/**
 * CommandService tests on a real cordis Context with fake slash/connection
 * faces and real session scopes (createScope): session-keyed candidate
 * synthesis (host catalog by sessionId + contributions by availability,
 * collision fail-loud), the dispatch decision table cell by cell, matchSpace
 * hot-key policy, matchEnter strong-wait / reject, the sessionId execute
 * payload, the scoped consume-token dispatch, per-session popupFor
 * lifecycle, and the directory invalidation event subscriptions.
 */
import { Context } from 'cordis'
import { describe, expect, it, vi } from 'vitest'
import { createScope, scopeOf } from '@deepseek-ai/dsh-client-runtime/client'
import type { SessionId } from '@deepseek-ai/dsh-client-runtime/client'
import type { ClientSessionContext, ConsumeTokenRequest, SlashPick, SlashSource } from '@deepseek-ai/dsh-client-ui-slash/client'
import type { CommandContribution, CommandUiSpec, SelectOption } from '../src/client/contract.ts'
import type { CommandDescriptor } from '../src/client/directory.ts'
import { CommandService } from '../src/client/service.ts'

const sid = (k: string): SessionId => k as SessionId

/** The agent-backed session projection (single state; identity only). */
const proj = (id: string): ClientSessionContext => ({ sessionId: sid(id) })

const S1_CMDS: CommandDescriptor[] = [
  { name: 'plan', description: 'bare kind' },
  { name: 'goal', description: 'leadingInput kind', input: { hint: 'goal text' } },
]

const S2_CMDS: CommandDescriptor[] = [
  ...S1_CMDS,
  { name: 'attach', description: 'scoped shadow', input: { hint: 'path' } },
]

type ExecuteValue = { matched: boolean; result?: { kind: 'success' | 'error'; text?: string } }

interface BenchOptions {
  /** Scripted catalog per list payload; default serves the fixed catalogs by session. */
  commands?: (payload: { sessionId: SessionId }) => Promise<{ commands: CommandDescriptor[] }>
  execute?: (payload: { sessionId: SessionId; line: string }) => Promise<ExecuteValue>
}

async function bench(opts: BenchOptions = {}) {
  const ctx = new Context()
  const registered = new Map<string, SlashSource>()
  const listCalls: Array<{ sessionId: SessionId }> = []
  const executeCalls: Array<{ sessionId: SessionId; line: string }> = []
  const api = {
    commands: {
      list: async (payload: { sessionId: SessionId }) => {
        listCalls.push(payload)
        const value = await (opts.commands ?? (p => Promise.resolve({
          commands: p.sessionId === sid('s2') ? S2_CMDS : S1_CMDS,
        })))(payload)
        return { result: { ok: true as const, value } }
      },
      execute: async (payload: { sessionId: SessionId; line: string }) => {
        executeCalls.push(payload)
        const value = await (opts.execute ?? (() => Promise.resolve({ matched: true })))(payload)
        return { result: { ok: true as const, value } }
      },
    },
  }
  ctx.provide('slash', {
    registerSource(src: SlashSource) {
      const key = `${src.trigger} ${src.name}`
      registered.set(key, src)
      return () => { registered.delete(key) }
    },
  })
  // Real scope tags behind a fake sessions face (scope/scopeOf are all the service reads).
  const scopes = new Map<SessionId, { ctx: Context; fiber: { dispose(): Promise<void> } }>()
  ctx.provide('sessions', {
    scope: (id: SessionId) => scopes.get(id)?.ctx,
    scopeOf: (c: Context) => scopeOf(c),
  })
  ctx.provide('connection', { api })
  /** Notices the fake conversation face collected (runDetached routing). */
  const notices: Array<{ scope: SessionId | undefined; level: 'info' | 'error'; text: string }> = []
  ctx.provide('conversation', {
    input: {
      for: (actx: Context) => ({
        notify: (level: 'info' | 'error', text: string) => {
          notices.push({ scope: scopeOf(actx), level, text })
        },
      }),
    },
  })
  const fiber = ctx.plugin(CommandService)
  await fiber.await()
  const command = ctx.get('command') as CommandService
  const source = registered.get('/ command')
  if (source === undefined) throw new Error('command source not registered')
  const mint = (key: string) => {
    const handle = createScope(ctx, sid(key))
    scopes.set(sid(key), handle)
    return handle
  }
  /** Warm one session's catalog through the source's own candidate pull. */
  const warm = async (session: ClientSessionContext) => {
    await source.candidates(session, { query: '', position: 'leading', signal: new AbortController().signal })
  }
  return { ctx, fiber, command, source, mint, warm, listCalls, executeCalls, registered, notices }
}

