/**
 * Conflict Detection Service Unit Tests
 *
 * Tests scheduling conflict detection for same-day collisions,
 * weekly frequency limits, and weekend warnings.
 */

import { describe, it, expect } from 'vitest'
import { detectConflicts, type CalendarEvent } from '@/lib/youtube/ConflictDetectionService'

const defaultSchedule = { longformPerWeek: 1, shortsPerWeek: 4 }

describe('ConflictDetectionService', () => {
  describe('same-day conflicts', () => {
    it('should detect two longform videos on the same day for the same channel', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-03', contentType: 'longform' },
        { id: 2, channelId: 1, scheduledDate: '2026-03-03', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const sameDay = conflicts.find((c) => c.type === 'same_day')

      expect(sameDay).toBeDefined()
      expect(sameDay!.severity).toBe('error')
      expect(sameDay!.eventIds).toContain(1)
      expect(sameDay!.eventIds).toContain(2)
    })

    it('should not flag conflicts for different channels on the same day', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-03', contentType: 'longform' },
        { id: 2, channelId: 2, scheduledDate: '2026-03-03', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const sameDayConflicts = conflicts.filter((c) => c.type === 'same_day')

      expect(sameDayConflicts).toHaveLength(0)
    })

    it('should not flag shorts on the same day as a same-day conflict', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-03', contentType: 'short' },
        { id: 2, channelId: 1, scheduledDate: '2026-03-03', contentType: 'short' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const sameDayConflicts = conflicts.filter((c) => c.type === 'same_day')

      expect(sameDayConflicts).toHaveLength(0)
    })
  })

  describe('weekly frequency', () => {
    it('should detect weekly frequency exceeded for longform', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-02', contentType: 'longform' },
        { id: 2, channelId: 1, scheduledDate: '2026-03-04', contentType: 'longform' },
        { id: 3, channelId: 1, scheduledDate: '2026-03-06', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const frequency = conflicts.find((c) => c.type === 'frequency_exceeded')

      expect(frequency).toBeDefined()
      expect(frequency!.severity).toBe('warning')
      expect(frequency!.eventIds).toHaveLength(3)
    })

    it('should detect weekly frequency exceeded for shorts', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-02', contentType: 'short' },
        { id: 2, channelId: 1, scheduledDate: '2026-03-03', contentType: 'short' },
        { id: 3, channelId: 1, scheduledDate: '2026-03-04', contentType: 'short' },
        { id: 4, channelId: 1, scheduledDate: '2026-03-05', contentType: 'short' },
        { id: 5, channelId: 1, scheduledDate: '2026-03-06', contentType: 'short' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const frequency = conflicts.find(
        (c) => c.type === 'frequency_exceeded' && c.message.includes('Shorts'),
      )

      expect(frequency).toBeDefined()
      expect(frequency!.eventIds).toHaveLength(5)
    })

    it('should not flag frequency when within limits', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-02', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      const frequencyConflicts = conflicts.filter((c) => c.type === 'frequency_exceeded')

      expect(frequencyConflicts).toHaveLength(0)
    })
  })

  describe('weekend warnings', () => {
    it('should detect weekend scheduling on Saturday', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-07', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, { longformPerWeek: 2, shortsPerWeek: 7 })
      const weekend = conflicts.find((c) => c.type === 'weekend')

      expect(weekend).toBeDefined()
      expect(weekend!.severity).toBe('warning')
    })

    it('should detect weekend scheduling on Sunday', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-08', contentType: 'short' },
      ]

      const conflicts = detectConflicts(events, { longformPerWeek: 2, shortsPerWeek: 7 })
      const weekend = conflicts.find((c) => c.type === 'weekend')

      expect(weekend).toBeDefined()
    })

    it('should not flag weekday scheduling', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-02', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, { longformPerWeek: 2, shortsPerWeek: 7 })
      const weekendConflicts = conflicts.filter((c) => c.type === 'weekend')

      expect(weekendConflicts).toHaveLength(0)
    })
  })

  describe('edge cases', () => {
    it('should return no conflicts for an empty event list', () => {
      const conflicts = detectConflicts([], defaultSchedule)
      expect(conflicts).toHaveLength(0)
    })

    it('should return no conflicts for a single weekday event within limits', () => {
      const events: CalendarEvent[] = [
        { id: 1, channelId: 1, scheduledDate: '2026-03-02', contentType: 'longform' },
      ]

      const conflicts = detectConflicts(events, defaultSchedule)
      expect(conflicts).toHaveLength(0)
    })
  })
})