import {describe, expect, it} from 'vitest'
import {parseTransitionEvent, replayTransitionEvents} from './transitionEvents'

function baseEvent() {
  const now = new Date().toISOString()
  return {
    id: crypto.randomUUID(),
    runId: 'run-1',
    tickId: 'tick-1',
    taskId: 'task-1',
    fromStateId: 'work',
    toStateId: 'done',
    event: 'done',
    reason: 'action.done' as const,
    attempt: 1,
    loopIteration: 0,
    timestamp: now,
  }
}

describe('transitionEvents', () => {
  it('rejects unknown reason codes', () => {
    const candidate = {
      ...baseEvent(),
      reason: 'action.custom',
    }
    expect(() => parseTransitionEvent(candidate)).toThrow()
  })

  it('rejects invalid reason/event pairings', () => {
    const candidate = {
      ...baseEvent(),
      event: 'feedback',
      reason: 'action.done' as const,
    }
    expect(() => parseTransitionEvent(candidate)).toThrow(
      'requires event `done`',
    )
  })

  it('replays with feedback resume discontinuity', () => {
    const now = new Date().toISOString()
    const replayed = replayTransitionEvents([
      {
        id: 'evt-1',
        runId: 'run-1',
        tickId: 'tick-1',
        taskId: 'task-1',
        fromStateId: 'work',
        toStateId: 'await_human',
        event: 'feedback',
        reason: 'action.feedback',
        attempt: 1,
        loopIteration: 0,
        timestamp: now,
      },
      {
        id: 'evt-2',
        runId: 'run-1',
        tickId: 'tick-2',
        taskId: 'task-1',
        fromStateId: 'work',
        toStateId: 'done',
        event: 'done',
        reason: 'action.done',
        attempt: 2,
        loopIteration: 0,
        timestamp: now,
      },
    ])
    expect(replayed).toBe('done')
  })

  it('fails replay when from-state continuity breaks without feedback resume', () => {
    const now = new Date().toISOString()
    expect(() =>
      replayTransitionEvents([
        {
          id: 'evt-1',
          runId: 'run-1',
          tickId: 'tick-1',
          taskId: 'task-1',
          fromStateId: 'work',
          toStateId: 'route',
          event: 'done',
          reason: 'action.done',
          attempt: 1,
          loopIteration: 0,
          timestamp: now,
        },
        {
          id: 'evt-2',
          runId: 'run-1',
          tickId: 'tick-1',
          taskId: 'task-1',
          fromStateId: 'other',
          toStateId: 'done',
          event: 'matched',
          reason: 'orchestrate.select',
          attempt: 1,
          loopIteration: 0,
          timestamp: now,
        },
      ]),
    ).toThrow('Replay mismatch')
  })
})