a2a

defmodule A2A.JSONRPC.Error do
  @moduledoc """
  JSON-RPC 2.0 error with A2A-specific error codes.

  Provides a struct and named constructors for the 12 error codes defined by
  the A2A protocol (5 standard JSON-RPC + 7 A2A-specific).

  ## Example

      iex> error = A2A.JSONRPC.Error.task_not_found()
      iex> error.code
      -32001
      iex> A2A.JSONRPC.Error.to_map(error)
      %{"code" => -32001, "message" => "Task not found"}
  """

  @type t :: %__MODULE__{
          code: integer(),
          message: String.t(),
          data: term()
        }

  @enforce_keys [:code, :message]
  defstruct [:code, :message, :data]

  @doc "Builds a parse error (-32700)."
  @spec parse_error(term()) :: t()
  def parse_error(data \\ nil) do
    %__MODULE__{code: -32_700, message: "Invalid JSON payload", data: data}
  end

  @doc "Builds an invalid request error (-32600)."
  @spec invalid_request(term()) :: t()
  def invalid_request(data \\ nil) do
    %__MODULE__{
      code: -32_600,
      message: "Request payload validation error",
      data: data
    }
  end

  @doc "Builds a method not found error (-32601)."
  @spec method_not_found(term()) :: t()
  def method_not_found(data \\ nil) do
    %__MODULE__{code: -32_601, message: "Method not found", data: data}
  end

  @doc "Builds an invalid params error (-32602)."
  @spec invalid_params(term()) :: t()
  def invalid_params(data \\ nil) do
    %__MODULE__{code: -32_602, message: "Invalid parameters", data: data}
  end

  @doc "Builds an internal error (-32603)."
  @spec internal_error(term()) :: t()
  def internal_error(data \\ nil) do
    %__MODULE__{code: -32_603, message: "Internal error", data: data}
  end

  @doc "Builds a task not found error (-32001)."
  @spec task_not_found(term()) :: t()
  def task_not_found(data \\ nil) do
    %__MODULE__{code: -32_001, message: "Task not found", data: data}
  end

  @doc "Builds a task not cancelable error (-32002)."
  @spec task_not_cancelable(term()) :: t()
  def task_not_cancelable(data \\ nil) do
    %__MODULE__{code: -32_002, message: "Task cannot be canceled", data: data}
  end

  @doc "Builds a push notification not supported error (-32003)."
  @spec push_notification_not_supported(term()) :: t()
  def push_notification_not_supported(data \\ nil) do
    %__MODULE__{
      code: -32_003,
      message: "Push Notification is not supported",
      data: data
    }
  end

  @doc "Builds an unsupported operation error (-32004)."
  @spec unsupported_operation(term()) :: t()
  def unsupported_operation(data \\ nil) do
    %__MODULE__{
      code: -32_004,
      message: "This operation is not supported",
      data: data
    }
  end

  @doc "Builds a content type not supported error (-32005)."
  @spec content_type_not_supported(term()) :: t()
  def content_type_not_supported(data \\ nil) do
    %__MODULE__{
      code: -32_005,
      message: "Incompatible content types",
      data: data
    }
  end

  @doc "Builds an invalid agent response error (-32006)."
  @spec invalid_agent_response(term()) :: t()
  def invalid_agent_response(data \\ nil) do
    %__MODULE__{
      code: -32_006,
      message: "Invalid agent response",
      data: data
    }
  end

  @doc "Builds an authenticated extended card not configured error (-32007)."
  @spec authenticated_extended_card_not_configured(term()) :: t()
  def authenticated_extended_card_not_configured(data \\ nil) do
    %__MODULE__{
      code: -32_007,
      message: "Authenticated Extended Card is not configured",
      data: data
    }
  end

  @doc """
  Converts an error struct to a JSON-ready map.

  The `"data"` key is only included when non-nil.

      iex> error = A2A.JSONRPC.Error.internal_error("boom")
      iex> A2A.JSONRPC.Error.to_map(error)
      %{"code" => -32603, "message" => "Internal error", "data" => "boom"}
  """
  @spec to_map(t()) :: map()
  def to_map(%__MODULE__{data: nil} = error) do
    %{"code" => error.code, "message" => error.message}
  end

  def to_map(%__MODULE__{} = error) do
    %{"code" => error.code, "message" => error.message, "data" => error.data}
  end
end