require 'base64'
require 'tempfile'

module Api
  module Helpers
    PRIVATE_TOKEN_PARAM = :private_token
    DEFAULT_ALLOWED_PARAMETERS = [:parent_id, :from, :until, :content_type, :author_id, :identifier, :archived]

    include SanitizeParams
    include Noosfero::Plugin::HotSpot
    include ForgotPasswordHelper
    include SearchTermHelper

    def set_locale
      I18n.locale = (params[:lang] || request.env['HTTP_ACCEPT_LANGUAGE'] || 'en')
    end

    def init_noosfero_plugins
      plugins
    end

    def current_user
      private_token = (params[PRIVATE_TOKEN_PARAM] || headers['Private-Token']).to_s
      @current_user ||= User.find_by private_token: private_token
      @current_user ||= plugins.dispatch("api_custom_login", request).first
      @current_user
    end

    def current_person
      current_user.person unless current_user.nil?
    end

    def is_admin?(environment)
      return false unless current_user
      return current_person.is_admin?(environment)
    end

    def logout
      @current_user = nil
    end

    def environment
      @environment
    end

    def present_partial(model, options)
      if(params[:fields].present?)
        begin
          fields = JSON.parse(params[:fields])
          if fields.present?
            options.merge!(fields.symbolize_keys.slice(:only, :except))
          end
        rescue
          fields = params[:fields]
          fields = fields.split(',') if fields.kind_of?(String)
          options[:only] = Array.wrap(fields)
        end
      end
      present model, options
    end

    include FindByContents

    ####################################################################
    #### SEARCH
    ####################################################################
    def multiple_search?(searches=nil)
      ['index', 'category_index'].include?(params[:action]) || (searches && searches.size > 1)
    end
    ####################################################################

    def logger
      logger = Logger.new(File.join(Rails.root, 'log', "#{ENV['RAILS_ENV'] || 'production'}_api.log"))
      logger.formatter = GrapeLogging::Formatters::Default.new
      logger
    end

    def limit
      limit = params[:limit].to_i
      limit = default_limit if limit <= 0
      limit
    end

    def period(from_date, until_date)
      return nil if from_date.nil? && until_date.nil?

      begin_period = from_date.nil? ? Time.at(0).to_datetime : from_date
      end_period = until_date.nil? ? DateTime.now : until_date

      begin_period..end_period
    end

    def parse_content_type(content_type)
      return nil if content_type.blank?
      content_type.split(',').map do |content_type|
        content_type.camelcase
      end
    end

    def find_article(articles, id)
      article = articles.find(id)
      article.display_to?(current_person) ? article : forbidden!
    end

    def post_article(asset, params)
      return forbidden! unless current_person.can_post_content?(asset)

      klass_type = params[:content_type] || params[:article].delete(:type) || TinyMceArticle.name
      return forbidden! unless klass_type.constantize <= Article

      article = klass_type.constantize.new(params[:article])
      article.last_changed_by = current_person
      article.created_by= current_person
      article.profile = asset

      if !article.save
        render_api_errors!(article.errors.full_messages)
      end
      present_partial article, :with => Entities::Article
    end

    def present_article(asset)
      article = find_article(asset.articles, params[:id])
      present_partial article, with: Entities::Article, params: params, current_person: current_person
    end

    def present_articles_for_asset(asset, method = 'articles')
      articles = find_articles(asset, method)
      present_articles(articles)
    end

    def present_articles(articles)
      present_partial paginate(articles), :with => Entities::Article, :params => params, current_person: current_person
    end

    def find_articles(asset, method = 'articles')
      articles = select_filtered_collection_of(asset, method, params)
      if current_person.present?
        articles = articles.display_filter(current_person, nil)
      else
        articles = articles.published
      end
      articles
    end

    def find_task(asset, id)
      task = asset.tasks.find(id)
      current_person.has_permission?(task.permission, asset) ? task : forbidden!
    end

    def post_task(asset, params)
      klass_type= params[:content_type].nil? ? 'Task' : params[:content_type]
      return forbidden! unless klass_type.constantize <= Task

