import { describe, expect, expectTypeOf, it } from 'vitest'
import { Context, Service, symbols } from 'cordis'
import type { Events } from 'cordis'
import { Session, SessionId } from '@deepseek-ai/dsh-session'
import AgentRegistry, { AgentId, agentEvents, observeAgentStart } from '@deepseek-ai/dsh-agent'
import type { Agent, AgentFactory, ContinuationStop, CreateAgentOptions, ResumeAgentOptions } from '@deepseek-ai/dsh-agent'

function stubAgent(rawId: string): Agent {
  const id = AgentId(rawId)
  return {
    id,
    options: {},
    session: new Session(SessionId(`${id}-session`)),
    status: 'idle',
    ctx: new Context(),
    send() {},
    steer() {},
    inject() {},
    cancel() {},
    whenIdle() { return Promise.resolve() },
  }
}

describe('AgentRegistry', () => {
  it('keeps terminal stop decisions synchronous', () => {
    type TurnStopListener = Events['agent/turn-stop']
    type AsyncTurnStopListener = () => Promise<ContinuationStop | undefined>

    expectTypeOf<AsyncTurnStopListener>().not.toExtend<TurnStopListener>()
    expectTypeOf<ReturnType<TurnStopListener>>().toEqualTypeOf<ContinuationStop | undefined>()
  })

  it('registers exact entries, emits lifecycle events, and unregisters on owner disposal', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const lifecycle: string[] = []
    ctx.on('agent/created', agent => void lifecycle.push(`created:${agent.id}`))
    ctx.on('agent/disposed', agent => void lifecycle.push(`disposed:${agent.id}`))

    const agent = stubAgent('a1')
    const dispose = ctx.agents.register(agent)
    expect(ctx.agents.get(agent.id)).toBe(agent)
    expect(ctx.agents.list()).toEqual([agent])
    expect(() => ctx.agents.register(stubAgent('a1'))).toThrow(/already registered/)

    dispose()
    expect(ctx.agents.get(agent.id)).toBeUndefined()
    expect(lifecycle).toEqual(['created:a1', 'disposed:a1'])
  })

  it('rolls an entry back and pairs a partially delivered creation when a listener throws', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const lifecycle: string[] = []
    ctx.on('agent/created', agent => void lifecycle.push(`created:${agent.id}`))
    ctx.on('agent/created', () => { throw new Error('creation veto') })
    ctx.on('agent/disposed', agent => void lifecycle.push(`disposed:${agent.id}`))

    expect(() => ctx.agents.register(stubAgent('vetoed'))).toThrow('creation veto')
    expect(ctx.agents.get(AgentId('vetoed'))).toBeUndefined()
    expect(lifecycle).toEqual(['created:vetoed', 'disposed:vetoed'])
  })

  it('contains asynchronous creation rejection and every disposal-listener failure', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const warnings: string[] = []
    const heard: string[] = []
    ctx.logger.warn = ((message: unknown) => { warnings.push(String(message)) }) as typeof ctx.logger.warn
    ctx.on('agent/created', () => Promise.reject(new Error('created async')) as never)
    ctx.on('agent/disposed', () => { throw new Error('disposed sync') })
    ctx.on('agent/disposed', () => Promise.reject(new Error('disposed async')) as never)
    ctx.on('agent/disposed', agent => void heard.push(agent.id))

    const dispose = ctx.agents.register(stubAgent('contained'))
    await Promise.resolve()
    dispose()
    await Promise.resolve()

    expect(heard).toEqual(['contained'])
    expect(warnings).toEqual([
      'agent "contained": agent/created listener rejected: Error: created async',
      'agent "contained": agent/disposed listener threw: Error: disposed sync',
      'agent "contained": agent/disposed listener rejected: Error: disposed async',
    ])
  })

  it('retains declarative startup failures, contains listeners, and clears stale records', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const warnings: string[] = []
    const heard: string[] = []
    ctx.logger.warn = ((message: unknown) => { warnings.push(String(message)) }) as typeof ctx.logger.warn
    ctx.on('agent/start-failed', () => { throw new Error('start sync') })
    ctx.on('agent/start-failed', () => Promise.reject(new Error('start async')) as never)
    ctx.on('agent/start-failed', id => void heard.push(id))

    const firstError = new Error('first failure')
    const disposeFirst = ctx.agents.reportStartFailure(AgentId('main'), firstError)
    expect(ctx.agents.getStartFailure(AgentId('main'))).toBe(firstError)
    await Promise.resolve()
    expect(heard).toEqual(['main'])
    expect(warnings).toEqual([
      'agent "main": agent/start-failed listener threw: Error: start sync',
      'agent "main": agent/start-failed listener rejected: Error: start async',
    ])
    disposeFirst()
    expect(ctx.agents.getStartFailure(AgentId('main'))).toBeUndefined()

