# frozen_string_literal: true

module Analytics
  module UsageTrends
    class Measurement < ApplicationRecord
      self.table_name = 'analytics_usage_trends_measurements'

      enum :identifier, {
        projects: 1,
        users: 2,
        issues: 3,
        merge_requests: 4,
        groups: 5,
        pipelines: 6,
        pipelines_succeeded: 7,
        pipelines_failed: 8,
        pipelines_canceled: 9,
        pipelines_skipped: 10,
        billable_users: 11
      }

      validates :recorded_at, :identifier, :count, presence: true
      validates :recorded_at, uniqueness: { scope: :identifier }

      scope :order_by_latest, -> { order(recorded_at: :desc) }
      scope :with_identifier, ->(identifier) { where(identifier: identifier) }
      scope :recorded_after, ->(date) { where(model.arel_table[:recorded_at].gteq(date)) if date.present? }
      scope :recorded_before, ->(date) { where(model.arel_table[:recorded_at].lteq(date)) if date.present? }

      def self.identifier_query_mapping
        {
          identifiers[:projects] => -> { Project },
          identifiers[:users] => -> { User },
          identifiers[:issues] => -> { Issue.where.not(project_id: nil) }, # Excludes group-level issues
          identifiers[:merge_requests] => -> { MergeRequest },
          identifiers[:groups] => -> { Group },
          identifiers[:pipelines] => -> { Ci::Pipeline },
          identifiers[:pipelines_succeeded] => -> { Ci::Pipeline.success },
          identifiers[:pipelines_failed] => -> { Ci::Pipeline.failed },
          identifiers[:pipelines_canceled] => -> { Ci::Pipeline.canceled },
          identifiers[:pipelines_skipped] => -> { Ci::Pipeline.skipped }
        }
      end

      # Customized min and max calculation, in some cases using the original scope is too slow.
      def self.identifier_min_max_queries
        {
          # Increase query performance by not using filters when fetching min/max ids
          identifiers[:issues] => {
            minimum_query: -> { ::Issue.minimum(:id) },
            maximum_query: -> { ::Issue.maximum(:id) }
          }
        }
      end

      def self.measurement_identifier_values
        identifiers.values
      end

      def self.find_latest_or_fallback(identifier)
        with_identifier(identifier).order_by_latest.first || identifier_query_mapping[identifiers[identifier]].call
      end
    end
  end
end

Analytics::UsageTrends::Measurement.prepend_mod_with('Analytics::UsageTrends::Measurement')
