Calendar/src/managers/AllDayManager.ts

// All-day row height management and animations

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

/**
 * AllDayManager - Handles all-day row height animations and management
 * Separated from HeaderManager for clean responsibility separation
 */
export class AllDayManager {
  private cachedAllDayContainer: HTMLElement | null = null;
  private cachedCalendarHeader: HTMLElement | null = null;
  private cachedHeaderSpacer: HTMLElement | null = null;

  constructor() {
    // Bind methods for event listeners
    this.checkAndAnimateAllDayHeight = this.checkAndAnimateAllDayHeight.bind(this);
  }

  /**
   * Get cached all-day container element
   */
  private getAllDayContainer(): HTMLElement | null {
    if (!this.cachedAllDayContainer) {
      const calendarHeader = this.getCalendarHeader();
      if (calendarHeader) {
        this.cachedAllDayContainer = calendarHeader.querySelector('swp-allday-container');
      }
    }
    return this.cachedAllDayContainer;
  }

  /**
   * Get cached calendar header element
   */
  private getCalendarHeader(): HTMLElement | null {
    if (!this.cachedCalendarHeader) {
      this.cachedCalendarHeader = document.querySelector('swp-calendar-header');
    }
    return this.cachedCalendarHeader;
  }

  /**
   * Get cached header spacer element
   */
  private getHeaderSpacer(): HTMLElement | null {
    if (!this.cachedHeaderSpacer) {
      this.cachedHeaderSpacer = document.querySelector('swp-header-spacer');
    }
    return this.cachedHeaderSpacer;
  }

  /**
   * Calculate all-day height based on number of rows
   */
  private calculateAllDayHeight(targetRows: number): {
    targetHeight: number;
    currentHeight: number;
    heightDifference: number;
  } {
    const root = document.documentElement;
    const targetHeight = targetRows * ALL_DAY_CONSTANTS.SINGLE_ROW_HEIGHT;
    const currentHeight = parseInt(getComputedStyle(root).getPropertyValue('--all-day-row-height') || '0');
    const heightDifference = targetHeight - currentHeight;
    
    return { targetHeight, currentHeight, heightDifference };
  }

  /**
   * Clear cached DOM elements (call when DOM structure changes)
   */
  private clearCache(): void {
    this.cachedCalendarHeader = null;
    this.cachedAllDayContainer = null;
    this.cachedHeaderSpacer = null;
  }

  /**
   * Expand all-day row to show events
   */
  public expandAllDayRow(): void {
    const { currentHeight } = this.calculateAllDayHeight(0);
    
    if (currentHeight === 0) {
      this.checkAndAnimateAllDayHeight();
    }
  }

  /**
   * Collapse all-day row when no events
   */
  public collapseAllDayRow(): void {
    this.animateToRows(0);
  }

  /**
   * Check current all-day events and animate to correct height
   */
  public checkAndAnimateAllDayHeight(): void {
    const container = this.getAllDayContainer();
    if (!container) return;
    
    const allDayEvents = container.querySelectorAll('swp-allday-event');
    
    // Calculate required rows - 0 if no events (will collapse)
    let maxRows = 0;
    
    if (allDayEvents.length > 0) {
      // Expand events to all dates they span and group by date
      const expandedEventsByDate: Record<string, string[]> = {};
      
      (Array.from(allDayEvents) as HTMLElement[]).forEach((event: HTMLElement) => {
        const startISO = event.dataset.start || '';
        const endISO = event.dataset.end || startISO;
        const eventId = event.dataset.eventId || '';
        
        // Extract dates from ISO strings
        const startDate = startISO.split('T')[0]; // YYYY-MM-DD
        const endDate = endISO.split('T')[0]; // YYYY-MM-DD
        
        // Loop through all dates from start to end
        let current = new Date(startDate);
        const end = new Date(endDate);
        
        while (current <= end) {
          const dateStr = current.toISOString().split('T')[0]; // YYYY-MM-DD format
          
          if (!expandedEventsByDate[dateStr]) {
            expandedEventsByDate[dateStr] = [];
          }
          expandedEventsByDate[dateStr].push(eventId);
          
          // Move to next day
          current.setDate(current.getDate() + 1);
        }
      });
      
      // Find max rows needed
      maxRows = Math.max(
        ...Object.values(expandedEventsByDate).map(ids => ids?.length || 0),
        0
      );
    }
    
    // Animate to required rows (0 = collapse, >0 = expand)
    this.animateToRows(maxRows);
  }

  /**
   * Animate all-day container to specific number of rows
   */
  public animateToRows(targetRows: number): void {
    const { targetHeight, currentHeight, heightDifference } = this.calculateAllDayHeight(targetRows);
    
    if (targetHeight === currentHeight) return; // No animation needed
    
    console.log(`🎬 All-day height animation: ${currentHeight}px → ${targetHeight}px (${Math.ceil(currentHeight / ALL_DAY_CONSTANTS.SINGLE_ROW_HEIGHT)} → ${targetRows} rows)`);
    
    // Get cached elements
    const calendarHeader = this.getCalendarHeader();
    const headerSpacer = this.getHeaderSpacer();
    const allDayContainer = this.getAllDayContainer();
    
    if (!calendarHeader || !allDayContainer) return;
    
    // Get current parent height for animation
    const currentParentHeight = parseFloat(getComputedStyle(calendarHeader).height);
    const targetParentHeight = currentParentHeight + heightDifference;
    
    const animations = [
      calendarHeader.animate([
        { height: `${currentParentHeight}px` },
        { height: `${targetParentHeight}px` }
      ], {
        duration: 300,
        easing: 'ease-out',
        fill: 'forwards'
      })
    ];
    
    // Add spacer animation if spacer exists
    if (headerSpacer) {
      const root = document.documentElement;
      const currentSpacerHeight = parseInt(getComputedStyle(root).getPropertyValue('--header-height')) + currentHeight;
      const targetSpacerHeight = parseInt(getComputedStyle(root).getPropertyValue('--header-height')) + targetHeight;
      
      animations.push(
        headerSpacer.animate([
          { height: `${currentSpacerHeight}px` },
          { height: `${targetSpacerHeight}px` }
        ], {
          duration: 300,
          easing: 'ease-out',
          fill: 'forwards'
        })
      );
    }
    
    // Update CSS variable after animation
    Promise.all(animations.map(anim => anim.finished)).then(() => {
      const root = document.documentElement;
      root.style.setProperty('--all-day-row-height', `${targetHeight}px`);
      eventBus.emit('header:height-changed');
    });
  }

  /**
   * Update row height when all-day events change
   */
  public updateRowHeight(): void {
    this.checkAndAnimateAllDayHeight();
  }

  /**
   * Clean up cached elements and resources
   */
  public destroy(): void {
    this.clearCache();
  }
}