package xsbt.boot
import scala.collection.immutable.List
import java.io.{File, FileFilter}
import java.net.{URL, URLClassLoader}
object Pre
{
def trimLeading(line: String) =
{
def newStart(i: Int): Int = if(i >= line.length || !Character.isWhitespace(line.charAt(i))) i else newStart(i+1)
line.substring(newStart(0))
}
def isEmpty(line: String) = line.length == 0
def isNonEmpty(line: String) = line.length > 0
def assert(condition: Boolean, msg: => String): Unit = if (!condition) throw new AssertionError(msg)
def assert(condition: Boolean): Unit = assert(condition, "Assertion failed")
def require(condition: Boolean, msg: => String): Unit = if (!condition) throw new IllegalArgumentException(msg)
def error(msg: String): Nothing = throw new BootException(prefixError(msg))
def declined(msg: String): Nothing = throw new BootException(msg)
def prefixError(msg: String): String = "Error during sbt execution: " + msg
def toBoolean(s: String) = java.lang.Boolean.parseBoolean(s)
def toArray[T : ClassManifest](list: List[T]) =
{
val arr = new Array[T](list.length)
def copy(i: Int, rem: List[T]): Unit =
if(i < arr.length)
{
arr(i) = rem.head
copy(i+1, rem.tail)
}
copy(0, list)
arr
}
def concat(a: Array[File], b: Array[File]): Array[File] =
{
val n = new Array[File](a.length + b.length)
java.lang.System.arraycopy(a, 0, n, 0, a.length)
java.lang.System.arraycopy(b, 0, n, a.length, b.length)
n
}
def array(files: File*): Array[File] = toArray(files.toList)
def orElse[T](opt: Option[T], default: T) = if(opt.isDefined) opt.get else default
def wrapNull(a: Array[File]): Array[File] = if(a == null) new Array[File](0) else a
def const[B](b: B): Any => B = _ => b
def strictOr[T](a: Option[T], b: Option[T]): Option[T] = a match { case None => b; case _ => a }
def getOrError[T](a: Option[T], msg: String): T = a match { case None => error(msg); case Some(x) => x }
def orNull[T >: Null](t: Option[T]): T = t match { case None => null; case Some(x) => x }
def getJars(directories: List[File]): Array[File] = toArray(directories.flatMap(directory => wrapNull(directory.listFiles(JarFilter))))
object JarFilter extends FileFilter
{
def accept(file: File) = !file.isDirectory && file.getName.endsWith(".jar")
}
def getMissing(loader: ClassLoader, classes: Iterable[String]): Iterable[String] =
{
def classMissing(c: String) = try { Class.forName(c, false, loader); false } catch { case e: ClassNotFoundException => true }
classes.toList.filter(classMissing)
}
def toURLs(files: Array[File]): Array[URL] = files.map(_.toURI.toURL)
}