refactor events facade so it uses separate classes and refactor query stuff

16 files changed, 196 insertions, 136 deletions

diff --git a/lib/gitlab/cycle_analytics/base_config.rb b/lib/gitlab/cycle_analytics/base_config.rb
deleted file mode 100644
index 06ae9a15a7a..00000000000
--- a/lib/gitlab/cycle_analytics/base_config.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-module Gitlab
-  module CycleAnalytics
-    class BaseConfig
-      extend MetricsFetcher
-
-      class << self
-        attr_reader :start_time_attrs, :end_time_attrs, :projections
-      end
-
-      def self.order
-        @order || @start_time_attrs
-      end
-
-      def self.query(base_query); end
-    end
-  end
-end
diff --git a/lib/gitlab/cycle_analytics/base_event.rb b/lib/gitlab/cycle_analytics/base_event.rb
new file mode 100644
index 00000000000..254e3621575
--- /dev/null
+++ b/lib/gitlab/cycle_analytics/base_event.rb
@@ -0,0 +1,27 @@
+module Gitlab
+  module CycleAnalytics
+    class BaseEvent
+      extend MetricsTables
+
+      class << self
+        attr_reader :stage, :start_time_attrs, :end_time_attrs, :projections
+
+        def order
+          @order || @start_time_attrs
+        end
+
+        def query(base_query); end
+
+        def fetch(query)
+          query.execute(self).map { |event| serialize(event, query) }
+        end
+
+        private
+
+        def serialize(event, query)
+          raise NotImplementedError.new("Expected #{self.name} to implement serialize(event)")
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/cycle_analytics/code_config.rb b/lib/gitlab/cycle_analytics/code_event.rb
index c27419310db..609b45579b4 100644
--- a/lib/gitlab/cycle_analytics/code_config.rb
+++ b/lib/gitlab/cycle_analytics/code_event.rb
@@ -1,6 +1,7 @@
 module Gitlab
   module CycleAnalytics
-    class CodeConfig < BaseConfig
+    class CodeEvent < BaseEvent
+      @stage = :code
       @start_time_attrs = issue_metrics_table[:first_mentioned_in_commit_at]
 
       @end_time_attrs = mr_table[:created_at]
@@ -13,6 +14,12 @@ module Gitlab
                       mr_table[:author_id]]
 
       @order = mr_table[:created_at]
+
+      def self.serialize(event, query)
+        event['author'] = User.find(event.delete('author_id'))
+
+        AnalyticsMergeRequestSerializer.new(project: query.project).represent(event).as_json
+      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/review_config.rb b/lib/gitlab/cycle_analytics/event_config.rb
index e91dc1ea104..2e1400c41b9 100644
--- a/lib/gitlab/cycle_analytics/review_config.rb
+++ b/lib/gitlab/cycle_analytics/event_config.rb
@@ -1,6 +1,6 @@
 module Gitlab
   module CycleAnalytics
-    class ReviewConfig < BaseConfig
+    class TestEvent < BaseEvent
       @start_time_attrs = mr_table[:created_at]
 
       @end_time_attrs = mr_metrics_table[:merged_at]
diff --git a/lib/gitlab/cycle_analytics/events.rb b/lib/gitlab/cycle_analytics/events.rb
index 8e6e6b2f4a3..6580c73128c 100644
--- a/lib/gitlab/cycle_analytics/events.rb
+++ b/lib/gitlab/cycle_analytics/events.rb
@@ -3,73 +3,35 @@ module Gitlab
     class Events
       def initialize(project:, options:)
         @project = project
-        @fetcher = EventsFetcher.new(project: project, options: options)
+        @query = EventsQuery.new(project: project, options: options)
       end
 
       def issue_events
-        @fetcher.fetch(stage: :issue).map { |event| serialize_event(event) }
+        IssueEvent.fetch(@query)
       end
 
