config-file.ts

import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';
import { z } from 'zod';
import { providerNames } from './engine/providers/provider.js';

const LEGACY_CONFIG_FILENAME = '.airc';
const CONFIG_FILENAME = '.airc.json';

const CommonProviderSchema = z.object({
  apiKey: z.string(),
  model: z.string().optional(),
  systemPrompt: z.string().optional(),
});

const ProvidersSchema = z.object({
  openAi: z.optional(CommonProviderSchema),
  anthropic: z.optional(CommonProviderSchema),
  perplexity: z.optional(CommonProviderSchema),
  mistral: z.optional(CommonProviderSchema),
});

const ConfigFileSchema = z.object({
  providers: ProvidersSchema,
});

export type ConfigFile = z.infer<typeof ConfigFileSchema>;

export function parseConfigFile() {
  const configPath = path.join(os.homedir(), CONFIG_FILENAME);

  const content = fs.readFileSync(configPath);
  const json = JSON.parse(content.toString());

  const typedConfig = ConfigFileSchema.parse(json);
  if (providerNames.every((p) => !typedConfig.providers[p]?.apiKey)) {
    throw new Error(`Add your provider API key to "~/${CONFIG_FILENAME}" and try again.`);
  }

  // Note: we return original json object, and not `typedConfig` because we want to preserve
  // the original order of providers in the config file.
  return json;
}

export function writeConfigFile(configContents: ConfigFile) {
  const configPath = path.join(os.homedir(), CONFIG_FILENAME);
  fs.writeFileSync(configPath, JSON.stringify(configContents, null, 2) + '\n');
}

export function checkIfConfigExists() {
  const legacyConfigPath = path.join(os.homedir(), LEGACY_CONFIG_FILENAME);
  const configPath = path.join(os.homedir(), CONFIG_FILENAME);

  if (fs.existsSync(legacyConfigPath) && !fs.existsSync(configPath)) {
    fs.renameSync(legacyConfigPath, configPath);
  }

  return fs.existsSync(configPath);
}