/**
 * SDK error hierarchy. Adapters (and tests) `instanceof`-check against these
 * to distinguish predictable failure modes from genuine bugs.
 */

export class SDKError extends Error {
  public override readonly cause?: unknown;
  constructor(message: string, cause?: unknown) {
    super(message);
    this.name = "SDKError";
    if (cause !== undefined) this.cause = cause;
  }
}

/**
 * Thrown by `appendMessage` on any duplicate key, and by `idempotentAppend`
 * only when the duplicate has a different canonical-JSON byte sequence.
 *
 * `existingBytes` and `attemptedBytes` capture what was stored vs what we
 * tried to write — useful for debugging conflict storms.
 */
export class MessageIDConflict extends SDKError {
  constructor(
    public readonly taskId: string,
    public readonly messageId: string,
    public readonly existingBytes: Uint8Array,
    public readonly attemptedBytes: Uint8Array,
  ) {
    super(`message ${messageId} already exists in task ${taskId} with different content`);
    this.name = "MessageIDConflict";
  }
}

export class ObjectURLError extends SDKError {
  constructor(message: string, cause?: unknown) {
    super(message, cause);
    this.name = "ObjectURLError";
  }
}

export class MaterializePartError extends SDKError {
  constructor(message: string, cause?: unknown) {
    super(message, cause);
    this.name = "MaterializePartError";
  }
}