src/main/scala/li/cil/oc/server/fs/FileInputStreamFileSystem.scala

package li.cil.oc.server.fs

import java.io

trait FileInputStreamFileSystem extends InputStreamFileSystem {
  protected def root: io.File

  // ----------------------------------------------------------------------- //

  override def spaceTotal = spaceUsed

  override def spaceUsed = spaceUsed_

  private lazy val spaceUsed_ = {
    def recurse(path: io.File): Long = {
      if (path.isDirectory)
        path.listFiles.foldLeft(0L)((acc, f) => acc + recurse(f))
      else
        path.length
    }
    recurse(root)
  }

  // ----------------------------------------------------------------------- //

  override def exists(path: String) = new io.File(root, FileSystem.validatePath(path)).exists()

  override def size(path: String) = new io.File(root, FileSystem.validatePath(path)) match {
    case file if file.isFile => file.length()
    case _ => 0L
  }

  override def isDirectory(path: String) = new io.File(root, FileSystem.validatePath(path)).isDirectory

  override def lastModified(path: String) = new io.File(root, FileSystem.validatePath(path)).lastModified

  override def list(path: String) = new io.File(root, FileSystem.validatePath(path)) match {
    case file if file.exists() && file.isFile => Array(file.getName)
    case directory if directory.exists() && directory.isDirectory && directory.list() != null =>
      directory.listFiles().map(file => if (file.isDirectory) file.getName + "/" else file.getName)
    case _ => throw new io.FileNotFoundException("no such file or directory: " + path)
  }

  // ----------------------------------------------------------------------- //

  override protected def openInputChannel(path: String) = Some(new FileChannel(new io.File(root, path)))

  protected class FileChannel(file: io.File) extends InputChannel {
    val channel = new io.RandomAccessFile(file, "r").getChannel

    override def position(newPosition: Long) = {
      channel.position(newPosition)
      channel.position
    }

    override def position = channel.position

    override def close() = channel.close()

    override def isOpen = channel.isOpen

    override def read(dst: Array[Byte]) = channel.read(java.nio.ByteBuffer.wrap(dst))
  }

}