/**
 * Tests for ConversationService and WebSocket chat integration
 *
 * ConversationService 管理 CLI 子进程的生命周期。
 * WebSocket 集成测试验证消息从客户端经过服务端到达 CLI 的完整流转。
 */

import { describe, it, expect, beforeAll, afterAll } from 'bun:test'
import * as fs from 'fs/promises'
import * as path from 'path'
import * as os from 'os'
import { fileURLToPath } from 'node:url'
import { ConversationService, conversationService } from '../services/conversationService.js'
import { SessionService } from '../services/sessionService.js'
import { ProviderService } from '../services/providerService.js'

// ============================================================================
// ConversationService unit tests
// ============================================================================

describe('ConversationService', () => {
  it('should report no session for unknown ID', () => {
    const svc = new ConversationService()
    const sid = crypto.randomUUID()
    expect(svc.hasSession(sid)).toBe(false)
  })

  it('should track active sessions as empty initially', () => {
    const svc = new ConversationService()
    expect(svc.getActiveSessions()).toEqual([])
  })

  it('should return false when sending message to non-existent session', async () => {
    const svc = new ConversationService()
    const result = await svc.sendMessage('no-such-session', 'hello')
    expect(result).toBe(false)
  })

  it('should return false when responding to permission for non-existent session', () => {
    const svc = new ConversationService()
    const result = svc.respondToPermission('no-such-session', 'req-1', true)
    expect(result).toBe(false)
  })

  it('should forward suggested permission updates for allow-for-session decisions', () => {
    const svc = new ConversationService()
    const sent: unknown[] = []

    ;(svc as any).sessions.set('session-1', {
      proc: null,
      outputCallbacks: [],
      workDir: process.cwd(),
      sdkToken: 'token',
      sdkSocket: {
        send(data: string) {
          sent.push(JSON.parse(data))
        },
      },
      pendingOutbound: [],
      stderrLines: [],
      sdkMessages: [],
      pendingPermissionRequests: new Map([
        ['req-1', {
          toolName: 'Bash',
          input: { command: 'ls src' },
          permissionSuggestions: [
            {
              type: 'addRules',
              rules: [{ toolName: 'Bash', ruleContent: 'ls src' }],
              behavior: 'allow',
              destination: 'localSettings',
            },
          ],
        }],
      ]),
    })

    const result = svc.respondToPermission('session-1', 'req-1', true, 'always')

    expect(result).toBe(true)
    expect(sent).toHaveLength(1)
    expect(sent[0]).toMatchObject({
      type: 'control_response',
      response: {
        response: {
          behavior: 'allow',
          updatedPermissions: [
            {
              type: 'addRules',
              rules: [{ toolName: 'Bash', ruleContent: 'ls src' }],
              behavior: 'allow',
              destination: 'session',
            },
          ],
        },
      },
    })
  })

  it('should send set_permission_mode requests to active sessions', () => {
    const svc = new ConversationService()
    const sent: unknown[] = []

    ;(svc as any).sessions.set('session-2', {
      proc: null,
      outputCallbacks: [],
      workDir: process.cwd(),
      sdkToken: 'token',
      sdkSocket: {
        send(data: string) {
          sent.push(JSON.parse(data))
        },
      },
      pendingOutbound: [],
      stderrLines: [],
      sdkMessages: [],
      pendingPermissionRequests: new Map(),
    })

    const result = svc.setPermissionMode('session-2', 'acceptEdits')

    expect(result).toBe(true)
    expect(sent).toHaveLength(1)
    expect(sent[0]).toMatchObject({
      type: 'control_request',
      request: {
        subtype: 'set_permission_mode',
        mode: 'acceptEdits',
      },
    })
  })

  it('should not inject a desktop-specific ask override in default permission mode', () => {
    const svc = new ConversationService()
    expect((svc as any).getPermissionArgs('default', false)).toEqual([
      '--permission-mode',
      'default',
    ])
  })

  it('should return false when sending interrupt to non-existent session', () => {
    const svc = new ConversationService()
    const result = svc.sendInterrupt('no-such-session')
    expect(result).toBe(false)
  })

  it('should not throw when stopping non-existent session', () => {
    const svc = new ConversationService()
    expect(() => svc.stopSession('no-such-session')).not.toThrow()
  })

  it('should not throw when registering callback for non-existent session', () => {
    const svc = new ConversationService()
    expect(() => svc.onOutput('no-such-session', () => {})).not.toThrow()
  })

  it('should ignore stale process exits after a session restarts', () => {
    const svc = new ConversationService()
    const oldProc = { pid: 1 } as any
    const newProc = { pid: 2 } as any

