module Travis::API::V3
  class Router
    not_found = '{"error":{"message":"not found"}}'.freeze
    headers   = { 'Content-Type'.freeze => 'application/json'.freeze, 'X-Cascade'.freeze => 'pass'.freeze, 'Content-Length'.freeze => not_found.bytesize }
    NOT_FOUND = [ 404, headers, not_found ]

    attr_accessor :routs, :not_found

    def initialize(routes = Routes, not_found: NOT_FOUND)
      @routes    = routes
      @not_found = not_found
    end

    def call(env)
      access_control  = AccessControl.new(env)
      factory, params = @routes.factory_for(env['REQUEST_METHOD'.freeze], env['PATH_INFO'.freeze])
      env_params      = params(env)
      if factory
        service       = factory.new(access_control, env_params.merge(params))
        result        = service.run
        render(result, env_params)
      else
        not_found
      end
    end

    def params(env)
      request    = Rack::Request.new(env)
      params     = request.params
      media_type = request.media_type

      if media_type == 'application/json'.freeze or media_type == 'text/json'.freeze
        request.body.rewind
        json_params = env['travis.input.json'.freeze] ||= JSON.load(request.body)
        params.merge! json_params if json_params.is_a? Hash
      end

      params
    end
  end
end