export type DiagnosticSeverity = 'info' | 'warning' | 'error';

export interface DiagnosticEvent {
  readonly code: string;
  readonly kind: string;
  readonly stage: string;
  readonly severity: DiagnosticSeverity;
  readonly message: string;
  readonly data?: Record<string, unknown>;
  readonly suggestion?: string;
}

export interface DiagnosticPayload extends DiagnosticEvent {
  readonly type: 'diagnostic';
}

export const STRUCTURED_DIAGNOSTIC_PREFIX = 'WEBSTIR_DIAGNOSTIC ';

export function emitDiagnostic(event: DiagnosticEvent): void {
  const payload: DiagnosticPayload = {
    type: 'diagnostic',
    ...event,
  };

  const logMessage = `[webstir-frontend][${event.code}] ${event.message}`;
  switch (event.severity) {
    case 'error':
      console.error(logMessage);
      break;
    case 'warning':
      console.warn(logMessage);
      break;
    default:
      console.info(logMessage);
      break;
  }

  const serialized = JSON.stringify(payload);
  console.log(`${STRUCTURED_DIAGNOSTIC_PREFIX}${serialized}`);
}