const fs = require('fs')

const Path = require('path')

const promisify = require('util').promisify

const readdir = promisify(fs.readdir)

const lstat = promisify(fs.lstat)

const rename = promisify(fs.rename)

/* Converts the old (pre-5.0.0) extensionless files to $-based files _with_ extensions

* to make them work in the new resource mapper (post-5.0.0).

* By default, all extensionless files (that used to be interpreted as Turtle) will now receive a '$.ttl' suffix. */

/* https://www.w3.org/DesignIssues/HTTPFilenameMapping.html */

module.exports = function (program) {

program

.command('migrate-legacy-resources')

.option('-p, --path <path>', 'Path to the data folder, defaults to \'data/\'')

.option('-s, --suffix <path>', 'The suffix to add to extensionless files, defaults to \'$.ttl\'')

.option('-v, --verbose', 'Path to the data folder')

.description('Migrate the data folder from node-solid-server 4 to node-solid-server 5')

.action(async (opts) => {

const verbose = opts.verbose

const suffix = opts.suffix || '$.ttl'

let paths = opts.path ? [opts.path] : ['data', 'config/templates']

paths = paths.map(path => path.startsWith(Path.sep) ? path : Path.join(process.cwd(), path))

try {

for (const path of paths) {

if (verbose) {

console.log(`Migrating files in ${path}`)

}

await migrate(path, suffix, verbose)

}

} catch (err) {

console.error(err)

}

})

}

async function migrate (path, suffix, verbose) {

const files = await readdir(path)

for (const file of files) {

const fullFilePath = Path.join(path, file)

const stat = await lstat(fullFilePath)

if (stat.isFile()) {

if (shouldMigrateFile(file)) {

const newFullFilePath = getNewFileName(fullFilePath, suffix)

if (verbose) {

console.log(`${fullFilePath}\n => ${newFullFilePath}`)

}

await rename(fullFilePath, newFullFilePath)

}

} else {

if (shouldMigrateFolder(file)) {

await migrate(fullFilePath, suffix, verbose)

}

}

}

}

function getNewFileName (fullFilePath, suffix) {

return fullFilePath + suffix

}

function shouldMigrateFile (filename) {

return filename.indexOf('.') < 0

}

function shouldMigrateFolder (foldername) {

return foldername[0] !== '.'

}