/**
 * RED scaffold — eventChangeDispatcher (Plan 05-05 turns this GREEN).
 *
 * Asserts that dispatchEventChange:
 *   - Fires for new events (operation='create')
 *   - Fires for updated events with meaningful changes: time/date/title/location (D-04)
 *   - Does NOT fire for description-only edits (D-04)
 *   - Excludes the actor's own push subscriptions (D-03)
 *
 * These tests fail now because eventChangeDispatcher.ts does not yet exist.
 * Run: pnpm --filter @familysync/api exec vitest run tests/lib/eventChangeDispatcher.test.ts
 */

import { describe, it, expect, vi, beforeEach } from 'vitest'

// Mock DB
vi.mock('../../src/db/client.js', () => ({
  db: {
    select: vi.fn().mockReturnValue({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue([]),
      }),
    }),
  },
}))

// Mock pushDispatcher
vi.mock('../../src/lib/pushDispatcher.js', () => ({
  dispatchPush: vi.fn().mockResolvedValue(undefined),
}))

describe('eventChangeDispatcher — trigger conditions (D-04)', () => {
  beforeEach(() => {
    vi.clearAllMocks()
    vi.resetModules()
  })

  it('dispatches for a new event (operation=create)', async () => {
    const { db } = await import('../../src/db/client.js')
    const { dispatchPush } = await import('../../src/lib/pushDispatcher.js')
    const { dispatchEventChange } = await import('../../src/lib/eventChangeDispatcher.js')

    const otherUserSub = { id: 2, userId: 2, endpoint: 'https://push.example.com/sub/2', p256dh: 'x', auth: 'y' }
    vi.mocked(db.select).mockReturnValue({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue([otherUserSub]),
      }),
    } as never)

    await dispatchEventChange(
      { uid: 'new-event-uid', title: 'Doctor appointment', operation: 'create' },
      /* actorUserId */ 1,
    )

    expect(vi.mocked(dispatchPush)).toHaveBeenCalled()
  })

  it('dispatches for an event with a title change', async () => {
    const { db } = await import('../../src/db/client.js')
    const { dispatchPush } = await import('../../src/lib/pushDispatcher.js')
    const { dispatchEventChange } = await import('../../src/lib/eventChangeDispatcher.js')

    const otherUserSub = { id: 2, userId: 2, endpoint: 'https://push.example.com/sub/2', p256dh: 'x', auth: 'y' }
    vi.mocked(db.select).mockReturnValue({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue([otherUserSub]),
      }),
    } as never)

    await dispatchEventChange(
      {
        uid: 'event-uid-1',
        title: 'Renamed Event',
        operation: 'update',
        changedFields: ['title'],
      },
      /* actorUserId */ 1,
    )

    expect(vi.mocked(dispatchPush)).toHaveBeenCalled()
  })

  it('does NOT dispatch for a description-only edit (D-04)', async () => {
    const { db } = await import('../../src/db/client.js')
    const { dispatchPush } = await import('../../src/lib/pushDispatcher.js')
    const { dispatchEventChange } = await import('../../src/lib/eventChangeDispatcher.js')

    vi.mocked(db.select).mockReturnValue({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue([
          { id: 2, userId: 2, endpoint: 'https://push.example.com/sub/2', p256dh: 'x', auth: 'y' },
        ]),
      }),
    } as never)

    await dispatchEventChange(
      {
        uid: 'event-uid-2',
        title: 'Team lunch',
        operation: 'update',
        changedFields: ['description'], // description-only — must NOT fire
      },
      /* actorUserId */ 1,
    )

    expect(vi.mocked(dispatchPush)).not.toHaveBeenCalled()
  })

  it('excludes the actor user subscriptions from dispatch (D-03)', async () => {
    const { db } = await import('../../src/db/client.js')
    const { dispatchPush } = await import('../../src/lib/pushDispatcher.js')
    const { dispatchEventChange } = await import('../../src/lib/eventChangeDispatcher.js')

    // DB returns only the actor's own subscription (userId 1)
    vi.mocked(db.select).mockReturnValue({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue([
          { id: 1, userId: 1, endpoint: 'https://push.example.com/sub/1', p256dh: 'x', auth: 'y' },
        ]),
      }),
    } as never)

    await dispatchEventChange(
      { uid: 'event-uid-3', title: 'Soccer practice', operation: 'create' },
      /* actorUserId */ 1, // actor is userId=1 — their subscription must be excluded
    )

    // No subscriptions remain after excluding the actor — nothing dispatched
    expect(vi.mocked(dispatchPush)).not.toHaveBeenCalled()
  })
})