chore: Provider API prototype (#3112)

Enabling Support for Whatsapp via 360Dialog as a prototype for the provider APIs. 

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/models/account.rb

@@ -53,6 +53,7 @@ class Account < ApplicationRecord
   has_many :api_channels, dependent: :destroy, class_name: '::Channel::Api'
   has_many :line_channels, dependent: :destroy, class_name: '::Channel::Line'
   has_many :telegram_channels, dependent: :destroy, class_name: '::Channel::Telegram'
+  has_many :whatsapp_channels, dependent: :destroy, class_name: '::Channel::Whatsapp'
   has_many :canned_responses, dependent: :destroy
   has_many :webhooks, dependent: :destroy
   has_many :labels, dependent: :destroy

app/models/channel/whatsapp.rb

@@ -0,0 +1,67 @@
+# == Schema Information
+#
+# Table name: channel_whatsapp
+#
+#  id              :bigint           not null, primary key
+#  phone_number    :string           not null
+#  provider        :string           default("default")
+#  provider_config :jsonb
+#  created_at      :datetime         not null
+#  updated_at      :datetime         not null
+#  account_id      :integer          not null
+#
+# Indexes
+#
+#  index_channel_whatsapp_on_phone_number  (phone_number) UNIQUE
+#
+
+class Channel::Whatsapp < ApplicationRecord
+  include Channelable
+
+  self.table_name = 'channel_whatsapp'
+  EDITABLE_ATTRS = [:phone_number, { provider_config: {} }].freeze
+
+  validates :phone_number, presence: true, uniqueness: true
+  before_save :validate_provider_config
+
+  def name
+    'Whatsapp'
+  end
+
+  # all this should happen in provider service . but hack mode on
+  def api_base_path
+    # provide the environment variable when testing against sandbox : 'https://waba-sandbox.360dialog.io/v1'
+    ENV.fetch('360DIALOG_BASE_URL', 'https://waba.360dialog.io/v1')
+  end
+
+  # Extract later into provider Service
+  def send_message(phone_number, message)
+    HTTParty.post(
+      "#{api_base_path}/messages",
+      headers: { 'D360-API-KEY': provider_config['api_key'], 'Content-Type': 'application/json' },
+      body: {
+        to: phone_number,
+        text: { body: message },
+        type: 'text'
+      }.to_json
+    )
+  end
+
+  def has_24_hour_messaging_window?
+    true
+  end
+
+  private
+
+  # Extract later into provider Service
+  def validate_provider_config
+    response = HTTParty.post(
+      "#{api_base_path}/configs/webhook",
+      headers: { 'D360-API-KEY': provider_config['api_key'], 'Content-Type': 'application/json' },
+      body: {
+        url: "#{ENV['FRONTEND_URL']}/webhooks/whatsapp/#{phone_number}"
+      }.to_json
+    )
+    errors.add(:bot_token, 'error setting up the webook') unless response.success?
+  end
+end