       def plan_events
-        @fetcher.fetch(stage: :plan).map do |event|
-          st_commit = first_time_reference_commit(event.delete('commits'), event)
-
-          next unless st_commit
-
-          serialize_commit(event, st_commit)
-        end
+        PlanEvent.fetch(@query)
       end
 
       def code_events
-        @fetcher.fetch(stage: :code).map { |event| serialize_event(event, entity: :merge_request) }
+        CodeEvent.fetch(@query)
       end
 
       def test_events
-        @fetcher.fetch(stage: :test).map { |event| serialize_build_event(event) }
+        TestEvent.fetch(@query)
       end
 
       def review_events
-        @fetcher.fetch(stage: :review).map { |event| serialize_event(event, entity: :merge_request) }
+        ReviewEvent.fetch(@query)
       end
 
       def staging_events
-        @fetcher.fetch(stage: :staging).map { |event| serialize_build_event(event) }
+        StagingEvent.fetch(@query)
       end
 
       def production_events
-        @fetcher.fetch(stage: :production).map { |event| serialize_event(event) }
-      end
-
-      private
-
-      def serialize_event(event, entity: :issue)
-        event['author'] = User.find(event.delete('author_id'))
-
-        AnalyticsGenericSerializer.new(project: @project, entity: entity).represent(event).as_json
-      end
-
-      def serialize_build_event(event)
-        build = ::Ci::Build.find(event['id'])
-
-        AnalyticsBuildSerializer.new.represent(build).as_json
-      end
-
-      def first_time_reference_commit(commits, event)
-        YAML.load(commits).find do |commit|
-          next unless commit[:committed_date] && event['first_mentioned_in_commit_at']
-
-          commit[:committed_date].to_i == DateTime.parse(event['first_mentioned_in_commit_at'].to_s).to_i
-        end
-      end
-
-      def serialize_commit(event, st_commit)
-        commit = Commit.new(Gitlab::Git::Commit.new(st_commit), @project)
-
-        AnalyticsCommitSerializer.new(project: @project, total_time: event['total_time']).represent(commit).as_json
-      end
-
-      def interval_in_words(diff)
-        "#{distance_of_time_in_words(diff.to_f)} ago"
+        ProductionEvent.fetch(@query)
       end
     end
   end
diff --git a/lib/gitlab/cycle_analytics/events_fetcher.rb b/lib/gitlab/cycle_analytics/events_fetcher.rb
index 4c1d19774f5..813db46f058 100644
--- a/lib/gitlab/cycle_analytics/events_fetcher.rb
+++ b/lib/gitlab/cycle_analytics/events_fetcher.rb
@@ -6,9 +6,7 @@ module Gitlab
       end
 
       def fetch(stage:)
-        @query.execute(stage) do |stage_class, base_query|
-          stage_class.query(base_query)
-        end
+        @query.execute(stage)
       end
     end
   end
diff --git a/lib/gitlab/cycle_analytics/events_query.rb b/lib/gitlab/cycle_analytics/events_query.rb
index b61320fc561..7ecdc07d17f 100644
--- a/lib/gitlab/cycle_analytics/events_query.rb
+++ b/lib/gitlab/cycle_analytics/events_query.rb
@@ -1,30 +1,30 @@
 module Gitlab
   module CycleAnalytics
     class EventsQuery
-      include MetricsFetcher
+      attr_reader :project
 
       def initialize(project:, options: {})
         @project = project
         @from = options[:from]
         @branch = options[:branch]
+        @fetcher = Gitlab::CycleAnalytics::MetricsFetcher.new(project: project, from: @from, branch: @branch)
       end
 
-      def execute(stage, &block)
-        @stage = stage
-        query = build_query(&block)
+      def execute(stage_class)
+        @stage_class = stage_class
 
