dev/third_party/pi/packages/coding-agent/examples/extensions/minimal-mode.ts

/**
 * Minimal Mode Example - Demonstrates a "minimal" tool display mode
 *
 * This extension overrides built-in tools to provide custom rendering:
 * - Collapsed mode: Only shows the tool call (command/path), no output
 * - Expanded mode: Shows full output like the built-in renderers
 *
 * This demonstrates how a "minimal mode" could work, where ctrl+o cycles through:
 * - Standard: Shows truncated output (current default)
 * - Expanded: Shows full output (current expanded)
 * - Minimal: Shows only tool call, no output (this extension's collapsed mode)
 *
 * Usage:
 *   pi -e ./minimal-mode.ts
 *
 * Then use ctrl+o to toggle between minimal (collapsed) and full (expanded) views.
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import {
	createBashToolDefinition,
	createEditToolDefinition,
	createFindToolDefinition,
	createGrepToolDefinition,
	createLsToolDefinition,
	createReadToolDefinition,
	createWriteToolDefinition,
	formatReadLineRange,
} from "@earendil-works/pi-coding-agent";
import { Text } from "@earendil-works/pi-tui";
import { homedir } from "os";

/**
 * Shorten a path by replacing home directory with ~
 */
function shortenPath(path: string): string {
	const home = homedir();
	if (path.startsWith(home)) {
		return `~${path.slice(home.length)}`;
	}
	return path;
}

function createBuiltInTools(cwd: string) {
	return {
		read: createReadToolDefinition(cwd),
		bash: createBashToolDefinition(cwd),
		edit: createEditToolDefinition(cwd),
		write: createWriteToolDefinition(cwd),
		find: createFindToolDefinition(cwd),
		grep: createGrepToolDefinition(cwd),
		ls: createLsToolDefinition(cwd),
	};
}

export default function (pi: ExtensionAPI) {
	const tools = createBuiltInTools(process.cwd());

	// =========================================================================
	// Read Tool
	// =========================================================================
	pi.registerTool({
		...tools.read,

		renderCall(args, theme, _context) {
			const path = shortenPath(args.path || "");
			let pathDisplay = path ? theme.fg("accent", path) : theme.fg("toolOutput", "...");

			const lineRange = formatReadLineRange(args.offset, args.limit);
			if (lineRange) {
				pathDisplay += theme.fg("warning", lineRange);
			}

			return new Text(`${theme.fg("toolTitle", theme.bold("read"))} ${pathDisplay}`, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			// Minimal mode: show nothing in collapsed state
			if (!expanded) {
				return new Text("", 0, 0);
			}

			// Expanded mode: show full output
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			const lines = textContent.text.split("\n");
			const output = lines.map((line) => theme.fg("toolOutput", line)).join("\n");
			return new Text(`\n${output}`, 0, 0);
		},
	});

	// =========================================================================
	// Bash Tool
	// =========================================================================
	pi.registerTool({
		...tools.bash,

		renderCall(args, theme, _context) {
			const command = args.command || "...";
			const timeout = args.timeout as number | undefined;
			const timeoutSuffix = timeout ? theme.fg("muted", ` (timeout ${timeout}s)`) : "";

			return new Text(theme.fg("toolTitle", theme.bold(`$ ${command}`)) + timeoutSuffix, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			// Minimal mode: show nothing in collapsed state
			if (!expanded) {
				return new Text("", 0, 0);
			}

			// Expanded mode: show full output
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			const output = textContent.text
				.trim()
				.split("\n")
				.map((line) => theme.fg("toolOutput", line))
				.join("\n");

			if (!output) {
				return new Text("", 0, 0);
			}

			return new Text(`\n${output}`, 0, 0);
		},
	});

	// =========================================================================
	// Write Tool
	// =========================================================================
	pi.registerTool({
		...tools.write,

		renderCall(args, theme, _context) {
			const path = shortenPath(args.path || "");
			const pathDisplay = path ? theme.fg("accent", path) : theme.fg("toolOutput", "...");
			const lineCount = args.content ? args.content.split("\n").length : 0;
			const lineInfo = lineCount > 0 ? theme.fg("muted", ` (${lineCount} lines)`) : "";

			return new Text(`${theme.fg("toolTitle", theme.bold("write"))} ${pathDisplay}${lineInfo}`, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			// Minimal mode: show nothing (file was written)
			if (!expanded) {
				return new Text("", 0, 0);
			}

			// Expanded mode: show error if any
			if (result.content.some((c) => c.type === "text" && c.text)) {
				const textContent = result.content.find((c) => c.type === "text");
				if (textContent?.type === "text" && textContent.text) {
					return new Text(`\n${theme.fg("error", textContent.text)}`, 0, 0);
				}
			}

			return new Text("", 0, 0);
		},
	});