    ;(svc as any).sessions.set('session-restart', {
      proc: newProc,
      outputCallbacks: [],
      workDir: process.cwd(),
      permissionMode: 'bypassPermissions',
      sdkToken: 'token',
      sdkSocket: null,
      pendingOutbound: [],
      stderrLines: [],
      sdkMessages: [],
      pendingPermissionRequests: new Map(),
    })

    ;(svc as any).handleProcessExit('session-restart', oldProc, 143)
    expect(svc.hasSession('session-restart')).toBe(true)

    ;(svc as any).handleProcessExit('session-restart', newProc, 0)
    expect(svc.hasSession('session-restart')).toBe(false)
  })

  it('should retain SDK init metadata after recent message trimming', () => {
    const svc = new ConversationService()

    ;(svc as any).sessions.set('session-init-retention', {
      proc: { pid: 1 },
      outputCallbacks: [],
      workDir: process.cwd(),
      permissionMode: 'default',
      sdkToken: 'token',
      sdkSocket: null,
      pendingOutbound: [],
      stderrLines: [],
      sdkMessages: [],
      initMessage: null,
      pendingPermissionRequests: new Map(),
    })

    ;(svc as any).handleSdkPayload('session-init-retention', JSON.stringify({
      type: 'system',
      subtype: 'init',
      model: 'mock-opus',
      claude_code_version: 'test-version',
      slash_commands: ['help', 'context'],
    }))

    for (let i = 0; i < 45; i++) {
      ;(svc as any).handleSdkPayload('session-init-retention', JSON.stringify({
        type: 'stream_event',
        event: { type: 'message_delta', index: i },
      }))
    }

    expect(svc.getRecentSdkMessages('session-init-retention').some((message) => message.subtype === 'init')).toBe(false)
    expect(svc.getSessionInitMessage('session-init-retention')).toMatchObject({
      model: 'mock-opus',
      claude_code_version: 'test-version',
      slash_commands: ['help', 'context'],
    })
  })

  it('should reconstruct usage and metadata from a persisted transcript', async () => {
    const previousConfigDir = process.env.CLAUDE_CONFIG_DIR
    const tmpConfigDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-transcript-'))
    const workDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-workdir-'))
    process.env.CLAUDE_CONFIG_DIR = tmpConfigDir

    try {
      const svc = new SessionService()
      const { sessionId } = await svc.createSession(workDir)
      const found = await svc.findSessionFile(sessionId)
      expect(found).not.toBeNull()

      await fs.appendFile(found!.filePath, JSON.stringify({
        type: 'assistant',
        uuid: crypto.randomUUID(),
        timestamp: '2026-04-27T12:00:00.000Z',
        cwd: workDir,
        version: '999.0.0-test',
        message: {
          role: 'assistant',
          model: 'mock-model',
          content: [{ type: 'text', text: 'hello' }],
          usage: {
            input_tokens: 1234,
            output_tokens: 56,
            cache_read_input_tokens: 7,
            cache_creation_input_tokens: 8,
            server_tool_use: { web_search_requests: 1 },
          },
        },
      }) + '\n')

      const metadata = await svc.getTranscriptMetadata(sessionId)
      const usage = await svc.getTranscriptUsage(sessionId)

      expect(metadata).toMatchObject({
        cwd: workDir,
        version: '999.0.0-test',
        model: 'mock-model',
      })
      expect(usage).toMatchObject({
        source: 'transcript',
        totalInputTokens: 1234,
        totalOutputTokens: 56,
        totalCacheReadInputTokens: 7,
        totalCacheCreationInputTokens: 8,
        totalWebSearchRequests: 1,
      })
      expect(usage?.models[0]?.model).toBe('mock-model')
    } finally {
      if (previousConfigDir === undefined) {
        delete process.env.CLAUDE_CONFIG_DIR
      } else {
        process.env.CLAUDE_CONFIG_DIR = previousConfigDir
      }
      await fs.rm(tmpConfigDir, { recursive: true, force: true })
      await fs.rm(workDir, { recursive: true, force: true })
    }
  })
})

