Headless enhancement: add stream-json as input-format/output-format to support programmatically use (#926)

packages/cli/src/nonInteractive/control/controllers/systemController.ts

@@ -0,0 +1,215 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * System Controller
+ *
+ * Handles system-level control requests:
+ * - initialize: Setup session and return system info
+ * - interrupt: Cancel current operations
+ * - set_model: Switch model (placeholder)
+ */
+
+import { BaseController } from './baseController.js';
+import type {
+  ControlRequestPayload,
+  CLIControlInitializeRequest,
+  CLIControlSetModelRequest,
+} from '../../types.js';
+
+export class SystemController extends BaseController {
+  /**
+   * Handle system control requests
+   */
+  protected async handleRequestPayload(
+    payload: ControlRequestPayload,
+    _signal: AbortSignal,
+  ): Promise<Record<string, unknown>> {
+    switch (payload.subtype) {
+      case 'initialize':
+        return this.handleInitialize(payload as CLIControlInitializeRequest);
+
+      case 'interrupt':
+        return this.handleInterrupt();
+
+      case 'set_model':
+        return this.handleSetModel(payload as CLIControlSetModelRequest);
+
+      case 'supported_commands':
+        return this.handleSupportedCommands();
+
+      default:
+        throw new Error(`Unsupported request subtype in SystemController`);
+    }
+  }
+
+  /**
+   * Handle initialize request
+   *
+   * Registers SDK MCP servers and returns capabilities
+   */
+  private async handleInitialize(
+    payload: CLIControlInitializeRequest,
+  ): Promise<Record<string, unknown>> {
+    // Register SDK MCP servers if provided
+    if (payload.sdkMcpServers && Array.isArray(payload.sdkMcpServers)) {
+      for (const serverName of payload.sdkMcpServers) {
+        this.context.sdkMcpServers.add(serverName);
+      }
+    }
+
+    // Build capabilities for response
+    const capabilities = this.buildControlCapabilities();
+
+    if (this.context.debugMode) {
+      console.error(
+        `[SystemController] Initialized with ${this.context.sdkMcpServers.size} SDK MCP servers`,
+      );
+    }
+
+    return {
+      subtype: 'initialize',
+      capabilities,
+    };
+  }
+
+  /**
+   * Build control capabilities for initialize control response
+   *
+   * This method constructs the control capabilities object that indicates
+   * what control features are available. It is used exclusively in the
+   * initialize control response.
+   */
+  buildControlCapabilities(): Record<string, unknown> {
+    const capabilities: Record<string, unknown> = {
+      can_handle_can_use_tool: true,
+      can_handle_hook_callback: true,
+      can_set_permission_mode:
+        typeof this.context.config.setApprovalMode === 'function',
+      can_set_model: typeof this.context.config.setModel === 'function',
+    };
+
+    // Check if MCP message handling is available
+    try {
+      const mcpProvider = this.context.config as unknown as {
+        getMcpServers?: () => Record<string, unknown> | undefined;
+      };
+      if (typeof mcpProvider.getMcpServers === 'function') {
+        const servers = mcpProvider.getMcpServers();
+        capabilities['can_handle_mcp_message'] = Boolean(
+          servers && Object.keys(servers).length > 0,
+        );
+      } else {
+        capabilities['can_handle_mcp_message'] = false;
+      }
+    } catch (error) {
+      if (this.context.debugMode) {
+        console.error(
+          '[SystemController] Failed to determine MCP capability:',
+          error,
+        );
+      }
+      capabilities['can_handle_mcp_message'] = false;
+    }
+
+    return capabilities;
+  }
+
+  /**
+   * Handle interrupt request
+   *
+   * Triggers the interrupt callback to cancel current operations
+   */
+  private async handleInterrupt(): Promise<Record<string, unknown>> {
+    // Trigger interrupt callback if available
+    if (this.context.onInterrupt) {
+      this.context.onInterrupt();
+    }
+
+    // Abort the main signal to cancel ongoing operations
+    if (this.context.abortSignal && !this.context.abortSignal.aborted) {
+      // Note: We can't directly abort the signal, but the onInterrupt callback should handle this
+      if (this.context.debugMode) {
+        console.error('[SystemController] Interrupt signal triggered');
+      }
+    }
+
+    if (this.context.debugMode) {
+      console.error('[SystemController] Interrupt handled');
+    }
+
+    return { subtype: 'interrupt' };
+  }
+
+  /**
+   * Handle set_model request
+   *
+   * Implements actual model switching with validation and error handling
+   */
+  private async handleSetModel(
+    payload: CLIControlSetModelRequest,
+  ): Promise<Record<string, unknown>> {
+    const model = payload.model;
+
+    // Validate model parameter
+    if (typeof model !== 'string' || model.trim() === '') {
+      throw new Error('Invalid model specified for set_model request');
+    }
+
+    try {
+      // Attempt to set the model using config
+      await this.context.config.setModel(model);
+
+      if (this.context.debugMode) {
+        console.error(`[SystemController] Model switched to: ${model}`);
+      }
+
+      return {
+        subtype: 'set_model',
+        model,
+      };
+    } catch (error) {
+      const errorMessage =
+        error instanceof Error ? error.message : 'Failed to set model';
+
+      if (this.context.debugMode) {
+        console.error(
+          `[SystemController] Failed to set model ${model}:`,
+          error,
+        );
+      }
+
+      throw new Error(errorMessage);
+    }
+  }
+
+  /**
+   * Handle supported_commands request
+   *
+   * Returns list of supported control commands
+   *
+   * Note: This list should match the ControlRequestType enum in
+   * packages/sdk/typescript/src/types/controlRequests.ts
+   */
+  private async handleSupportedCommands(): Promise<Record<string, unknown>> {
+    const commands = [
+      'initialize',
+      'interrupt',
+      'set_model',
+      'supported_commands',
+      'can_use_tool',
+      'set_permission_mode',
+      'mcp_message',
+      'mcp_server_status',
+      'hook_callback',
+    ];
+
+    return {
+      subtype: 'supported_commands',
+      commands,
+    };
+  }
+}