import React from 'react'
import { render, waitFor } from '@testing-library/react'
import { beforeEach, describe, expect, it, vi } from 'vitest'
import useLazyProfileFavourites from './useLazyProfileFavourites'

function Harness({ username = 'alice', initial = null, enabled = false }) {
  const state = useLazyProfileFavourites({
    username,
    initialFavourites: initial,
    enabled,
  })

  return <output data-testid="state">{JSON.stringify(state)}</output>
}

describe('useLazyProfileFavourites', () => {
  beforeEach(() => {
    vi.restoreAllMocks()
  })

  it('does not request before activation and requests page one once on activation', async () => {
    const fetchMock = vi.spyOn(globalThis, 'fetch').mockResolvedValue({
      ok: true,
      json: async () => ({ data: [{ id: 1 }], next_cursor: 'c1' }),
    })
    const view = render(<Harness />)

    expect(fetchMock).not.toHaveBeenCalled()
    view.rerender(<Harness enabled />)

    await waitFor(() => expect(fetchMock).toHaveBeenCalledTimes(1))
    expect(fetchMock).toHaveBeenCalledWith('/api/profile/alice/favourites', expect.objectContaining({
      credentials: 'same-origin',
    }))
  })

  it('uses SSR data without a page-one request and survives rerenders', async () => {
    const fetchMock = vi.spyOn(globalThis, 'fetch')
    const view = render(<Harness enabled initial={{ data: [{ id: 9 }], next_cursor: 'c2' }} />)
    view.rerender(<Harness enabled initial={{ data: [{ id: 9 }], next_cursor: 'c2' }} />)

    await waitFor(() => expect(JSON.parse(view.getByTestId('state').textContent).items).toEqual([{ id: 9 }]))
    expect(fetchMock).not.toHaveBeenCalled()
  })

  it('does not refetch after switching away and back', async () => {
    const fetchMock = vi.spyOn(globalThis, 'fetch').mockResolvedValue({
      ok: true,
      json: async () => ({ data: [{ id: 3 }], next_cursor: null }),
    })
    const view = render(<Harness enabled />)
    await waitFor(() => expect(fetchMock).toHaveBeenCalledTimes(1))

    view.rerender(<Harness enabled={false} />)
    view.rerender(<Harness enabled />)
    await waitFor(() => expect(JSON.parse(view.getByTestId('state').textContent).items).toEqual([{ id: 3 }]))
    expect(fetchMock).toHaveBeenCalledTimes(1)
  })

  it('resets profile state and ignores a stale response', async () => {
    let resolveRequest
    const fetchMock = vi.spyOn(globalThis, 'fetch').mockImplementation(() => new Promise((resolve) => {
      resolveRequest = resolve
    }))
    const view = render(<Harness username="alice" enabled />)
    await waitFor(() => expect(fetchMock).toHaveBeenCalledTimes(1))

    view.rerender(<Harness username="bob" enabled />)
    expect(JSON.parse(view.getByTestId('state').textContent).items).toEqual([])
    resolveRequest({ ok: true, json: async () => ({ data: [{ id: 1 }], next_cursor: null }) })

    await waitFor(() => expect(JSON.parse(view.getByTestId('state').textContent).items).toEqual([]))
  })
})