package filesystem

import java.nio.file.FileAlreadyExistsException
import java.nio.file.FileSystemException
import java.nio.file.Files
import java.nio.file.Path

class FSCreator {
    // Create entry, leaving existing folders' contents, but overwriting existing files.
    @Throws(FileSystemException::class)
    fun create(entryToCreate: FSEntry, destination: String) {
        val queue = ArrayDeque<Pair<FSEntry, Path>>()
        queue.add(entryToCreate to Path.of(destination))

        while (queue.isNotEmpty()) {
            val (entry, dest) = queue.removeFirst()
            val path = dest.resolve(entry.name)
            try {
                when (entry) {
                    is FSFile -> Files.createFile(path)
                    is FSFolder -> Files.createDirectory(path)
                }
            } catch (_: FileAlreadyExistsException) {} // Allow files/folders to already exist.
            when (entry) {
                is FSFile -> Files.write(path, entry.content.toByteArray())
                is FSFolder -> queue.addAll(entry.entries.map { it to path })
            }
        }
    }
}