Enhancement: Move reporting metrics to postgres (#606)

app/builders/v2/report_builder.rb

@@ -0,0 +1,110 @@
+class V2::ReportBuilder
+  attr_reader :account, :params
+
+  def initialize(account, params)
+    @account = account
+    @params = params
+  end
+
+  def timeseries
+    send(params[:metric])
+  end
+
+  # For backward compatible with old report
+  def build
+    timeseries.each_with_object([]) do |p, arr|
+      arr << { value: p[1], timestamp: p[0].to_time.to_i }
+    end
+  end
+
+  def summary
+    {
+      conversations_count: conversations_count.values.sum,
+      incoming_messages_count: incoming_messages_count.values.sum,
+      outgoing_messages_count: outgoing_messages_count.values.sum,
+      avg_first_response_time: avg_first_response_time_summary,
+      avg_resolution_time: avg_resolution_time_summary,
+      resolutions_count: resolutions_count.values.sum
+    }
+  end
+
+  private
+
+  def scope
+    return account if params[:type].match?('account')
+    return inbox if params[:type].match?('inbox')
+    return user if params[:type].match?('agent')
+  end
+
+  def inbox
+    @inbox ||= account.inboxes.where(id: params[:id]).first
+  end
+
+  def user
+    @user ||= account.users.where(id: params[:id]).first
+  end
+
+  def conversations_count
+    scope.conversations
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .count
+  end
+
+  def incoming_messages_count
+    scope.messages.unscoped.incoming
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .count
+  end
+
+  def outgoing_messages_count
+    scope.messages.unscoped.outgoing
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .count
+  end
+
+  def resolutions_count
+    scope.conversations
+         .resolved
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .count
+  end
+
+  def avg_first_response_time
+    scope.events
+         .where(name: 'first_response')
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .average(:value)
+  end
+
+  def avg_resolution_time
+    scope.events.where(name: 'conversation_resolved')
+         .group_by_day(:created_at, range: range, default_value: 0)
+         .average(:value)
+  end
+
+  def range
+    parse_date_time(params[:since])..parse_date_time(params[:until])
+  end
+
+  # Taking average of average is not too accurate
+  # https://en.wikipedia.org/wiki/Simpson's_paradox
+  # TODO: Will optimize this later
+  def avg_resolution_time_summary
+    return 0 if avg_resolution_time.values.empty?
+
+    (avg_resolution_time.values.sum / avg_resolution_time.values.length)
+  end
+
+  def avg_first_response_time_summary
+    return 0 if avg_first_response_time.values.empty?
+
+    (avg_first_response_time.values.sum / avg_first_response_time.values.length)
+  end
+
+  def parse_date_time(datetime)
+    return datetime if datetime.is_a?(DateTime)
+    return datetime.to_datetime if datetime.is_a?(Time) || datetime.is_a?(Date)
+
+    DateTime.strptime(datetime, '%s')
+  end
+end