import { EventBus } from '../core/EventBus';
import { IEventBus, CalendarEvent, RenderContext } from '../types/CalendarTypes';
import { CoreEvents } from '../constants/CoreEvents';
import { calendarConfig } from '../core/CalendarConfig';
import { CalendarTypeFactory } from '../factories/CalendarTypeFactory';
import { EventManager } from '../managers/EventManager';
import { EventRendererStrategy } from './EventRenderer';
import { SwpEventElement } from '../elements/SwpEventElement';
import { AllDayEventRenderer } from './AllDayEventRenderer';
import { DragStartEventPayload, DragMoveEventPayload, DragEndEventPayload, DragMouseEnterHeaderEventPayload, DragMouseLeaveHeaderEventPayload, HeaderReadyEventPayload } from '../types/EventTypes';
/**
 * EventRenderingService - Render events i DOM med positionering using Strategy Pattern
 * Håndterer event positioning og overlap detection
 */
export class EventRenderingService {
    private eventBus: IEventBus;
    private eventManager: EventManager;
    private strategy: EventRendererStrategy;
    private allDayEventRenderer: AllDayEventRenderer;
    

    private dragMouseLeaveHeaderListener: ((event: Event) => void) | null = null;

    constructor(eventBus: IEventBus, eventManager: EventManager) {
        this.eventBus = eventBus;
        this.eventManager = eventManager;

        // Cache strategy at initialization
        const calendarType = calendarConfig.getCalendarMode();
        this.strategy = CalendarTypeFactory.getEventRenderer(calendarType);
        
        // Initialize all-day event renderer
        this.allDayEventRenderer = new AllDayEventRenderer();

        this.setupEventListeners();
    }

    /**
     * Render events in a specific container for a given period
     */
    public renderEvents(context: RenderContext): void {
        // Clear existing events in the specific container first
        this.strategy.clearEvents(context.container);

        // Get events from EventManager for the period
        const events = this.eventManager.getEventsForPeriod(
            context.startDate,
            context.endDate
        );

        if (events.length === 0) {
            return;
        }

        // Filter events by type - only render timed events here
        const timedEvents = events.filter(event => !event.allDay);

        console.log('🎯 EventRenderingService: Event filtering', {
            totalEvents: events.length,
            timedEvents: timedEvents.length,
            allDayEvents: events.length - timedEvents.length
        });

        // Render timed events using existing strategy
        if (timedEvents.length > 0) {
            this.strategy.renderEvents(timedEvents, context.container);
        }

        // Emit EVENTS_RENDERED event for filtering system
        this.eventBus.emit(CoreEvents.EVENTS_RENDERED, {
            events: events,
            container: context.container
        });
    }

    private setupEventListeners(): void {

        this.eventBus.on(CoreEvents.GRID_RENDERED, (event: Event) => {
            this.handleGridRendered(event as CustomEvent);
        });

        this.eventBus.on(CoreEvents.VIEW_CHANGED, (event: Event) => {
            this.handleViewChanged(event as CustomEvent);
        });

        // Listen for header ready - when dates are populated with period data
        this.eventBus.on('header:ready', (event: Event) => {
            const { startDate, endDate } = (event as CustomEvent<HeaderReadyEventPayload>).detail;
            console.log('🎯 EventRendererManager: Header ready with period data', {
                startDate: startDate.toISOString(),
                endDate: endDate.toISOString()
            });
            
            // Render all-day events using period from header
            this.renderAllDayEventsForPeriod(startDate, endDate);
        });

        // Handle all drag events and delegate to appropriate renderer
        this.setupDragEventListeners();

        // Listen for conversion from all-day event to time event
        this.eventBus.on('drag:convert-to-time_event', (event: Event) => {
            const { draggedElement, mousePosition, column } = (event as CustomEvent).detail;
            console.log('🔄 EventRendererManager: Received drag:convert-to-time_event', {
                draggedElement: draggedElement?.dataset.eventId,
                mousePosition,
                column
            });
            this.handleConvertToTimeEvent(draggedElement, mousePosition, column);
        });

    }


    /**
     * Handle GRID_RENDERED event - render events in the current grid
     */
    private handleGridRendered(event: CustomEvent): void {
        const { container, startDate, endDate, currentDate, isNavigation } = event.detail;

        if (!container) {
            return;
        }


        let periodStart: Date;
        let periodEnd: Date;

        if (startDate && endDate) {
            // Direct date format - use as provided
            periodStart = startDate;
            periodEnd = endDate;
        } else if (currentDate) {
            return;
        } else {
            return;
        }

        this.renderEvents({
            container: container,
            startDate: periodStart,
            endDate: periodEnd
        });
    }

