Split main-new.ts into modules: cli/args, cli/file-processor, cli/session-picker, core/system-prompt, core/model-resolver

packages/coding-agent/src/core/system-prompt.ts

@@ -0,0 +1,247 @@
+/**
+ * System prompt construction and project context loading
+ */
+
+import chalk from "chalk";
+import { existsSync, readFileSync } from "fs";
+import { join, resolve } from "path";
+import { getAgentDir, getReadmePath } from "../utils/config.js";
+import type { ToolName } from "./tools/index.js";
+
+/** Tool descriptions for system prompt */
+const toolDescriptions: Record<ToolName, string> = {
+	read: "Read file contents",
+	bash: "Execute bash commands (ls, grep, find, etc.)",
+	edit: "Make surgical edits to files (find exact text and replace)",
+	write: "Create or overwrite files",
+	grep: "Search file contents for patterns (respects .gitignore)",
+	find: "Find files by glob pattern (respects .gitignore)",
+	ls: "List directory contents",
+};
+
+/** Resolve input as file path or literal string */
+function resolvePromptInput(input: string | undefined, description: string): string | undefined {
+	if (!input) {
+		return undefined;
+	}
+
+	if (existsSync(input)) {
+		try {
+			return readFileSync(input, "utf-8");
+		} catch (error) {
+			console.error(chalk.yellow(`Warning: Could not read ${description} file ${input}: ${error}`));
+			return input;
+		}
+	}
+
+	return input;
+}
+
+/** Look for AGENTS.md or CLAUDE.md in a directory (prefers AGENTS.md) */
+function loadContextFileFromDir(dir: string): { path: string; content: string } | null {
+	const candidates = ["AGENTS.md", "CLAUDE.md"];
+	for (const filename of candidates) {
+		const filePath = join(dir, filename);
+		if (existsSync(filePath)) {
+			try {
+				return {
+					path: filePath,
+					content: readFileSync(filePath, "utf-8"),
+				};
+			} catch (error) {
+				console.error(chalk.yellow(`Warning: Could not read ${filePath}: ${error}`));
+			}
+		}
+	}
+	return null;
+}
+
+/**
+ * Load all project context files in order:
+ * 1. Global: ~/{CONFIG_DIR_NAME}/agent/AGENTS.md or CLAUDE.md
+ * 2. Parent directories (top-most first) down to cwd
+ * Each returns {path, content} for separate messages
+ */
+export function loadProjectContextFiles(): Array<{ path: string; content: string }> {
+	const contextFiles: Array<{ path: string; content: string }> = [];
+
+	// 1. Load global context from ~/{CONFIG_DIR_NAME}/agent/
+	const globalContextDir = getAgentDir();
+	const globalContext = loadContextFileFromDir(globalContextDir);
+	if (globalContext) {
+		contextFiles.push(globalContext);
+	}
+
+	// 2. Walk up from cwd to root, collecting all context files
+	const cwd = process.cwd();
+	const ancestorContextFiles: Array<{ path: string; content: string }> = [];
+
+	let currentDir = cwd;
+	const root = resolve("/");
+
+	while (true) {
+		const contextFile = loadContextFileFromDir(currentDir);
+		if (contextFile) {
+			// Add to beginning so we get top-most parent first
+			ancestorContextFiles.unshift(contextFile);
+		}
+
+		// Stop if we've reached root
+		if (currentDir === root) break;
+
+		// Move up one directory
+		const parentDir = resolve(currentDir, "..");
+		if (parentDir === currentDir) break; // Safety check
+		currentDir = parentDir;
+	}
+
+	// Add ancestor files in order (top-most → cwd)
+	contextFiles.push(...ancestorContextFiles);
+
+	return contextFiles;
+}
+
+/** Build the system prompt with tools, guidelines, and context */
+export function buildSystemPrompt(
+	customPrompt?: string,
+	selectedTools?: ToolName[],
+	appendSystemPrompt?: string,
+): string {
+	const resolvedCustomPrompt = resolvePromptInput(customPrompt, "system prompt");
+	const resolvedAppendPrompt = resolvePromptInput(appendSystemPrompt, "append system prompt");
+
+	const now = new Date();
+	const dateTime = now.toLocaleString("en-US", {
+		weekday: "long",
+		year: "numeric",
+		month: "long",
+		day: "numeric",
+		hour: "2-digit",
+		minute: "2-digit",
+		second: "2-digit",
+		timeZoneName: "short",
+	});
+
+	const appendSection = resolvedAppendPrompt ? `\n\n${resolvedAppendPrompt}` : "";
+