// ============================================================================
// WebSocket integration tests (with mock CLI using the SDK websocket protocol)
// ============================================================================

describe('WebSocket Chat Integration', () => {
  let server: ReturnType<typeof Bun.serve>
  let baseUrl: string
  let wsUrl: string
  let tmpDir: string

  async function withMockInitMode<T>(
    mode: string | undefined,
    callback: () => Promise<T>,
  ): Promise<T> {
    const previousMode = process.env.MOCK_SDK_INIT_MODE

    if (mode) {
      process.env.MOCK_SDK_INIT_MODE = mode
    } else {
      delete process.env.MOCK_SDK_INIT_MODE
    }

    try {
      return await callback()
    } finally {
      if (previousMode === undefined) {
        delete process.env.MOCK_SDK_INIT_MODE
      } else {
        process.env.MOCK_SDK_INIT_MODE = previousMode
      }
    }
  }

  async function withMockStreamDelay<T>(
    delayMs: number | undefined,
    callback: () => Promise<T>,
  ): Promise<T> {
    const previousDelay = process.env.MOCK_SDK_STREAM_DELAY_MS

    if (delayMs && delayMs > 0) {
      process.env.MOCK_SDK_STREAM_DELAY_MS = String(delayMs)
    } else {
      delete process.env.MOCK_SDK_STREAM_DELAY_MS
    }

    try {
      return await callback()
    } finally {
      if (previousDelay === undefined) {
        delete process.env.MOCK_SDK_STREAM_DELAY_MS
      } else {
        process.env.MOCK_SDK_STREAM_DELAY_MS = previousDelay
      }
    }
  }

  async function withMockExitAfterFirstUser<T>(
    delayMs: number | undefined,
    callback: () => Promise<T>,
  ): Promise<T> {
    const previousDelay = process.env.MOCK_SDK_EXIT_AFTER_FIRST_USER_MS

    if (delayMs && delayMs > 0) {
      process.env.MOCK_SDK_EXIT_AFTER_FIRST_USER_MS = String(delayMs)
    } else {
      delete process.env.MOCK_SDK_EXIT_AFTER_FIRST_USER_MS
    }

    try {
      return await callback()
    } finally {
      if (previousDelay === undefined) {
        delete process.env.MOCK_SDK_EXIT_AFTER_FIRST_USER_MS
      } else {
        process.env.MOCK_SDK_EXIT_AFTER_FIRST_USER_MS = previousDelay
      }
    }
  }

  async function runTurn(sessionId: string, content: string, allowError = false): Promise<any[]> {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)

    await new Promise<void>((resolve, reject) => {
      const timeout = setTimeout(() => {
        ws.close()
        reject(new Error(`Timed out waiting for completion for session ${sessionId}`))
      }, 30000)

      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          ws.send(JSON.stringify({ type: 'user_message', content }))
        }
        if (msg.type === 'error') {
          clearTimeout(timeout)
          ws.close()
          if (allowError) {
            resolve()
          } else {
            reject(new Error(msg.message))
          }
        }
        if (msg.type === 'message_complete') {
          clearTimeout(timeout)
          ws.close()
          resolve()
        }
      }

      ws.onerror = () => {
        clearTimeout(timeout)
        ws.close()
        reject(new Error(`WebSocket error for session ${sessionId}`))
      }
    })

    return messages
  }

  async function runTurnUntilComplete(sessionId: string, content: string): Promise<any[]> {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)

    await new Promise<void>((resolve, reject) => {
      const timeout = setTimeout(() => {
        ws.close()
        reject(new Error(`Timed out waiting for terminal event for session ${sessionId}`))
      }, 10000)

      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          ws.send(JSON.stringify({ type: 'user_message', content }))
        }
        if (msg.type === 'message_complete') {
          clearTimeout(timeout)
          ws.close()
          resolve()
        }
      }

      ws.onerror = () => {
        clearTimeout(timeout)
        ws.close()
        reject(new Error(`WebSocket error for session ${sessionId}`))
      }
    })

    return messages
  }

  async function waitUntil(
    predicate: () => boolean | Promise<boolean>,
    label: string,
    timeoutMs = 8000,
  ): Promise<void> {
    const startedAt = Date.now()
    while (Date.now() - startedAt < timeoutMs) {
      if (await predicate()) return
      await new Promise((resolve) => setTimeout(resolve, 50))
    }
    throw new Error(`Timed out waiting for ${label}`)
  }
  const originalCliPath = process.env.CLAUDE_CLI_PATH

  beforeAll(async () => {
    tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'claude-conv-'))
    process.env.CLAUDE_CONFIG_DIR = tmpDir
    process.env.CLAUDE_CLI_PATH = fileURLToPath(
      new URL('./fixtures/mock-sdk-cli.ts', import.meta.url)
    )
    await fs.mkdir(path.join(tmpDir, 'projects'), { recursive: true })

    const port = 15000 + Math.floor(Math.random() * 1000)
    const { startServer } = await import('../index.js')
    server = startServer(port, '127.0.0.1')
    baseUrl = `http://127.0.0.1:${port}`
    wsUrl = `ws://127.0.0.1:${port}`
  })