      task = klass_type.constantize.new(params[:task])
      task.requestor_id = current_person.id
      task.target_id = asset.id
      task.target_type = 'Profile'

      if !task.save
        render_api_errors!(task.errors.full_messages)
      end
      present_partial task, :with => Entities::Task
    end

    def present_task(asset)
      task = find_task(asset, params[:id])
      present_partial task, :with => Entities::Task
    end

    def present_tasks(asset)
      tasks = select_filtered_collection_of(asset, 'tasks', params)
      tasks = tasks.select {|t| current_person.has_permission?(t.permission, asset)}
      return forbidden! if tasks.empty? && !current_person.has_permission?(:perform_task, asset)
      present_partial tasks, :with => Entities::Task
    end

    def make_conditions_with_parameter(params = {})
      parsed_params = parser_params(params)
      conditions = {}
      from_date = DateTime.parse(parsed_params.delete(:from)) if parsed_params[:from]
      until_date = DateTime.parse(parsed_params.delete(:until)) if parsed_params[:until]

      conditions[:type] = parse_content_type(parsed_params.delete(:content_type)) unless parsed_params[:content_type].nil?

      conditions[:created_at] = period(from_date, until_date) if from_date || until_date
      conditions.merge!(parsed_params)

      conditions
    end

    # changing make_order_with_parameters to avoid sql injection
    def make_order_with_parameters(object, method, params)
      order = "created_at DESC"
      unless params[:order].blank?
        if params[:order].include? '\'' or params[:order].include? '"'
          order = "created_at DESC"
        elsif ['RANDOM()', 'RANDOM'].include? params[:order].upcase
          order = 'RANDOM()'
        else
          field_name, direction = params[:order].split(' ')
          assoc = object.class.reflect_on_association(method.to_sym)
          if !field_name.blank? and assoc
            if assoc.klass.attribute_names.include? field_name
              if direction.present? and ['ASC','DESC'].include? direction.upcase
                order = "#{field_name} #{direction.upcase}"
              end
            end
          end
        end
      end
      return order
    end

    def make_timestamp_with_parameters_and_method(params, method)
      timestamp = nil
      if params[:timestamp]
        datetime = DateTime.parse(params[:timestamp])
        table_name = method.to_s.singularize.camelize.constantize.table_name
        timestamp = "#{table_name}.updated_at >= '#{datetime}'"
      end

      timestamp
    end

    def by_reference(scope, params)
      reference_id = params[:reference_id].to_i == 0 ? nil : params[:reference_id].to_i
      if reference_id.nil?
        scope
      else
        created_at = scope.find(reference_id).created_at
        scope.send("#{params.key?(:oldest) ? 'older_than' : 'younger_than'}", created_at)
      end
    end

    def by_categories(scope, params)
      category_ids = params[:category_ids]
      if category_ids.nil?
        scope
      else
        scope.joins(:categories).where(:categories => {:id => category_ids})
      end
    end

    def select_filtered_collection_of(object, method, params)
      conditions = make_conditions_with_parameter(params)
      order = make_order_with_parameters(object,method,params)
      timestamp = make_timestamp_with_parameters_and_method(params, method)

      objects = object.send(method)
      objects = by_reference(objects, params)
      objects = by_categories(objects, params)

      objects = objects.where(conditions).where(timestamp).reorder(order)

      params[:page] ||= 1
      params[:per_page] ||= limit
      paginate(objects)
    end

    def authenticate!
      unauthorized! unless current_user
    end

    def profiles_for_person(profiles, person)
      if person
        profiles.listed_for_person(person)
      else
        profiles.visible
      end
    end

    # Checks the occurrences of uniqueness of attributes, each attribute must be present in the params hash
    # or a Bad Request error is invoked.
    #
    # Parameters:
    #   keys (unique) - A hash consisting of keys that must be unique
    def unique_attributes!(obj, keys)
      keys.each do |key|
        cant_be_saved_request!(key) if obj.find_by(key.to_s => params[key])
      end
    end

    def attributes_for_keys(keys)
      attrs = {}
      keys.each do |key|
        attrs[key] = params[key] if params[key].present? or (params.has_key?(key) and params[key] == false)
      end
      attrs
    end

