feat(v4): Add API to fetch aggregate reports for inboxes (#10604)

The Inbox Overview section is being updated to offer a more detailed
report, showing an overall view of the account grouped by inboxes. To
view detailed reports and access specific graphs for individual inboxes,
click on the inbox name to navigate to its dedicated report page.

---------

Co-authored-by: Sojan Jose <sojan@pepalo.com>

app/builders/v2/reports/inbox_summary_builder.rb

@@ -0,0 +1,62 @@
+class V2::Reports::InboxSummaryBuilder < V2::Reports::BaseSummaryBuilder
+  pattr_initialize [:account!, :params!]
+
+  def build
+    load_data
+    prepare_report
+  end
+
+  private
+
+  attr_reader :conversations_count, :resolved_count,
+              :avg_resolution_time, :avg_first_response_time, :avg_reply_time
+
+  def load_data
+    @conversations_count = fetch_conversations_count
+    @resolved_count = fetch_resolved_count
+    @avg_resolution_time = fetch_average_time('conversation_resolved')
+    @avg_first_response_time = fetch_average_time('first_response')
+    @avg_reply_time = fetch_average_time('reply_time')
+  end
+
+  def fetch_conversations_count
+    account.conversations.where(created_at: range).group(group_by_key).count
+  end
+
+  def fetch_resolved_count
+    reporting_events.where(name: 'conversation_resolved').group(group_by_key).count
+  end
+
+  def fetch_average_time(event_name)
+    get_grouped_average(reporting_events.where(name: event_name))
+  end
+
+  def reporting_events
+    @reporting_events ||= account.reporting_events.where(created_at: range)
+  end
+
+  def prepare_report
+    account.inboxes.map do |inbox|
+      build_inbox_stats(inbox)
+    end
+  end
+
+  def build_inbox_stats(inbox)
+    {
+      id: inbox.id,
+      conversations_count: conversations_count[inbox.id] || 0,
+      resolved_conversations_count: resolved_count[inbox.id] || 0,
+      avg_resolution_time: avg_resolution_time[inbox.id],
+      avg_first_response_time: avg_first_response_time[inbox.id],
+      avg_reply_time: avg_reply_time[inbox.id]
+    }
+  end
+
+  def group_by_key
+    :inbox_id
+  end
+
+  def average_value_key
+    ActiveModel::Type::Boolean.new.cast(params[:business_hours]) ? :value_in_business_hours : :value
+  end
+end

app/controllers/api/v2/accounts/summary_reports_controller.rb

@@ -1,6 +1,6 @@
 class Api::V2::Accounts::SummaryReportsController < Api::V1::Accounts::BaseController
   before_action :check_authorization
-  before_action :prepare_builder_params, only: [:agent, :team]
+  before_action :prepare_builder_params, only: [:agent, :team, :inbox]
 
   def agent
     render_report_with(V2::Reports::AgentSummaryBuilder)
@@ -10,6 +10,10 @@ class Api::V2::Accounts::SummaryReportsController < Api::V1::Accounts::BaseContr
     render_report_with(V2::Reports::TeamSummaryBuilder)
   end
 
+  def inbox
+    render_report_with(V2::Reports::InboxSummaryBuilder)
+  end
+
   private
 
   def check_authorization
@@ -26,8 +30,7 @@ class Api::V2::Accounts::SummaryReportsController < Api::V1::Accounts::BaseContr
 
   def render_report_with(builder_class)
     builder = builder_class.new(account: Current.account, params: @builder_params)
-    data = builder.build
-    render json: data
+    render json: builder.build
   end
 
   def permitted_params