+	if (resolvedCustomPrompt) {
+		let prompt = resolvedCustomPrompt;
+
+		if (appendSection) {
+			prompt += appendSection;
+		}
+
+		// Append project context files
+		const contextFiles = loadProjectContextFiles();
+		if (contextFiles.length > 0) {
+			prompt += "\n\n# Project Context\n\n";
+			prompt += "The following project context files have been loaded:\n\n";
+			for (const { path: filePath, content } of contextFiles) {
+				prompt += `## ${filePath}\n\n${content}\n\n`;
+			}
+		}
+
+		// Add date/time and working directory last
+		prompt += `\nCurrent date and time: ${dateTime}`;
+		prompt += `\nCurrent working directory: ${process.cwd()}`;
+
+		return prompt;
+	}
+
+	// Get absolute path to README.md
+	const readmePath = getReadmePath();
+
+	// Build tools list based on selected tools
+	const tools = selectedTools || (["read", "bash", "edit", "write"] as ToolName[]);
+	const toolsList = tools.map((t) => `- ${t}: ${toolDescriptions[t]}`).join("\n");
+
+	// Build guidelines based on which tools are actually available
+	const guidelinesList: string[] = [];
+
+	const hasBash = tools.includes("bash");
+	const hasEdit = tools.includes("edit");
+	const hasWrite = tools.includes("write");
+	const hasGrep = tools.includes("grep");
+	const hasFind = tools.includes("find");
+	const hasLs = tools.includes("ls");
+	const hasRead = tools.includes("read");
+
+	// Read-only mode notice (no bash, edit, or write)
+	if (!hasBash && !hasEdit && !hasWrite) {
+		guidelinesList.push("You are in READ-ONLY mode - you cannot modify files or execute arbitrary commands");
+	}
+
+	// Bash without edit/write = read-only bash mode
+	if (hasBash && !hasEdit && !hasWrite) {
+		guidelinesList.push(
+			"Use bash ONLY for read-only operations (git log, gh issue view, curl, etc.) - do NOT modify any files",
+		);
+	}
+
+	// File exploration guidelines
+	if (hasBash && !hasGrep && !hasFind && !hasLs) {
+		guidelinesList.push("Use bash for file operations like ls, grep, find");
+	} else if (hasBash && (hasGrep || hasFind || hasLs)) {
+		guidelinesList.push("Prefer grep/find/ls tools over bash for file exploration (faster, respects .gitignore)");
+	}
+
+	// Read before edit guideline
+	if (hasRead && hasEdit) {
+		guidelinesList.push("Use read to examine files before editing");
+	}
+
+	// Edit guideline
+	if (hasEdit) {
+		guidelinesList.push("Use edit for precise changes (old text must match exactly)");
+	}
+
+	// Write guideline
+	if (hasWrite) {
+		guidelinesList.push("Use write only for new files or complete rewrites");
+	}
+
+	// Output guideline (only when actually writing/executing)
+	if (hasEdit || hasWrite) {
+		guidelinesList.push(
+			"When summarizing your actions, output plain text directly - do NOT use cat or bash to display what you did",
+		);
+	}
+
+	// Always include these
+	guidelinesList.push("Be concise in your responses");
+	guidelinesList.push("Show file paths clearly when working with files");
+
+	const guidelines = guidelinesList.map((g) => `- ${g}`).join("\n");
+
+	let prompt = `You are an expert coding assistant. You help users with coding tasks by reading files, executing commands, editing code, and writing new files.
+
+Available tools:
+${toolsList}
+
+Guidelines:
+${guidelines}
+
+Documentation:
+- Your own documentation (including custom model setup and theme creation) is at: ${readmePath}
+- Read it when users ask about features, configuration, or setup, and especially if the user asks you to add a custom model or provider, or create a custom theme.`;
+
+	if (appendSection) {
+		prompt += appendSection;
+	}
+
+	// Append project context files
+	const contextFiles = loadProjectContextFiles();
+	if (contextFiles.length > 0) {
+		prompt += "\n\n# Project Context\n\n";
+		prompt += "The following project context files have been loaded:\n\n";
+		for (const { path: filePath, content } of contextFiles) {
+			prompt += `## ${filePath}\n\n${content}\n\n`;
+		}
+	}
+
+	// Add date/time and working directory last
+	prompt += `\nCurrent date and time: ${dateTime}`;
+	prompt += `\nCurrent working directory: ${process.cwd()}`;
+
+	return prompt;
+}