Add param handling to command router

src/cli/command_router.cr

@@ -1,17 +1,42 @@
 class CLI::CommandRouter
   def initialize
-    @mappings = [] of {String, Proc(Nil)}
+    @mappings = [] of {Regex, Proc(Hash(String, String), Nil)}
   end
 
-  def add(route, &block)
-    @mappings.push({route, block})
+  def add(route, &block : Hash(String, String) -> Nil)
+    pattern = route_to_regex(route)
+    @mappings.push({pattern, block})
   end
 
   def handle(command)
-    @mappings.each do |i|
-      if i[0] == command
-        i[1].call
-      end
+    @mappings.each do |handler|
+      handle_pattern(command, *handler)
     end
   end
+
+  private def handle_pattern(command, pattern, cb)
+    m = command.match(pattern)
+    return if m.nil?
+    groups = m.named_captures
+    nil_groups = groups.select { |k, v| v.nil? }
+    return if nil_groups.size != 0
+    params = groups.transform_values { |v| v.to_s }
+    cb.call params
+  end
+
+  private def route_to_regex(route) : Regex
+    vals = route.partition(/\{[a-z]+?\}/)
+    param = vals[1].lstrip('{').rstrip('}')
+    result = ""
+    if vals[0] != ""
+      result += Regex.escape(vals[0])
+    end
+    if vals[1] != ""
+      result += sprintf "(?P<%s>.+?)", param
+    end
+    if vals[2] != ""
+      result += route_to_regex(vals[2]).source
+    end
+    Regex.new(result)
+  end
 end