import * as fs from 'fs/promises';
import { ExtractFunctionArgs } from '../types.js';
import { LSPClientManager } from '../lsp/client.js';
import { findWorkspaceRoot } from '../lsp/utils.js';
export async function extractFunction(args: ExtractFunctionArgs, clientManager: LSPClientManager) {
const {
file,
startLine,
startCharacter = 0,
endLine,
endCharacter = 0,
functionName: _functionName,
language = 'typescript',
} = args;
const workspaceRoot = findWorkspaceRoot(file);
try {
const client = await clientManager.getOrCreateLSPClient(language, workspaceRoot);
// Open the file
const content = await fs.readFile(file, 'utf-8');
await clientManager.sendLSPNotification(client, 'textDocument/didOpen', {
textDocument: {
uri: `file://${file}`,
languageId: language,
version: 1,
text: content,
},
});
// Request LSP code actions for extract function
const codeActions = await clientManager.sendLSPRequest(client, 'textDocument/codeAction', {
textDocument: { uri: `file://${file}` },
range: {
start: { line: startLine - 1, character: startCharacter },
end: { line: endLine - 1, character: endCharacter },
},
context: {
diagnostics: [],
only: ['refactor.extract.function'],
},
});
const actions = Array.isArray(codeActions) ? codeActions : [];
if (actions.length === 0) {
return {
content: [
{
type: 'text',
text: `No extract function refactoring available for the selected range in ${file}. This could be because the range does not contain extractable code or the language server doesn't support this refactoring.`,
},
],
};
}
// Apply the first extract function action
const action = actions[0];
if (!action.edit) {
return {
content: [
{
type: 'text',
text: `Extract function code action does not contain workspace edit. The language server may not be configured properly for refactoring operations.`,
},
],
};
}
const { applyWorkspaceEdit } = await import('../lsp/utils.js');
await applyWorkspaceEdit(action.edit);
return {
content: [
{
type: 'text',
text: `Successfully extracted function from lines ${startLine}-${endLine} in ${file}`,
},
],
};
} catch (error) {
return {
content: [
{
type: 'text',
text: `Failed to extract function: ${error instanceof Error ? error.message : String(error)}`,
},
],
};
}
}