    /**
     * Handle CONTAINER_READY_FOR_EVENTS event - render events in pre-rendered container
     */
    private handleContainerReady(event: CustomEvent): void {
        const { container, startDate, endDate } = event.detail;

        if (!container || !startDate || !endDate) {
            return;
        }

        this.renderEvents({
            container: container,
            startDate: new Date(startDate),
            endDate: new Date(endDate)
        });
    }

    /**
     * Handle VIEW_CHANGED event - clear and re-render for new view
     */
    private handleViewChanged(event: CustomEvent): void {
        // Clear all existing events since view structure may have changed
        this.clearEvents();

        // New rendering will be triggered by subsequent GRID_RENDERED event
    }


    /**
     * Setup all drag event listeners - moved from EventRenderer for better separation of concerns
     */
    private setupDragEventListeners(): void {
        // Handle drag start
        this.eventBus.on('drag:start', (event: Event) => {
            const { draggedElement, mouseOffset, column } = (event as CustomEvent<DragStartEventPayload>).detail;
            // Use the draggedElement directly - no need for DOM query
            if (draggedElement && this.strategy.handleDragStart && column) {
                const eventId = draggedElement.dataset.eventId || '';
                this.strategy.handleDragStart(draggedElement, eventId, mouseOffset, column);
            }
        });

        // Handle drag move
        this.eventBus.on('drag:move', (event: Event) => {
            const { draggedElement, snappedY, column, mouseOffset } = (event as CustomEvent<DragMoveEventPayload>).detail;
            if (this.strategy.handleDragMove && column) {
                const eventId = draggedElement.dataset.eventId || '';
                this.strategy.handleDragMove(eventId, snappedY, column, mouseOffset);
            }
        });

        // Handle drag auto-scroll
        this.eventBus.on('drag:auto-scroll', (event: Event) => {
            const { draggedElement, snappedY } = (event as CustomEvent).detail;
            if (this.strategy.handleDragAutoScroll) {
                const eventId = draggedElement.dataset.eventId || '';
                this.strategy.handleDragAutoScroll(eventId, snappedY);
            }
        });

        // Handle drag end events and delegate to appropriate renderer
        this.eventBus.on('drag:end', (event: Event) => {
            const { draggedElement, finalPosition, target } = (event as CustomEvent<DragEndEventPayload>).detail;
            const finalColumn = finalPosition.column;
            const finalY = finalPosition.snappedY;
            const eventId = draggedElement.dataset.eventId || '';

            // Only handle day column drops for EventRenderer
            if (target === 'swp-day-column' && finalColumn) {
                // Find dragged clone - use draggedElement as original
                const draggedClone = document.querySelector(`swp-day-column swp-event[data-event-id="clone-${eventId}"]`) as HTMLElement;

                if (draggedElement && draggedClone && this.strategy.handleDragEnd) {
                    this.strategy.handleDragEnd(eventId, draggedElement, draggedClone, finalColumn, finalY);
                }
            }

            // Clean up any remaining day event clones
            const dayEventClone = document.querySelector(`swp-day-column swp-event[data-event-id="clone-${eventId}"]`);
            if (dayEventClone) {
                dayEventClone.remove();
            }
        });

        // Handle click (when drag threshold not reached)
        this.eventBus.on('event:click', (event: Event) => {
            const { draggedElement } = (event as CustomEvent).detail;
            // Use draggedElement directly - no need for DOM query
            if (draggedElement && this.strategy.handleEventClick) {
                const eventId = draggedElement.dataset.eventId || '';
                this.strategy.handleEventClick(eventId, draggedElement);
            }
        });

        // Handle column change
        this.eventBus.on('drag:column-change', (event: Event) => {
            const { draggedElement, newColumn } = (event as CustomEvent).detail;
            if (this.strategy.handleColumnChange) {
                const eventId = draggedElement.dataset.eventId || '';
                this.strategy.handleColumnChange(eventId, newColumn);
            }
        });


        this.dragMouseLeaveHeaderListener = (event: Event) => {
            const { targetDate, mousePosition, originalElement, cloneElement } = (event as CustomEvent<DragMouseLeaveHeaderEventPayload>).detail;

            if (cloneElement)
                cloneElement.style.display = '';

            console.log('🚪 EventRendererManager: Received drag:mouseleave-header', {
                targetDate,
                originalElement: originalElement,
                cloneElement: cloneElement
            });