         ActiveRecord::Base.connection.exec_query(query.to_sql)
       end
 
       private
 
-      def build_query
-        base_query = base_query_for(@stage)
-        diff_fn = subtract_datetimes_diff(base_query, stage_class.start_time_attrs, stage_class.end_time_attrs)
+      def query
+        base_query = @fetcher.base_query_for(@stage_class.stage)
+        diff_fn = @fetcher.subtract_datetimes_diff(base_query, @stage_class.start_time_attrs, @stage_class.end_time_attrs)
 
-        yield(stage_class, base_query) if block_given?
+        @stage_class.query(base_query)
 
-        base_query.project(extract_epoch(diff_fn).as('total_time'), *stage_class.projections).order(stage_class.order.desc)
+        base_query.project(extract_epoch(diff_fn).as('total_time'), *@stage_class.projections).order(@stage_class.order.desc)
       end
 
       def extract_epoch(arel_attribute)
@@ -32,10 +32,6 @@ module Gitlab
 
         Arel.sql(%Q{EXTRACT(EPOCH FROM (#{arel_attribute.to_sql}))})
       end
-
-      def stage_class
-        @stage_class ||= "Gitlab::CycleAnalytics::#{@stage.to_s.camelize}Config".constantize
-      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/issue_config.rb b/lib/gitlab/cycle_analytics/issue_event.rb
index 985ac76feb2..9cfcdc9b20e 100644
--- a/lib/gitlab/cycle_analytics/issue_config.rb
+++ b/lib/gitlab/cycle_analytics/issue_event.rb
@@ -1,6 +1,7 @@
 module Gitlab
   module CycleAnalytics
-    class IssueConfig < BaseConfig
+    class IssueEvent < BaseEvent
+      @stage = :issue
       @start_time_attrs = issue_table[:created_at]
 
       @end_time_attrs = [issue_metrics_table[:first_associated_with_milestone_at],
@@ -11,6 +12,12 @@ module Gitlab
                       issue_table[:id],
                       issue_table[:created_at],
                       issue_table[:author_id]]
+
+      def self.serialize(event, query)
+        event['author'] = User.find(event.delete('author_id'))
+
+        AnalyticsIssueSerializer.new(project: query.project).represent(event).as_json
+      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/metrics_fetcher.rb b/lib/gitlab/cycle_analytics/metrics_fetcher.rb
index 6743cbcc9e0..b71e8735e27 100644
--- a/lib/gitlab/cycle_analytics/metrics_fetcher.rb
+++ b/lib/gitlab/cycle_analytics/metrics_fetcher.rb
@@ -1,12 +1,18 @@
 module Gitlab
   module CycleAnalytics
-    module MetricsFetcher
+    class MetricsFetcher
       include Gitlab::Database::Median
       include Gitlab::Database::DateTime
+      include MetricsTables
 
       DEPLOYMENT_METRIC_STAGES = %i[production staging]
 
-      private
+      def initialize(project:, from:, branch:)
+        @project = project
+        @project = project
+        @from = from
+        @branch = branch
+      end
 
       def calculate_metric(name, start_time_attrs, end_time_attrs)
         cte_table = Arel::Table.new("cte_table_for_#{name}")
@@ -49,38 +55,6 @@ module Gitlab
 
