/**
 * DragDropManager - Advanced drag-and-drop system with smooth animations and event type conversion
 *
 * ARCHITECTURE OVERVIEW:
 * =====================
 * DragDropManager provides a sophisticated drag-and-drop system for calendar events that supports:
 * - Smooth animated dragging with requestAnimationFrame
 * - Automatic event type conversion (timed events ↔ all-day events)
 * - Scroll compensation during edge scrolling
 * - Grid snapping for precise event placement
 * - Column detection and change tracking
 *
 * KEY FEATURES:
 * =============
 * 1. DRAG DETECTION
 *    - Movement threshold (5px) to distinguish clicks from drags
 *    - Immediate visual feedback with cloned element
 *    - Mouse offset tracking for natural drag feel
 *
 * 2. SMOOTH ANIMATION
 *    - Uses requestAnimationFrame for 60fps animations
 *    - Interpolated movement (30% per frame) for smooth transitions
 *    - Continuous drag:move events for real-time updates
 *
 * 3. EVENT TYPE CONVERSION
 *    - Timed → All-day: When dragging into calendar header
 *    - All-day → Timed: When dragging into day columns
 *    - Automatic clone replacement with appropriate element type
 *
 * 4. SCROLL COMPENSATION
 *    - Tracks scroll delta during edge-scrolling
 *    - Compensates dragged element position during scroll
 *    - Prevents visual "jumping" when scrolling while dragging
 *
 * 5. GRID SNAPPING
 *    - Snaps to time grid on mouse up
 *    - Uses PositionUtils for consistent positioning
 *    - Accounts for mouse offset within event
 *
 * STATE MANAGEMENT:
 * =================
 * Mouse Tracking:
 *   - mouseDownPosition: Initial click position
 *   - currentMousePosition: Latest mouse position
 *   - mouseOffset: Click offset within event (for natural dragging)
 *
 * Drag State:
 *   - originalElement: Source event being dragged
 *   - draggedClone: Animated clone following mouse
 *   - currentColumn: Column mouse is currently over
 *   - previousColumn: Last column (for detecting changes)
 *   - isDragStarted: Whether drag threshold exceeded
 *
 * Scroll State:
 *   - scrollDeltaY: Accumulated scroll offset during drag
 *   - lastScrollTop: Previous scroll position
 *   - isScrollCompensating: Whether edge-scroll is active
 *
 * Animation State:
 *   - dragAnimationId: requestAnimationFrame ID
 *   - targetY: Desired position for smooth interpolation
 *   - currentY: Current interpolated position
 *
 * EVENT FLOW:
 * ===========
 * 1. Mouse Down (handleMouseDown)
 *    ├─ Store originalElement and mouse offset
 *    └─ Wait for movement
 *
 * 2. Mouse Move (handleMouseMove)
 *    ├─ Check movement threshold
 *    ├─ Initialize drag if threshold exceeded (initializeDrag)
 *    │  ├─ Create clone
 *    │  ├─ Emit drag:start
 *    │  └─ Start animation loop
 *    ├─ Continue drag (continueDrag)
 *    │  ├─ Calculate target position with scroll compensation
 *    │  └─ Update animation target
 *    └─ Detect column changes (detectColumnChange)
 *       └─ Emit drag:column-change
 *
 * 3. Animation Loop (animateDrag)
 *    ├─ Interpolate currentY toward targetY
 *    ├─ Emit drag:move on each frame
 *    └─ Schedule next frame until target reached
 *
 * 4. Event Type Conversion
 *    ├─ Entering header (handleHeaderMouseEnter)
 *    │  ├─ Emit drag:mouseenter-header
 *    │  └─ AllDayManager creates all-day clone
 *    └─ Entering column (handleColumnMouseEnter)
 *       ├─ Emit drag:mouseenter-column
 *       └─ EventRenderingService creates timed clone
 *
 * 5. Mouse Up (handleMouseUp)
 *    ├─ Stop animation
 *    ├─ Snap to grid
 *    ├─ Detect drop target (header or column)
 *    ├─ Emit drag:end with final position
 *    └─ Cleanup drag state
 *
 * SCROLL COMPENSATION SYSTEM:
 * ===========================
 * Problem: When EdgeScrollManager scrolls the grid during drag, the dragged element
 *          can appear to "jump" because the mouse position stays the same but the
 *          coordinate system (scrollable content) has moved.