	// =========================================================================
	// Edit Tool
	// =========================================================================
	pi.registerTool({
		...tools.edit,
		renderShell: "default",

		renderCall(args, theme, _context) {
			const path = shortenPath(args.path || "");
			const pathDisplay = path ? theme.fg("accent", path) : theme.fg("toolOutput", "...");

			return new Text(`${theme.fg("toolTitle", theme.bold("edit"))} ${pathDisplay}`, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			// Minimal mode: show nothing in collapsed state
			if (!expanded) {
				return new Text("", 0, 0);
			}

			// Expanded mode: show diff or error
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			// For errors, show the error message
			const text = textContent.text;
			if (text.includes("Error") || text.includes("error")) {
				return new Text(`\n${theme.fg("error", text)}`, 0, 0);
			}

			// Otherwise show the text (would be nice to show actual diff here)
			return new Text(`\n${theme.fg("toolOutput", text)}`, 0, 0);
		},
	});

	// =========================================================================
	// Find Tool
	// =========================================================================
	pi.registerTool({
		...tools.find,

		renderCall(args, theme, _context) {
			const pattern = args.pattern || "";
			const path = shortenPath(args.path || ".");
			const limit = args.limit;

			let text = `${theme.fg("toolTitle", theme.bold("find"))} ${theme.fg("accent", pattern)}`;
			text += theme.fg("toolOutput", ` in ${path}`);
			if (limit !== undefined) {
				text += theme.fg("toolOutput", ` (limit ${limit})`);
			}

			return new Text(text, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			if (!expanded) {
				// Minimal: just show count
				const textContent = result.content.find((c) => c.type === "text");
				if (textContent?.type === "text") {
					const count = textContent.text.trim().split("\n").filter(Boolean).length;
					if (count > 0) {
						return new Text(theme.fg("muted", ` → ${count} files`), 0, 0);
					}
				}
				return new Text("", 0, 0);
			}

			// Expanded: show full results
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			const output = textContent.text
				.trim()
				.split("\n")
				.map((line) => theme.fg("toolOutput", line))
				.join("\n");

			return new Text(`\n${output}`, 0, 0);
		},
	});

	// =========================================================================
	// Grep Tool
	// =========================================================================
	pi.registerTool({
		...tools.grep,

		renderCall(args, theme, _context) {
			const pattern = args.pattern || "";
			const path = shortenPath(args.path || ".");
			const glob = args.glob;
			const limit = args.limit;

			let text = `${theme.fg("toolTitle", theme.bold("grep"))} ${theme.fg("accent", `/${pattern}/`)}`;
			text += theme.fg("toolOutput", ` in ${path}`);
			if (glob) {
				text += theme.fg("toolOutput", ` (${glob})`);
			}
			if (limit !== undefined) {
				text += theme.fg("toolOutput", ` limit ${limit}`);
			}

			return new Text(text, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			if (!expanded) {
				// Minimal: just show match count
				const textContent = result.content.find((c) => c.type === "text");
				if (textContent?.type === "text") {
					const count = textContent.text.trim().split("\n").filter(Boolean).length;
					if (count > 0) {
						return new Text(theme.fg("muted", ` → ${count} matches`), 0, 0);
					}
				}
				return new Text("", 0, 0);
			}

			// Expanded: show full results
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			const output = textContent.text
				.trim()
				.split("\n")
				.map((line) => theme.fg("toolOutput", line))
				.join("\n");

			return new Text(`\n${output}`, 0, 0);
		},
	});

	// =========================================================================
	// Ls Tool
	// =========================================================================
	pi.registerTool({
		...tools.ls,

		renderCall(args, theme, _context) {
			const path = shortenPath(args.path || ".");
			const limit = args.limit;

			let text = `${theme.fg("toolTitle", theme.bold("ls"))} ${theme.fg("accent", path)}`;
			if (limit !== undefined) {
				text += theme.fg("toolOutput", ` (limit ${limit})`);
			}

			return new Text(text, 0, 0);
		},

		renderResult(result, { expanded }, theme, _context) {
			if (!expanded) {
				// Minimal: just show entry count
				const textContent = result.content.find((c) => c.type === "text");
				if (textContent?.type === "text") {
					const count = textContent.text.trim().split("\n").filter(Boolean).length;
					if (count > 0) {
						return new Text(theme.fg("muted", ` → ${count} entries`), 0, 0);
					}
				}
				return new Text("", 0, 0);
			}

			// Expanded: show full listing
			const textContent = result.content.find((c) => c.type === "text");
			if (!textContent || textContent.type !== "text") {
				return new Text("", 0, 0);
			}

			const output = textContent.text
				.trim()
				.split("\n")
				.map((line) => theme.fg("toolOutput", line))
				.join("\n");

			return new Text(`\n${output}`, 0, 0);
		},
	});
}