import fs from "node:fs/promises";

import os from "node:os";

import path from "node:path";

import findCacheDir from "find-cache-dir";

import { isJson, statSafe } from "./utils.js";

/**

* Find default cache file (`./node_modules/.cache/prettier/.prettier-cache`) using https://github.com/avajs/find-cache-dir

*/

function findDefaultCacheFile() {

const cacheDir =

findCacheDir({ name: "prettier", create: true }) || os.tmpdir();

const cacheFilePath = path.join(cacheDir, ".prettier-cache");

return cacheFilePath;

}

async function findCacheFileFromOption(cacheLocation) {

const cacheFile = path.resolve(cacheLocation);

const stat = await statSafe(cacheFile);

if (stat) {

if (stat.isDirectory()) {

throw new Error(

`Resolved --cache-location '${cacheFile}' is a directory`,

);

}

const data = await fs.readFile(cacheFile, "utf8");

if (!isJson(data)) {

throw new Error(`'${cacheFile}' isn't a valid JSON file`);

}

}

return cacheFile;

}

/**

* @param {string | undefined} cacheLocation

* @returns {Promise<string>}

*/

async function findCacheFile(cacheLocation) {

if (!cacheLocation) {

return findDefaultCacheFile();

}

const cacheFile = await findCacheFileFromOption(cacheLocation);

return cacheFile;

}

export default findCacheFile;