import { mkdir, readFile, writeFile } from 'node:fs/promises';
import { resolve, dirname } from 'node:path';
import { configService } from './services/config-service.js';
import { logger } from './logger.js';
const BLOCK_START = '# cache.overflow';
// Matches "# cache.overflow", "## cache.overflow", "### cache.overflow", etc.
const BLOCK_REGEX = /#{1,6} cache\.overflow\n```\n[\s\S]*?\n```/;
function wrapInstructions(instructions: string): string {
return `${BLOCK_START}\n\`\`\`\n${instructions}\n\`\`\``;
}
/**
* Initialize a repository file with cache.overflow server instructions.
*
* Fetches the latest instructions from the cache.overflow API and injects
* them into the given file, wrapped in a recognizable block. If the block
* already exists, it is replaced in-place. Otherwise it is appended.
*/
export async function initAgent(filePath: string): Promise<void> {
const resolvedPath = resolve(process.cwd(), filePath);
// 1. Fetch instructions from the API
console.log('Fetching cache.overflow instructions...');
const remoteConfig = await configService.fetchConfig();
if (!remoteConfig.instructions) {
throw new Error('Remote config missing instructions field');
}
const block = wrapInstructions(remoteConfig.instructions);
// 2. Ensure parent directories exist
const parentDir = dirname(resolvedPath);
await mkdir(parentDir, { recursive: true });
// 3. Read existing file content (or start empty)
let existingContent = '';
try {
existingContent = await readFile(resolvedPath, 'utf-8');
} catch (err: unknown) {
if ((err as NodeJS.ErrnoException).code !== 'ENOENT') {
throw err;
}
// File doesn't exist yet — that's fine, we'll create it
}
// 4. Inject or replace the block
let newContent: string;
if (BLOCK_REGEX.test(existingContent)) {
// Replace existing block in-place
newContent = existingContent.replace(BLOCK_REGEX, block);
console.log('Replaced existing cache.overflow block.');
} else if (existingContent.length > 0) {
// Append to existing content with a blank line separator
newContent = existingContent.trimEnd() + '\n\n' + block + '\n';
console.log('Appended cache.overflow block to existing file.');
} else {
// New file
newContent = block + '\n';
console.log('Created new file with cache.overflow block.');
}
// 5. Write the file
await writeFile(resolvedPath, newContent, 'utf-8');
logger.info('Injected cache.overflow instructions', {
filePath: resolvedPath,
replaced: BLOCK_REGEX.test(existingContent),
});
console.log(`cache.overflow instructions injected into ${filePath}`);
}
