feat: more work on mcp server integration

src/main/engine/MCPAgentConfigEngine.ts

@@ -0,0 +1,156 @@
+/**
+ * MCPAgentConfigEngine – adds the bDS MCP server entry to coding-agent config files.
+ *
+ * Supports: Claude Code, GitHub Copilot (VS Code), Gemini CLI, OpenCode.
+ * Each agent has its own config file format; this engine reads, merges, and writes
+ * the appropriate JSON structure without overwriting existing entries.
+ */
+
+import { readFileSync, writeFileSync, existsSync, mkdirSync } from 'fs';
+import path from 'path';
+
+// ── Public types ─────────────────────────────────────────────────────
+
+export type MCPAgentId = 'claude-code' | 'github-copilot' | 'gemini-cli' | 'opencode';
+
+export interface AgentDefinition {
+  id: MCPAgentId;
+  label: string;
+}
+
+export interface AgentConfigResult {
+  success: boolean;
+  configPath: string;
+  error?: string;
+}
+
+export interface MCPAgentConfigOptions {
+  homeDir: string;
+  platform: NodeJS.Platform;
+  mcpUrl: string;
+}
+
+// ── Agent definitions ────────────────────────────────────────────────
+
+const AGENTS: AgentDefinition[] = [
+  { id: 'claude-code', label: 'Claude Code' },
+  { id: 'github-copilot', label: 'GitHub Copilot' },
+  { id: 'gemini-cli', label: 'Gemini CLI' },
+  { id: 'opencode', label: 'OpenCode' },
+];
+
+const SERVER_NAME = 'bDS';
+
+// ── Engine ───────────────────────────────────────────────────────────
+
+export class MCPAgentConfigEngine {
+  private readonly homeDir: string;
+  private readonly platform: NodeJS.Platform;
+  private readonly mcpUrl: string;
+
+  constructor(opts: MCPAgentConfigOptions) {
+    this.homeDir = opts.homeDir;
+    this.platform = opts.platform;
+    this.mcpUrl = opts.mcpUrl;
+  }
+
+  /** Return the list of supported agent definitions. */
+  getAgents(): AgentDefinition[] {
+    return [...AGENTS];
+  }
+
+  /** Resolve the absolute path to the config file for the given agent. */
+  getConfigPath(agentId: MCPAgentId): string {
+    switch (agentId) {
+      case 'claude-code':
+        return path.join(this.homeDir, '.claude.json');
+      case 'github-copilot':
+        return this.vsCodeMcpPath();
+      case 'gemini-cli':
+        return path.join(this.homeDir, '.gemini', 'settings.json');
+      case 'opencode':
+        return path.join(this.homeDir, '.opencode.json');
+    }
+  }
+
+  /** Read-merge-write the bDS MCP server entry into the agent's config file. */
+  addToConfig(agentId: MCPAgentId): AgentConfigResult {
+    const configPath = this.getConfigPath(agentId);
+    try {
+      const existing = this.readExisting(configPath);
+      const merged = this.merge(agentId, existing);
+      this.ensureDir(configPath);
+      writeFileSync(configPath, JSON.stringify(merged, null, 2) + '\n', 'utf-8');
+      return { success: true, configPath };
+    } catch (err: unknown) {
+      const message = err instanceof Error ? err.message : String(err);
+      return { success: false, configPath, error: message };
+    }
+  }
+
+  /** Check whether the bDS entry already exists in the agent's config. */
+  isConfigured(agentId: MCPAgentId): boolean {
+    const configPath = this.getConfigPath(agentId);
+    if (!existsSync(configPath)) return false;
+    try {
+      const data = JSON.parse(readFileSync(configPath, 'utf-8'));
+      const serversKey = agentId === 'github-copilot' ? 'servers' : 'mcpServers';
+      return !!data?.[serversKey]?.[SERVER_NAME];
+    } catch {
+      return false;
+    }
+  }
+
+  // ── Private helpers ──────────────────────────────────────────────
+
+  private vsCodeMcpPath(): string {
+    if (this.platform === 'darwin') {
+      return path.join(this.homeDir, 'Library', 'Application Support', 'Code', 'User', 'mcp.json');
+    }
+    if (this.platform === 'win32') {
+      return path.join(this.homeDir, 'AppData', 'Roaming', 'Code', 'User', 'mcp.json');
+    }
+    // linux and others
+    return path.join(this.homeDir, '.config', 'Code', 'User', 'mcp.json');
+  }
+
+  private readExisting(configPath: string): Record<string, unknown> {
+    if (!existsSync(configPath)) return {};
+    const raw = readFileSync(configPath, 'utf-8');
+    return JSON.parse(raw) as Record<string, unknown>;
+  }
+
+  private merge(agentId: MCPAgentId, existing: Record<string, unknown>): Record<string, unknown> {
+    const entry = this.buildEntry(agentId);
+    const serversKey = agentId === 'github-copilot' ? 'servers' : 'mcpServers';
+    const currentServers = (existing[serversKey] as Record<string, unknown> | undefined) ?? {};
+
+    return {
+      ...existing,
+      [serversKey]: {
+        ...currentServers,
+        [SERVER_NAME]: entry,
+      },
+    };
+  }
+
+  private buildEntry(agentId: MCPAgentId): Record<string, unknown> {
+    switch (agentId) {
+      case 'claude-code':
+        return { type: 'http', url: this.mcpUrl };
+      case 'github-copilot':
+        return { type: 'http', url: this.mcpUrl };
+      case 'gemini-cli':
+        return { httpUrl: this.mcpUrl };
+      case 'opencode':
+        return { type: 'sse', url: this.mcpUrl };
+    }
+  }
+
+  private ensureDir(filePath: string): void {
+    const dir = path.dirname(filePath);
+    if (!existsSync(dir)) {
+      mkdirSync(dir, { recursive: true });
+    }
+  }
+}