require 'spec_helper'
require 'flydata/source_postgresql/query_based_sync/query_based_sync_postgresql_context'
require 'flydata/source_postgresql/query_based_sync/resource_requester'


module Flydata
module SourcePostgresql
module QueryBasedSync

describe ResourceRequester do
  include_context 'query based sync postgresql context'

  let(:subject_object) { described_class.new(context) }

  describe '#create_resource_client' do
    subject { subject_object.create_resource_client(context) }
    it { is_expected.to be_kind_of(FlydataCore::Postgresql::PGClient) }
  end

  describe '#fetch_responses_once' do
    let(:table_name) { 'table_1' }
    let(:result) { double('result') }
    let(:response) { double('response') }
    let(:query_cond) { {} }
    let(:latest_src_pos) { FlydataCore::Postgresql::SourcePos.new(current_snapshot) }

    subject { subject_object.fetch_responses_once(table_name, latest_src_pos) }

    shared_examples 'returning expected responses' do
      it 'runs a query and return responses' do
        expect_any_instance_of(FlydataCore::Postgresql::PGClient).
          to receive(:query).and_return(result)
        expect(Response).to receive(:create_responses).with(context, table_name, result, query_cond).and_return([response])
        expect(subject).to eq([response])
      end
    end

    context 'when table_src_pos file exists but does not have pk_values' do
      let(:table_1_snapshot) { create_ss('1015:1015:') }
      let(:query_cond) { {from_sid: create_ss('1015:1015:'), to_sid: create_ss('1020:1020:'), pk_values: nil} }
      it_behaves_like 'returning expected responses'
    end

    context 'when table_src_pos file does not exist' do
      before do
        FileUtils.rm(table_1_src_pos_file.path)
      end
      let(:query_cond) { {from_sid: create_ss('1010:1010:'), to_sid: create_ss('1020:1020:'), pk_values: nil} }
      it_behaves_like 'returning expected responses'
    end

    context 'when table_src_pos has pk_values' do
      let(:table_1_snapshot) { create_ss('1012:1012:') }
      let(:table_1_to_snapshot) { create_ss('1020:1020:') }
      let(:table_1_pk_values) { [{"id"=>2}] }

      let(:query_cond) { {from_sid: create_ss('1012:1012:'), to_sid: create_ss('1020:1020:'), pk_values: [{"id"=>2}]} }
      it_behaves_like 'returning expected responses'
    end

    context 'when table_src_pos snapshot is up to date' do
      let(:table_1_snapshot) { current_snapshot }
      it { is_expected.to be_nil }
    end

    context 'when getting PG::TRSerializationFailure' do
      before do
        allow_any_instance_of(FlydataCore::Postgresql::PGClient).to receive(:query).and_raise(
          PG::TRSerializationFailure.new("ERROR:  canceling statement due to conflict with recovery DETAIL:  User query might have needed to see row versions that must be removed.")
        )
      end

      it { expect{subject}.to raise_error(FlydataCore::RetryableError) }
    end
  end
end

end
end
end