function menuPick(source: SlashSource, name: string, session: ClientSessionContext, end?: number) {
  const pick: SlashPick = {
    candidate: { name },
    session,
    position: 'leading',
    via: 'menu',
    span: { start: 0, end: end ?? name.length + 1, draftRev: 3 },
  }
  return source.onPick(pick)
}

const themeUi = (over: Partial<CommandUiSpec> = {}): CommandUiSpec => ({
  kind: 'popupSelect',
  options: () => Promise.resolve([{ id: 'dark', label: 'Dark' }]),
  onSelect: () => undefined,
  ...over,
})

const themeContribution = (over: Partial<CommandContribution> = {}): CommandContribution => ({
  name: 'theme',
  description: 'client popup kind',
  available: () => true,
  ui: themeUi(),
  ...over,
})

const req = (query: string, position: 'leading' | 'inline' = 'leading') =>
  ({ query, position, signal: new AbortController().signal })

describe('registration', () => {
  it('registers the "/" source with matchSpace/matchEnter/warm hooks and removes it on fiber disposal', async () => {
    const { registered, source, fiber } = await bench()
    expect(typeof source.matchSpace).toBe('function')
    expect(typeof source.matchEnter).toBe('function')
    expect(typeof source.warm).toBe('function')
    expect([...registered.keys()]).toEqual(['/ command'])
    await fiber.dispose()
    expect(registered.size).toBe(0)
  })

  it('the warm hook prewarms the session key: one pull per session, no duplicate over pending', async () => {
    const { source, listCalls } = await bench()
    source.warm!(proj('s1'))
    expect(listCalls).toEqual([{ sessionId: sid('s1') }])
    source.warm!(proj('s2'))
    expect(listCalls).toEqual([{ sessionId: sid('s1') }, { sessionId: sid('s2') }])
    source.warm!(proj('s1')) // s1 already pending → no duplicate pull
    expect(listCalls).toHaveLength(2)
  })
})

describe('candidates', () => {
  it('pulls the session catalog; prefix filter and hint mapping apply', async () => {
    const { source, listCalls } = await bench()
    const list = await source.candidates(proj('s1'), req('g'))
    expect(listCalls).toEqual([{ sessionId: sid('s1') }])
    expect(list).toEqual([{ name: 'goal', description: 'leadingInput kind', hint: 'goal text' }])
  })

  it('catalogs are per session: another session pulls its own key', async () => {
    const { source, listCalls } = await bench()
    const names = (await source.candidates(proj('s2'), req(''))).map(c => c.name)
    expect(listCalls).toEqual([{ sessionId: sid('s2') }])
    expect(names).toEqual(['plan', 'goal', 'attach'])
  })

  it('hides leadingInput commands at inline position', async () => {
    const { source } = await bench()
    const names = (await source.candidates(proj('s1'), req('', 'inline'))).map(c => c.name)
    expect(names).toEqual(['plan'])
  })

  it('merges available contributions and filters unavailable ones with the per-call projection', async () => {
    const { command, source } = await bench()
    const available = vi.fn((session: ClientSessionContext) => session.sessionId === sid('s1'))
    command.register(themeContribution({ available }))
    const s1Names = (await source.candidates(proj('s1'), req(''))).map(c => c.name)
    expect(s1Names).toEqual(['plan', 'goal', 'theme'])
    expect(available).toHaveBeenLastCalledWith(proj('s1'))
    const s2Names = (await source.candidates(proj('s2'), req(''))).map(c => c.name)
    expect(s2Names).not.toContain('theme')
  })

