import { STORE_LINKS, retrieveDenominator,

substituteDenominator } from '../prelude/common.js';

import path from 'path';

const win32 = process.platform === 'win32';

function hasParent (file, records) {

const dirname = path.dirname(file);

if (dirname === file) return false; // root directory

return Boolean(records[dirname]);

}

function purgeTopDirectories (records) {

while (true) {

let found = false;

for (const file in records) {

const record = records[file];

const links = record[STORE_LINKS];

if (links && links.length === 1) {

if (!hasParent(file, records)) {

const file2 = path.join(file, links[0]);

const record2 = records[file2];

const links2 = record2[STORE_LINKS];

if (links2 && links2.length === 1) {

const file3 = path.join(file2, links2[0]);

const record3 = records[file3];

const links3 = record3[STORE_LINKS];

if (links3) {

delete records[file];

found = true;

}

}

}

}

}

if (!found) break;

}

}

function denominate (records, entrypoint, denominator) {

const newRecords = {};

for (const file in records) {

let snap = substituteDenominator(file, denominator);

if (win32) {

if (snap.slice(1) === ':') snap += '\\';

} else {

if (snap === '') snap = '/';

}

newRecords[snap] = records[file];

}

return {

records: newRecords,

entrypoint: substituteDenominator(entrypoint, denominator)

};

}

export default function (records, entrypoint) {

purgeTopDirectories(records);

const denominator = retrieveDenominator(Object.keys(records));

return denominate(records, entrypoint, denominator);

}