  afterAll(async () => {
    server?.stop()
    if (tmpDir) {
      await fs.rm(tmpDir, { recursive: true, force: true })
    }
    if (originalCliPath) {
      process.env.CLAUDE_CLI_PATH = originalCliPath
    } else {
      delete process.env.CLAUDE_CLI_PATH
    }
    delete process.env.CLAUDE_CONFIG_DIR
  })

  it('should connect and receive connected event', async () => {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/chat-test-1`)

    await new Promise<void>((resolve) => {
      ws.onmessage = (e) => {
        messages.push(JSON.parse(e.data as string))
        if (messages.length >= 1) {
          ws.close()
          resolve()
        }
      }
      ws.onerror = () => {
        ws.close()
        resolve()
      }
      setTimeout(() => {
        ws.close()
        resolve()
      }, 3000)
    })

    expect(messages[0].type).toBe('connected')
    expect(messages[0].sessionId).toBe('chat-test-1')
  })

  it('should handle stop_generation and return idle status', async () => {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/chat-test-2`)

    await new Promise<void>((resolve) => {
      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          ws.send(JSON.stringify({ type: 'stop_generation' }))
        }
        if (msg.type === 'status' && msg.state === 'idle') {
          ws.close()
          resolve()
        }
      }
      ws.onerror = () => {
        ws.close()
        resolve()
      }
      setTimeout(() => {
        ws.close()
        resolve()
      }, 3000)
    })

    expect(messages.some((m) => m.type === 'status' && m.state === 'idle')).toBe(true)
  })

  it('should send user_message and receive streamed SDK response', async () => {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/chat-test-3`)

    await new Promise<void>((resolve) => {
      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          ws.send(
            JSON.stringify({ type: 'user_message', content: 'Hello from test' })
          )
        }
        // Wait until we receive completion after the streamed response
        if (
          msg.type === 'message_complete' &&
          messages.some((entry) => entry.type === 'thinking')
        ) {
          ws.close()
          resolve()
        }
      }
      ws.onerror = () => {
        ws.close()
        resolve()
      }
      setTimeout(() => {
        ws.close()
        resolve()
      }, 5000)
    })

    const types = messages.map((m) => m.type)
    expect(types).toContain('connected')
    expect(types).toContain('status')
    // Mock SDK flow produces text streaming, thinking, and completion events.
    expect(types).toContain('content_start')
    expect(types).toContain('content_delta')
    expect(types).toContain('thinking')
    expect(types).toContain('message_complete')

    // Verify thinking was first status
    const statusMsgs = messages.filter((m) => m.type === 'status')
    expect(statusMsgs[0].state).toBe('thinking')
  })

  it('should continue chat when SDK init arrives only after the first user turn', async () => {
    const messages = await withMockInitMode('on_first_user', () =>
      runTurn('chat-test-lazy-init', 'Hello after lazy init'),
    )

    expect(messages.some((m) => m.type === 'message_complete')).toBe(true)
    expect(messages.some((m) => m.type === 'error')).toBe(false)
    expect(
      messages.some(
        (m) => m.type === 'system_notification' && m.subtype === 'init',
      ),
    ).toBe(true)
  })

  it('should display CLI /cost local command output', async () => {
    const messages = await runTurn(`chat-cost-${crypto.randomUUID()}`, '/cost')

    expect(messages.some((m) => m.type === 'error')).toBe(false)
    expect(
      messages.some(
        (m) =>
          m.type === 'content_delta' &&
          typeof m.text === 'string' &&
          m.text.includes('Total cost: $0.0000'),
      ),
    ).toBe(true)
    expect(messages.some((m) => m.type === 'message_complete')).toBe(true)
  })

  it('should display CLI /context local command output', async () => {
    const messages = await runTurn(`chat-context-${crypto.randomUUID()}`, '/context')

    expect(messages.some((m) => m.type === 'error')).toBe(false)
    expect(
      messages.some(
        (m) =>
          m.type === 'content_delta' &&
          typeof m.text === 'string' &&
          m.text.includes('## Context Usage'),
      ),
    ).toBe(true)
    expect(messages.some((m) => m.type === 'message_complete')).toBe(true)
  })

  it('should expose structured session inspection data from the active CLI', async () => {
    const sessionId = `chat-inspection-${crypto.randomUUID()}`
    await runTurn(sessionId, 'hello before inspection')

    const res = await fetch(`${baseUrl}/api/sessions/${sessionId}/inspection`)
    expect(res.status).toBe(200)
    const body = await res.json() as any

