/**
 * MonthViewStrategy - Strategy for month view rendering
 * Completely different from week view - no time axis, cell-based events
 */

import { ViewStrategy, ViewContext, ViewLayoutConfig } from './ViewStrategy';
import { DateCalculator } from '../utils/DateCalculator';
import { calendarConfig } from '../core/CalendarConfig';

export class MonthViewStrategy implements ViewStrategy {
  private dateCalculator: DateCalculator;
  
  constructor() {
    this.dateCalculator = new DateCalculator(calendarConfig);
  }
  
  getLayoutConfig(): ViewLayoutConfig {
    return {
      needsTimeAxis: false,        // No time axis in month view!
      columnCount: 7,              // Always 7 days (Mon-Sun)
      scrollable: false,           // Month fits in viewport
      eventPositioning: 'cell-based'  // Events go in day cells
    };
  }
  
  renderGrid(context: ViewContext): void {
    console.group(`📅 MONTH VIEW: Rendering grid for ${context.currentDate.toDateString()}`);
    
    // Clear existing content
    context.container.innerHTML = '';
    
    // Create month grid (completely different from week!)
    this.createMonthGrid(context);
    
    console.log('Month grid rendered with 7x6 layout');
    console.groupEnd();
  }
  
  private createMonthGrid(context: ViewContext): void {
    const monthGrid = document.createElement('div');
    monthGrid.className = 'month-grid';
    monthGrid.style.display = 'grid';
    monthGrid.style.gridTemplateColumns = 'repeat(7, 1fr)';
    monthGrid.style.gridTemplateRows = 'auto repeat(6, 1fr)';
    monthGrid.style.height = '100%';
    
    // Add day headers (Mon, Tue, Wed, etc.)
    this.createDayHeaders(monthGrid);
    
    // Add 6 weeks of day cells
    this.createDayCells(monthGrid, context.currentDate);
    
    // Render events in day cells
    this.renderMonthEvents(monthGrid, context.allDayEvents);
    
    context.container.appendChild(monthGrid);
  }
  
  private createDayHeaders(container: HTMLElement): void {
    const dayNames = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'];
    
    dayNames.forEach(dayName => {
      const header = document.createElement('div');
      header.className = 'month-day-header';
      header.textContent = dayName;
      header.style.padding = '8px';
      header.style.fontWeight = 'bold';
      header.style.textAlign = 'center';
      header.style.borderBottom = '1px solid #e0e0e0';
      container.appendChild(header);
    });
  }
  
  private createDayCells(container: HTMLElement, monthDate: Date): void {
    const dates = this.getMonthDates(monthDate);
    
    dates.forEach(date => {
      const cell = document.createElement('div');
      cell.className = 'month-day-cell';
      cell.dataset.date = this.dateCalculator.formatISODate(date);
      cell.style.border = '1px solid #e0e0e0';
      cell.style.minHeight = '100px';
      cell.style.padding = '4px';
      cell.style.position = 'relative';
      
      // Day number
      const dayNumber = document.createElement('div');
      dayNumber.className = 'month-day-number';
      dayNumber.textContent = date.getDate().toString();
      dayNumber.style.fontWeight = 'bold';
      dayNumber.style.marginBottom = '4px';
      
      // Check if today
      if (this.dateCalculator.isToday(date)) {
        dayNumber.style.color = '#1976d2';
        cell.style.backgroundColor = '#f5f5f5';
      }
      
      cell.appendChild(dayNumber);
      container.appendChild(cell);
    });
  }
  
  private getMonthDates(monthDate: Date): Date[] {
    // Get first day of month
    const firstOfMonth = new Date(monthDate.getFullYear(), monthDate.getMonth(), 1);
    
    // Get Monday of the week containing first day
    const startDate = this.dateCalculator.getISOWeekStart(firstOfMonth);
    
    // Generate 42 days (6 weeks)
    const dates: Date[] = [];
    for (let i = 0; i < 42; i++) {
      dates.push(this.dateCalculator.addDays(startDate, i));
    }
    
    return dates;
  }
  
  private renderMonthEvents(container: HTMLElement, events: any[]): void {
    // TODO: Implement month event rendering
    // Events will be small blocks in day cells
    console.log(`MonthViewStrategy: Would render ${events.length} events`);
  }
  
  getNextPeriod(currentDate: Date): Date {
    return new Date(currentDate.getFullYear(), currentDate.getMonth() + 1, 1);
  }
  
  getPreviousPeriod(currentDate: Date): Date {
    return new Date(currentDate.getFullYear(), currentDate.getMonth() - 1, 1);
  }
  
  getPeriodLabel(date: Date): string {
    const monthNames = ['January', 'February', 'March', 'April', 'May', 'June',
                       'July', 'August', 'September', 'October', 'November', 'December'];
    
    return `${monthNames[date.getMonth()]} ${date.getFullYear()}`;
  }
  
  getDisplayDates(baseDate: Date): Date[] {
    return this.getMonthDates(baseDate);
  }
  
  destroy(): void {
    console.log('MonthViewStrategy: Cleaning up');
  }
}