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

import { mutateCanonical, retireCanonicalControls } from '../app/slash/canonicalSessionControls.js'

// A lost-reply control may be retried only as the session's very next control: after another verb,
// re-issuing it must mint a fresh request_id instead of replaying the stale receipt.
function gateway() {
  const mutations: Array<Record<string, unknown>> = []
  let lose = true

  return {
    mutations,
    deliver: () => (lose = false),
    request: async (method: string, params?: Record<string, unknown>) => {
      if (method === 'session.resume') {
        return { revision: 7, execution_generation: 3 }
      }

      mutations.push(params!)

      if (lose) {
        throw new Error('transport closed') // a lost reply: not a structured refusal
      }

      return { revision: 8, execution_generation: 3 }
    }
  }
}

describe('retained canonical controls', () => {
  it('another control retires a lost-reply control', async () => {
    const gw = gateway()
    await expect(mutateCanonical(gw, 's', 'model', { model: 'A' })).rejects.toThrow()
    gw.deliver()
    await mutateCanonical(gw, 's', 'model', { model: 'B' })
    await mutateCanonical(gw, 's', 'model', { model: 'A' })
    expect(gw.mutations[2].request_id).not.toBe(gw.mutations[0].request_id)
  })

  it('a prompt submit retires the session lost-reply controls', async () => {
    const gw = gateway()
    await expect(mutateCanonical(gw, 's', 'model', { model: 'A' })).rejects.toThrow()
    gw.deliver()
    retireCanonicalControls(gw, 's')
    await mutateCanonical(gw, 's', 'model', { model: 'A' })
    expect(gw.mutations[1].request_id).not.toBe(gw.mutations[0].request_id)
  })

  it('the immediate retry of the same control keeps its identity', async () => {
    const gw = gateway()
    await expect(mutateCanonical(gw, 's', 'model', { model: 'A' })).rejects.toThrow()
    gw.deliver()
    await mutateCanonical(gw, 's', 'model', { model: 'A' })
    expect(gw.mutations[1].request_id).toBe(gw.mutations[0].request_id)
  })
})