    ##########################################
    #              error helpers             #
    ##########################################

    def not_found!
      render_api_error!('404 Not found', 404)
    end

    def forbidden!
      render_api_error!('403 Forbidden', 403)
    end

    def cant_be_saved_request!(attribute)
      message = _("(Invalid request) %s can't be saved").html_safe % attribute
      render_api_error!(message, 400)
    end

    def bad_request!(attribute)
      message = _("(Invalid request) %s not given").html_safe % attribute
      render_api_error!(message, 400)
    end

    def something_wrong!
      message = _("Something wrong happened")
      render_api_error!(message, 400)
    end

    def unauthorized!
      render_api_error!(_('Unauthorized'), 401)
    end

    def not_allowed!
      render_api_error!(_('Method Not Allowed'), 405)
    end

    # javascript_console_message is supposed to be executed as console.log()
    def render_api_error!(user_message, status, log_message = nil, javascript_console_message = nil)
      message_hash = {'message' => user_message, :code => status}
      message_hash[:javascript_console_message] = javascript_console_message if javascript_console_message.present?
      log_msg = "#{status}, User message: #{user_message}"
      log_msg = "#{log_message}, #{log_msg}" if log_message.present?
      log_msg = "#{log_msg}, Javascript Console Message: #{javascript_console_message}" if javascript_console_message.present?
      logger.error log_msg unless Rails.env.test?
      error!(message_hash, status)
    end

    def render_api_errors!(messages)
      messages = messages.to_a if messages.class == ActiveModel::Errors
      render_api_error!(messages.join(','), 400)
    end

    protected

    def set_session_cookie
      cookies['_noosfero_api_session'] = { value: @current_user.private_token, httponly: true } if @current_user.present?
    end

    def setup_multitenancy
      Noosfero::MultiTenancy.setup!(request.host)
    end

    def detect_stuff_by_domain
      @domain = Domain.by_name(request.host)
      if @domain.nil?
        @environment = Environment.default
        if @environment.nil? && Rails.env.development?
          # This should only happen in development ...
          @environment = Environment.create!(:name => "Noosfero", :is_default => true)
        end
      else
        @environment = @domain.environment
      end
    end

    def filter_disabled_plugins_endpoints
      not_found! if Api::App.endpoint_unavailable?(self, @environment)
    end

    def asset_with_image params
      if params.has_key? :image_builder
        asset_api_params = params
        asset_api_params[:image_builder] = base64_to_uploadedfile(asset_api_params[:image_builder])
        return asset_api_params
      end
        params
    end

    def base64_to_uploadedfile(base64_image)
      tempfile = base64_to_tempfile base64_image
      converted_image = base64_image
      converted_image[:tempfile] = tempfile
      return {uploaded_data: ActionDispatch::Http::UploadedFile.new(converted_image)}
    end

    def base64_to_tempfile base64_image
      base64_img_str = base64_image[:tempfile]
      decoded_base64_str = Base64.decode64(base64_img_str)
      tempfile = Tempfile.new(base64_image[:filename])
      tempfile.write(decoded_base64_str.encode("ascii-8bit").force_encoding("utf-8"))
      tempfile.rewind
      tempfile
    end
    private

    def parser_params(params)
      parsed_params = {}
      params.map do |k,v|
        parsed_params[k.to_sym] = v if DEFAULT_ALLOWED_PARAMETERS.include?(k.to_sym)
      end
      parsed_params
    end

    def default_limit
      20
    end

    def parse_content_type(content_type)
      return nil if content_type.blank?
      content_types = content_type.split(',').map do |content_type|
        content_type = content_type.camelcase
        content_type == 'TextArticle' ? Article.text_article_types : content_type
      end
      content_types.flatten.uniq
    end

    def period(from_date, until_date)
      begin_period = from_date.nil? ? Time.at(0).to_datetime : from_date
      end_period = until_date.nil? ? DateTime.now : until_date
      begin_period..end_period
    end
  end
end