// Calendar configuration management

import { eventBus } from './EventBus';
import { EventTypes } from '../constants/EventTypes';
import { CalendarConfig as ICalendarConfig, ViewType, CalendarType } from '../types/CalendarTypes';

/**
 * View-specific settings interface
 */
interface ViewSettings {
  columns: number;
  showAllDay: boolean;
  scrollToHour: number | null;
}

/**
 * Calendar configuration management
 */
export class CalendarConfig {
  private config: ICalendarConfig;
  private calendarType: CalendarType = 'date';
  private selectedDate: Date | null = null;

  constructor() {
    this.config = {
      // View settings
      view: 'week',           // 'day' | 'week' | 'month'
      weekDays: 7,            // 4-7 days for week view
      firstDayOfWeek: 1,      // 0 = Sunday, 1 = Monday
      
      // Time settings
      dayStartHour: 0,        // Calendar starts at midnight (default)
      dayEndHour: 24,         // Calendar ends at midnight (default)
      workStartHour: 8,       // Work hours start
      workEndHour: 17,        // Work hours end
      snapInterval: 15,       // Minutes: 5, 10, 15, 30, 60
      
      // Display settings
      hourHeight: 60,         // Pixels per hour
      showCurrentTime: true,
      showWorkHours: true,
      fitToWidth: false,       // Fit columns to calendar width (no horizontal scroll)
      
      // Scrollbar styling
      scrollbarWidth: 16,     // Width of scrollbar in pixels
      scrollbarColor: '#666', // Scrollbar thumb color
      scrollbarTrackColor: '#f0f0f0', // Scrollbar track color
      scrollbarHoverColor: '#b53f7aff', // Scrollbar thumb hover color
      scrollbarBorderRadius: 6, // Border radius for scrollbar thumb
      
      // Interaction settings
      allowDrag: true,
      allowResize: true,
      allowCreate: true,
      
      // API settings
      apiEndpoint: '/api/events',
      dateFormat: 'YYYY-MM-DD',
      timeFormat: 'HH:mm',
      
      // Feature flags
      enableSearch: true,
      enableTouch: true,
      
      // Event defaults
      defaultEventDuration: 60, // Minutes
      minEventDuration: 15,     // Will be same as snapInterval
      maxEventDuration: 480     // 8 hours
    };

    // Set computed values
    this.config.minEventDuration = this.config.snapInterval;
    
    // Load calendar type from URL parameter
    this.loadCalendarType();
    
    // Load from data attributes
    this.loadFromDOM();
  }

  /**
   * Load calendar type and date from URL parameters
   */
  private loadCalendarType(): void {
    const urlParams = new URLSearchParams(window.location.search);
    const typeParam = urlParams.get('type');
    const dateParam = urlParams.get('date');
    
    // Set calendar type
    if (typeParam === 'resource' || typeParam === 'date') {
      this.calendarType = typeParam;
      console.log(`CalendarConfig: Calendar type set to '${this.calendarType}' from URL parameter`);
    } else {
      this.calendarType = 'date'; // Default
      console.log(`CalendarConfig: Calendar type defaulted to '${this.calendarType}'`);
    }
    
    // Set selected date
    if (dateParam) {
      const parsedDate = new Date(dateParam);
      if (!isNaN(parsedDate.getTime())) {
        this.selectedDate = parsedDate;
        console.log(`CalendarConfig: Selected date set to '${this.selectedDate.toISOString()}' from URL parameter`);
      } else {
        console.warn(`CalendarConfig: Invalid date parameter '${dateParam}', using current date`);
        this.selectedDate = new Date();
      }
    } else {
      this.selectedDate = new Date(); // Default to today
      console.log(`CalendarConfig: Selected date defaulted to today: ${this.selectedDate.toISOString()}`);
    }
  }

  /**
   * Load configuration from DOM data attributes
   */
  private loadFromDOM(): void {
    const calendar = document.querySelector('swp-calendar') as HTMLElement;
    if (!calendar) return;

