require 'json'
require_relative '../../../models/synchronization/member'
require_relative '../../../models/synchronization/collection'
require_relative '../../../../services/datasources/lib/datasources'
require_relative '../../../../services/platform-limits/platform_limits'
require_dependency 'carto/url_validator'

class Api::Json::SynchronizationsController < Api::ApplicationController
  include CartoDB
  include Carto::UrlValidator

  ssl_required :create, :update, :destroy, :sync, :sync_now

  before_filter :set_external_source, only: [ :create ]

  # Upon creation, no rate limit checks
  def create
    return head(401) unless current_user.sync_tables_enabled || @external_source

    @stats_aggregator.timing('synchronizations.create') do

      begin
        member_attributes = setup_member_attributes
        member = Synchronization::Member.new(member_attributes)
        member = @stats_aggregator.timing('member.save') do
          member.store
        end

        options = setup_data_import_options(member_attributes, member.id)
        data_import = @stats_aggregator.timing('save') do
          DataImport.create(options)
        end

        if @external_source
          @stats_aggregator.timing('external-data-import.save') do
            Carto::ExternalDataImport.new(
              data_import_id: data_import.id,
              external_source_id: @external_source.id,
              synchronization_id: member.id
            ).save
          end
        end

        ::Resque.enqueue(::Resque::ImporterJobs, job_id: data_import.id)

        # Need to mark the synchronization job as queued state.
        # If this is missed there is an error state that can be
        # achieved where the synchronization job can never be
        # manually kicked off ever again.  This state will occur if the
        # resque job fails to mark the synchronization state to success or
        # failure (ie: resque never runs, or bug in ImporterJobs code)
        member.state = Synchronization::Member::STATE_QUEUED
        member.store

        response = {
          data_import: {
            endpoint:       '/api/v1/imports',
            item_queue_id:  data_import.id
          }
        }.merge(member.to_hash)

        render_jsonp(response)
      rescue CartoDB::InvalidMember => exception
        render_jsonp({ errors: member.full_errors }, 400)
        puts exception.to_s
        puts exception.backtrace
      rescue CartoDB::InvalidInterval => exception
        render_jsonp({ errors: "#{exception.detail['message']}: #{exception.detail['hint']}" }, 400)
      rescue InvalidUrlError => exception
        render_jsonp({ errors: exception.message }, 400)
      end

    end
  end

  def sync(from_sync_now=false)
    @stats_aggregator.timing('synchronizations.sync') do

      begin
        enqueued = false
        member = Synchronization::Member.new(id: params[:id]).fetch
        return head(401) unless member.authorize?(current_user)

        # @see /services/synchronizer/lib/synchronizer/collection.rb -> enqueue_rate_limited()
        if ( member.should_auto_sync? || (from_sync_now && member.can_manually_sync?) )
          platform_limit = CartoDB::PlatformLimits::Importer::UserConcurrentSyncsAmount.new({
            user: current_user, redis: { db: $users_metadata }
          })
          if platform_limit.is_within_limit?
            @stats_aggregator.timing('enqueue') do
              member.enqueue
            end
            enqueued = true
            platform_limit.increment!
          end
        end

        render_jsonp( { enqueued: enqueued, synchronization_id: member.id})
      rescue StandardError => exception
        CartoDB.notify_exception(exception)
        head(404)
      end

    end
  end

  def sync_now
    sync(true)
  end

  def update
    @stats_aggregator.timing('synchronizations.update') do

      begin
        member = Synchronization::Member.new(id: params.fetch('id')).fetch
        return head(401) unless member.authorize?(current_user)

        member.attributes = payload
        member = @stats_aggregator.timing('save') do
          member.store.fetch
        end
        render_jsonp(member)
      rescue KeyError
        head(404)
      rescue CartoDB::InvalidMember
        render_jsonp({ errors: member.full_errors }, 400)
      end

    end
  end

  def destroy
    @stats_aggregator.timing('synchronizations.destroy') do

      begin
        member = Synchronization::Member.new(id: params.fetch('id')).fetch
        return(head 401) unless member.authorize?(current_user)

        @stats_aggregator.timing('delete') do
          member.delete
        end

        return head 204
      rescue KeyError
        head(404)
      end

    end
  end

  private

  def set_external_source
    @external_source =
      if params[:remote_visualization_id].present?
        get_external_source(params[:remote_visualization_id])
      end
  end

  def setup_member_attributes
    member_attributes = payload.merge(
      name:                   params[:table_name],
      user_id:                current_user.id,
      state:                  Synchronization::Member::STATE_CREATED,
      # Keep in sync with https://carto.com/developers/import-api/guides/sync-tables/#params-1
      type_guessing:          !["false", false].include?(params[:type_guessing]),
      quoted_fields_guessing: !["false", false].include?(params[:quoted_fields_guessing]),
      content_guessing:       ["true", true].include?(params[:content_guessing])
    )

    if from_sync_file_provider?
      member_attributes = member_attributes.merge({
              service_name: params[:service_name],
              service_item_id: params[:service_item_id]
          })
    end

    if params[:remote_visualization_id].present?
      member_attributes[:interval] = Carto::ExternalSource::REFRESH_INTERVAL
      external_source = @external_source
      member_attributes[:url] = external_source.import_url.presence
      member_attributes[:service_item_id] = external_source.import_url.presence
    end

    if params[:connector].present?
      member_attributes[:service_name]    = 'connector'
      member_attributes[:service_item_id] = connector_parameters
    end

    member_attributes
  end

  def setup_data_import_options(member_attributes, member_id)
    if from_sync_file_provider?
      service_name = params[:service_name]
      service_item_id = params[:service_item_id]
    else
      service_name = CartoDB::Datasources::Url::PublicUrl::DATASOURCE_NAME
      service_item_id = params[:url].presence
    end

    options = {
      user_id:                current_user.id,
      table_name:             params[:table_name].presence,
      service_name:           service_name,
      service_item_id:        service_item_id,
      type_guessing:          member_attributes[:type_guessing],
      quoted_fields_guessing: member_attributes[:quoted_fields_guessing],
      content_guessing:       member_attributes[:content_guessing],
      create_visualization:   ["true", true].include?(params[:create_vis])
    }

    if params[:remote_visualization_id].present?
      external_source = get_external_source(params[:remote_visualization_id])
      options.merge!(data_source: external_source.import_url.presence)
    elsif params[:connector].present?
      options[:service_name]    = 'connector'
      options[:service_item_id] = connector_parameters
    else
      url = params[:url]
      validate_url!(url) unless Rails.env.development? || Rails.env.test? || url.nil? || url.empty?
      options.merge!(data_source: url)
    end

    options.merge!({ synchronization_id: member_id })

    options
  end

  def from_sync_file_provider?
    params.include?(:service_name) && params.include?(:service_item_id)
  end

  def payload
    request.body.rewind
    ::JSON.parse(request.body.read.to_s || String.new)
  end

  def get_external_source(remote_visualization_id)
    external_source = Carto::ExternalSource.where(visualization_id: remote_visualization_id).first
    unless remote_visualization_id.present? && external_source.importable_by?(current_user)
      raise CartoDB::Datasources::AuthError.new('Illegal external load')
    end
    external_source
  end

  def connector_parameters
    Carto::Connector.normalized_parameters(user: current_user, parameters: params[:connector]).to_json
  end
end
