feat(ee): Captain custom http tools (#12584)

To test this out, use the following PR:
https://github.com/chatwoot/chatwoot/pull/12585

---------

Co-authored-by: Pranav <pranavrajs@gmail.com>

enterprise/app/models/captain/custom_tool.rb

@@ -0,0 +1,91 @@
+# == Schema Information
+#
+# Table name: captain_custom_tools
+#
+#  id                :bigint           not null, primary key
+#  auth_config       :jsonb
+#  auth_type         :string           default("none")
+#  description       :text
+#  enabled           :boolean          default(TRUE), not null
+#  endpoint_url      :text             not null
+#  http_method       :string           default("GET"), not null
+#  param_schema      :jsonb
+#  request_template  :text
+#  response_template :text
+#  slug              :string           not null
+#  title             :string           not null
+#  created_at        :datetime         not null
+#  updated_at        :datetime         not null
+#  account_id        :bigint           not null
+#
+# Indexes
+#
+#  index_captain_custom_tools_on_account_id           (account_id)
+#  index_captain_custom_tools_on_account_id_and_slug  (account_id,slug) UNIQUE
+#
+class Captain::CustomTool < ApplicationRecord
+  include Concerns::Toolable
+  include Concerns::SafeEndpointValidatable
+
+  self.table_name = 'captain_custom_tools'
+
+  PARAM_SCHEMA_VALIDATION = {
+    'type': 'array',
+    'items': {
+      'type': 'object',
+      'properties': {
+        'name': { 'type': 'string' },
+        'type': { 'type': 'string' },
+        'description': { 'type': 'string' },
+        'required': { 'type': 'boolean' }
+      },
+      'required': %w[name type description],
+      'additionalProperties': false
+    }
+  }.to_json.freeze
+
+  belongs_to :account
+
+  enum :http_method, %w[GET POST].index_by(&:itself), validate: true
+  enum :auth_type, %w[none bearer basic api_key].index_by(&:itself), default: :none, validate: true, prefix: :auth
+
+  before_validation :generate_slug
+
+  validates :slug, presence: true, uniqueness: { scope: :account_id }
+  validates :title, presence: true
+  validates :endpoint_url, presence: true
+  validates_with JsonSchemaValidator,
+                 schema: PARAM_SCHEMA_VALIDATION,
+                 attribute_resolver: ->(record) { record.param_schema }
+
+  scope :enabled, -> { where(enabled: true) }
+
+  def to_tool_metadata
+    {
+      id: slug,
+      title: title,
+      description: description,
+      custom: true
+    }
+  end
+
+  private
+
+  def generate_slug
+    return if slug.present?
+
+    base_slug = title.present? ? "custom_#{title.parameterize}" : "custom_#{SecureRandom.uuid}"
+    self.slug = find_unique_slug(base_slug)
+  end
+
+  def find_unique_slug(base_slug, counter = 0)
+    slug_candidate = counter.zero? ? base_slug : "#{base_slug}-#{counter}"
+    return find_unique_slug(base_slug, counter + 1) if slug_exists?(slug_candidate)
+
+    slug_candidate
+  end
+
+  def slug_exists?(candidate)
+    self.class.exists?(account_id: account_id, slug: candidate)
+  end
+end