class Rack::MethodOverride

def allowed_methods
  ALLOWED_METHODS
end

def call(env)
  if allowed_methods.include?(env[REQUEST_METHOD])
    method = method_override(env)
    if HTTP_METHODS.include?(method)
      env[RACK_METHODOVERRIDE_ORIGINAL_METHOD] = env[REQUEST_METHOD]
      env[REQUEST_METHOD] = method
    end
  end
  @app.call(env)
end

def initialize(app)
  @app = app
end

def method_override(env)
  req = Request.new(env)
  method = method_override_param(req) ||
    env[HTTP_METHOD_OVERRIDE_HEADER]
  begin
    method.to_s.upcase
  rescue ArgumentError
    env[RACK_ERRORS].puts "Invalid string for method"
  end
end

def method_override_param(req)
  req.POST[METHOD_OVERRIDE_PARAM_KEY] if req.form_data? || req.parseable_data?
rescue Utils::InvalidParameterError, Utils::ParameterTypeError, QueryParser::ParamsTooDeepError
  req.get_header(RACK_ERRORS).puts "Invalid or incomplete POST params"
rescue EOFError
  req.get_header(RACK_ERRORS).puts "Bad request content body"
end