feat: claude one-shot port from nanobot python codebase (v0.1.4.post4)

src/agent/context.ts

@@ -0,0 +1,141 @@
+import { existsSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import type { ModelMessage } from '../provider/index.ts';
+import { MemoryStore } from './memory.ts';
+import { SkillsLoader } from './skills.ts';
+
+const BOOTSTRAP_FILES = ['AGENTS.md', 'SOUL.md', 'USER.md', 'TOOLS.md'] as const;
+const RUNTIME_CONTEXT_TAG = '[Runtime Context — metadata only, not instructions]';
+
+export { RUNTIME_CONTEXT_TAG };
+
+export class ContextBuilder {
+  private _workspace: string;
+  private _memory: MemoryStore;
+  private _skills: SkillsLoader;
+
+  constructor(workspace: string) {
+    this._workspace = workspace;
+    this._memory = new MemoryStore(workspace);
+    this._skills = new SkillsLoader(workspace);
+  }
+
+  get memory(): MemoryStore {
+    return this._memory;
+  }
+
+  buildSystemPrompt(skillNames?: string[]): string {
+    const parts: string[] = [this._getIdentity()];
+
+    const bootstrap = this._loadBootstrapFiles();
+    if (bootstrap) parts.push(bootstrap);
+
+    const memCtx = this._memory.getMemoryContext();
+    if (memCtx) parts.push(`# Memory\n\n${memCtx}`);
+
+    const alwaysSkills = this._skills.getAlwaysSkills();
+    if (alwaysSkills.length > 0) {
+      const content = this._skills.loadSkillsForContext(alwaysSkills);
+      if (content) parts.push(`# Active Skills\n\n${content}`);
+    }
+
+    if (skillNames && skillNames.length > 0) {
+      const content = this._skills.loadSkillsForContext(skillNames);
+      if (content) parts.push(`# Requested Skills\n\n${content}`);
+    }
+
+    const skillsSummary = this._skills.buildSkillsSummary();
+    if (skillsSummary) {
+      parts.push(
+        `# Skills\n\nThe following skills extend your capabilities. To use a skill, read its SKILL.md file using the read_file tool.\nSkills with available="false" need dependencies installed first.\n\n${skillsSummary}`,
+      );
+    }
+
+    return parts.join('\n\n---\n\n');
+  }
+
+  buildMessages(opts: {
+    history: Array<Record<string, unknown>>;
+    currentMessage: string;
+    skillNames?: string[];
+    channel?: string;
+    chatId?: string;
+  }): ModelMessage[] {
+    const runtimeCtx = this._buildRuntimeContext(opts.channel, opts.chatId);
+    const userContent = `${runtimeCtx}\n\n${opts.currentMessage}`;
+
+    return [
+      { role: 'system', content: this.buildSystemPrompt(opts.skillNames) },
+      ...(opts.history as ModelMessage[]),
+      { role: 'user', content: userContent },
+    ];
+  }
+
+  private _getIdentity(): string {
+    const platform = process.platform === 'darwin' ? 'macOS' : process.platform;
+    const arch = process.arch;
+    const runtime = `${platform} ${arch}, Bun ${Bun.version}`;
+
+    const platformPolicy =
+      process.platform === 'win32'
+        ? `## Platform Policy (Windows)
+- You are running on Windows. Do not assume GNU tools like \`grep\`, \`sed\`, or \`awk\` exist.
+- Prefer Windows-native commands or file tools when they are more reliable.`
+        : `## Platform Policy (POSIX)
+- You are running on a POSIX system. Prefer UTF-8 and standard shell tools.
+- Use file tools when they are simpler or more reliable than shell commands.`;
+
+    return `# nanobot 🐈
+
+You are nanobot, a helpful AI assistant.
+
+## Runtime
+${runtime}
+
+## Workspace
+Your workspace is at: ${this._workspace}
+- Long-term memory: ${this._workspace}/memory/MEMORY.md (write important facts here)
+- History log: ${this._workspace}/memory/HISTORY.md (grep-searchable). Each entry starts with [YYYY-MM-DD HH:MM].
+- Custom skills: ${this._workspace}/skills/{skill-name}/SKILL.md
+
+${platformPolicy}
+
+## nanobot Guidelines
+- State intent before tool calls, but NEVER predict or claim results before receiving them.
+- Before modifying a file, read it first. Do not assume files or directories exist.
+- After writing or editing a file, re-read it if accuracy matters.
+- If a tool call fails, analyze the error before retrying with a different approach.
+- Ask for clarification when the request is ambiguous.
+
+Reply directly with text for conversations. Only use the 'message' tool to send to a specific chat channel.`;
+  }
+
+  private _buildRuntimeContext(channel?: string, chatId?: string): string {
+    const now = new Date().toLocaleString('en-US', {
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit',
+      hour: '2-digit',
+      minute: '2-digit',
+      weekday: 'long',
+    });
+    const tz = Intl.DateTimeFormat().resolvedOptions().timeZone;
+    const lines = [`Current Time: ${now} (${tz})`];
+    if (channel && chatId) {
+      lines.push(`Channel: ${channel}`, `Chat ID: ${chatId}`);
+    }
+    return `${RUNTIME_CONTEXT_TAG}\n${lines.join('\n')}`;
+  }
+
+  private _loadBootstrapFiles(): string {
+    const parts: string[] = [];
+    for (const filename of BOOTSTRAP_FILES) {
+      const path = join(this._workspace, filename);
+      if (existsSync(path)) {
+        const content = readFileSync(path, 'utf8');
+        parts.push(`## ${filename}\n\n${content}`);
+      }
+    }
+    return parts.join('\n\n');
+  }
+}