import { EventBus } from '../core/EventBus';
import { IEventBus, CalendarEvent, ResourceCalendarData } from '../types/CalendarTypes';
import { CoreEvents } from '../constants/CoreEvents';
import { calendarConfig } from '../core/CalendarConfig';

/**
 * EventManager - Administrerer event lifecycle og CRUD operationer
 * Håndterer mock data og event synchronization
 */
export class EventManager {
    private eventBus: IEventBus;
    private events: CalendarEvent[] = [];

    constructor(eventBus: IEventBus) {
        console.log('EventManager: Constructor called');
        this.eventBus = eventBus;
        this.setupEventListeners();
        console.log('EventManager: Waiting for CALENDAR_INITIALIZED before loading data');
    }

    private setupEventListeners(): void {
        // NOTE: Removed POC event listener to prevent interference with production code
        // POC sliding animation should not trigger separate event rendering
        // this.eventBus.on(CoreEvents.WEEK_CONTENT_RENDERED, ...);
    }

    /**
     * Public method to load data - called directly by CalendarManager
     */
    public async loadData(): Promise<void> {
        console.log('EventManager: Loading data via direct call');
        await this.loadMockData();
        console.log(`EventManager: Data loaded successfully - ${this.events.length} events`);
        
        // Debug: Log first few events
        if (this.events.length > 0) {
            console.log('EventManager: First event:', {
                title: this.events[0].title,
                start: this.events[0].start,
                end: this.events[0].end
            });
        }
    }

    private async loadMockData(): Promise<void> {
        try {
            const calendarType = calendarConfig.getCalendarMode();
            let jsonFile: string;
            
            console.log(`EventManager: Calendar type detected: '${calendarType}'`);
            
            if (calendarType === 'resource') {
                jsonFile = '/src/data/mock-resource-events.json';
            } else {
                jsonFile = '/src/data/mock-events.json';
            }
            
            console.log(`EventManager: Loading ${calendarType} calendar data from ${jsonFile}`);
            
            const response = await fetch(jsonFile);
            if (!response.ok) {
                throw new Error(`Failed to load mock events: ${response.status}`);
            }
            
            const data = await response.json();
            console.log(`EventManager: Loaded data for ${calendarType} calendar`);
            
            // Store raw data for GridManager
            this.rawData = data;
            
            // Process data for internal use
            this.processCalendarData(calendarType, data);
        } catch (error) {
            console.error('EventManager: Failed to load mock events:', error);
            this.events = []; // Fallback to empty array
        }
    }

    private processCalendarData(calendarType: string, data: any): void {
        if (calendarType === 'resource') {
            const resourceData = data as ResourceCalendarData;
            this.events = resourceData.resources.flatMap(resource => 
                resource.events.map(event => ({
                    ...event,
                    resourceName: resource.name,
                    resourceDisplayName: resource.displayName,
                    resourceEmployeeId: resource.employeeId
                }))
            );
            console.log(`EventManager: Processed ${this.events.length} events from ${resourceData.resources.length} resources`);
        } else {
            this.events = data as CalendarEvent[];
            console.log(`EventManager: Processed ${this.events.length} date events`);
        }
    }

    private syncEvents(): void {
        // Events are synced during initialization
        // This method maintained for internal state management only
        console.log(`EventManager: Internal sync - ${this.events.length} events in memory`);
    }

    public getEvents(): CalendarEvent[] {
        return [...this.events];
    }

    /**
     * Get raw resource data for resource calendar mode
     */
    public getResourceData(): any {
        return this.rawData;
    }

    private rawData: any = null;


    public getEventById(id: string): CalendarEvent | undefined {
        return this.events.find(event => event.id === id);
    }

    /**
     * Get events for a specific time period
     */
    public getEventsForPeriod(startDate: Date, endDate: Date): CalendarEvent[] {
        console.log(`EventManager.getEventsForPeriod: Checking ${this.events.length} events for period ${startDate.toDateString()} - ${endDate.toDateString()}`);
        return this.events.filter(event => {
            const eventStart = new Date(event.start);
            const eventEnd = new Date(event.end);
            
            // Event overlaps period if it starts before period ends AND ends after period starts
            return eventStart <= endDate && eventEnd >= startDate;
        });
    }

    public addEvent(event: Omit<CalendarEvent, 'id'>): CalendarEvent {
        const newEvent: CalendarEvent = {
            ...event,
            id: Date.now().toString()
        };
        
        this.events.push(newEvent);
        this.syncEvents();
        
        this.eventBus.emit(CoreEvents.EVENT_CREATED, {
            event: newEvent
        });

        return newEvent;
    }

    public updateEvent(id: string, updates: Partial<CalendarEvent>): CalendarEvent | null {
        const eventIndex = this.events.findIndex(event => event.id === id);
        if (eventIndex === -1) return null;

        const updatedEvent = { ...this.events[eventIndex], ...updates };
        this.events[eventIndex] = updatedEvent;
        
        this.syncEvents();
        
        this.eventBus.emit(CoreEvents.EVENT_UPDATED, {
            event: updatedEvent
        });

        return updatedEvent;
    }

    public deleteEvent(id: string): boolean {
        const eventIndex = this.events.findIndex(event => event.id === id);
        if (eventIndex === -1) return false;

        const deletedEvent = this.events[eventIndex];
        this.events.splice(eventIndex, 1);
        
        this.syncEvents();
        
        this.eventBus.emit(CoreEvents.EVENT_DELETED, {
            event: deletedEvent
        });

        return true;
    }

    public refresh(): void {
        this.syncEvents();
    }


    public destroy(): void {
        this.events = [];
    }
}