ghq.sbt

lazy val ghqGetDepndencies = taskKey[Unit]("""Download dependencies using "ghq get".""")

ghqGetDepndencies <<= (ivyPaths, libraryDependencies, streams) map {
  (ivyPaths, libraryDependencies, s) =>
    new IvyCache(ivyPaths.ivyHome).withDefaultCache(None, s.log) {
      cache =>
        libraryDependencies.foreach {
          m =>
            import org.apache.ivy.core.module.id.ModuleRevisionId
            import scala.collection.JavaConversions._
            import scala.xml.parsing.ConstructingParser

            val modRevId = ModuleRevisionId.newInstance(m.organization, m.name, m.revision, m.extraAttributes)

            val path = cache.getIvyFileInCache(modRevId).getPath
            try {
              val doc = ConstructingParser.fromSource(io.Source.fromFile(s"$path.original"), preserveWS = false).document()
              val pat = "^scm:(?:git|hg|svn):(.+)$".r

              (doc \ "scm" \ "connection").text match {
                case pat(url) =>
                  s.log.info(s"$modRevId :: $url")
                  Process(Seq("ghq", "get", url)) !

                case _ =>
                  s.log.info(s"$modRevId :: (not found)")
              }
            } catch {
              case e: Throwable =>
                s.log.warn(s"$modRevId :: $e")
            }
        }
    }
}