import { mkdir, readFile, writeFile } from 'node:fs/promises';

import path from 'node:path';

const cacheGitignore = '*\n';

type ProjectCacheResult =

{ status: 'available'; path: string } | { status: 'unavailable'; path: string; error: unknown };

/** Returns the disposable cache directory for a resolved Rstack project root. */

const getProjectCacheDir = (rootPath: string): string => path.join(rootPath, '.rstack', 'cache');

/** Creates the project cache directory without making cache failures fatal. */

const ensureProjectCacheDir = async (rootPath: string): Promise<ProjectCacheResult> => {

const cachePath = getProjectCacheDir(rootPath);

const ignorePath = path.join(cachePath, '.gitignore');

try {

if ((await readFile(ignorePath, 'utf8')) === cacheGitignore) {

return { status: 'available', path: cachePath };

}

} catch {

// Create or repair the marker below.

}

try {

await mkdir(cachePath, { recursive: true });

await writeFile(ignorePath, cacheGitignore);

return { status: 'available', path: cachePath };

} catch (error) {

return { status: 'unavailable', path: cachePath, error };

}

};

export { ensureProjectCacheDir };

export type { ProjectCacheResult };