  it('contribution rows ride the same query prefix filter', async () => {
    const { command, source } = await bench()
    command.register(themeContribution())
    const names = (await source.candidates(proj('s1'), req('th'))).map(c => c.name)
    expect(names).toEqual(['theme'])
  })

  it('a contribution/host name collision fails loud', async () => {
    const { command, source } = await bench()
    command.register(themeContribution({ name: 'plan' }))
    await expect(source.candidates(proj('s1'), req(''))).rejects.toThrow('collides with a host command')
  })
})

describe('dispatch (menu column)', () => {
  it('contribution → opens the session popup with the open-time projection, no execute', async () => {
    const { command, source, mint, warm, executeCalls } = await bench()
    const options = vi.fn((_s: ClientSessionContext) => Promise.resolve([{ id: 'dark', label: 'Dark' }]))
    command.register(themeContribution({ ui: themeUi({ options }) }))
    const scope = mint('s1')
    await warm(proj('s1'))
    expect(menuPick(source, 'theme', proj('s1'))).toBe('handled')
    const popup = command.popupFor(scope.ctx)
    expect(popup.state.getSnapshot()).toMatchObject({ open: true, command: 'theme' })
    expect(options).toHaveBeenCalledExactlyOnceWith(proj('s1'), expect.any(AbortSignal))
    expect(executeCalls).toEqual([])
  })

  it('an unavailable contribution falls through to the host catalog', async () => {
    const { command, source, mint, warm } = await bench()
    command.register(themeContribution({ available: () => false }))
    const scope = mint('s1')
    await warm(proj('s1'))
    expect(menuPick(source, 'theme', proj('s1'))).toBeUndefined() // no host 'theme' either
    expect(command.popupFor(scope.ctx).state.getSnapshot().open).toBe(false)
  })

  it('host leadingInput → {claim} with token "/name " and hint; claiming never executes', async () => {
    const { source, warm, executeCalls } = await bench()
    await warm(proj('s1'))
    const outcome = menuPick(source, 'goal', proj('s1'))
    if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
    expect(outcome.claim.token).toBe('/goal ')
    expect(outcome.claim.hint).toBe('goal text')
    expect(executeCalls).toEqual([])
  })

  it('host bare → consume-token span guard on the session scope + detached execute', async () => {
    const { source, mint, warm, executeCalls } = await bench()
    const scope = mint('s1')
    const consumes: ConsumeTokenRequest[] = []
    scope.ctx.on('slash/input-consume-token', (r) => {
      consumes.push(r)
      return true
    })
    await warm(proj('s1'))
    expect(menuPick(source, 'plan', proj('s1'), 5)).toBe('handled')
    expect(consumes).toEqual([{ guard: { kind: 'span', span: { start: 0, end: 5, draftRev: 3 } } }])
    await Promise.resolve()
    expect(executeCalls).toEqual([{ sessionId: sid('s1'), line: '/plan' }])
  })

  it('a name the directory no longer serves → undefined (snapshot swapped between menu and pick)', async () => {
    const { source, warm } = await bench()
    await warm(proj('s1'))
    expect(menuPick(source, 'gone', proj('s1'))).toBeUndefined()
  })
})

describe('matchSpace (space column)', () => {
  it('answers undefined from a not-ready key (no waiting, no RPC)', async () => {
    const { source, listCalls } = await bench()
    expect(source.matchSpace!(proj('s1'), '/goal')).toBeUndefined()
    expect(listCalls).toEqual([])
  })

  it('hot leadingInput exact token → {claim}; the key axis is the session', async () => {
    const { source, warm } = await bench()
    await warm(proj('s2'))
    const outcome = source.matchSpace!(proj('s2'), '/attach')
    if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
    expect(outcome.claim.token).toBe('/attach ')
    // s1's key is still cold: the same token answers undefined there.
    expect(source.matchSpace!(proj('s1'), '/attach')).toBeUndefined()
  })