    const disposeSecond = ctx.agents.reportStartFailure(AgentId('main'), new Error('second failure'))
    const thirdError = new Error('third failure')
    const disposeThird = ctx.agents.reportStartFailure(AgentId('main'), thirdError)
    expect(ctx.agents.getStartFailure(AgentId('main'))).toBe(thirdError)
    disposeSecond()
    expect(ctx.agents.getStartFailure(AgentId('main'))).toBe(thirdError)
    disposeThird()

    const disposeOccupiedAgent = ctx.agents.register(stubAgent('occupied'))
    const occupiedError = new Error('occupied failure')
    const disposeOccupiedFailure = ctx.agents.reportStartFailure(AgentId('occupied'), occupiedError)
    expect(() => { ctx.agents.enter(stubAgent('occupied')) }).toThrow(/already registered/)
    expect(ctx.agents.getStartFailure(AgentId('occupied'))).toBe(occupiedError)
    disposeOccupiedFailure()
    disposeOccupiedAgent()

    const disposeCleared = ctx.agents.reportStartFailure(AgentId('main'), new Error('cleared failure'))
    ctx.agents.register(stubAgent('main'))()
    expect(ctx.agents.getStartFailure(AgentId('main'))).toBeUndefined()
    disposeCleared()
    await ctx.fiber.dispose()
  })

  it('observes immediate, retained, live, unrelated, and cancelled startup outcomes', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const outcomes: string[] = []

    const existing = stubAgent('existing')
    const disposeExisting = ctx.agents.register(existing)
    observeAgentStart(ctx, existing.id, {
      onStarted: agent => void outcomes.push(`started:${agent.id}`),
      onFailed: error => void outcomes.push(`failed:${error.message}`),
    })()

    const retainedError = new Error('retained')
    const disposeRetained = ctx.agents.reportStartFailure(AgentId('retained'), retainedError)
    observeAgentStart(ctx, AgentId('retained'), {
      onStarted: agent => void outcomes.push(`started:${agent.id}`),
      onFailed: error => void outcomes.push(`failed:${error.message}`),
    })()

    const stopLiveStart = observeAgentStart(ctx, AgentId('live-start'), {
      onStarted: agent => void outcomes.push(`started:${agent.id}`),
      onFailed: error => void outcomes.push(`failed:${error.message}`),
    })
    const disposeUnrelatedAgent = ctx.agents.register(stubAgent('unrelated'))
    const disposeUnrelatedFailure = ctx.agents.reportStartFailure(AgentId('unrelated'), new Error('unrelated'))
    const disposeLiveAgent = ctx.agents.register(stubAgent('live-start'))
    stopLiveStart()

    const stopLiveFailure = observeAgentStart(ctx, AgentId('live-failure'), {
      onStarted: agent => void outcomes.push(`started:${agent.id}`),
      onFailed: error => void outcomes.push(`failed:${error.message}`),
    })
    const disposeLiveFailure = ctx.agents.reportStartFailure(AgentId('live-failure'), new Error('live'))
    stopLiveFailure()

    const stopCancelled = observeAgentStart(ctx, AgentId('cancelled'), {
      onStarted: agent => void outcomes.push(`started:${agent.id}`),
      onFailed: error => void outcomes.push(`failed:${error.message}`),
    })
    stopCancelled()
    const disposeCancelledFailure = ctx.agents.reportStartFailure(AgentId('cancelled'), new Error('cancelled'))

    expect(outcomes).toEqual([
      'started:existing',
      'failed:retained',
      'started:live-start',
      'failed:live',
    ])

    disposeCancelledFailure()
    disposeLiveFailure()
    disposeLiveAgent()
    disposeUnrelatedFailure()
    disposeUnrelatedAgent()
    disposeRetained()
    disposeExisting()
    await ctx.fiber.dispose()
  })

  it('separates entry from announcement and stale/idempotent detach cannot remove a replacement', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const lifecycle: string[] = []
    ctx.on('agent/created', agent => void lifecycle.push(`created:${agent.id}`))
    ctx.on('agent/disposed', agent => void lifecycle.push(`disposed:${agent.id}`))

    const first = stubAgent('split')
    const detachFirst = ctx.agents.enter(first)
    expect(lifecycle).toEqual([])
    ctx.agents.announce(first)
    expect(() => { ctx.agents.announce(first) }).toThrow(/already announced/)
    detachFirst()
    detachFirst()

    const replacement = stubAgent('split')
    const detachReplacement = ctx.agents.enter(replacement)
    detachFirst()
    expect(ctx.agents.get(replacement.id)).toBe(replacement)
    expect(() => { ctx.agents.announce(first) }).toThrow(/not live/)
    detachReplacement()
    expect(lifecycle).toEqual(['created:split', 'disposed:split'])
  })

  it('defers detach requested by a creation listener until that dispatch unwinds', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const order: string[] = []
    const agent = stubAgent('reentrant')
    ctx.on('agent/created', () => {
      order.push(`first:${ctx.agents.get(agent.id) === agent}`)
      detach()
      order.push(`after-detach:${ctx.agents.get(agent.id) === agent}`)
    })
    ctx.on('agent/created', () => void order.push(`second:${ctx.agents.get(agent.id) === agent}`))
    ctx.on('agent/disposed', () => void order.push('disposed'))
    const detach = ctx.agents.enter(agent)
    ctx.agents.announce(agent)
    expect(order).toEqual(['first:true', 'after-detach:true', 'second:true', 'disposed'])
    expect(ctx.agents.get(agent.id)).toBeUndefined()
  })
})

