require 'net/https'
require 'cgi/util'
require 'multi_json'
# helpers
require 'domoscio_rails/version'
require 'domoscio_rails/json'
require 'domoscio_rails/errors'
require 'domoscio_rails/authorization_token'
# resources
require 'domoscio_rails/http_calls'
require 'domoscio_rails/resource'
require 'domoscio_rails/data/content'
require 'domoscio_rails/data/event'
require 'domoscio_rails/data/instance'
require 'domoscio_rails/data/recommendation'
require 'domoscio_rails/data/learning_session_recommendation'
require 'domoscio_rails/data/learning_session_knowledge_node'
require 'domoscio_rails/data/learning_session'
require 'domoscio_rails/data/scorm'
require 'domoscio_rails/data/student'
require 'domoscio_rails/data/student_group'
require 'domoscio_rails/knowledge/knowledge_edge'
require 'domoscio_rails/knowledge/knowledge_graph'
require 'domoscio_rails/knowledge/scale'
require 'domoscio_rails/knowledge/knowledge_graph_scale'
require 'domoscio_rails/knowledge/knowledge_graph_node'
require 'domoscio_rails/knowledge/knowledge_node_content'
require 'domoscio_rails/knowledge/knowledge_node_student'
require 'domoscio_rails/knowledge/knowledge_node'
require 'domoscio_rails/objective/learning_program_student'
require 'domoscio_rails/objective/learning_program'
require 'domoscio_rails/objective/objective_knowledge_node_student'
require 'domoscio_rails/objective/objective_knowledge_node'
require 'domoscio_rails/objective/objective_student'
require 'domoscio_rails/objective/objective'
require 'domoscio_rails/objective/subscription'
require 'domoscio_rails/tag/tag_edge'
require 'domoscio_rails/tag/tag_set'
require 'domoscio_rails/tag/tag'
require 'domoscio_rails/tag/tagging'
require 'domoscio_rails/utils/analytic'
require 'domoscio_rails/utils/gameplay_util'
require 'domoscio_rails/utils/recommendation_util'
require 'domoscio_rails/utils/review_util'
require 'domoscio_rails/utils/stats_util'
require 'domoscio_rails/utils/lxp'

module DomoscioRails
  # Configurable attributes and default values
  class Configuration
    attr_accessor :client_id, :client_passphrase, :temp_dir, :version,
                  :root_url, :file_storage, :access_token, :refresh_token

    def initialize
      @version = 2
      @root_url = ''
      @file_storage ||= true
    end
  end

  class << self
    attr_accessor :configuration
  end

  def self.configure
    self.configuration ||= Configuration.new
    yield configuration
  end

  def self.api_uri(url = '')
    URI(configuration.root_url + url)
  end

  #
  # - +method+: HTTP method; lowercase symbol, e.g. :get, :post etc.
  # - +url+: the part after Configuration#root_url
  # - +params+: hash; entity data for creation, update etc.; will dump it by JSON and assign to Net::HTTPRequest#body
  #
  # Performs HTTP requests to Adaptive Engine
  # On token issues, will try once to get a new token then will output a DomoscioRails::ReponseError with details
  #
  # Raises DomoscioRails::ResponseError on Adaptive Error Status
  # Raises DomoscioRails::ProcessingError on Internal Error
  #
  def self.request(method, url, params = {})
    params ||= {}
    store_tokens, headers = request_headers
    params.merge!({ 'per_page': 1000 }) unless params[:per_page]
    uri = api_uri(url)
    response = DomoscioRails.send_request(uri, method, params, headers)
    return response if response.is_a? DomoscioRails::ProcessingError

    begin
      raise_http_failure(uri, response, params)

      if response['Content-Type'] == 'application/zip'
        data = response
      else
        data = DomoscioRails::JSON.load(response.body.nil? ? '' : response.body)
      end

      if store_tokens
        DomoscioRails::AuthorizationToken::Manager.storage.store({
                                                                   access_token: response['Accesstoken'],
                                                                   refresh_token: response['Refreshtoken']
                                                                 })
      end
    rescue MultiJson::LoadError => e
      data = ProcessingError.new(uri, 500, e, response.body, params)
    rescue ResponseError => e
      data = e
    end

