import { EventBus } from '../core/EventBus.js';
import { EventTypes } from '../constants/EventTypes.js';
import { CalendarConfig } from '../core/CalendarConfig.js';
import { CalendarEvent, CalendarView, IEventBus } from '../types/CalendarTypes.js';
import { CalendarStateManager } from './CalendarStateManager.js';
import { StateEvents } from '../types/CalendarState.js';

/**
 * CalendarManager - Main coordinator for all calendar managers
 * Now delegates initialization to CalendarStateManager for better coordination
 */
export class CalendarManager {
    private eventBus: IEventBus;
    private config: CalendarConfig;
    private stateManager: CalendarStateManager;
    private currentView: CalendarView = 'week';
    private currentDate: Date = new Date();
    private isInitialized: boolean = false;

    constructor(eventBus: IEventBus, config: CalendarConfig) {
        this.eventBus = eventBus;
        this.config = config;
        this.stateManager = new CalendarStateManager();
        this.setupEventListeners();
        console.log('📋 CalendarManager: Created with state management');
    }

    /**
     * Initialize calendar system using state-driven approach
     */
    public async initialize(): Promise<void> {
        if (this.isInitialized) {
            console.warn('CalendarManager is already initialized');
            return;
        }

        console.log('🚀 CalendarManager: Starting state-driven initialization');
        
        try {
            // Delegate to StateManager for coordinated initialization
            await this.stateManager.initialize();
            
            // Set initial view and date after successful initialization
            this.setView(this.currentView);
            this.setCurrentDate(this.currentDate);
            
            this.isInitialized = true;
            console.log('✅ CalendarManager: Initialization complete');
            
        } catch (error) {
            console.error('❌ CalendarManager initialization failed:', error);
            throw error; // Let the caller handle the error
        }
    }

    /**
     * Skift calendar view (dag/uge/måned)
     */
    public setView(view: CalendarView): void {
        if (this.currentView === view) {
            return;
        }

        const previousView = this.currentView;
        this.currentView = view;

        console.log(`Changing view from ${previousView} to ${view}`);

        // Emit view change event
        this.eventBus.emit(EventTypes.VIEW_CHANGED, {
            previousView,
            currentView: view,
            date: this.currentDate
        });
    }

    /**
     * Sæt aktuel dato
     */
    public setCurrentDate(date: Date): void {
        const previousDate = this.currentDate;
        this.currentDate = new Date(date);

        console.log(`Changing date from ${previousDate.toISOString()} to ${date.toISOString()}`);

        // Emit date change event
        this.eventBus.emit(EventTypes.DATE_CHANGED, {
            previousDate,
            currentDate: this.currentDate,
            view: this.currentView
        });
    }

    /**
     * Naviger til i dag
     */
    public goToToday(): void {
        this.setCurrentDate(new Date());
    }

    /**
     * Naviger til næste periode (dag/uge/måned afhængig af view)
     */
    public goToNext(): void {
        const nextDate = this.calculateNextDate();
        this.setCurrentDate(nextDate);
    }

    /**
     * Naviger til forrige periode (dag/uge/måned afhængig af view)
     */
    public goToPrevious(): void {
        const previousDate = this.calculatePreviousDate();
        this.setCurrentDate(previousDate);
    }

    /**
     * Hent aktuel view
     */
    public getCurrentView(): CalendarView {
        return this.currentView;
    }

    /**
     * Hent aktuel dato
     */
    public getCurrentDate(): Date {
        return new Date(this.currentDate);
    }

    /**
     * Hent calendar konfiguration
     */
    public getConfig(): CalendarConfig {
        return this.config;
    }

    /**
     * Check om calendar er initialiseret
     */
    public isCalendarInitialized(): boolean {
        return this.isInitialized && this.stateManager.isReady();
    }

    /**
     * Get current calendar state
     */
    public getCurrentState(): string {
        return this.stateManager.getCurrentState();
    }

    /**
     * Get state manager for advanced operations
     */
    public getStateManager(): CalendarStateManager {
        return this.stateManager;
    }

    /**
     * Get initialization report for debugging
     */
    public getInitializationReport(): any {
        return this.stateManager.getInitializationReport();
    }

    /**
     * Genindlæs calendar data
     */
    public refresh(): void {
        console.log('Refreshing calendar...');
        
        this.eventBus.emit(EventTypes.CALENDAR_REFRESH_REQUESTED, {
            view: this.currentView,
            date: this.currentDate
        });
    }

    /**
     * Ryd calendar og nulstil til standard tilstand
     */
    public reset(): void {
        console.log('Resetting calendar...');
        
        this.currentView = 'week';
        this.currentDate = new Date();
        
        this.eventBus.emit(EventTypes.CALENDAR_RESET, {
            view: this.currentView,
            date: this.currentDate
        });
    }

    /**
     * Setup event listeners for at håndtere events fra andre managers
     */
    private setupEventListeners(): void {
        // Lyt efter navigation events
        this.eventBus.on(EventTypes.NAVIGATE_TO_DATE, (event) => {
            const customEvent = event as CustomEvent;
            const { date } = customEvent.detail;
            this.setCurrentDate(new Date(date));
        });

        // Lyt efter view change requests
        this.eventBus.on(EventTypes.VIEW_CHANGE_REQUESTED, (event) => {
            const customEvent = event as CustomEvent;
            const { view } = customEvent.detail;
            this.setView(view);
        });

        // Lyt efter today navigation
        this.eventBus.on(EventTypes.NAVIGATE_TO_TODAY, () => {
            this.goToToday();
        });

        // Lyt efter next/previous navigation
        this.eventBus.on(EventTypes.NAVIGATE_NEXT, () => {
            this.goToNext();
        });

        this.eventBus.on(EventTypes.NAVIGATE_PREVIOUS, () => {
            this.goToPrevious();
        });

        // Lyt efter refresh requests
        this.eventBus.on(EventTypes.REFRESH_REQUESTED, () => {
            this.refresh();
        });

        // Lyt efter reset requests
        this.eventBus.on(EventTypes.RESET_REQUESTED, () => {
            this.reset();
        });
    }

    /**
     * Beregn næste dato baseret på aktuel view
     */
    private calculateNextDate(): Date {
        const nextDate = new Date(this.currentDate);
        
        switch (this.currentView) {
            case 'day':
                nextDate.setDate(nextDate.getDate() + 1);
                break;
            case 'week':
                nextDate.setDate(nextDate.getDate() + 7);
                break;
            case 'month':
                nextDate.setMonth(nextDate.getMonth() + 1);
                break;
        }
        
        return nextDate;
    }

    /**
     * Beregn forrige dato baseret på aktuel view
     */
    private calculatePreviousDate(): Date {
        const previousDate = new Date(this.currentDate);
        
        switch (this.currentView) {
            case 'day':
                previousDate.setDate(previousDate.getDate() - 1);
                break;
            case 'week':
                previousDate.setDate(previousDate.getDate() - 7);
                break;
            case 'month':
                previousDate.setMonth(previousDate.getMonth() - 1);
                break;
        }
        
        return previousDate;
    }
}