co-mono/packages/coding-agent/src/core/tools/ls.ts

import type { AgentTool } from "@mariozechner/pi-ai";
import { Type } from "@sinclair/typebox";
import { existsSync, readdirSync, statSync } from "fs";
import nodePath from "path";
import { resolveToCwd } from "./path-utils.js";
import { DEFAULT_MAX_BYTES, formatSize, type TruncationResult, truncateHead } from "./truncate.js";

const lsSchema = Type.Object({
	path: Type.Optional(Type.String({ description: "Directory to list (default: current directory)" })),
	limit: Type.Optional(Type.Number({ description: "Maximum number of entries to return (default: 500)" })),
});

const DEFAULT_LIMIT = 500;

export interface LsToolDetails {
	truncation?: TruncationResult;
	entryLimitReached?: number;
}

export function createLsTool(cwd: string): AgentTool<typeof lsSchema> {
	return {
		name: "ls",
		label: "ls",
		description: `List directory contents. Returns entries sorted alphabetically, with '/' suffix for directories. Includes dotfiles. Output is truncated to ${DEFAULT_LIMIT} entries or ${DEFAULT_MAX_BYTES / 1024}KB (whichever is hit first).`,
		parameters: lsSchema,
		execute: async (
			_toolCallId: string,
			{ path, limit }: { path?: string; limit?: number },
			signal?: AbortSignal,
		) => {
			return new Promise((resolve, reject) => {
				if (signal?.aborted) {
					reject(new Error("Operation aborted"));
					return;
				}

				const onAbort = () => reject(new Error("Operation aborted"));
				signal?.addEventListener("abort", onAbort, { once: true });

				try {
					const dirPath = resolveToCwd(path || ".", cwd);
					const effectiveLimit = limit ?? DEFAULT_LIMIT;

					// Check if path exists
					if (!existsSync(dirPath)) {
						reject(new Error(`Path not found: ${dirPath}`));
						return;
					}

					// Check if path is a directory
					const stat = statSync(dirPath);
					if (!stat.isDirectory()) {
						reject(new Error(`Not a directory: ${dirPath}`));
						return;
					}

					// Read directory entries
					let entries: string[];
					try {
						entries = readdirSync(dirPath);
					} catch (e: any) {
						reject(new Error(`Cannot read directory: ${e.message}`));
						return;
					}

					// Sort alphabetically (case-insensitive)
					entries.sort((a, b) => a.toLowerCase().localeCompare(b.toLowerCase()));

					// Format entries with directory indicators
					const results: string[] = [];
					let entryLimitReached = false;

					for (const entry of entries) {
						if (results.length >= effectiveLimit) {
							entryLimitReached = true;
							break;
						}

						const fullPath = nodePath.join(dirPath, entry);
						let suffix = "";

						try {
							const entryStat = statSync(fullPath);
							if (entryStat.isDirectory()) {
								suffix = "/";
							}
						} catch {
							// Skip entries we can't stat
							continue;
						}

						results.push(entry + suffix);
					}

					signal?.removeEventListener("abort", onAbort);

					if (results.length === 0) {
						resolve({ content: [{ type: "text", text: "(empty directory)" }], details: undefined });
						return;
					}

					// Apply byte truncation (no line limit since we already have entry limit)
					const rawOutput = results.join("\n");
					const truncation = truncateHead(rawOutput, { maxLines: Number.MAX_SAFE_INTEGER });

					let output = truncation.content;
					const details: LsToolDetails = {};

					// Build notices
					const notices: string[] = [];

					if (entryLimitReached) {
						notices.push(`${effectiveLimit} entries limit reached. Use limit=${effectiveLimit * 2} for more`);
						details.entryLimitReached = effectiveLimit;
					}

					if (truncation.truncated) {
						notices.push(`${formatSize(DEFAULT_MAX_BYTES)} limit reached`);
						details.truncation = truncation;
					}

					if (notices.length > 0) {
						output += `\n\n[${notices.join(". ")}]`;
					}

					resolve({
						content: [{ type: "text", text: output }],
						details: Object.keys(details).length > 0 ? details : undefined,
					});
				} catch (e: any) {
					signal?.removeEventListener("abort", onAbort);
					reject(e);
				}
			});
		},
	};
}

/** Default ls tool using process.cwd() - for backwards compatibility */
export const lsTool = createLsTool(process.cwd());