request.mirah

import java.util.HashMap
import java.util.Map

class Params
  def initialize(request:HttpServletRequest)
    @request = request
    @params = HashMap.new
  end

  def get(name:String)
    values = array(name)
    values[0] if values && values.size > 0
  end

  macro def [](name)
    quote { get(name) }
  end

  macro def []=(name, value)
    quote { put(name, value) }
  end

  def array(name:String)
    String[].cast(@params.get(name)) || @request.getParameterValues(name)
  end

  macro def values(name)
    quote { array(name) }
  end

  def map(name:String)
    Map(map_params.get(name))
  end

  def put(name:String, values:String[])
    @params.put(name, value)
  end

  def put(name:String, value:String)
    values = String[1]
    values[0] = value
    put(values)
  end

  private
  def map_params
    @maps ||= parse_maps
  end

  def parse_maps
    map = HashMap.new
    path_re = /[\[\]]+/
    @request.getParameterMap.entrySet.each do |entry|
      name = String(entry.getKey)
      values = String[].cast(entry.getValue)
      path = path_re.split(name)
      current_map = map
      last = path.size - 1
      last.times do |i|
        next_map = current_map.get(path[i])
        unless next_map.kind_of?(Map)
          next_map = HashMap.new
          current_map.put(path[i], next_map)
        end
        current_map = next_map
      end

      if values.length == 1
        current_map.put(path[last], values[0])
      else
        current_map.put(path[last], values)
      end
    end
    Map(map)
  end
end