// Work hours management for per-column scheduling

import { DateCalculator } from '../utils/DateCalculator';
import { CalendarConfig } from '../core/CalendarConfig';

/**
 * Work hours for a specific day
 */
export interface DayWorkHours {
  start: number; // Hour (0-23)
  end: number;   // Hour (0-23)
}

/**
 * Work schedule configuration
 */
export interface WorkScheduleConfig {
  weeklyDefault: {
    monday: DayWorkHours | 'off';
    tuesday: DayWorkHours | 'off';
    wednesday: DayWorkHours | 'off';
    thursday: DayWorkHours | 'off';
    friday: DayWorkHours | 'off';
    saturday: DayWorkHours | 'off';
    sunday: DayWorkHours | 'off';
  };
  dateOverrides: {
    [dateString: string]: DayWorkHours | 'off'; // YYYY-MM-DD format
  };
}

/**
 * Manages work hours scheduling with weekly defaults and date-specific overrides
 */
export class WorkHoursManager {
  private config: CalendarConfig;
  private dateCalculator: DateCalculator;
  private workSchedule: WorkScheduleConfig;

  constructor(config: CalendarConfig) {
    this.config = config;
    DateCalculator.initialize(config);
    this.dateCalculator = new DateCalculator();
    
    // Default work schedule - will be loaded from JSON later
    this.workSchedule = {
      weeklyDefault: {
        monday: { start: 9, end: 17 },
        tuesday: { start: 9, end: 17 },
        wednesday: { start: 9, end: 17 },
        thursday: { start: 9, end: 17 },
        friday: { start: 9, end: 15 },
        saturday: 'off',
        sunday: 'off'
      },
      dateOverrides: {
        '2025-01-20': { start: 10, end: 16 },
        '2025-01-21': { start: 8, end: 14 },
        '2025-01-22': 'off'
      }
    };
  }

  /**
   * Get work hours for a specific date
   */
  getWorkHoursForDate(date: Date): DayWorkHours | 'off' {
    const dateString = DateCalculator.formatISODate(date);
    
    // Check for date-specific override first
    if (this.workSchedule.dateOverrides[dateString]) {
      return this.workSchedule.dateOverrides[dateString];
    }
    
    // Fall back to weekly default
    const dayName = this.getDayName(date);
    return this.workSchedule.weeklyDefault[dayName];
  }

  /**
   * Get work hours for multiple dates (used by GridManager)
   */
  getWorkHoursForDateRange(dates: Date[]): Map<string, DayWorkHours | 'off'> {
    const workHoursMap = new Map<string, DayWorkHours | 'off'>();
    
    dates.forEach(date => {
      const dateString = DateCalculator.formatISODate(date);
      const workHours = this.getWorkHoursForDate(date);
      workHoursMap.set(dateString, workHours);
    });
    
    return workHoursMap;
  }

  /**
   * Calculate CSS custom properties for non-work hour overlays (before and after work)
   */
  calculateNonWorkHoursStyle(workHours: DayWorkHours | 'off'): { beforeWorkHeight: number; afterWorkTop: number } | null {
    if (workHours === 'off') {
      return null; // Full day will be colored via CSS background
    }
    
    const gridSettings = this.config.getGridSettings();
    const dayStartHour = gridSettings.dayStartHour;
    const dayEndHour = gridSettings.dayEndHour;
    const hourHeight = gridSettings.hourHeight;
    
    // Before work: from day start to work start
    const beforeWorkHeight = (workHours.start - dayStartHour) * hourHeight;
    
    // After work: from work end to day end
    const afterWorkTop = (workHours.end - dayStartHour) * hourHeight;
    
    return { 
      beforeWorkHeight: Math.max(0, beforeWorkHeight), 
      afterWorkTop: Math.max(0, afterWorkTop) 
    };
  }

  /**
   * Calculate CSS custom properties for work hours overlay (legacy - for backward compatibility)
   */
  calculateWorkHoursStyle(workHours: DayWorkHours | 'off'): { top: number; height: number } | null {
    if (workHours === 'off') {
      return null;
    }
    
    const gridSettings = this.config.getGridSettings();
    const dayStartHour = gridSettings.dayStartHour;
    const hourHeight = gridSettings.hourHeight;
    
    const top = (workHours.start - dayStartHour) * hourHeight;
    const height = (workHours.end - workHours.start) * hourHeight;
    
    return { top, height };
  }

  /**
   * Load work schedule from JSON (future implementation)
   */
  async loadWorkSchedule(jsonData: WorkScheduleConfig): Promise<void> {
    this.workSchedule = jsonData;
  }

  /**
   * Get current work schedule configuration
   */
  getWorkSchedule(): WorkScheduleConfig {
    return this.workSchedule;
  }

  /**
   * Convert Date to day name key
   */
  private getDayName(date: Date): keyof WorkScheduleConfig['weeklyDefault'] {
    const dayNames: (keyof WorkScheduleConfig['weeklyDefault'])[] = [
      'sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday'
    ];
    return dayNames[date.getDay()];
  }
}