  it('bare kind and contribution names stay plain text', async () => {
    const { command, source, warm } = await bench()
    command.register(themeContribution())
    await warm(proj('s1'))
    expect(source.matchSpace!(proj('s1'), '/plan')).toBeUndefined()
    expect(source.matchSpace!(proj('s1'), '/theme')).toBeUndefined()
  })

  it('unknown token / non-slash token → undefined', async () => {
    const { source, warm } = await bench()
    await warm(proj('s1'))
    expect(source.matchSpace!(proj('s1'), '/nope')).toBeUndefined()
    expect(source.matchSpace!(proj('s1'), 'plan')).toBeUndefined()
  })
})

describe('matchEnter (enter column)', () => {
  const signal = () => new AbortController().signal

  it('strong-waits a cold key before adjudicating', async () => {
    let release!: (value: { commands: CommandDescriptor[] }) => void
    const { source } = await bench({
      commands: () => new Promise((resolve) => { release = resolve }),
    })
    const wait = source.matchEnter!(proj('s1'), '/goal args', signal())
    release({ commands: S1_CMDS })
    const outcome = await wait
    if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
    expect(outcome.claim.token).toBe('/goal ')
  })

  it('rejects when warmup fails (never a silent downgrade)', async () => {
    const { source } = await bench({
      commands: () => Promise.reject(new Error('warmup boom')),
    })
    await expect(source.matchEnter!(proj('s1'), '/goal', signal())).rejects.toThrow('warmup boom')
  })

  it('leadingInput claims args-tolerant (bare and with trailing text)', async () => {
    const { source, warm } = await bench()
    await warm(proj('s1'))
    for (const line of ['/goal', '/goal refactor the loop']) {
      const outcome = await source.matchEnter!(proj('s1'), line, signal())
      if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
      expect(outcome.claim.token).toBe('/goal ')
    }
  })

  it('bare host command executes detached with the bare-token consume guard', async () => {
    const { source, mint, warm, executeCalls } = await bench()
    const scope = mint('s1')
    const consumes: ConsumeTokenRequest[] = []
    scope.ctx.on('slash/input-consume-token', (r) => {
      consumes.push(r)
      return true
    })
    await warm(proj('s1'))
    await expect(source.matchEnter!(proj('s1'), '/plan', signal())).resolves.toBe('handled')
    expect(consumes).toEqual([{ guard: { kind: 'bare-token', token: '/plan' } }])
    await Promise.resolve()
    expect(executeCalls).toEqual([{ sessionId: sid('s1'), line: '/plan' }])
  })

  it('bare kind with trailing text → undefined and no RPC (default sink owns the line)', async () => {
    const { source, warm, executeCalls } = await bench()
    await warm(proj('s1'))
    await expect(source.matchEnter!(proj('s1'), '/plan now', signal())).resolves.toBeUndefined()
    expect(executeCalls).toEqual([])
  })

  it('contribution: bare token opens the popup without touching the directory; args → undefined', async () => {
    const { command, source, mint, listCalls } = await bench()
    command.register(themeContribution())
    const scope = mint('s1')
    await expect(source.matchEnter!(proj('s1'), '/theme', signal())).resolves.toBe('handled')
    expect(command.popupFor(scope.ctx).state.getSnapshot().open).toBe(true)
    expect(listCalls).toEqual([]) // contribution short-circuits ahead of ensureReady
    await expect(source.matchEnter!(proj('s1'), '/theme dark', signal())).resolves.toBeUndefined()
  })

  it('unknown name, bare "/", and non-slash lines → undefined', async () => {
    const { source, warm } = await bench()
    await warm(proj('s1'))
    await expect(source.matchEnter!(proj('s1'), '/nope', signal())).resolves.toBeUndefined()
    await expect(source.matchEnter!(proj('s1'), '/', signal())).resolves.toBeUndefined()
    await expect(source.matchEnter!(proj('s1'), 'plain text', signal())).resolves.toBeUndefined()
  })
})

