package ru.dbotthepony.kstarbound.api

import java.io.*
import java.nio.ByteBuffer

interface IVFS {
	fun pathExists(path: String): Boolean

	fun read(path: String): ByteBuffer {
		return readOrNull(path) ?: throw FileNotFoundException("No such file $path")
	}

	fun readOrNull(path: String): ByteBuffer?

	fun readString(path: String): String {
		return read(path).array().toString(Charsets.UTF_8)
	}

	fun getReader(path: String): Reader {
		return InputStreamReader(ByteArrayInputStream(read(path).array()))
	}

	fun listFiles(path: String): Collection<String>

	fun readDirect(path: String): ByteBuffer {
		val read = read(path)

		val buf = ByteBuffer.allocateDirect(read.capacity())

		read.position(0)

		for (i in 0 until read.capacity()) {
			buf.put(read[i])
		}

		buf.position(0)

		return buf
	}
}

class PhysicalFS(root: File) : IVFS {
	val root: File = root.absoluteFile

	override fun pathExists(path: String): Boolean {
		if (path.contains("..")) {
			return false
		}

		return File(root.absolutePath, path).exists()
	}

	override fun readOrNull(path: String): ByteBuffer? {
		if (path.contains("..")) {
			return null
		}

		val fpath = File(root.path, path)

		if (!fpath.exists()) {
			return null
		}

		val reader = fpath.inputStream()
		val buf = ByteBuffer.allocate(reader.channel.size().toInt())
		reader.read(buf.array())
		return buf
	}

	override fun listFiles(path: String): List<String> {
		if (path.contains("..")) {
			return listOf()
		}
		val fpath = File(root.absolutePath, path)
		return fpath.listFiles()?.map {
			it.path.replace('\\', '/').substring(root.path.length)
		} ?: return listOf()
	}
}