describe('agentEvents()', () => {
  it('contains each synchronous throw and returned-promise rejection', async () => {
    const ctx = new Context()
    const warnings: string[] = []
    const heard: string[] = []
    ctx.logger.warn = ((message: unknown) => { warnings.push(String(message)) }) as typeof ctx.logger.warn
    const agent = stubAgent('event')
    ctx.on('agent/status', () => { throw new Error('sync listener') })
    ctx.on('agent/status', () => Promise.reject(new Error('async listener')) as never)
    ctx.on('agent/status', (_agent, status) => void heard.push(status))

    agentEvents(ctx, agent).emit('agent/status', 'running')
    await Promise.resolve()
    expect(heard).toEqual(['running'])
    expect(warnings).toEqual([
      'agent event "agent/status" listener threw: Error: sync listener',
      'agent event "agent/status" listener rejected: Error: async listener',
    ])
  })
})

describe('AgentRegistry factory seam', () => {
  function stubFactory() {
    const calls: {
      create: Array<{ ownerCtx: Context; options: CreateAgentOptions }>
      resume: Array<{ ownerCtx: Context; options: ResumeAgentOptions }>
    } = { create: [], resume: [] }
    const factory: AgentFactory = {
      async createAgent(ownerCtx, options) {
        calls.create.push({ ownerCtx, options })
        return { agent: stubAgent(options.agentId), dispose: () => Promise.resolve() }
      },
      async resume(ownerCtx, options) {
        calls.resume.push({ ownerCtx, options })
        return { agent: stubAgent(options.agentId), dispose: () => Promise.resolve() }
      },
    }
    return { factory, calls }
  }

  it('requires a factory and delegates through the calling context', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    await expect(ctx.agents.create({ agentId: AgentId('a'), sessionId: SessionId('s') })).rejects.toThrow(/no agent factory/)
    const { factory, calls } = stubFactory()
    ctx.agents.setFactory(factory)

    let callerFiber: Context['fiber'] | undefined
    await ctx.plugin(Object.assign(async (inner: Context) => {
      callerFiber = inner.fiber
      await inner.agents.create({ agentId: AgentId('create'), sessionId: SessionId('create-s') })
      await inner.agents.resume({ agentId: AgentId('resume'), resumeSessionId: SessionId('resume-s') })
    }, { inject: ['agents'] }))
    expect(calls.create[0]?.ownerCtx.fiber).toBe(callerFiber)
    expect(calls.resume[0]?.ownerCtx.fiber).toBe(callerFiber)
  })

  it('rejects a second factory and clears the slot with its owner (HMR)', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const owner = await ctx.plugin(Object.assign((inner: Context) => {
      inner.agents.setFactory(stubFactory().factory)
      expect(() => inner.agents.setFactory(stubFactory().factory)).toThrow(/already registered/)
    }, { inject: ['agents'] }))
    await expect(ctx.agents.create({ agentId: AgentId('before'), sessionId: SessionId('before-s') })).resolves.toBeDefined()
    await owner.dispose()
    await expect(ctx.agents.create({ agentId: AgentId('after'), sessionId: SessionId('after-s') })).rejects.toThrow(/no agent factory/)
  })

  it('canonicalizes an already traced Service before tracing it for the caller', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const states = new WeakMap<object, string[]>()
    class TracedFactory extends Service implements AgentFactory {
      constructor(inner: Context) {
        super(inner, 'tracedFactory')
        states.set(this, [])
      }
      private calls(): string[] {
        const original = (this as unknown as { [symbols.original]?: TracedFactory })[symbols.original] ?? this
        const calls = states.get(original)
        if (calls === undefined) throw new Error('factory receiver was not canonicalized')
        return calls
      }
      async createAgent(_ownerCtx: Context, options: CreateAgentOptions) {
        this.calls().push('create')
        return { agent: stubAgent(options.agentId), dispose: () => Promise.resolve() }
      }
      async resume(_ownerCtx: Context, options: ResumeAgentOptions) {
        this.calls().push('resume')
        return { agent: stubAgent(options.agentId), dispose: () => Promise.resolve() }
      }
    }
    await ctx.plugin(TracedFactory)
    const traced = (ctx as Context & { tracedFactory: TracedFactory }).tracedFactory
    ctx.agents.setFactory(traced)
    await ctx.agents.create({ agentId: AgentId('create'), sessionId: SessionId('create-s') })
    await ctx.agents.resume({ agentId: AgentId('resume'), resumeSessionId: SessionId('resume-s') })
    const raw = (traced as unknown as { [symbols.original]?: TracedFactory })[symbols.original]
    expect(states.get(raw!)).toEqual(['create', 'resume'])
  })
})