require "api_problem/version"
require "api_problem/railtie" if defined? Rails

module ApiProblem
  MissingTitle       = Class.new(StandardError)
  MissingProblemType = Class.new(StandardError)

  def self.build(problem_type, title, options={})
    response ={}
    raise ApiProblem::MissingProblemType if problem_type.nil?
    raise ApiProblem::MissingTitle if title.nil?
    new_options = build_options(options)
    unless new_options.empty?
      { problemType: problem_type, title: title }.merge(new_options)
    else
      { problemType: problem_type, title: title }
    end
  end

  def api_problem(problem_type, title, options={})
    ApiProblem.build problem_type, title, options
  end

  private
  def self.build_options(options)
    new_options ={}
    options.each do |key, value|
      key = convert_key(key)
      value = convert_value(key, value)
      new_options[key] = value
    end
    new_options
  end

  def self.convert_key(key)
    if key == :http_status || key == "http_status"
      key = "httpStatus"
    elsif key == :problem_instance || key == "problem_instance"
      key = "problemInstance"
    end
    key.to_s
  end

  def self.convert_value(key, value)
    if key == "httpStatus"
      value = value.to_i
    end
    value
  end
end