describe('execute payload', () => {
  it('claim.submit addresses the session and maps the detached result', async () => {
    const { source, warm, executeCalls } = await bench({
      execute: () => Promise.resolve({ matched: true, result: { kind: 'success', text: 'goal set' } }),
    })
    await warm(proj('s1'))
    const outcome = source.matchSpace!(proj('s1'), '/goal')
    if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
    const settled = await outcome.claim.submit('ship it', new Context())
    expect(executeCalls).toEqual([{ sessionId: sid('s1'), line: '/goal ship it' }])
    expect(settled).toEqual({ kind: 'success', text: 'goal set' })
  })

  it('maps matched:false to an error outcome and a matched bare result to success', async () => {
    const claimOf = async (opts: BenchOptions) => {
      const b = await bench(opts)
      await b.warm(proj('s1'))
      const outcome = b.source.matchSpace!(proj('s1'), '/goal')
      if (outcome === undefined || outcome === 'handled' || !('claim' in outcome)) throw new Error('expected claim')
      return outcome.claim
    }
    const first = await claimOf({ execute: () => Promise.resolve({ matched: false }) })
    const bad = await first.submit('x', new Context())
    expect(bad.kind).toBe('error')
    const second = await claimOf({ execute: () => Promise.resolve({ matched: true }) })
    await expect(second.submit('', new Context())).resolves.toEqual({ kind: 'success' })
  })
})

describe('detached result notices', () => {
  const flush = () => new Promise(resolve => setTimeout(resolve, 0))

  it('success text → info; error result → error; rejection → error, all on the triggering session', async () => {
    let mode: 'info' | 'error' | 'reject' = 'info'
    const { source, mint, warm, notices } = await bench({
      execute: () => {
        if (mode === 'reject') return Promise.reject(new Error('network down'))
        return Promise.resolve({
          matched: true,
          result: mode === 'info'
            ? { kind: 'success' as const, text: 'compacted 12 messages' }
            : { kind: 'error' as const, text: 'plan mode refused' },
        })
      },
    })
    mint('s1')
    await warm(proj('s1'))
    menuPick(source, 'plan', proj('s1'))
    await flush()
    expect(notices).toEqual([{ scope: sid('s1'), level: 'info', text: 'compacted 12 messages' }])

    notices.length = 0
    mode = 'error'
    await source.matchEnter!(proj('s1'), '/plan', new AbortController().signal)
    await flush()
    expect(notices).toEqual([{ scope: sid('s1'), level: 'error', text: 'plan mode refused' }])

    notices.length = 0
    mode = 'reject'
    menuPick(source, 'plan', proj('s1'))
    await flush()
    expect(notices).toEqual([{ scope: sid('s1'), level: 'error', text: 'network down' }])
  })

  it('success without text stays silent; a torn-down scope drops the notice', async () => {
    const { source, warm, notices } = await bench({
      execute: () => Promise.resolve({ matched: true, result: { kind: 'success' as const, text: 'orphan' } }),
    })
    await warm(proj('ghost')) // never minted: scopeFor misses
    menuPick(source, 'plan', proj('ghost'))
    await flush()
    expect(notices).toEqual([])
  })
})

describe('register (contribution face)', () => {
  it('duplicate registration throws; the disposer frees the name', async () => {
    const { command } = await bench()
    const dispose = command.register(themeContribution())
    expect(() => command.register(themeContribution())).toThrow('duplicate contribution')
    dispose()
    command.register(themeContribution())()
  })
})

describe('popupFor', () => {
  it('resolves lazily per session; a foreign session gets its own controller; unscoped ctx throws', async () => {
    const { ctx, command, mint } = await bench()
    const a = mint('s1')
    const first = command.popupFor(a.ctx)
    expect(command.popupFor(a.ctx)).toBe(first)
    expect(command.popupFor(mint('s2').ctx)).not.toBe(first)
    expect(() => command.popupFor(ctx)).toThrow('requires a session scope')
  })

