1 files changed, 136 insertions, 0 deletions
diff --git a/src/main/scala/router.scala b/src/main/scala/router.scala
new file mode 100644
index 0000000..f1fbfa7
--- /dev/null
+++ b/src/main/scala/router.scala
@@ -0,0 +1,136 @@
+package router
+
+import scala.collection.mutable.ArrayBuffer
+import scala.util.matching.Regex
+
+class Router[T] {
+  val routes = new ArrayBuffer[Route[T]]()
+
+  def addRoute (
+    path:        String,
+    target:      T,
+    defaults:    Map[String, String] = Map(),
+    validations: Map[String, Regex]  = Map()
+  ) {
+    routes += new Route(path, defaults, validations, target)
+  }
+
+  def insertRoute (
+    path:        String,
+    target:      T,
+    defaults:    Map[String, String] = Map(),
+    validations: Map[String, Regex]  = Map(),
+    at:          Int                 = 0
+  ) {
+    routes insert (
+      at min routes.length,
+      new Route(path, defaults, validations, target)
+    )
+  }
+
+  def route (path: String): Option[Match[T]] = {
+    def _route (
+      components: Seq[String],
+      routes:     List[Route[T]]
+    ): Option[Match[T]] = routes match {
+      case r :: rs => r.route(components) match {
+        case Some(found) => Some(found)
+        case None        => _route(components, rs)
+      }
+      case _ => None
+    }
+    _route(path.split("/"), routes.toList)
+  }
+
+  def uriFor (mapping: Map[String, String]): String = {
+    throw new Error("unimplemented")
+  }
+}
+
+class Route[T] (
+  val path:        String,
+  val defaults:    Map[String, String],
+  val validations: Map[String, Regex],
+  val target:      T
+) {
+  def route(
+    parts:      Seq[String],
+    components: Seq[String]         = components,
+    mapping:    Map[String, String] = defaults
+  ): Option[Match[T]] = {
+    if (components.length == 0 && parts.length == 0) {
+      Some(new Match[T](path, mapping, target))
+    }
+    else if (components.length == 0 || parts.length == 0) {
+      None
+    }
+    else {
+      components.head match {
+        case Optional(name) => {
+          throw new Error("unsupported")
+        }
+        case Variable(name) => {
+          if (validate(name, parts.head)) {
+            route(parts.tail, components.tail, mapping + (name -> parts.head))
+          }
+          else {
+            None
+          }
+        }
+        case literal => parts.head match {
+          case `literal` => route(parts.tail, components.tail, mapping)
+          case _         => None
+        }
+      }
+    }
+  }
+
+  override def toString = path
+
+  private lazy val components =
+    path.split("/").filter(_.length > 0)
+
+  private lazy val length =
+    components.length
+
+  private lazy val lengthWithoutOptionals =
+    components.filter(!isOptional(_)).length
+
+  private lazy val requiredVariableComponentNames =
+    for (c <- components if isVariable(c) && !isOptional(c))
+      yield getComponentName(c)
+
+  private lazy val optionalVariableComponentNames =
+    for (c <- components if isVariable(c) && isOptional(c))
+      yield getComponentName(c)
+
+  private val Optional = """^\?:(.*)$""".r
+  private val Variable = """^\??:(.*)$""".r
+
+  private def isOptional (component: String): Boolean = component match {
+    case Optional(_) => true
+    case _           => false
+  }
+
+  private def isVariable (component: String): Boolean = component match {
+    case Variable(_) => true
+    case _           => false
+  }
+
+  private def getComponentName (component: String) = component match {
+    case Variable(name) => Some(name)
+    case _              => None
+  }
+
+  private def validate (name: String, component: String): Boolean =
+    validations get name match {
+      case Some(rx) => rx.findFirstIn(component).nonEmpty
+      case None     => true
+    }
+}
+
+class Match[T] (
+  val path:    String,
+  val mapping: Map[String, String],
+  val target:  T
+)