import { Context } from "@opentelemetry/api";
import {
  ReadableSpan,
  Span,
  SpanProcessor,
} from "@opentelemetry/sdk-trace-base";
import { SignalAttributeValue } from "../index.js";

export class EnrichSpanProcessor implements SpanProcessor {
  private _spanAttributes:
    | Record<string, SignalAttributeValue | (() => SignalAttributeValue)>
    | undefined;

  constructor(
    spanAttributes?: Record<
      string,
      SignalAttributeValue | (() => SignalAttributeValue)
    >,
  ) {
    this._spanAttributes = spanAttributes;
  }

  forceFlush(): Promise<void> {
    return Promise.resolve();
  }
  onStart(span: Span, _context: Context): void {
    if (this._spanAttributes != undefined) {
      for (const [key, value] of Object.entries(this._spanAttributes)) {
        span.setAttribute(key, typeof value === "function" ? value() : value);
      }
    }
  }
  onEnd(_span: ReadableSpan): void {
    return;
  }
  shutdown(): Promise<void> {
    return Promise.resolve();
  }
}