         query
       end
-
-      def mr_metrics_table
-        MergeRequest::Metrics.arel_table
-      end
-
-      def mr_table
-        MergeRequest.arel_table
-      end
-
-      def mr_diff_table
-        MergeRequestDiff.arel_table
-      end
-
-      def mr_closing_issues_table
-        MergeRequestsClosingIssues.arel_table
-      end
-
-      def issue_table
-        Issue.arel_table
-      end
-
-      def issue_metrics_table
-        Issue::Metrics.arel_table
-      end
-
-      def user_table
-        User.arel_table
-      end
-
-      def build_table
-        ::CommitStatus.arel_table
-      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/metrics_tables.rb b/lib/gitlab/cycle_analytics/metrics_tables.rb
new file mode 100644
index 00000000000..9d25ef078e8
--- /dev/null
+++ b/lib/gitlab/cycle_analytics/metrics_tables.rb
@@ -0,0 +1,37 @@
+module Gitlab
+  module CycleAnalytics
+    module MetricsTables
+      def mr_metrics_table
+        MergeRequest::Metrics.arel_table
+      end
+
+      def mr_table
+        MergeRequest.arel_table
+      end
+
+      def mr_diff_table
+        MergeRequestDiff.arel_table
+      end
+
+      def mr_closing_issues_table
+        MergeRequestsClosingIssues.arel_table
+      end
+
+      def issue_table
+        Issue.arel_table
+      end
+
+      def issue_metrics_table
+        Issue::Metrics.arel_table
+      end
+
+      def user_table
+        User.arel_table
+      end
+
+      def build_table
+        ::CommitStatus.arel_table
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/cycle_analytics/plan_config.rb b/lib/gitlab/cycle_analytics/plan_config.rb
deleted file mode 100644
index 453ee26b4c9..00000000000
--- a/lib/gitlab/cycle_analytics/plan_config.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-module Gitlab
-  module CycleAnalytics
-    class PlanConfig < BaseConfig
-      @start_time_attrs = issue_metrics_table[:first_associated_with_milestone_at]
-
-      @end_time_attrs = [issue_metrics_table[:first_added_to_board_at],
-                         issue_metrics_table[:first_mentioned_in_commit_at]]
-
-      @projections = [mr_diff_table[:st_commits].as('commits'),
-                      issue_metrics_table[:first_mentioned_in_commit_at]]
-
-      def self.query(base_query)
-        base_query.join(mr_diff_table).on(mr_diff_table[:merge_request_id].eq(mr_table[:id]))
-      end
-    end
-  end
-end
diff --git a/lib/gitlab/cycle_analytics/plan_event.rb b/lib/gitlab/cycle_analytics/plan_event.rb
new file mode 100644
index 00000000000..b8107b06228
--- /dev/null
+++ b/lib/gitlab/cycle_analytics/plan_event.rb
@@ -0,0 +1,44 @@
+module Gitlab
+  module CycleAnalytics
+    class PlanEvent < BaseEvent
+      @stage = :plan
+      @start_time_attrs = issue_metrics_table[:first_associated_with_milestone_at]
+
+      @end_time_attrs = [issue_metrics_table[:first_added_to_board_at],
+                         issue_metrics_table[:first_mentioned_in_commit_at]]
+
+      @projections = [mr_diff_table[:st_commits].as('commits'),
+                      issue_metrics_table[:first_mentioned_in_commit_at]]
+
+      class << self
+        def query(base_query)
+          base_query.join(mr_diff_table).on(mr_diff_table[:merge_request_id].eq(mr_table[:id]))
+        end
+
+        private
+
+        def serialize(event, query)
+          st_commit = first_time_reference_commit(event.delete('commits'), event)
+
+          return unless st_commit
+
+          serialize_commit(event, st_commit, query)
+        end
+
+        def first_time_reference_commit(commits, event)
+          YAML.load(commits).find do |commit|
+            next unless commit[:committed_date] && event['first_mentioned_in_commit_at']
+
+            commit[:committed_date].to_i == DateTime.parse(event['first_mentioned_in_commit_at'].to_s).to_i
+          end
+        end
+
+        def serialize_commit(event, st_commit, query)
+          commit = Commit.new(Gitlab::Git::Commit.new(st_commit), @project)
+
+          AnalyticsCommitSerializer.new(project: query.project, total_time: event['total_time']).represent(commit).as_json
+        end
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/gitlab/cycle_analytics/production_config.rb b/lib/gitlab/cycle_analytics/production_event.rb
index dc9f1d5d059..b0b2d94f7e7 100644
--- a/lib/gitlab/cycle_analytics/production_config.rb
+++ b/lib/gitlab/cycle_analytics/production_event.rb
@@ -1,6 +1,7 @@
 module Gitlab
   module CycleAnalytics
-    class ProductionConfig < BaseConfig
+    class ProductionEvent < BaseEvent
+      @stage = :production
       @start_time_attrs = issue_table[:created_at]
 
