@mock_only
Feature: A2A SSE streaming for task updates and artifacts
  As a CleverAgents developer
  I want the A2A event system to support SSE streaming
  So that clients can receive real-time task status and artifact updates

  Scenario: SSE event formatter produces valid text/event-stream output
    Given an A2aEvent with type "TaskStatusUpdateEvent" and plan_id "plan-001"
    When I format the event as SSE
    Then the SSE output should contain "event: TaskStatusUpdateEvent"
    And the SSE output should contain "id: "
    And the SSE output should contain "data: "
    And the SSE output should end with two newlines

  Scenario: SSE keepalive produces a comment line
    When I format a keepalive SSE message
    Then the keepalive should start with ":"

  Scenario: EventBusBridge translates plan status events
    Given an A2aEventQueue for SSE testing
    And a mock EventBus
    And an EventBusBridge connecting bus to queue
    When the bridge receives a PLAN_CREATED domain event
    Then the queue should contain a TaskStatusUpdateEvent

  Scenario: EventBusBridge translates artifact events
    Given an A2aEventQueue for SSE testing
    And a mock EventBus
    And an EventBusBridge connecting bus to queue
    When the bridge receives a CHECKPOINT_RESTORED domain event
    Then the queue should contain a TaskArtifactUpdateEvent

  Scenario: EventBusBridge handles closed queue gracefully
    Given an A2aEventQueue for SSE testing
    And a mock EventBus
    And an EventBusBridge connecting bus to queue
    When the queue is closed
    And the bridge receives a PLAN_CREATED domain event
    Then no error should be raised from the bridge

  Scenario: TaskStatusUpdateEvent type constant is defined
    Then the TASK_STATUS_UPDATE constant should equal "TaskStatusUpdateEvent"

  Scenario: TaskArtifactUpdateEvent type constant is defined
    Then the TASK_ARTIFACT_UPDATE constant should equal "TaskArtifactUpdateEvent"

  Scenario: SseEventFormatter data payload is valid JSON
    Given an A2aEvent with type "TaskStatusUpdateEvent" and plan_id "plan-002"
    When I format the event as SSE
    Then the SSE data line should contain valid JSON
    And the JSON should have key "event_type" with value "TaskStatusUpdateEvent"
    And the JSON should have key "plan_id" with value "plan-002"