require_dependency 'rest_client'
require_dependency 'version'

module DiscourseHub

  class NicknameUnavailable < RuntimeError
    def initialize(nickname)
      @nickname = nickname
    end

    def response_message
      {
        success: false,
        message: I18n.t(
          "login.errors",
          errors:I18n.t(
            "login.not_available", suggestion: UserNameSuggester.suggest(@nickname)
          )
        )
      }
    end 

  end

  def self.nickname_available?(nickname)
    json = get('/users/nickname_available', {nickname: nickname})
    [json['available'], json['suggestion']]
  end

  def self.nickname_match?(nickname, email)
    json = get('/users/nickname_match', {nickname: nickname, email: email})
    [json['match'], json['available'] || false, json['suggestion']]
  end

  def self.register_nickname(nickname, email)
    json = post('/users', {nickname: nickname, email: email})
    if json.has_key?('success')
      true
    else
      raise NicknameUnavailable.new(nickname)  # TODO: report ALL the errors
    end
  end

  def self.unregister_nickname(nickname)
    json = delete('/memberships/' + nickname)
    json.has_key?('success')
  end

  def self.change_nickname(current_nickname, new_nickname)
    json = put("/users/#{current_nickname}/nickname", {nickname: new_nickname})
    if json.has_key?('success')
      true
    else
      raise NicknameUnavailable.new(new_nickname)  # TODO: report ALL the errors
    end
  end


  def self.discourse_version_check
    get('/version_check', {
      installed_version: Discourse::VERSION::STRING,
      forum_title: SiteSetting.title,
      forum_url: Discourse.base_url,
      contact_email: SiteSetting.contact_email,
      topic_count: Topic.listable_topics.count,
      user_count: User.count,
      login_required: SiteSetting.login_required
    })
  end


  private

  def self.get(rel_url, params={})
    singular_action :get, rel_url, params
  end

  def self.post(rel_url, params={})
    collection_action :post, rel_url, params
  end

  def self.put(rel_url, params={})
    collection_action :put, rel_url, params
  end

  def self.delete(rel_url, params={})
    singular_action :delete, rel_url, params
  end

  def self.singular_action(action, rel_url, params={})
    JSON.parse RestClient.send(action, "#{hub_base_url}#{rel_url}", {params: {access_token: access_token}.merge(params), accept: accepts } )
  end

  def self.collection_action(action, rel_url, params={})
    JSON.parse RestClient.send(action, "#{hub_base_url}#{rel_url}", {access_token: access_token}.merge(params), content_type: :json, accept: accepts )
  end

  def self.hub_base_url
    if Rails.env == 'production'
      'http://api.discourse.org/api'
    else
      'http://local.hub:3000/api'
    end
  end

  def self.access_token
    SiteSetting.discourse_org_access_key
  end

  def self.accepts
    [:json, 'application/vnd.discoursehub.v1']
  end

  def self.nickname_operation
    if SiteSetting.call_discourse_hub?
      begin
        yield
      rescue DiscourseHub::NicknameUnavailable
        false
      rescue => e
        Rails.logger.error e.message + "\n" + e.backtrace.join("\n")
      end
    end
  end
end