feat: config file at ~/.aicommits (#51)

Co-authored-by: Yu Le <is.yuler@gmail.com>

src/cli.ts

@@ -3,11 +3,15 @@
 import { execSync } from 'child_process';
 import chalk from 'chalk';
 import inquirer from 'inquirer';
-import { generateCommitMessage } from './utils';
-
-const OPENAI_KEY = process.env.OPENAI_KEY ?? process.env.OPENAI_API_KEY;
+import {
+	getConfig,
+	generateCommitMessage,
+} from './utils';
 
 (async () => {
+	const config = await getConfig();
+	const OPENAI_KEY = process.env.OPENAI_KEY ?? process.env.OPENAI_API_KEY ?? config.OPENAI_KEY;
+
 	console.log(chalk.white('▲ ') + chalk.green('Welcome to AICommits!'));
 
 	if (!OPENAI_KEY) {

src/utils.ts

@@ -1,5 +1,26 @@
+import fs from 'fs/promises';
+import path from 'path';
+import os from 'os';
+import ini from 'ini';
 import { Configuration, OpenAIApi } from 'openai';
 
+const fileExists = (filePath: string) => fs.access(filePath).then(() => true, () => false);
+
+type ConfigType = {
+	OPENAI_KEY?: string;
+};
+
+export const getConfig = async (): Promise<ConfigType> => {
+	const configPath = path.join(os.homedir(), '.aicommits');
+	const configExists = await fileExists(configPath);
+	if (!configExists) {
+		return {};
+	}
+
+	const configString = await fs.readFile(configPath, 'utf8');
+	return ini.parse(configString);
+};
+
 export const generateCommitMessage = async (
 	apiKey: string,
 	prompt: string,