        };

        this.eventBus.on('drag:mouseleave-header', this.dragMouseLeaveHeaderListener);

        // Handle navigation period change
        this.eventBus.on(CoreEvents.NAVIGATION_COMPLETED, () => {
            // Delegate to strategy if it handles navigation
            if (this.strategy.handleNavigationCompleted) {
                this.strategy.handleNavigationCompleted();
            }
        });
    }

    /**
     * Handle conversion from all-day event to time event
     */
    private handleConvertToTimeEvent(draggedElement: HTMLElement, mousePosition: any, column: string): void {
        // Use the provided draggedElement directly
        const allDayClone = draggedElement;
        const draggedEventId = draggedElement?.dataset.eventId?.replace('clone-', '') || '';


        // Use SwpEventElement factory to create day event from all-day event
        const dayEventElement = SwpEventElement.fromAllDayElement(allDayClone as HTMLElement);
        const dayElement = dayEventElement.getElement();

        // Remove the all-day clone - it's no longer needed since we're converting to day event
        allDayClone.remove();

        // Set clone ID
        dayElement.dataset.eventId = `clone-${draggedEventId}`;

        // Find target column
        const columnElement = document.querySelector(`swp-day-column[data-date="${column}"]`);
        if (!columnElement) {
            console.warn('EventRendererManager: Target column not found', { column });
            return;
        }

        // Find events layer in the column
        const eventsLayer = columnElement.querySelector('swp-events-layer');
        if (!eventsLayer) {
            console.warn('EventRendererManager: Events layer not found in column');
            return;
        }

        // Add to events layer
        eventsLayer.appendChild(dayElement);

        // Position based on mouse Y coordinate
        const columnRect = columnElement.getBoundingClientRect();
        const relativeY = Math.max(0, mousePosition.y - columnRect.top);
        dayElement.style.top = `${relativeY}px`;

        // Set drag styling
        dayElement.style.zIndex = '1000';
        dayElement.style.cursor = 'grabbing';
        dayElement.style.opacity = '';
        dayElement.style.transform = '';

        console.log('✅ EventRendererManager: Converted all-day event to time event', {
            draggedEventId,
            column,
            mousePosition,
            relativeY
        });
    }

    /**
     * Render all-day events for specific period using AllDayEventRenderer
     */
    private renderAllDayEventsForPeriod(startDate: Date, endDate: Date): void {
        // Get events from EventManager for the period
        const events = this.eventManager.getEventsForPeriod(startDate, endDate);

        // Filter for all-day events
        const allDayEvents = events.filter(event => event.allDay);

        console.log('🏗️ EventRenderingService: Rendering all-day events', {
            period: {
                start: startDate.toISOString(),
                end: endDate.toISOString()
            },
            count: allDayEvents.length,
            events: allDayEvents.map(e => ({ id: e.id, title: e.title }))
        });

        // Clear existing all-day events first
        this.clearAllDayEvents();

        // Render each all-day event
        allDayEvents.forEach(event => {
            const renderedElement = this.allDayEventRenderer.renderAllDayEvent(event);
            if (renderedElement) {
                console.log('✅ EventRenderingService: Rendered all-day event', {
                    id: event.id,
                    title: event.title,
                    element: renderedElement.tagName
                });
            } else {
                console.warn('❌ EventRenderingService: Failed to render all-day event', {
                    id: event.id,
                    title: event.title
                });
            }
        });

        // Check and adjust all-day container height after rendering
        this.eventBus.emit('allday:checkHeight');
    }

    /**
     * Clear only all-day events
     */
    private clearAllDayEvents(): void {
        const allDayContainer = document.querySelector('swp-allday-container');
        if (allDayContainer) {
            allDayContainer.querySelectorAll('swp-event').forEach(event => event.remove());
        }
    }

    private clearEvents(container?: HTMLElement): void {
        this.strategy.clearEvents(container);
        
        // Also clear all-day events
        this.clearAllDayEvents();
    }

    public refresh(container?: HTMLElement): void {
        // Clear events in specific container or globally
        this.clearEvents(container);
    }

    public destroy(): void {
        this.clearEvents();
    }
}