 *
 * Solution: Track cumulative scroll delta and add it to mouse position calculations
 *
 * Flow:
 * 1. EdgeScrollManager starts scrolling → emit edgescroll:started
 * 2. DragDropManager sets isScrollCompensating = true
 * 3. On each scroll event:
 *    ├─ Calculate scrollDelta = currentScrollTop - lastScrollTop
 *    ├─ Accumulate into scrollDeltaY
 *    └─ Call continueDrag with adjusted position
 * 4. continueDrag adds scrollDeltaY to mouse Y coordinate
 * 5. On event conversion, reset scrollDeltaY (new clone, new coordinate system)
 *
 * PERFORMANCE OPTIMIZATIONS:
 * ==========================
 * - Uses ColumnDetectionUtils cache for fast column lookups
 * - Single requestAnimationFrame loop (not per-mousemove)
 * - Interpolated animation reduces update frequency
 * - Passive scroll listeners
 * - Event delegation for header/column detection
 *
 * USAGE:
 * ======
 * const dragDropManager = new DragDropManager(eventBus, positionUtils);
 * // Automatically attaches event listeners and manages drag lifecycle
 * // Other managers listen to drag:start, drag:move, drag:end, etc.
 */
import { IEventBus } from '../types/CalendarTypes';
import { PositionUtils } from '../utils/PositionUtils';
export declare class DragDropManager {
    private eventBus;
    private mouseDownPosition;
    private currentMousePosition;
    private mouseOffset;
    private originalElement;
    private draggedClone;
    private currentColumn;
    private previousColumn;
    private originalSourceColumn;
    private isDragStarted;
    private readonly dragThreshold;
    private scrollableContent;
    private scrollDeltaY;
    private lastScrollTop;
    private isScrollCompensating;
    private dragAnimationId;
    private targetY;
    private currentY;
    private targetColumn;
    private positionUtils;
    constructor(eventBus: IEventBus, positionUtils: PositionUtils);
    /**
     * Initialize with optimized event listener setup
     */
    private init;
    private handleGridRendered;
    private handleMouseDown;
    private handleMouseMove;
    /**
     * Try to initialize drag based on movement threshold
     * Returns true if drag was initialized, false if not enough movement
     */
    private initializeDrag;
    private continueDrag;
    /**
     * Detect column change and emit event
     */
    private detectColumnChange;
    /**
     * Optimized mouse up handler with consolidated cleanup
     */
    private handleMouseUp;
    private cleanupAllClones;
    /**
     * Cancel drag operation when mouse leaves grid container
     * Animates clone back to original position before cleanup
     */
    private cancelDrag;
    /**
     * Optimized snap position calculation using PositionUtils
     */
    private calculateSnapPosition;
    /**
     * Smooth drag animation using requestAnimationFrame
     * Emits drag:move events with current draggedClone reference on each frame
     */
    private animateDrag;
    /**
     * Handle scroll during drag - update scrollDeltaY and call continueDrag
     */
    private handleScroll;
    /**
     * Stop drag animation
     */
    private stopDragAnimation;
    /**
     * Clean up drag state
     */
    private cleanupDragState;
    /**
     * Detect drop target - whether dropped in swp-day-column or swp-day-header
     */
    private detectDropTarget;
    /**
     * Handle mouse enter on calendar header - simplified using native events
     */
    private handleHeaderMouseEnter;
    /**
     * Handle mouse enter on day column - for converting all-day to timed events
     */
    private handleColumnMouseEnter;
    /**
     * Handle mouse leave from calendar header - simplified using native events
     */
    private handleHeaderMouseLeave;
}