import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import { api, onRefreshed, onUnauthorized, refreshSession, REQUESTED_WITH } from '../../src/api/client'
import { API, json, pathOf } from '../helpers'

const unauthenticated = { error: { code: 'unauthenticated', message: 'Unauthenticated', details: {} } }
const refreshed = (expiresIn: unknown) => json(200, { data: { token_type: 'cookie', expires_in: expiresIn }, meta: {} })
const navigation = { data: [], meta: {} }

/** fetch mock driven by a handler; every request is recorded. */
function serve(handler: (request: Request) => Response | Promise<Response>): Request[] {
  const seen: Request[] = []
  vi.spyOn(globalThis, 'fetch').mockImplementation(async (input: RequestInfo | URL) => {
    const request = input as Request
    seen.push(request)
    return handler(request)
  })
  return seen
}

const count = (seen: Request[], path: string) => seen.filter((request) => pathOf(request) === `${API}${path}`).length

beforeEach(() => {
  onUnauthorized(null)
  onRefreshed(null)
})

afterEach(() => {
  onUnauthorized(null)
  onRefreshed(null)
})

describe('transport', () => {
  it('sends X-Requested-With and same-origin credentials on every request to the runtime API base', async () => {
    const seen = serve(() => json(200, navigation))
    await api.GET('/navigation')
    await api.POST('/auth/login', { body: { login: 'dev', password: 'x' } })
    expect(REQUESTED_WITH).toBe('XMLHttpRequest')
    for (const request of seen) {
      expect(request.headers.get('X-Requested-With')).toBe('XMLHttpRequest')
      expect(request.credentials).toBe('same-origin')
      expect(pathOf(request).startsWith(API)).toBe(true)
    }
    expect(seen.map(pathOf)).toEqual([`${API}/navigation`, `${API}/auth/login`])
  })

  it('passes a 401 from login or refresh through without refreshing', async () => {
    const seen = serve(() => json(401, unauthenticated))
    const handler = vi.fn()
    onUnauthorized(handler)

    const login = await api.POST('/auth/login', { body: { login: 'dev', password: 'bad' } })
    const refresh = await api.POST('/auth/refresh')

    expect(login.response.status).toBe(401)
    expect(refresh.response.status).toBe(401)
    expect(count(seen, '/auth/refresh')).toBe(1)
    expect(handler).not.toHaveBeenCalled()
  })

  it('leaves other statuses alone', async () => {
    const seen = serve(() => json(403, { error: { code: 'forbidden', message: 'no', details: {} } }))
    const handler = vi.fn()
    onUnauthorized(handler)
    const result = await api.GET('/navigation')
    expect(result.response.status).toBe(403)
    expect(seen).toHaveLength(1)
    expect(handler).not.toHaveBeenCalled()
  })

  it('single-flights one refresh for concurrent 401s and replays each request once with its body', async () => {
    let session = false
    const seen = serve(async (request) => {
      if (pathOf(request) === `${API}/auth/refresh`) {
        await new Promise((resolve) => setTimeout(resolve, 5))
        session = true
        return refreshed(900)
      }
      if (!session) {
        return json(401, unauthenticated)
      }
      if (request.method === 'PUT') {
        return json(200, { data: await request.json(), meta: { labels: {} } })
      }
      return json(200, navigation)
    })
    const lifetimes: Array<number | null> = []
    onRefreshed((seconds) => lifetimes.push(seconds))
    const handler = vi.fn()
    onUnauthorized(handler)

    const path = { vendor: 'acme', plugin: 'demo', controller: 'widgets', id: 1 }
    const [a, b, put] = await Promise.all([
      api.GET('/navigation'),
      api.GET('/navigation'),
      api.PUT('/{vendor}/{plugin}/{controller}/{id}', { params: { path }, body: { name: 'Replayed' } }),
    ])

    expect(a.response.status).toBe(200)
    expect(b.response.status).toBe(200)
    expect(put.data?.data).toEqual({ name: 'Replayed' })
    expect(count(seen, '/auth/refresh')).toBe(1)
    expect(count(seen, '/navigation')).toBe(4)
    expect(count(seen, '/acme/demo/widgets/1')).toBe(2)
    expect(lifetimes).toEqual([900])
    expect(handler).not.toHaveBeenCalled()
  })

  it('reports the session gone when the refresh fails, without replaying', async () => {
    const seen = serve((request) =>
      pathOf(request) === `${API}/auth/refresh` ? json(401, unauthenticated) : json(401, unauthenticated),
    )
    const handler = vi.fn()
    onUnauthorized(handler)
    const result = await api.GET('/navigation')
    expect(result.response.status).toBe(401)
    expect(count(seen, '/navigation')).toBe(1)
    expect(handler).toHaveBeenCalledTimes(1)
  })

  it('reports the session gone when the replay is still 401, and replays only once', async () => {
    const seen = serve((request) => (pathOf(request) === `${API}/auth/refresh` ? refreshed(60) : json(401, unauthenticated)))
    const handler = vi.fn()
    onUnauthorized(handler)
    const result = await api.GET('/navigation')
    expect(result.response.status).toBe(401)
    expect(count(seen, '/navigation')).toBe(2)
    expect(count(seen, '/auth/refresh')).toBe(1)
    expect(handler).toHaveBeenCalledTimes(1)
  })
})

describe('refreshSession', () => {
  it('shares one in-flight request between concurrent callers and starts a new one afterwards', async () => {
    const seen = serve(async () => {
      await new Promise((resolve) => setTimeout(resolve, 5))
      return refreshed(120)
    })
    const first = refreshSession()
    const second = refreshSession()
    expect(second).toBe(first)
    expect(await first).toBe(true)
    expect(count(seen, '/auth/refresh')).toBe(1)
    expect(await refreshSession()).toBe(true)
    expect(count(seen, '/auth/refresh')).toBe(2)
  })

  it('reports a missing lifetime as null', async () => {
    serve(() => refreshed('soon'))
    const lifetimes: Array<number | null> = []
    onRefreshed((seconds) => lifetimes.push(seconds))
    expect(await refreshSession()).toBe(true)
    expect(lifetimes).toEqual([null])
  })

  it('answers false on an error status or a network failure', async () => {
    serve(() => json(500, { error: { code: 'server', message: 'x', details: {} } }))
    expect(await refreshSession()).toBe(false)
    vi.spyOn(globalThis, 'fetch').mockRejectedValue(new TypeError('network'))
    expect(await refreshSession()).toBe(false)
  })
})