Feature: A2A JSON-RPC 2.0 wire format compliance
  As a developer maintaining the A2A protocol layer
  I want A2aRequest and A2aResponse to use JSON-RPC 2.0 field names
  So that external A2A-compliant clients can communicate with the server

  # -------------------------------------------------------------------
  # A2aRequest serialisation — JSON-RPC 2.0 field names
  # -------------------------------------------------------------------

  Scenario: A2aRequest serialises with jsonrpc field set to "2.0"
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should contain key "jsonrpc" with value "2.0"

  Scenario: A2aRequest serialises with id field
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should contain key "id"

  Scenario: A2aRequest serialises with method field
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should contain key "method" with value "_cleveragents/plan/status"

  Scenario: A2aRequest serialises with params field
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should contain key "params"

  Scenario: A2aRequest does not contain non-standard field a2a_version
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should not contain key "a2a_version"

  Scenario: A2aRequest does not contain non-standard field request_id
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should not contain key "request_id"

  Scenario: A2aRequest does not contain non-standard field operation
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should not contain key "operation"

  Scenario: A2aRequest does not contain non-standard field auth
    Given a valid A2aRequest with method "_cleveragents/plan/status" and params {"plan_id": "P1"}
    When I serialise the request to a dict
    Then the serialised dict should not contain key "auth"

  Scenario: A2aRequest auto-generates id when not provided
    Given a valid A2aRequest with method "session.create" and params {}
    Then the request id should be non-empty

  Scenario: A2aRequest accepts explicit id
    Given an A2aRequest with method "session.create" and id "my-custom-id"
    Then the request id should equal "my-custom-id"

  Scenario: A2aRequest rejects empty method
    When I try to create an A2aRequest with empty method
    Then a wire format ValidationError should be raised

  Scenario: A2aRequest rejects non-2.0 jsonrpc version
    When I try to create an A2aRequest with jsonrpc "1.0"
    Then a wire format ValidationError should be raised

  # -------------------------------------------------------------------
  # A2aResponse serialisation — JSON-RPC 2.0 field names (success)
  # -------------------------------------------------------------------

  Scenario: A2aResponse success serialises with jsonrpc field set to "2.0"
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should contain key "jsonrpc" with value "2.0"

  Scenario: A2aResponse success serialises with id field
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should contain key "id" with value "REQ-001"

  Scenario: A2aResponse success serialises with result field
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should contain key "result"

  Scenario: A2aResponse success does not contain non-standard field a2a_version
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should not contain key "a2a_version"

  Scenario: A2aResponse success does not contain non-standard field request_id
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should not contain key "request_id"

  Scenario: A2aResponse success does not contain non-standard field status
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should not contain key "status"

  Scenario: A2aResponse success does not contain non-standard field data
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should not contain key "data"

  Scenario: A2aResponse success does not contain non-standard field timing_ms
    Given a successful A2aResponse with id "REQ-001" and result {"status": "ok"}
    When I serialise the response to a dict
    Then the serialised dict should not contain key "timing_ms"

  # -------------------------------------------------------------------
  # A2aResponse serialisation — JSON-RPC 2.0 field names (error)
  # -------------------------------------------------------------------

  Scenario: A2aResponse error serialises with error field
    Given an error A2aResponse with id "REQ-002" and error code "NOT_FOUND"
    When I serialise the response to a dict
    Then the serialised dict should contain key "error"

  Scenario: A2aResponse error does not contain result field
    Given an error A2aResponse with id "REQ-002" and error code "NOT_FOUND"
    When I serialise the response to a dict
    Then the serialised dict should not contain key "result"

  Scenario: A2aResponse error does not contain non-standard field status
    Given an error A2aResponse with id "REQ-002" and error code "NOT_FOUND"
    When I serialise the response to a dict
    Then the serialised dict should not contain key "status"

  # -------------------------------------------------------------------
  # A2aResponse validation — mutual exclusion of result and error
  # -------------------------------------------------------------------

  Scenario: A2aResponse requires either result or error
    When I try to create an A2aResponse with neither result nor error
    Then a wire format ValidationError should be raised

  Scenario: A2aResponse rejects both result and error set simultaneously
    When I try to create an A2aResponse with both result and error
    Then a wire format ValidationError should be raised

  # -------------------------------------------------------------------
  # Deserialisation — inbound JSON-RPC 2.0 payloads
  # -------------------------------------------------------------------

  Scenario: A2aRequest deserialises from JSON-RPC 2.0 compliant dict
    Given a JSON-RPC 2.0 request dict with method "message/send" and id "42"
    When I deserialise the dict into an A2aRequest
    Then the request method should equal "message/send"
    And the request id should equal "42"
    And the request jsonrpc should equal "2.0"

  Scenario: A2aResponse deserialises from JSON-RPC 2.0 success dict
    Given a JSON-RPC 2.0 success response dict with id "42" and result {"plan_id": "P1"}
    When I deserialise the dict into an A2aResponse
    Then the response result should contain key "plan_id"
    And the response error should be None

  Scenario: A2aResponse deserialises from JSON-RPC 2.0 error dict
    Given a JSON-RPC 2.0 error response dict with id "42" and error code "NOT_FOUND"
    When I deserialise the dict into an A2aResponse
    Then the response error should not be None
    And the response result should be None

  # -------------------------------------------------------------------
  # Facade dispatch — produces JSON-RPC 2.0 compliant responses
  # -------------------------------------------------------------------

  Scenario: Facade dispatch produces response with jsonrpc "2.0"
    Given a wire-format facade with no services
    When I dispatch wire-format method "_cleveragents/health/check" with params {}
    Then the wire-format response jsonrpc should equal "2.0"

  Scenario: Facade dispatch success produces response with result field
    Given a wire-format facade with no services
    When I dispatch wire-format method "_cleveragents/health/check" with params {}
    Then the wire-format response result should not be None

  Scenario: Facade dispatch success produces response without error field
    Given a wire-format facade with no services
    When I dispatch wire-format method "_cleveragents/health/check" with params {}
    Then the wire-format response error should be None

  Scenario: Facade dispatch error produces response with error field
    Given a wire-format facade with no services
    When I dispatch wire-format method "unknown/method" with params {}
    Then the wire-format response error should not be None

  Scenario: Facade dispatch preserves request id in response
    Given a wire-format facade with no services
    When I dispatch wire-format method "_cleveragents/health/check" with id "test-id-123" and params {}
    Then the wire-format response id should equal "test-id-123"