import { describe, it, expect } from 'vitest';
import { AllDayLayoutEngine } from '../../src/utils/AllDayLayoutEngine';
import { CalendarEvent } from '../../src/types/CalendarTypes';

describe('AllDay Layout Engine - Pure Data Tests', () => {
  const weekDates = [
    '2025-09-22', '2025-09-23', '2025-09-24', '2025-09-25',
    '2025-09-26', '2025-09-27', '2025-09-28'
  ];
  const layoutEngine = new AllDayLayoutEngine(weekDates);
  
  // Test data: events med start/end datoer og forventet grid-area
  const testCases = [
    {
      name: 'Single day events - no overlap',
      events: [
        { id: '1', title: 'Event 1', start: new Date('2025-09-22'), end: new Date('2025-09-22'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '2', title: 'Event 2', start: new Date('2025-09-24'), end: new Date('2025-09-24'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: '1', gridArea: '1 / 1 / 2 / 2' }, // row 1, column 1 (Sept 22)
        { id: '2', gridArea: '1 / 3 / 2 / 4' }  // row 1, column 3 (Sept 24)
      ]
    },
    
    {
      name: 'Overlapping multi-day events - Autumn Equinox vs Teknisk Workshop',
      events: [
        { id: 'autumn', title: 'Autumn Equinox', start: new Date('2025-09-22'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: 'workshop', title: 'Teknisk Workshop', start: new Date('2025-09-23'), end: new Date('2025-09-26'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: 'autumn', gridArea: '2 / 1 / 3 / 3' },   // row 2, columns 1-2 (2 dage, processed second)
        { id: 'workshop', gridArea: '1 / 2 / 2 / 6' }  // row 1, columns 2-5 (4 dage, processed first)
      ]
    },
    
    {
      name: 'Multiple events same column',
      events: [
        { id: '1', title: 'Event 1', start: new Date('2025-09-23'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '2', title: 'Event 2', start: new Date('2025-09-23'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '3', title: 'Event 3', start: new Date('2025-09-23'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: '1', gridArea: '1 / 2 / 2 / 3' }, // row 1, column 2 (Sept 23)
        { id: '2', gridArea: '2 / 2 / 3 / 3' }, // row 2, column 2 (Sept 23)
        { id: '3', gridArea: '3 / 2 / 4 / 3' }  // row 3, column 2 (Sept 23)
      ]
    },
    
    {
      name: 'Partial overlaps',
      events: [
        { id: '1', title: 'Event 1', start: new Date('2025-09-22'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '2', title: 'Event 2', start: new Date('2025-09-23'), end: new Date('2025-09-24'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '3', title: 'Event 3', start: new Date('2025-09-25'), end: new Date('2025-09-26'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: '1', gridArea: '1 / 1 / 2 / 3' }, // row 1, columns 1-2 (Sept 22-23)
        { id: '2', gridArea: '2 / 2 / 3 / 4' }, // row 2, columns 2-3 (Sept 23-24, overlap på column 2)
        { id: '3', gridArea: '1 / 4 / 2 / 6' }  // row 1, columns 4-5 (Sept 25-26, no overlap)
      ]
    },
    
    {
      name: 'Complex overlapping pattern',
      events: [
        { id: '1', title: 'Long Event', start: new Date('2025-09-22'), end: new Date('2025-09-25'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '2', title: 'Short Event', start: new Date('2025-09-23'), end: new Date('2025-09-24'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '3', title: 'Another Event', start: new Date('2025-09-24'), end: new Date('2025-09-26'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: '1', gridArea: '1 / 1 / 2 / 5' }, // row 1, columns 1-4 (4 dage, processed first)
        { id: '2', gridArea: '3 / 2 / 4 / 4' }, // row 3, columns 2-3 (2 dage, processed last)
        { id: '3', gridArea: '2 / 3 / 3 / 6' }  // row 2, columns 3-5 (3 dage, processed second)
      ]
    },
    
    {
      name: 'Real-world bug scenario - Multiple overlapping events (Sept 21-28)',
      events: [
        { id: '112', title: 'Autumn Equinox', start: new Date('2025-09-22'), end: new Date('2025-09-23'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '122', title: 'Multi-Day Conference', start: new Date('2025-09-21'), end: new Date('2025-09-24'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '123', title: 'Project Sprint', start: new Date('2025-09-22'), end: new Date('2025-09-25'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '143', title: 'Weekend Hackathon', start: new Date('2025-09-26'), end: new Date('2025-09-28'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent,
        { id: '161', title: 'Teknisk Workshop', start: new Date('2025-09-23'), end: new Date('2025-09-26'), type: 'work', allDay: true, syncStatus: 'synced' } as CalendarEvent
      ],
      expected: [
        { id: '112', gridArea: '4 / 1 / 5 / 3' },   // Autumn Equinox: row 4, columns 1-2 (2 dage, processed last)
        { id: '122', gridArea: '1 / 1 / 2 / 4' },   // Multi-Day Conference: row 1, columns 1-3 (4 dage, starts 21/9, processed first)
        { id: '123', gridArea: '2 / 1 / 3 / 5' },   // Project Sprint: row 2, columns 1-4 (4 dage, starts 22/9, processed second)
        { id: '143', gridArea: '1 / 5 / 2 / 8' },   // Weekend Hackathon: row 1, columns 5-7 (3 dage, no overlap, reuse row 1)
        { id: '161', gridArea: '3 / 2 / 4 / 6' }    // Teknisk Workshop: row 3, columns 2-5 (4 dage, starts 23/9, processed third)
      ]
    }
  ];

  testCases.forEach(testCase => {
    it(testCase.name, () => {
      // Calculate actual layouts using AllDayLayoutEngine
      const layouts = layoutEngine.calculateLayout(testCase.events);
      
      // Verify we got layouts for all events
      expect(layouts.size).toBe(testCase.events.length);
      
      // Check each expected result
      testCase.expected.forEach(expected => {
        const actualLayout = layouts.get(expected.id);
        expect(actualLayout).toBeDefined();
        expect(actualLayout!.gridArea).toBe(expected.gridArea);
      });
    });
  });
  
  it('Grid-area format validation', () => {
    // Test at grid-area format er korrekt
    const gridArea = '2 / 3 / 3 / 5'; // row 2, columns 3-4
    const parts = gridArea.split(' / ');
    
    const rowStart = parseInt(parts[0]); // 2
    const colStart = parseInt(parts[1]); // 3  
    const rowEnd = parseInt(parts[2]);   // 3
    const colEnd = parseInt(parts[3]);   // 5
    
    expect(rowStart).toBe(2);
    expect(colStart).toBe(3);
    expect(rowEnd).toBe(3);
    expect(colEnd).toBe(5);
    
    // Verify spans
    const rowSpan = rowEnd - rowStart; // 1 row
    const colSpan = colEnd - colStart; // 2 columns
    
    expect(rowSpan).toBe(1);
    expect(colSpan).toBe(2);
  });
});