    expect(body.active).toBe(true)
    expect(body.status.model).toBe('mock-opus')
    expect(body.status.slashCommandCount).toBe(1)
    expect(body.usage.costDisplay).toBe('$0.1234')
    expect(body.usage.source).toBe('current_process')
    expect(body.context.model).toBe('mock-opus')
    expect(body.status.mcpServers).toEqual([{ name: 'mock', status: 'connected' }])
  })

  it('should complete the client turn when the CLI exits after startup', async () => {
    const messages = await withMockExitAfterFirstUser(50, () =>
      runTurnUntilComplete(`chat-late-exit-${crypto.randomUUID()}`, 'trigger late exit'),
    )

    expect(
      messages.some(
        (m) =>
          m.type === 'error' &&
          m.code === 'CLI_ERROR' &&
          typeof m.message === 'string' &&
          m.message.includes('CLI process exited unexpectedly'),
      ),
    ).toBe(true)
    expect(messages.some((m) => m.type === 'message_complete')).toBe(true)
    expect(messages.at(-1)?.type).toBe('message_complete')
  }, 15_000)

  it('should handle permission_response without error', async () => {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/chat-test-4`)

    await new Promise<void>((resolve) => {
      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          // Send a permission response (no active session, should not crash)
          ws.send(
            JSON.stringify({
              type: 'permission_response',
              requestId: 'test-req-1',
              allowed: true,
            })
          )
          // Give a moment then close
          setTimeout(() => {
            ws.close()
            resolve()
          }, 500)
        }
      }
      ws.onerror = () => {
        ws.close()
        resolve()
      }
      setTimeout(() => {
        ws.close()
        resolve()
      }, 3000)
    })

    // Should have received connected and no error
    expect(messages[0].type).toBe('connected')
    expect(messages.some((m) => m.type === 'error')).toBe(false)
  })

  it('should handle ping/pong', async () => {
    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/chat-test-5`)

    await new Promise<void>((resolve) => {
      ws.onmessage = (e) => {
        const msg = JSON.parse(e.data as string)
        messages.push(msg)
        if (msg.type === 'connected') {
          ws.send(JSON.stringify({ type: 'ping' }))
        }
        if (msg.type === 'pong') {
          ws.close()
          resolve()
        }
      }
      ws.onerror = () => {
        ws.close()
        resolve()
      }
      setTimeout(() => {
        ws.close()
        resolve()
      }, 3000)
    })

    expect(messages.some((m) => m.type === 'pong')).toBe(true)
  })

  it('should start a placeholder REST session and continue it on a later reconnect', async () => {
    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    const firstTurn = await runTurn(sessionId, 'reply with first')
    expect(firstTurn.some((m) => m.type === 'message_complete')).toBe(true)
    expect(firstTurn.some((m) => m.type === 'error')).toBe(false)

    await new Promise((resolve) => setTimeout(resolve, 1000))

    const secondTurn = await runTurn(sessionId, 'reply with second')
    expect(secondTurn.some((m) => m.type === 'message_complete')).toBe(true)
    expect(secondTurn.some((m) => m.type === 'error')).toBe(false)
  })

  it('should clear a desktop session without sending /clear to the CLI turn loop', async () => {
    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    const firstTurn = await runTurn(sessionId, 'message before clear')
    expect(firstTurn.some((m) => m.type === 'message_complete')).toBe(true)

    const clearTurn = await runTurn(sessionId, '/clear')
    expect(
      clearTurn.some(
        (m) => m.type === 'system_notification' && m.subtype === 'session_cleared',
      ),
    ).toBe(true)
    expect(clearTurn.some((m) => m.type === 'content_delta')).toBe(false)

    const messagesRes = await fetch(`${baseUrl}/api/sessions/${sessionId}/messages`)
    expect(messagesRes.status).toBe(200)
    const body = await messagesRes.json() as { messages: unknown[] }
    expect(body.messages).toEqual([])
  })

  it('should reject /clear arguments without clearing the desktop session', async () => {
    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    await runTurn(sessionId, 'message before invalid clear')

    const clearTurn = await runTurn(sessionId, '/clear please keep this', true)
    expect(
      clearTurn.some(
        (m) => m.type === 'error' && m.code === 'INVALID_SLASH_COMMAND_ARGS',
      ),
    ).toBe(true)
    expect(
      clearTurn.some(
        (m) => m.type === 'system_notification' && m.subtype === 'session_cleared',
      ),
    ).toBe(false)

    const nextTurn = await runTurn(sessionId, 'message after invalid clear')
    expect(nextTurn.some((m) => m.type === 'message_complete')).toBe(true)
  })