  it('a successful select dispatches the scoped consume-token and fires the bound composer focus', async () => {
    const { command, source, mint } = await bench()
    const onSelect = vi.fn()
    command.register(themeContribution({ ui: themeUi({ onSelect }) }))
    const scope = mint('s1')
    const consumes: ConsumeTokenRequest[] = []
    scope.ctx.on('slash/input-consume-token', (r) => {
      consumes.push(r)
      return true
    })
    const focus = vi.fn()
    command.bindComposerFocus(sid('s1'), focus)

    expect(menuPick(source, 'theme', proj('s1'), 6)).toBe('handled')
    const popup = command.popupFor(scope.ctx)
    await Promise.resolve() // options land
    await popup.select(0)
    expect(onSelect).toHaveBeenCalledExactlyOnceWith({ id: 'dark', label: 'Dark' } satisfies SelectOption, proj('s1'))
    expect(consumes).toEqual([{ guard: { kind: 'span', span: { start: 0, end: 6, draftRev: 3 } } }])
    expect(focus).toHaveBeenCalledTimes(1)
  })

  it('the enter path opens with the bare-token guard', async () => {
    const { command, source, mint } = await bench()
    command.register(themeContribution())
    const scope = mint('s1')
    const consumes: ConsumeTokenRequest[] = []
    scope.ctx.on('slash/input-consume-token', (r) => {
      consumes.push(r)
      return true
    })
    await source.matchEnter!(proj('s1'), '/theme', new AbortController().signal)
    const popup = command.popupFor(scope.ctx)
    await Promise.resolve()
    await popup.select(0)
    expect(consumes).toEqual([{ guard: { kind: 'bare-token', token: '/theme' } }])
  })

  it('the scope disposer disposes the controller and a re-mint resolves fresh', async () => {
    const { command, source, mint } = await bench()
    command.register(themeContribution())
    const scope = mint('s1')
    await source.matchEnter!(proj('s1'), '/theme', new AbortController().signal)
    const popup = command.popupFor(scope.ctx)
    expect(popup.state.getSnapshot().open).toBe(true)

    await scope.fiber.dispose()
    expect(popup.state.getSnapshot().open).toBe(false)
    expect(command.popupFor(mint('s1').ctx)).not.toBe(popup)
  })
})

describe('directory invalidation events', () => {
  it('commands/changed repulls in the background while the old snapshot serves', async () => {
    let round = 0
    const { ctx, source, warm } = await bench({
      commands: () => {
        round += 1
        return Promise.resolve({
          commands: round === 1
            ? S1_CMDS
            : [{ name: 'fresh', description: '', input: { hint: 'h' } }],
        })
      },
    })
    await warm(proj('s1'))
    ctx.emit('commands/changed')
    await new Promise(resolve => setTimeout(resolve, 0))
    expect(source.matchSpace!(proj('s1'), '/fresh')).not.toBeUndefined()
    expect(source.matchSpace!(proj('s1'), '/goal')).toBeUndefined()
  })

  it('connection/reset hard-drops every session key until its rewarm lands', async () => {
    let block = false
    let release!: (value: { commands: CommandDescriptor[] }) => void
    const { ctx, source, warm } = await bench({
      commands: () => (block
        ? new Promise((resolve) => { release = resolve })
        : Promise.resolve({ commands: S2_CMDS })),
    })
    await warm(proj('s2'))
    expect(source.matchSpace!(proj('s2'), '/attach')).not.toBeUndefined()
    block = true
    ctx.emit('connection/reset')
    // Hard reset: silent until the rewarm lands.
    expect(source.matchSpace!(proj('s2'), '/attach')).toBeUndefined()
    release({ commands: S2_CMDS })
    await new Promise(resolve => setTimeout(resolve, 0))
    expect(source.matchSpace!(proj('s2'), '/attach')).not.toBeUndefined()
  })
})