       @end_time_attrs = mr_metrics_table[:first_deployed_to_production_at]
@@ -10,6 +11,12 @@ module Gitlab
                       issue_table[:id],
                       issue_table[:created_at],
                       issue_table[:author_id]]
+
+      def self.serialize(event, query)
+        event['author'] = User.find(event.delete('author_id'))
+
+        AnalyticsIssueSerializer.new(project: query.project).represent(event).as_json
+      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/review_event.rb b/lib/gitlab/cycle_analytics/review_event.rb
new file mode 100644
index 00000000000..dcd138eaa92
--- /dev/null
+++ b/lib/gitlab/cycle_analytics/review_event.rb
@@ -0,0 +1,21 @@
+module Gitlab
+  module CycleAnalytics
+    class ReviewEvent < BaseEvent
+      @stage = :review
+      @start_time_attrs = mr_table[:created_at]
+      @end_time_attrs = mr_metrics_table[:merged_at]
+      @projections = [mr_table[:title],
+                      mr_table[:iid],
+                      mr_table[:id],
+                      mr_table[:created_at],
+                      mr_table[:state],
+                      mr_table[:author_id]]
+
+      def self.serialize(event, _query)
+        event['author'] = User.find(event.delete('author_id'))
+
+        AnalyticsMergeRequestSerializer.new(project: query.project).represent(event).as_json
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/cycle_analytics/staging_config.rb b/lib/gitlab/cycle_analytics/staging_event.rb
index f6f471286a0..a8872b50cfd 100644
--- a/lib/gitlab/cycle_analytics/staging_config.rb
+++ b/lib/gitlab/cycle_analytics/staging_event.rb
@@ -1,6 +1,7 @@
 module Gitlab
   module CycleAnalytics
-    class StagingConfig < BaseConfig
+    class StagingEvent < BaseEvent
+      @stage = :staging
       @start_time_attrs = mr_metrics_table[:merged_at]
       @end_time_attrs = mr_metrics_table[:first_deployed_to_production_at]
       @projections = [build_table[:id]]
@@ -9,6 +10,12 @@ module Gitlab
       def self.query(base_query)
         base_query.join(build_table).on(mr_metrics_table[:pipeline_id].eq(build_table[:commit_id]))
       end
+
+      def self.serialize(event, _query)
+        build = ::Ci::Build.find(event['id'])
+
+        AnalyticsBuildSerializer.new.represent(build).as_json
+      end
     end
   end
 end
diff --git a/lib/gitlab/cycle_analytics/test_config.rb b/lib/gitlab/cycle_analytics/test_event.rb
index 6cb80f9a62c..c91d3f47da0 100644
--- a/lib/gitlab/cycle_analytics/test_config.rb
+++ b/lib/gitlab/cycle_analytics/test_event.rb
@@ -1,6 +1,7 @@
 module Gitlab
   module CycleAnalytics
-    class TestConfig < BaseConfig
+    class TestEvent < BaseEvent
+      @stage = :test
       @start_time_attrs =  mr_metrics_table[:latest_build_started_at]
       @end_time_attrs = mr_metrics_table[:latest_build_finished_at]
       @projections = [build_table[:id]]
@@ -9,6 +10,12 @@ module Gitlab
       def self.query(base_query)
         base_query.join(build_table).on(mr_metrics_table[:pipeline_id].eq(build_table[:commit_id]))
       end
+
+      def self.serialize(event, _query)
+        build = ::Ci::Build.find(event['id'])
+
+        AnalyticsBuildSerializer.new.represent(build).as_json
+      end
     end
   end
 end