/**
* Copyright (c) 2026 Ivan Iraci <ivan.iraci@professioneit.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
import type { TextEdit, FormattingOptions } from 'vscode-languageserver-protocol';
import type { FormatDocumentInput } from '../schemas/tool-schemas.js';
import type { FormatDocumentResponse, FormatEdit } from '../types.js';
import { prepareFile } from './utils.js';
import { readFile } from '../utils/uri.js';
import * as fs from 'fs/promises';
/**
* Convert TextEdit to FormatEdit.
*/
function convertEdit(edit: TextEdit): FormatEdit {
return {
range: {
start: { line: edit.range.start.line + 1, column: edit.range.start.character + 1 },
end: { line: edit.range.end.line + 1, column: edit.range.end.character + 1 },
},
new_text: edit.newText,
};
}
/**
* Apply edits to content (edits must be sorted by position, applied from end to start).
*/
function applyEdits(content: string, edits: TextEdit[]): string {
// Sort edits by position in reverse order (apply from end to start)
const sortedEdits = [...edits].sort((a, b) => {
if (a.range.start.line !== b.range.start.line) {
return b.range.start.line - a.range.start.line;
}
return b.range.start.character - a.range.start.character;
});
const lines = content.split('\n');
let result = content;
for (const edit of sortedEdits) {
// Calculate byte offsets
let startOffset = 0;
for (let i = 0; i < edit.range.start.line; i++) {
startOffset += (lines[i]?.length ?? 0) + 1; // +1 for newline
}
startOffset += edit.range.start.character;
let endOffset = 0;
for (let i = 0; i < edit.range.end.line; i++) {
endOffset += (lines[i]?.length ?? 0) + 1;
}
endOffset += edit.range.end.character;
// Apply the edit
result = result.substring(0, startOffset) + edit.newText + result.substring(endOffset);
}
return result;
}
/**
* Handle lsp_format_document tool call.
*/
export async function handleFormatDocument(
input: FormatDocumentInput
): Promise<FormatDocumentResponse> {
const { file_path, tab_size, insert_spaces, apply } = input;
const { client, uri } = await prepareFile(file_path);
// Build formatting options
const options: FormattingOptions = {
tabSize: tab_size,
insertSpaces: insert_spaces,
};
// Call LSP
const result = await client.formatDocument(uri, options);
if (!result || result.length === 0) {
return {
edits: [],
edits_count: 0,
applied: false,
};
}
// Convert edits
const edits = result.map(convertEdit);
// Apply changes if requested
if (apply) {
const currentContent = await readFile(file_path);
const newContent = applyEdits(currentContent, result);
await fs.writeFile(file_path, newContent, 'utf-8');
}
return {
edits,
edits_count: edits.length,
applied: apply,
};
}
