
        }
      }
    }

    // Find hvilket element musen er over (altid)
    {
      const elementUnder = document.elementFromPoint(event.clientX, event.clientY);
      if (!elementUnder) {
        // Ingen element under musen
        if (this.currentColumn !== null) {
          console.log('Left all columns');
          this.currentColumn = null;
        }
        return;
      }

      // Gå op gennem DOM træet for at finde swp-day-column
      let element = elementUnder as HTMLElement;
      while (element && element.tagName !== 'SWP-DAY-COLUMN') {
        element = element.parentElement as HTMLElement;
        if (!element) {
          // Ikke i en kolonne
          if (this.currentColumn !== null) {
            console.log('Left all columns');
            this.currentColumn = null;
          }
          return;
        }
      }

      // Vi fandt en kolonne
      const date = element.dataset.date;
      if (date && date !== this.currentColumn) {
        console.log('Entered column:', date);
        this.currentColumn = date;
        
        // Flyt klonen til ny kolonne ved kolonneskift
        if (this.draggedClone && this.isMouseDown) {
          // Flyt klonen til den nye kolonne
          const newColumnElement = document.querySelector(`swp-day-column[data-date="${date}"]`);
          if (newColumnElement) {
            newColumnElement.appendChild(this.draggedClone);
            // Opdater Y-position relativt til den nye kolonne
            const columnRect = newColumnElement.getBoundingClientRect();
            const relativeY = event.clientY - columnRect.top - this.mouseOffset.y;
            this.draggedClone.style.top = relativeY + 'px';
          }
        }
      }
    }
  }

  private handleClick(event: MouseEvent): void {
    const target = event.target as HTMLElement;
    
    // Find event element
    let eventElement = target;
    while (eventElement && eventElement.tagName !== 'SWP-EVENTS-LAYER') {
      if (eventElement.tagName === 'SWP-EVENT' || eventElement.tagName === 'SWP-ALLDAY-EVENT') {
        break;
      }
      eventElement = eventElement.parentElement as HTMLElement;
      if (!eventElement) return;
    }
    
    // Hvis vi nåede til SWP-EVENTS-LAYER uden at finde et event, så return
    if (!eventElement || eventElement.tagName === 'SWP-EVENTS-LAYER') {
      return;
    }

    // Log event info
    const eventId = eventElement.dataset.eventId;
    const eventType = eventElement.dataset.type;
    console.log('Clicked event:', {
      id: eventId,
      type: eventType,
      element: eventElement,
      title: eventElement.textContent
    });
  }

  private handleMouseDown(event: MouseEvent): void {
    this.isMouseDown = true;
    this.lastMousePosition = { x: event.clientX, y: event.clientY };
    this.lastLoggedPosition = { x: event.clientX, y: event.clientY };
    console.log('Mouse down at:', this.lastMousePosition);

    // Tjek om mousedown er på et event
    const target = event.target as HTMLElement;
    let eventElement = target;
    while (eventElement && eventElement.tagName !== 'SWP-EVENTS-LAYER') {
      if (eventElement.tagName === 'SWP-EVENT' || eventElement.tagName === 'SWP-ALLDAY-EVENT') {
        break;
      }
      eventElement = eventElement.parentElement as HTMLElement;
      if (!eventElement) return;
    }
    
    // Hvis vi nåede til SWP-EVENTS-LAYER uden at finde et event, så return
    if (!eventElement || eventElement.tagName === 'SWP-EVENTS-LAYER') {
      return;
    }

    // Hvis vi fandt et event, lav en clone
    if (eventElement) {
      // Gem reference til original event
      this.originalEvent = eventElement;
      this.cloneEvent(eventElement, event);
      // Sæt originalen til gennemsigtig og forhindre text selection mens der trækkes
      eventElement.style.opacity = '0.6';
      eventElement.style.userSelect = 'none';
    }
  }

  private cloneEvent(originalEvent: HTMLElement, mouseEvent: MouseEvent): void {
    // Lav en clone
    const clone = originalEvent.cloneNode(true) as HTMLElement;
    
    // Præfiks ID med "clone-"
    const originalId = originalEvent.dataset.eventId;
    if (originalId) {
      clone.dataset.eventId = `clone-${originalId}`;
    }
    
    // Beregn hvor på event'et musen klikkede
    const eventRect = originalEvent.getBoundingClientRect();
    this.mouseOffset = {
      x: mouseEvent.clientX - eventRect.left, // Stadig nødvendig for cursor placering
      y: mouseEvent.clientY - eventRect.top
    };
    
    // Gør klonen ready til at blive trukket
    clone.style.position = 'absolute';
    clone.style.zIndex = '999999';
    clone.style.pointerEvents = 'none';
    
    // Sæt størrelse fra det originale event
    clone.style.width = eventRect.width + 'px';
    clone.style.height = eventRect.height + 'px';
    
    // Find den aktuelle kolonne og placer klonen der
    const currentColumnElement = document.querySelector(`swp-day-column[data-date="${this.currentColumn}"]`);
    if (currentColumnElement) {
      // Sæt initial position relativt til kolonnen
      const columnRect = currentColumnElement.getBoundingClientRect();
      const relativeY = mouseEvent.clientY - columnRect.top - this.mouseOffset.y;
      clone.style.top = relativeY + 'px';
      
      currentColumnElement.appendChild(clone);
    } else {
      console.error('Could not find current column element:', this.currentColumn);
      // Fallback til original placering
      originalEvent.parentNode?.insertBefore(clone, originalEvent.nextSibling);
    }
    
    // Gem reference til klonen
    this.draggedClone = clone;
    
    console.log('Cloned event:', {
      original: originalId,
      clone: clone.dataset.eventId,
      offset: this.mouseOffset
    });
  }

  private handleMouseUp(event: MouseEvent): void {
    this.isMouseDown = false;
    console.log('Mouse up at:', { x: event.clientX, y: event.clientY });

    // Drop operationen: fade out original og remove clone suffix
    if (this.originalEvent && this.draggedClone) {
      // Fade out og fjern originalen
      this.fadeOutAndRemove(this.originalEvent);
      
      // Fjern clone suffix fra klonen
      this.removeClonePrefix(this.draggedClone);
      
      // Ryd op
      this.originalEvent = null;
      this.draggedClone = null;
      
      console.log('Drop completed: original faded out and removed, clone became permanent');
    }

    // Cleanup hvis ingen drop (ingen clone var aktiv)
    if (this.originalEvent && !this.draggedClone) {
      this.originalEvent.style.opacity = '';
      this.originalEvent.style.userSelect = '';
      this.originalEvent = null;
    }
  }

  /**
   * Expand header to show all-day row when clone is dragged into header
   */
  private expandHeaderForAllDay(): void {
    const root = document.documentElement;
    const currentHeight = parseInt(getComputedStyle(root).getPropertyValue('--all-day-row-height') || '0');
    
    if (currentHeight === 0) {
      root.style.setProperty('--all-day-row-height', `${ALL_DAY_CONSTANTS.SINGLE_ROW_HEIGHT}px`);
      console.log('Header expanded for all-day row');
    }
  }

  public destroy(): void {
    document.body.removeEventListener('mousemove', this.handleMouseMove.bind(this));
    document.body.removeEventListener('click', this.handleClick.bind(this));
    document.body.removeEventListener('mousedown', this.handleMouseDown.bind(this));
    document.body.removeEventListener('mouseup', this.handleMouseUp.bind(this));
  }
}