import { mergeMeasurements } from '../src/sync/syncService'
import { Measurement } from '../src/types'

jest.mock('expo-sqlite', () => ({
  openDatabaseAsync: jest.fn(),
}))

const base: Measurement = {
  id: 'id-1',
  weight: 75,
  bmi: 22,
  bodyFatPercentage: 15,
  fatMass: 10,
  musclePercentage: 40,
  muscleMass: 30,
  visceralFat: 8,
  bmr: 1600,
  measuredAt: '2024-06-01T08:00:00.000Z',
  createdAt: '2024-06-01T08:00:00.000Z',
  updatedAt: '2024-06-01T08:00:00.000Z',
  syncStatus: 'local',
  deleted: 0,
}

describe('mergeMeasurements', () => {
  it('returns empty array when both are empty', () => {
    expect(mergeMeasurements([], [])).toEqual([])
  })

  it('keeps local items not on remote', () => {
    const result = mergeMeasurements([base], [])
    expect(result).toHaveLength(1)
    expect(result[0].id).toBe('id-1')
  })

  it('keeps remote items not on local', () => {
    const remote = { ...base, syncStatus: 'synced' as const }
    const result = mergeMeasurements([], [remote])
    expect(result).toHaveLength(1)
    expect(result[0].id).toBe('id-1')
  })

  it('picks the newer version when both have same id', () => {
    const local = { ...base, weight: 75, updatedAt: '2024-06-02T08:00:00.000Z' }
    const remote = { ...base, weight: 76, updatedAt: '2024-06-03T08:00:00.000Z' }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(1)
    expect(result[0].weight).toBe(76)
  })

  it('picks local when local is newer', () => {
    const local = { ...base, weight: 77, updatedAt: '2024-06-04T08:00:00.000Z' }
    const remote = { ...base, weight: 76, updatedAt: '2024-06-03T08:00:00.000Z' }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(1)
    expect(result[0].weight).toBe(77)
  })

  it('filters out locally deleted items even if present on remote', () => {
    const local = { ...base, deleted: 1 as const, updatedAt: '2024-06-05T08:00:00.000Z' }
    const remote = { ...base, deleted: 0 as const, updatedAt: '2024-06-03T08:00:00.000Z' }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(0)
  })

  it('filters out remotely deleted items when remote is newer', () => {
    const local = { ...base, deleted: 0 as const, updatedAt: '2024-06-04T08:00:00.000Z' }
    const remote = { ...base, deleted: 1 as const, updatedAt: '2024-06-05T08:00:00.000Z' }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(0)
  })

  it('keeps local active item when local is newer than remote deletion', () => {
    const local = { ...base, deleted: 0 as const, weight: 78, updatedAt: '2024-06-06T08:00:00.000Z' }
    const remote = { ...base, deleted: 1 as const, updatedAt: '2024-06-05T08:00:00.000Z' }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(1)
    expect(result[0].weight).toBe(78)
  })

  it('keeps active item when local deleted is older than remote active', () => {
    const local = { ...base, deleted: 1 as const, updatedAt: '2024-06-01T08:00:00.000Z' }
    const remote = { ...base, deleted: 0 as const, updatedAt: '2024-06-05T08:00:00.000Z', syncStatus: 'synced' as const }
    const result = mergeMeasurements([local], [remote])
    expect(result).toHaveLength(1)
    expect(result[0].weight).toBe(75)
  })

  it('merges multiple active and deleted items correctly', () => {
    const localActive = { ...base, id: 'a', weight: 70, updatedAt: '2024-06-05T08:00:00.000Z' }
    const localDeleted = { ...base, id: 'b', weight: 80, deleted: 1 as const, updatedAt: '2024-06-05T08:00:00.000Z' }
    const remoteActive = { ...base, id: 'c', weight: 90, updatedAt: '2024-06-03T08:00:00.000Z', syncStatus: 'synced' as const }
    const remoteDeleted = { ...base, id: 'd', weight: 100, deleted: 1 as const, updatedAt: '2024-06-05T08:00:00.000Z' }

    const result = mergeMeasurements(
      [localActive, localDeleted],
      [remoteActive, remoteDeleted]
    )
    expect(result).toHaveLength(2)
    expect(result.map(m => m.id).sort()).toEqual(['a', 'c'])
  })
})