  it('should prewarm the CLI before the first user turn and reuse that process', async () => {
    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    const originalStartSession = conversationService.startSession.bind(conversationService)
    const startCalls: Array<{ sessionId: string }> = []

    conversationService.startSession = (async function patchedStartSession(
      sid: string,
      workDir: string,
      sdkUrl: string,
      options?: { permissionMode?: string; model?: string; effort?: string; providerId?: string | null },
    ) {
      startCalls.push({ sessionId: sid })
      return originalStartSession(sid, workDir, sdkUrl, options)
    }) as typeof conversationService.startSession

    const messages: any[] = []
    const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)
    let connected = false
    let awaitingCompletion = false
    let preUserMessageCount = 0
    let resolveCompletion: (() => void) | null = null
    let rejectCompletion: ((err: Error) => void) | null = null

    try {
      await new Promise<void>((resolve, reject) => {
        const timeout = setTimeout(() => {
          reject(new Error(`Timed out waiting for prewarm connection for session ${sessionId}`))
        }, 5000)

        ws.onmessage = (event) => {
          const msg = JSON.parse(event.data as string)
          messages.push(msg)

          if (msg.type === 'connected' && !connected) {
            connected = true
            clearTimeout(timeout)
            ws.send(JSON.stringify({ type: 'prewarm_session' }))
            resolve()
            return
          }

          if (msg.type === 'error') {
            const err = new Error(msg.message)
            clearTimeout(timeout)
            rejectCompletion?.(err)
            reject(err)
            return
          }

          if (awaitingCompletion && msg.type === 'message_complete') {
            resolveCompletion?.()
          }
        }

        ws.onerror = () => {
          const err = new Error(`WebSocket error for prewarm session ${sessionId}`)
          clearTimeout(timeout)
          rejectCompletion?.(err)
          reject(err)
        }
      })

      await waitUntil(
        () => startCalls.length === 1 && conversationService.hasSession(sessionId),
        `prewarmed CLI process for ${sessionId}`,
      )
      await waitUntil(async () => {
        const commandsRes = await fetch(`${baseUrl}/api/sessions/${sessionId}/slash-commands`)
        if (!commandsRes.ok) return false
        const { commands } = await commandsRes.json() as { commands?: Array<{ name: string }> }
        if (!Array.isArray(commands)) return false
        return commands.some((command) => command.name === 'help')
      }, `prewarmed slash commands for ${sessionId}`)

      preUserMessageCount = messages.length
      expect(
        messages
          .slice(0, preUserMessageCount)
          .some((msg) => ['content_start', 'content_delta', 'thinking', 'message_complete'].includes(msg.type)),
      ).toBe(false)

      awaitingCompletion = true
      const completion = new Promise<void>((resolve, reject) => {
        const timeout = setTimeout(() => {
          reject(new Error(`Timed out waiting for completion after prewarm for session ${sessionId}`))
        }, 10_000)
        resolveCompletion = () => {
          clearTimeout(timeout)
          resolve()
        }
        rejectCompletion = (err) => {
          clearTimeout(timeout)
          reject(err)
        }
      })

      ws.send(JSON.stringify({ type: 'user_message', content: 'first turn after prewarm' }))
      await completion

      expect(startCalls).toHaveLength(1)
      expect(messages.some((msg) => msg.type === 'content_delta')).toBe(true)
      expect(messages.some((msg) => msg.type === 'message_complete')).toBe(true)
      expect(messages.some((msg) => msg.type === 'error')).toBe(false)
    } finally {
      ws.close()
      conversationService.startSession = originalStartSession
      conversationService.stopSession(sessionId)
    }
  }, 20_000)

  it('should resume streaming to a reconnected client during an active turn', async () => {
    await withMockStreamDelay(150, async () => {
      const sessionId = `chat-reconnect-${crypto.randomUUID()}`
      const firstMessages: any[] = []
      const secondMessages: any[] = []

      await new Promise<void>((resolve, reject) => {
        let reconnected = false
        let ws2: WebSocket | null = null
        const timeout = setTimeout(() => {
          ws2?.close()
          reject(new Error(`Timed out waiting for reconnect completion for session ${sessionId}`))
        }, 10_000)

        const cleanup = () => {
          clearTimeout(timeout)
          ws2?.close()
          resolve()
        }

        const handleFailure = (message: string) => {
          clearTimeout(timeout)
          ws2?.close()
          reject(new Error(message))
        }

        const ws1 = new WebSocket(`${wsUrl}/ws/${sessionId}`)
        ws1.onmessage = (event) => {
          const msg = JSON.parse(event.data as string)
          firstMessages.push(msg)

