/**
 * eventChangeDispatcher tests (D-04, D-02/D-03 actor naming — IN-01 fix).
 *
 * 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)
 *   - Names the actor in the notification title (IN-01 / D-02/D-03)
 *   - Falls back to 'A family member' when the actor row is missing (IN-01)
 *
 * 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(),
  },
}))

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

// ---------------------------------------------------------------------------
// Helper: build a mock db.select chain.
// dispatchEventChange now calls Promise.all([actorQuery, subsQuery]).
// The first select is for the actor name (users table, returns [{displayName}]),
// the second is for push subscriptions (returns sub rows).
// ---------------------------------------------------------------------------
function mockDbSelect(
  db: { select: ReturnType<typeof vi.fn> },
  actorDisplayName: string | null,
  subRows: Array<{ id: number; userId: number; endpoint: string; p256dh: string; auth: string }>,
) {
  // Two sequential .select() calls via Promise.all:
  // First call  → actor name query  (select.from.where.limit → [{ displayName }])
  // Second call → subscriptions query (select.from.where → subRows)
  db.select
    .mockReturnValueOnce({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockReturnValue({
          limit: vi.fn().mockResolvedValue(
            actorDisplayName !== null ? [{ displayName: actorDisplayName }] : [],
          ),
        }),
      }),
    })
    .mockReturnValueOnce({
      from: vi.fn().mockReturnValue({
        where: vi.fn().mockResolvedValue(subRows),
      }),
    })
}

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' }
    mockDbSelect(vi.mocked(db), 'Lucas', [otherUserSub])

    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' }
    mockDbSelect(vi.mocked(db), 'Lucas', [otherUserSub])

    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')

    // isMeaningfulChange returns false before DB is queried — no select needed.
    // But set up a mock just in case (won't be called).
    mockDbSelect(vi.mocked(db), 'Lucas', [
      { id: 2, userId: 2, endpoint: 'https://push.example.com/sub/2', p256dh: 'x', auth: 'y' },
    ])

    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).
    // The ne() filter in the SQL should exclude it, but here we simulate that
    // the application-level filter also catches it.
    mockDbSelect(vi.mocked(db), 'Lucas', [
      { id: 1, userId: 1, endpoint: 'https://push.example.com/sub/1', p256dh: 'x', auth: 'y' },
    ])

    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()
  })

  it('names the actor in the notification title (IN-01 / D-02/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')

    const otherUserSub = { id: 2, userId: 2, endpoint: 'https://push.example.com/sub/2', p256dh: 'x', auth: 'y' }
    mockDbSelect(vi.mocked(db), 'Lucas', [otherUserSub])

    await dispatchEventChange(
      { uid: 'event-uid-4', title: 'Dentist', operation: 'create' },
      /* actorUserId */ 1,
    )

    expect(vi.mocked(dispatchPush)).toHaveBeenCalled()
    const calledWith = vi.mocked(dispatchPush).mock.calls[0][1]
    expect(calledWith.title).toContain('Lucas')
  })

  it('falls back to "A family member" when actor row is missing (IN-01)', 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' }
    mockDbSelect(vi.mocked(db), null, [otherUserSub]) // actor row absent → null

    await dispatchEventChange(
      { uid: 'event-uid-5', title: 'Soccer', operation: 'create' },
      /* actorUserId */ 99, // non-existent user
    )

    expect(vi.mocked(dispatchPush)).toHaveBeenCalled()
    const calledWith = vi.mocked(dispatchPush).mock.calls[0][1]
    expect(calledWith.title).toContain('A family member')
  })
})