feat: Add unified Call model for voice calling (#14026)

Adds a Call model to track voice call state across providers (Twilio,
WhatsApp). This replaces storing call data in
conversation.additional_attributes and provides a foundation for call
analytics multi-call-per-conversation support, and future voice
providers.

---------

Co-authored-by: Muhsin <12408980+muhsin-k@users.noreply.github.com>

app/models/message.rb

@@ -450,3 +450,4 @@ class Message < ApplicationRecord
 end
 
 Message.prepend_mod_with('Message')
+Message.include_mod_with('Concerns::Message')

db/migrate/20260408170902_create_calls.rb

@@ -0,0 +1,34 @@
+class CreateCalls < ActiveRecord::Migration[7.0]
+  def change
+    create_table :calls do |t|
+      t.bigint :account_id, null: false
+      t.bigint :inbox_id, null: false
+      t.bigint :conversation_id, null: false
+      t.bigint :contact_id, null: false
+      t.bigint :message_id
+      t.bigint :accepted_by_agent_id
+      t.string :provider_call_id, null: false
+      t.integer :provider, null: false, default: 0
+      t.integer :direction, null: false
+      t.string :status, null: false, default: 'ringing'
+      t.datetime :started_at
+      t.integer :duration_seconds
+      t.string :end_reason
+      t.jsonb :meta, default: {}
+      t.text :transcript
+
+      t.timestamps
+    end
+
+    add_call_indexes
+  end
+
+  private
+
+  def add_call_indexes
+    add_index :calls, [:provider, :provider_call_id], unique: true
+    add_index :calls, [:account_id, :conversation_id]
+    add_index :calls, [:account_id, :contact_id]
+    add_index :calls, :message_id
+  end
+end

db/schema.rb

@@ -261,6 +261,30 @@ ActiveRecord::Schema[7.1].define(version: 2026_04_09_091202) do
     t.index ["account_id"], name: "index_automation_rules_on_account_id"
   end
 
+  create_table "calls", force: :cascade do |t|
+    t.bigint "account_id", null: false
+    t.bigint "inbox_id", null: false
+    t.bigint "conversation_id", null: false
+    t.bigint "contact_id", null: false
+    t.bigint "message_id"
+    t.bigint "accepted_by_agent_id"
+    t.string "provider_call_id", null: false
+    t.integer "provider", default: 0, null: false
+    t.integer "direction", null: false
+    t.string "status", default: "ringing", null: false
+    t.datetime "started_at"
+    t.integer "duration_seconds"
+    t.string "end_reason"
+    t.jsonb "meta", default: {}
+    t.text "transcript"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id", "contact_id"], name: "index_calls_on_account_id_and_contact_id"
+    t.index ["account_id", "conversation_id"], name: "index_calls_on_account_id_and_conversation_id"
+    t.index ["message_id"], name: "index_calls_on_message_id"
+    t.index ["provider", "provider_call_id"], name: "index_calls_on_provider_and_provider_call_id", unique: true
+  end
+
   create_table "campaigns", force: :cascade do |t|
     t.integer "display_id", null: false
     t.string "title", null: false

enterprise/app/models/call.rb

@@ -0,0 +1,55 @@
+# == Schema Information
+#
+# Table name: calls
+#
+#  id                   :bigint           not null, primary key
+#  direction            :integer          not null
+#  duration_seconds     :integer
+#  end_reason           :string
+#  meta                 :jsonb
+#  provider             :integer          default("twilio"), not null
+#  started_at           :datetime
+#  status               :string           default("ringing"), not null
+#  transcript           :text
+#  created_at           :datetime         not null
+#  updated_at           :datetime         not null
+#  accepted_by_agent_id :bigint
+#  account_id           :bigint           not null
+#  contact_id           :bigint           not null
+#  conversation_id      :bigint           not null
+#  inbox_id             :bigint           not null
+#  message_id           :bigint
+#  provider_call_id     :string           not null
+#
+# Indexes
+#
+#  index_calls_on_account_id_and_contact_id       (account_id,contact_id)
+#  index_calls_on_account_id_and_conversation_id  (account_id,conversation_id)
+#  index_calls_on_message_id                      (message_id)
+#  index_calls_on_provider_and_provider_call_id   (provider,provider_call_id) UNIQUE
+#
+class Call < ApplicationRecord
+  # All valid call statuses
+  STATUSES = %w[ringing in_progress completed no_answer failed].freeze
+  # Statuses where the call is finished and won't change again
+  TERMINAL_STATUSES = %w[completed no_answer failed].freeze
+
+  enum :provider, { twilio: 0, whatsapp: 1 }
+  enum :direction, { incoming: 0, outgoing: 1 }
+
+  belongs_to :account
+  belongs_to :inbox
+  belongs_to :conversation
+  belongs_to :contact
+  belongs_to :message, optional: true
+  belongs_to :accepted_by_agent, class_name: 'User', optional: true
+
+  has_one_attached :recording
+
+  validates :provider_call_id, presence: true
+  validates :provider, presence: true
+  validates :direction, presence: true
+  validates :status, presence: true, inclusion: { in: STATUSES }
+
+  scope :active, -> { where.not(status: TERMINAL_STATUSES) }
+end

enterprise/app/models/enterprise/concerns/account.rb

@@ -17,6 +17,7 @@ module Enterprise::Concerns::Account
     has_many :copilot_threads, dependent: :destroy_async
     has_many :companies, dependent: :destroy_async
     has_many :voice_channels, dependent: :destroy_async, class_name: '::Channel::Voice'
+    has_many :calls, dependent: :destroy_async
 
     has_one :saml_settings, dependent: :destroy_async, class_name: 'AccountSamlSettings'
   end

enterprise/app/models/enterprise/concerns/conversation.rb

@@ -5,6 +5,7 @@ module Enterprise::Concerns::Conversation
     belongs_to :sla_policy, optional: true
     has_one :applied_sla, dependent: :destroy_async
     has_many :sla_events, dependent: :destroy_async
+    has_many :calls, dependent: :destroy_async
     has_many :captain_responses, class_name: 'Captain::AssistantResponse', dependent: :nullify, as: :documentable
     before_validation :validate_sla_policy, if: -> { sla_policy_id_changed? }
     around_save :ensure_applied_sla_is_created, if: -> { sla_policy_id_changed? }

enterprise/app/models/enterprise/concerns/inbox.rb

@@ -7,5 +7,6 @@ module Enterprise::Concerns::Inbox
             through: :captain_inbox,
             class_name: 'Captain::Assistant'
     has_many :inbox_capacity_limits, dependent: :destroy
+    has_many :calls, dependent: :destroy_async
   end
 end

enterprise/app/models/enterprise/concerns/message.rb

@@ -0,0 +1,7 @@
+module Enterprise::Concerns::Message
+  extend ActiveSupport::Concern
+
+  included do
+    has_one :call, dependent: :nullify
+  end
+end