# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Gitlab::Usage::ServicePingReport, :use_clean_rails_memory_store_caching do
  include UsageDataHelpers

  let(:usage_data) { { uuid: "1111", counts: { issue: 0 } }.deep_stringify_keys }

  before do
    allow_next_instance_of(Gitlab::Usage::ServicePing::PayloadKeysProcessor) do |instance|
      allow(instance).to receive(:missing_key_paths).and_return([])
    end

    allow_next_instance_of(Gitlab::Usage::ServicePing::InstrumentedPayload) do |instance|
      allow(instance).to receive(:build).and_return({})
    end
  end

  context 'all_metrics_values' do
    it 'generates the service ping when there are no missing values' do
      expect(Gitlab::UsageData).to receive(:data).and_return(usage_data)
      expect(described_class.for(output: :all_metrics_values)).to eq({ uuid: "1111", counts: { issue: 0 } }.deep_stringify_keys)
    end

    it 'generates the service ping with the missing values' do
      expect_next_instance_of(Gitlab::Usage::ServicePing::PayloadKeysProcessor, usage_data) do |instance|
        expect(instance).to receive(:missing_instrumented_metrics_key_paths).and_return(['counts.boards'])
      end

      expect_next_instance_of(Gitlab::Usage::ServicePing::InstrumentedPayload, ['counts.boards'], :with_value) do |instance|
        expect(instance).to receive(:build).and_return({ counts: { boards: 1 } })
      end

      expect(Gitlab::UsageData).to receive(:data).and_return(usage_data)
      expect(described_class.for(output: :all_metrics_values)).to eq({ uuid: "1111", counts: { issue: 0, boards: 1 } }.deep_stringify_keys)
    end

    context 'with usage data payload with symbol keys and instrumented payload with string keys' do
      let(:usage_data) { { uuid: "1111", counts: { issue: 0 } } }

      it 'correctly merges string and symbol keys' do
        expect_next_instance_of(Gitlab::Usage::ServicePing::PayloadKeysProcessor, usage_data) do |instance|
          expect(instance).to receive(:missing_instrumented_metrics_key_paths).and_return(['counts.boards'])
        end

        expect_next_instance_of(Gitlab::Usage::ServicePing::InstrumentedPayload, ['counts.boards'], :with_value) do |instance|
          expect(instance).to receive(:build).and_return({ 'counts' => { 'boards' => 1 } })
        end

        expect(Gitlab::UsageData).to receive(:data).and_return(usage_data)
        expect(described_class.for(output: :all_metrics_values)).to eq({ uuid: "1111", counts: { issue: 0, boards: 1 } }.deep_stringify_keys)
      end
    end
  end

  context 'for output: :metrics_queries' do
    it 'generates the service ping' do
      expect(Gitlab::UsageData).to receive(:data).and_return(usage_data)

      described_class.for(output: :metrics_queries)
    end
  end

  context 'for output: :non_sql_metrics_values' do
    it 'generates the service ping' do
      expect(Gitlab::UsageData).to receive(:data).and_return(usage_data)

      described_class.for(output: :non_sql_metrics_values)
    end
  end

  context 'when using cached' do
    let(:new_usage_data) { { 'uuid' => '1112' } }

    context 'for cached: true' do
      it 'caches the values' do
        allow(Gitlab::UsageData).to receive(:data).and_return(usage_data, new_usage_data)

        expect(described_class.for(output: :all_metrics_values)).to eq(usage_data)
        expect(described_class.for(output: :all_metrics_values, cached: true)).to eq(usage_data)

        expect(Rails.cache.fetch('usage_data')).to eq(usage_data)
      end

      it 'writes to cache and returns fresh data' do
        allow(Gitlab::UsageData).to receive(:data).and_return(usage_data, new_usage_data)

        expect(described_class.for(output: :all_metrics_values)).to eq(usage_data)
        expect(described_class.for(output: :all_metrics_values)).to eq(new_usage_data)
        expect(described_class.for(output: :all_metrics_values, cached: true)).to eq(new_usage_data)

        expect(Rails.cache.fetch('usage_data')).to eq(new_usage_data)
      end
    end

    context 'when no caching' do
      it 'returns fresh data' do
        allow(Gitlab::UsageData).to receive(:data).and_return(usage_data, new_usage_data)

        expect(described_class.for(output: :all_metrics_values)).to eq(usage_data)
        expect(described_class.for(output: :all_metrics_values)).to eq(new_usage_data)

        expect(Rails.cache.fetch('usage_data')).to eq(new_usage_data)
      end
    end
  end

  context 'cross test values against queries' do
    def fetch_value_by_query(query)
      # Because test cases are run inside a transaction, if any query raise and error all queries that follows
      # it are automatically canceled by PostgreSQL, to avoid that problem, and to provide exhaustive information
      # about every metric, queries are wrapped explicitly in sub transactions.
      ApplicationRecord.transaction do
        ApplicationRecord.connection.execute(query)&.first&.values&.first
      end
    rescue ActiveRecord::StatementInvalid => e
      e.message
    end

    def build_payload_from_queries(payload, accumulator = [], key_path = [])
      payload.each do |key, value|
        if value.is_a?(Hash)
          build_payload_from_queries(value, accumulator, key_path.dup << key)
        elsif value.is_a?(String) && /SELECT .* FROM.*/ =~ value
          accumulator << [key_path.dup << key, value, fetch_value_by_query(value)]
        end
      end
      accumulator
    end

    def type_cast_to_defined_type(value, metric_definition)
      case metric_definition&.attributes&.fetch(:value_type)
      when "string"
        value.to_s
      when "number"
        value.to_i
      when "object"
        case metric_definition&.json_schema&.fetch("type")
        when "array"
          value.to_a
        else
          value.to_h
        end
      else
        value
      end
    end

    before do
      stub_usage_data_connections
      stub_object_store_settings
      stub_prometheus_queries
      memoized_constatns = Gitlab::UsageData::CE_MEMOIZED_VALUES
      memoized_constatns += Gitlab::UsageData::EE_MEMOIZED_VALUES if defined? Gitlab::UsageData::EE_MEMOIZED_VALUES
      memoized_constatns.each { |v| Gitlab::UsageData.clear_memoization(v) }
      stub_database_flavor_check('Cloud SQL for PostgreSQL')

      # in_product_marketing_email metrics values are extracted from a single group by query
      # to check if the queries for individual metrics return the same value as group by when the value is non-zero
      create(:in_product_marketing_email, track: :create, series: 0, cta_clicked_at: Time.current)
      create(:in_product_marketing_email, track: :verify, series: 0)
    end

    let(:service_ping_payload) { described_class.for(output: :all_metrics_values) }
    let(:metrics_queries_with_values) { build_payload_from_queries(described_class.for(output: :metrics_queries)) }
    let(:metric_definitions) { ::Gitlab::Usage::MetricDefinition.definitions }

    it 'generates queries that match collected data', :aggregate_failures do
      message = "Expected %{query} result to match %{value} for %{key_path} metric"

      metrics_queries_with_values.each do |key_path, query, value|
        value = type_cast_to_defined_type(value, metric_definitions[key_path.join('.')])

        expect(value).to(
          eq(service_ping_payload.dig(*key_path)),
          message % { query: query, value: (value || 'NULL'), key_path: key_path.join('.') }
        )
      end
    end
  end
end