import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
import { readFile, writeFile } from 'node:fs/promises';
import { join, relative } from 'node:path';
import { scanSchemeFiles, findSymbolOccurrences } from './parse-utils.js';
function escapeRegExp(s: string): string {
return s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}
function replaceSymbolInContent(
content: string,
oldName: string,
newName: string,
): string {
const escaped = escapeRegExp(oldName);
// Use Scheme word boundaries for safe replacement
const pattern = new RegExp(
`(?<=[ \\t\\n\\r()\\[\\]{}"',;\`#]|^)${escaped}(?=[ \\t\\n\\r()\\[\\]{}"',;\`#]|$)`,
'gm',
);
return content.replace(pattern, newName);
}
export function registerRenameSymbolTool(server: McpServer): void {
server.registerTool(
'gerbil_rename_symbol',
{
title: 'Project-Wide Rename',
description:
'Rename a symbol across all .ss files in a project directory. ' +
'Default is dry-run mode (showing proposed changes). ' +
'Set dry_run to false to apply changes. Uses word-boundary detection ' +
'to avoid renaming partial matches.',
annotations: {
readOnlyHint: false,
idempotentHint: true,
},
inputSchema: {
old_name: z.string().describe('Current symbol name to rename'),
new_name: z.string().describe('New symbol name'),
directory: z
.string()
.optional()
.describe('Project directory to search (absolute path). Required unless file_path is provided.'),
file_path: z
.string()
.optional()
.describe('Single file to rename in (absolute path). Alternative to directory for local renames.'),
dry_run: z
.boolean()
.optional()
.describe(
'If true (default), only show changes without applying them',
),
},
},
async ({ old_name, new_name, directory, file_path, dry_run }) => {
const isDryRun = dry_run !== false;
if (!directory && !file_path) {
return {
content: [{
type: 'text' as const,
text: 'Either "directory" or "file_path" must be provided.',
}],
isError: true,
};
}
if (old_name === new_name) {
return {
content: [
{
type: 'text' as const,
text: 'Old and new names are identical. Nothing to do.',
},
],
};
}
// Single-file mode or directory mode
const files = file_path
? [file_path]
: await scanSchemeFiles(directory!);
const baseDir = directory || (file_path ? join(file_path, '..') : '.');
if (files.length === 0) {
return {
content: [
{
type: 'text' as const,
text: `No .ss files found in ${baseDir}.`,
},
],
};
}
const allChanges: Array<{
file: string;
line: number;
column: number;
lineText: string;
}> = [];
for (const file of files) {
try {
const content = await readFile(file, 'utf-8');
const occurrences = findSymbolOccurrences(content, old_name);
for (const occ of occurrences) {
allChanges.push({
file: relative(baseDir, file),
line: occ.line,
column: occ.column,
lineText: occ.lineText,
});
}
} catch {
/* skip unreadable files */
}
}
if (allChanges.length === 0) {
return {
content: [
{
type: 'text' as const,
text: `No occurrences of "${old_name}" found in ${file_path || directory}.`,
},
],
};
}
if (isDryRun) {
const sections: string[] = [
`Dry run: ${allChanges.length} occurrence${allChanges.length === 1 ? '' : 's'} of "${old_name}" -> "${new_name}":`,
'',
];
const byFile = new Map<string, typeof allChanges>();
for (const ch of allChanges) {
if (!byFile.has(ch.file)) byFile.set(ch.file, []);
byFile.get(ch.file)!.push(ch);
}
for (const [file, changes] of byFile) {
sections.push(` ${file} (${changes.length}):`);
for (const ch of changes) {
const preview = ch.lineText.trim();
const replaced = replaceSymbolInContent(
preview,
old_name,
new_name,
);
sections.push(` L${ch.line}:${ch.column} ${preview}`);
if (replaced !== preview) {
sections.push(` -> ${replaced}`);
}
}
}
sections.push('');
sections.push('Set dry_run to false to apply these changes.');
return {
content: [{ type: 'text' as const, text: sections.join('\n') }],
};
}
// Apply changes
const filesModified = new Set<string>();
for (const file of files) {
const fullPath = file;
try {
const content = await readFile(fullPath, 'utf-8');
const replaced = replaceSymbolInContent(content, old_name, new_name);
if (replaced !== content) {
await writeFile(fullPath, replaced, 'utf-8');
filesModified.add(relative(baseDir, fullPath));
}
} catch {
/* skip unreadable files */
}
}
return {
content: [
{
type: 'text' as const,
text:
`Renamed "${old_name}" -> "${new_name}": ` +
`${allChanges.length} occurrence${allChanges.length === 1 ? '' : 's'} ` +
`in ${filesModified.size} file${filesModified.size === 1 ? '' : 's'}.`,
},
],
};
},
);
}