          if (msg.type === 'connected') {
            ws1.send(JSON.stringify({ type: 'user_message', content: 'resume after reconnect' }))
            return
          }

          if (msg.type === 'thinking' && !reconnected) {
            reconnected = true
            ws1.close()

            setTimeout(() => {
              ws2 = new WebSocket(`${wsUrl}/ws/${sessionId}`)
              ws2.onmessage = (reconnectEvent) => {
                const reconnectMsg = JSON.parse(reconnectEvent.data as string)
                secondMessages.push(reconnectMsg)
                if (reconnectMsg.type === 'error') {
                  handleFailure(reconnectMsg.message)
                  return
                }
                if (reconnectMsg.type === 'message_complete') {
                  cleanup()
                }
              }
              ws2.onerror = () => handleFailure(`WebSocket reconnect error for session ${sessionId}`)
            }, 50)
          }
        }

        ws1.onerror = () => handleFailure(`Initial WebSocket error for session ${sessionId}`)
      })

      expect(firstMessages.some((msg) => msg.type === 'thinking')).toBe(true)
      expect(secondMessages.some((msg) => msg.type === 'connected')).toBe(true)
      expect(secondMessages.some((msg) => msg.type === 'content_delta')).toBe(true)
      expect(secondMessages.some((msg) => msg.type === 'message_complete')).toBe(true)
    })
  })

  it('should keep using the selected runtime config across the whole session until changed', async () => {
    const providerService = new ProviderService()
    const providerA = await providerService.addProvider({
      presetId: 'custom',
      name: 'Provider A',
      apiKey: 'key-a',
      baseUrl: 'http://127.0.0.1:1/anthropic',
      apiFormat: 'anthropic',
      models: {
        main: 'model-a-main',
        haiku: 'model-a-haiku',
        sonnet: 'model-a-sonnet',
        opus: 'model-a-opus',
      },
    })
    const providerB = await providerService.addProvider({
      presetId: 'custom',
      name: 'Provider B',
      apiKey: 'key-b',
      baseUrl: 'http://127.0.0.1:1/anthropic',
      apiFormat: 'anthropic',
      models: {
        main: 'model-b-main',
        haiku: 'model-b-haiku',
        sonnet: 'model-b-sonnet',
        opus: 'model-b-opus',
      },
    })

    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    const originalStartSession = conversationService.startSession.bind(conversationService)
    const startCalls: Array<{
      sessionId: string
      options: { permissionMode?: string; model?: string; effort?: string; providerId?: string | null } | undefined
    }> = []

    conversationService.startSession = (async function patchedStartSession(
      sid: string,
      workDir: string,
      sdkUrl: string,
      options?: { permissionMode?: string; model?: string; effort?: string; providerId?: string | null },
    ) {
      startCalls.push({ sessionId: sid, options })
      return originalStartSession(sid, workDir, sdkUrl, options)
    }) as typeof conversationService.startSession

    try {
      const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)
      let phase: 'boot' | 'turn1' | 'switching' | 'turn2' | 'turn3' | 'done' = 'boot'
      let switchingTriggered = false

      await new Promise<void>((resolve, reject) => {
        const timeout = setTimeout(() => {
          ws.close()
          reject(new Error(`Timed out waiting for runtime persistence flow for session ${sessionId}`))
        }, 15_000)

        ws.onmessage = (event) => {
          const msg = JSON.parse(event.data as string)

          if (msg.type === 'connected' && phase === 'boot') {
            ws.send(JSON.stringify({
              type: 'set_runtime_config',
              providerId: providerA.id,
              modelId: 'model-a-sonnet',
            }))
            ws.send(JSON.stringify({ type: 'user_message', content: 'first turn' }))
            phase = 'turn1'
            return
          }

          if (msg.type === 'error') {
            clearTimeout(timeout)
            ws.close()
            reject(new Error(msg.message))
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn1' && !switchingTriggered) {
            switchingTriggered = true
            phase = 'switching'
            ws.send(JSON.stringify({
              type: 'set_runtime_config',
              providerId: providerB.id,
              modelId: 'model-b-opus',
            }))
            return
          }

          if (
            msg.type === 'status' &&
            msg.state === 'idle' &&
            phase === 'switching'
          ) {
            ws.send(JSON.stringify({ type: 'user_message', content: 'second turn' }))
            phase = 'turn2'
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn2') {
            ws.send(JSON.stringify({ type: 'user_message', content: 'third turn' }))
            phase = 'turn3'
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn3') {
            clearTimeout(timeout)
            phase = 'done'
            ws.close()
            resolve()
          }
        }

        ws.onerror = () => {
          reject(new Error(`WebSocket error for runtime persistence session ${sessionId}`))
        }
      })