    // Read data attributes
    const attrs = calendar.dataset;
    
    if (attrs.view) this.config.view = attrs.view as ViewType;
    if (attrs.weekDays) this.config.weekDays = parseInt(attrs.weekDays);
    if (attrs.snapInterval) this.config.snapInterval = parseInt(attrs.snapInterval);
    if (attrs.dayStartHour) this.config.dayStartHour = parseInt(attrs.dayStartHour);
    if (attrs.dayEndHour) this.config.dayEndHour = parseInt(attrs.dayEndHour);
    if (attrs.hourHeight) this.config.hourHeight = parseInt(attrs.hourHeight);
    if (attrs.fitToWidth !== undefined) this.config.fitToWidth = attrs.fitToWidth === 'true';
  }

  /**
   * Get a config value
   */
  get<K extends keyof ICalendarConfig>(key: K): ICalendarConfig[K] {
    return this.config[key];
  }

  /**
   * Set a config value
   */
  set<K extends keyof ICalendarConfig>(key: K, value: ICalendarConfig[K]): void {
    const oldValue = this.config[key];
    this.config[key] = value;

    // Update computed values
    if (key === 'snapInterval') {
      this.config.minEventDuration = value as number;
    }

    // Emit config update event
    eventBus.emit(EventTypes.CONFIG_UPDATE, {
      key,
      value,
      oldValue
    });
  }

  /**
   * Update multiple config values
   */
  update(updates: Partial<ICalendarConfig>): void {
    Object.entries(updates).forEach(([key, value]) => {
      this.set(key as keyof ICalendarConfig, value);
    });
  }

  /**
   * Get all config
   */
  getAll(): ICalendarConfig {
    return { ...this.config };
  }

  /**
   * Calculate derived values
   */
  
  get minuteHeight(): number {
    return this.config.hourHeight / 60;
  }

  get totalHours(): number {
    return this.config.dayEndHour - this.config.dayStartHour;
  }

  get totalMinutes(): number {
    return this.totalHours * 60;
  }

  get slotsPerHour(): number {
    return 60 / this.config.snapInterval;
  }

  get totalSlots(): number {
    return this.totalHours * this.slotsPerHour;
  }

  get slotHeight(): number {
    return this.config.hourHeight / this.slotsPerHour;
  }

  /**
   * Validate snap interval
   */
  isValidSnapInterval(interval: number): boolean {
    return [5, 10, 15, 30, 60].includes(interval);
  }

  /**
   * Get view-specific settings
   */
  getViewSettings(view: ViewType = this.config.view): ViewSettings {
    const settings: Record<ViewType, ViewSettings> = {
      day: {
        columns: 1,
        showAllDay: true,
        scrollToHour: 8
      },
      week: {
        columns: this.config.weekDays,
        showAllDay: true,
        scrollToHour: 8
      },
      month: {
        columns: 7,
        showAllDay: false,
        scrollToHour: null
      }
    };

    return settings[view] || settings.week;
  }

  /**
   * Get calendar type
   */
  getCalendarType(): CalendarType {
    return this.calendarType;
  }

  /**
   * Set calendar type
   */
  setCalendarType(type: CalendarType): void {
    const oldType = this.calendarType;
    this.calendarType = type;
    
    // Emit calendar type change event
    eventBus.emit(EventTypes.CALENDAR_TYPE_CHANGED, {
      oldType,
      newType: type
    });
  }

  /**
   * Get selected date
   */
  getSelectedDate(): Date | null {
    return this.selectedDate;
  }

  /**
   * Set selected date
   */
  setSelectedDate(date: Date): void {
    this.selectedDate = date;
    
    // Emit date change event
    eventBus.emit(EventTypes.SELECTED_DATE_CHANGED, {
      date: date
    });
  }
}

// Create singleton instance
export const calendarConfig = new CalendarConfig();