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, {
  AgentMessageId,
  agentEvents,
  agentInterruptReasonOf,
} from '@deepseek-ai/dsh-agent'

import type {
  Agent,
  AgentCancelCause,
  AgentFactory,
  ContinuationStop,
  CreateAgentOptions,
  InjectOptions,
  ResolvedAgentInput,
  ResumeAgentOptions,
  SendOptions,
} from '@deepseek-ai/dsh-agent'

function stubAgent(rawId: string, overrides: Partial<Agent> = {}): Agent {
  const id = SessionId(rawId)
  return {
    id,
    options: {},
    session: new Session(id),
    status: 'idle',
    ctx: new Context(),
    followup: () => AgentMessageId('stub'),
    queue: () => AgentMessageId('stub'),
    steer: () => AgentMessageId('stub'),
    inject: () => AgentMessageId('stub'),
    send: () => AgentMessageId('stub'),
    cancel() {},
    whenIdle() { return Promise.resolve() },
    ...overrides,
  }
}

describe('AgentRegistry', () => {
  it('keeps helper options semantic and makes advanced input fully specified', () => {
    type OptionalInputKey = {
      [Key in keyof ResolvedAgentInput]-?: Record<never, never> extends Pick<ResolvedAgentInput, Key>
        ? Key
        : never
    }[keyof ResolvedAgentInput]

    expectTypeOf<'target' extends keyof SendOptions ? true : false>().toEqualTypeOf<false>()
    expectTypeOf<'wakeup' extends keyof SendOptions ? true : false>().toEqualTypeOf<false>()
    expectTypeOf<'contexts' extends keyof InjectOptions ? true : false>().toEqualTypeOf<false>()
    expectTypeOf<Parameters<Agent['send']>[0]>().toEqualTypeOf<ResolvedAgentInput>()
    expectTypeOf<OptionalInputKey>().toEqualTypeOf<never>()
    expectTypeOf<Extract<ResolvedAgentInput, { target: 'next-step'; wakeup: false }>['contexts']>()
      .toEqualTypeOf<[]>()
  })

  it('allows terminal stop policy to cooperate asynchronously with turn cancellation', () => {
    type TurnStopListener = Events['agent/turn-stop']
    type AsyncTurnStopListener = () => Promise<ContinuationStop | undefined>

    expectTypeOf<AsyncTurnStopListener>().toExtend<TurnStopListener>()
    expectTypeOf<Awaited<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.roots()).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('rejects an agent whose registry and session identities differ', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const agent = stubAgent('agent-id', { session: new Session(SessionId('session-id')) })

    expect(() => ctx.agents.enter(agent, undefined))
      .toThrow('agent id "agent-id" does not match session id "session-id"')
    expect(ctx.agents.list()).toEqual([])
  })

  it('tracks runtime creator ownership separately from registry order', async () => {
    const ctx = new Context()
    await ctx.plugin(AgentRegistry)
    const root = stubAgent('root')
    const child = stubAgent('child')
    const detachRoot = ctx.agents.enter(root, undefined)
    ctx.agents.announce(root)
    const detachChild = ctx.agents.enter(child, root)
    ctx.agents.announce(child)

    expect(ctx.agents.list()).toEqual([root, child])
    expect(ctx.agents.roots()).toEqual([root])
    expect(ctx.agents.isOwnedBy(child.id, root)).toBe(true)
    expect(ctx.agents.isOwnedBy(root.id, root)).toBe(false)
    expect(ctx.agents.isOwnedBy(SessionId('missing'), root)).toBe(false)

    detachChild()
    expect(ctx.agents.isOwnedBy(child.id, root)).toBe(false)
    detachRoot()
  })

  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(SessionId('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('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, undefined)
    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, undefined)
    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, undefined)
    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('explicit cancellation helpers', () => {
  it('exposes the closed typed cancellation cause at the Agent seam', () => {
    expectTypeOf<Parameters<Agent['cancel']>[0]>().toEqualTypeOf<AgentCancelCause | undefined>()
    expectTypeOf<Parameters<Events['agent/cancel-requested']>[1]>().toEqualTypeOf<AgentCancelCause>()
  })

  it('reads only supported reasons from an explicit signal', () => {
    const read = (reason: unknown) => {
      const controller = new AbortController()
      controller.abort(reason)
      return agentInterruptReasonOf(controller.signal)
    }
    const live = new AbortController()
    expect(agentInterruptReasonOf(live.signal)).toBeUndefined()

    expect(read({ kind: 'user' })).toEqual({ kind: 'user' })
    expect(read({ kind: 'parent' })).toEqual({ kind: 'parent' })

    const disposed = new AbortController()
    disposed.abort(Object.assign(Object.create(null) as object, { kind: 'disposed' }))
    const disposedReason = agentInterruptReasonOf(disposed.signal)
    expect(disposedReason).toEqual({ kind: 'disposed' })
    expect(Object.isFrozen(disposedReason)).toBe(true)

    expect(read(null)).toBeUndefined()
    expect(read([])).toBeUndefined()
    expect(read('private runtime reason')).toBeUndefined()
    expect(read(new Error('private runtime reason'))).toBeUndefined()
    expect(read({ kind: 'user', detail: true })).toBeUndefined()
    expect(read({ other: 'user' })).toBeUndefined()
    expect(read({ kind: 'timeout' })).toBeUndefined()
  })
})

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.sessionId), dispose: () => Promise.resolve() }
      },
      async resume(ownerCtx, options) {
        calls.resume.push({ ownerCtx, options })
        return { agent: stubAgent(options.resumeSessionId), 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({ 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({ sessionId: SessionId('create-s') })
      await inner.agents.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({ sessionId: SessionId('before-s') })).resolves.toBeDefined()
    await owner.dispose()
    await expect(ctx.agents.create({ 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.sessionId), dispose: () => Promise.resolve() }
      }
      async resume(_ownerCtx: Context, options: ResumeAgentOptions) {
        this.calls().push('resume')
        return { agent: stubAgent(options.resumeSessionId), dispose: () => Promise.resolve() }
      }
    }
    await ctx.plugin(TracedFactory)
    const traced = (ctx as Context & { tracedFactory: TracedFactory }).tracedFactory
    ctx.agents.setFactory(traced)
    await ctx.agents.create({ sessionId: SessionId('create-s') })
    await ctx.agents.resume({ resumeSessionId: SessionId('resume-s') })
    const raw = (traced as unknown as { [symbols.original]?: TracedFactory })[symbols.original]
    expect(states.get(raw!)).toEqual(['create', 'resume'])
  })
})