      expect(startCalls).toHaveLength(2)
      expect(startCalls[0]).toMatchObject({
        sessionId,
        options: {
          providerId: providerA.id,
          model: 'model-a-sonnet',
        },
      })
      expect(startCalls[1]).toMatchObject({
        sessionId,
        options: {
          providerId: providerB.id,
          model: 'model-b-opus',
        },
      })
    } finally {
      conversationService.startSession = originalStartSession
      conversationService.stopSession(sessionId)
    }
  }, 20_000)

  it('should wait for an in-flight runtime restart before sending the next user turn', async () => {
    const providerService = new ProviderService()
    const providerA = await providerService.addProvider({
      presetId: 'custom',
      name: 'Provider Restart A',
      apiKey: 'key-a',
      baseUrl: 'http://127.0.0.1:1/anthropic',
      apiFormat: 'anthropic',
      models: {
        main: 'restart-a-main',
        haiku: 'restart-a-haiku',
        sonnet: 'restart-a-sonnet',
        opus: 'restart-a-opus',
      },
    })
    const providerB = await providerService.addProvider({
      presetId: 'custom',
      name: 'Provider Restart B',
      apiKey: 'key-b',
      baseUrl: 'http://127.0.0.1:1/anthropic',
      apiFormat: 'anthropic',
      models: {
        main: 'restart-b-main',
        haiku: 'restart-b-haiku',
        sonnet: 'restart-b-sonnet',
        opus: 'restart-b-opus',
      },
    })

    const createRes = await fetch(`${baseUrl}/api/sessions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ workDir: process.cwd() }),
    })
    expect(createRes.status).toBe(201)
    const { sessionId } = await createRes.json() as { sessionId: string }

    const originalStartSession = conversationService.startSession.bind(conversationService)
    const startCalls: Array<{
      sessionId: string
      options: { permissionMode?: string; model?: string; effort?: string; providerId?: string | null } | undefined
    }> = []

    conversationService.startSession = (async function patchedStartSession(
      sid: string,
      workDir: string,
      sdkUrl: string,
      options?: { permissionMode?: string; model?: string; effort?: string; providerId?: string | null },
    ) {
      startCalls.push({ sessionId: sid, options })
      return originalStartSession(sid, workDir, sdkUrl, options)
    }) as typeof conversationService.startSession

    try {
      const ws = new WebSocket(`${wsUrl}/ws/${sessionId}`)
      let phase: 'boot' | 'turn1' | 'turn2' | 'turn3' | 'done' = 'boot'

      await new Promise<void>((resolve, reject) => {
        const timeout = setTimeout(() => {
          ws.close()
          reject(new Error(`Timed out waiting for runtime restart synchronization flow for session ${sessionId}`))
        }, 15_000)

        ws.onmessage = (event) => {
          const msg = JSON.parse(event.data as string)

          if (msg.type === 'connected' && phase === 'boot') {
            ws.send(JSON.stringify({
              type: 'set_runtime_config',
              providerId: providerA.id,
              modelId: 'restart-a-sonnet',
            }))
            ws.send(JSON.stringify({ type: 'user_message', content: 'first turn' }))
            phase = 'turn1'
            return
          }

          if (msg.type === 'error') {
            clearTimeout(timeout)
            ws.close()
            reject(new Error(msg.message))
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn1') {
            ws.send(JSON.stringify({
              type: 'set_runtime_config',
              providerId: providerB.id,
              modelId: 'restart-b-opus',
            }))
            ws.send(JSON.stringify({ type: 'user_message', content: 'second turn immediately after switch' }))
            phase = 'turn2'
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn2') {
            ws.send(JSON.stringify({ type: 'user_message', content: 'third turn should reuse restarted runtime' }))
            phase = 'turn3'
            return
          }

          if (msg.type === 'message_complete' && phase === 'turn3') {
            clearTimeout(timeout)
            phase = 'done'
            ws.close()
            resolve()
          }
        }

        ws.onerror = () => {
          reject(new Error(`WebSocket error for runtime restart synchronization session ${sessionId}`))
        }
      })

      expect(startCalls).toHaveLength(2)
      expect(startCalls[0]).toMatchObject({
        sessionId,
        options: {
          providerId: providerA.id,
          model: 'restart-a-sonnet',
        },
      })
      expect(startCalls[1]).toMatchObject({
        sessionId,
        options: {
          providerId: providerB.id,
          model: 'restart-b-opus',
        },
      })
    } finally {
      conversationService.startSession = originalStartSession
      conversationService.stopSession(sessionId)
    }
  }, 20_000)
})