    if response['Total']
      pagetotal = (response['Total'].to_i / response['Per-Page'].to_f).ceil
      (2..pagetotal).each do |j|
        response = DomoscioRails.send_request(uri, method, params.merge({ page: j }), headers)
        return response if response.is_a? DomoscioRails::ProcessingError

        begin
          raise_http_failure(uri, response, params)
          body = DomoscioRails::JSON.load(response.body.nil? ? '' : response.body)
          data += body
          data.flatten!
        rescue MultiJson::LoadError => e
          return ProcessingError.new(uri, 500, e, response.body, params)
        rescue ResponseError => e
          return e
        end
      end
    end
    data
  end

  # This function catches usual Http errors during callsheaders
  #
  def self.send_request(uri, method, params, headers)
    response = perform_call(uri, method, params, headers)
    response = retry_call_and_store_tokens(uri, method, params) if %w[401 403].include? response.code
    response
  rescue Timeout::Error, Errno::EINVAL, Errno::ECONNREFUSED, Errno::ECONNRESET,
         EOFError, Net::HTTPBadResponse, Net::HTTPHeaderSyntaxError, Net::ProtocolError => e
    ProcessingError.new(uri, 500, e, response)
  end

  # This helper will check the response status and build the correcponding DomoscioRails::ResponseError
  #
  def self.raise_http_failure(uri, response, params)
    return if response.is_a? Net::HTTPSuccess

    raise ResponseError.new(
      uri,
      response.code.to_i,
      DomoscioRails::JSON.load((response.body.nil? ? '' : response.body), symbolize_keys: true),
      response.body, params
    )
  end

  # Actual HTTP call is performed here
  #
  def self.perform_call(uri, method, params, headers)
    Net::HTTP.start(uri.host, uri.port, use_ssl: uri.scheme == 'https') do |http|
      req = Net::HTTP.const_get(method.capitalize).new(uri.request_uri, headers)
      req.body = DomoscioRails::JSON.dump(params)
      http.request req
    end
  end

  # This method is called when AdaptiveEngine returns tokens errors
  # Action on those errors is to retry and request new tokens, those new token are then stored
  def self.retry_call_and_store_tokens(uri, method, params)
    headers = request_new_tokens
    response = perform_call(uri, method, params, headers)
    DomoscioRails::AuthorizationToken::Manager.storage.store({
                                                               access_token: response['Accesstoken'],
                                                               refresh_token: response['Refreshtoken']
                                                             })
    response
  end

  def self.user_agent
    @uname ||= uname
    {
      bindings_version: DomoscioRails::VERSION,
      lang: 'ruby',
      lang_version: "#{RUBY_VERSION} p#{RUBY_PATCHLEVEL} (#{RUBY_RELEASE_DATE})",
      platform: RUBY_PLATFORM,
      uname: @uname
    }.to_s
  end

  def self.uname
    `uname -a 2>/dev/null` if RUBY_PLATFORM =~ /linux|darwin/i
  rescue Errno::ENOMEM
    'uname lookup failed'
  end

  # Process the token loading and analyze
  # will return the processed headers and a token store flag
  #
  def self.request_headers
    auth_token = DomoscioRails::AuthorizationToken::Manager.token
    if auth_token && auth_token[:access_token] && auth_token[:refresh_token]
      [false, send_current_tokens(auth_token)]
    else
      [true, request_new_tokens]
    end
  rescue SyntaxError, StandardError
    [true, request_new_tokens]
  end

  # If stored token successfully loaded we build the header with them
  #
  def self.send_current_tokens(auth_token)
    {
      'user_agent' => DomoscioRails.user_agent.to_s,
      'AccessToken' => auth_token[:access_token].to_s,
      'RefreshToken' => auth_token[:refresh_token].to_s,
      'Content-Type' => 'application/json'
    }
  end

  # If we cant find tokens of they are corrupted / expired, then we set headers to request new ones
  def self.request_new_tokens
    {
      'user_agent' => DomoscioRails.user_agent.to_s,
      'Authorization' => "Token token=#{DomoscioRails.configuration.client_passphrase}",
      'Content-Type' => 'application/json'
    }
  end
end