async start()

in apps/chat/src/utils/server/index.ts [165:221]
47 lines of code
10 McCabe index (conditional complexity)

    async start(controller) {
      const onParse = (event: ParsedEvent | ReconnectInterval) => {
        if (isFinished) {
          return;
        }

        if (event.type === 'event') {
          try {
            if (event.data === '[DONE]') {
              controller.close();
              isFinished = true;
              return;
            }
            const data = event.data;
            const json = JSON.parse(data);
            if (json.error) {
              throw new DialAIError(
                json.error.message,
                json.error.type,
                json.error.param,
                json.error.code,
                json.error.display_message,
              );
            }
            if (!idSend) {
              appendChunk(controller, { responseId: json.id });
              idSend = true;
            }

            if (json.choices?.[0]?.delta) {
              if (json.choices[0].finish_reason === 'content_filter') {
                throw new DialAIError(
                  errorsMessages.contentFiltering,
                  '',
                  '',
                  'content_filter',
                );
              }

              appendChunk(controller, json.choices[0].delta);
            }
          } catch (e) {
            controller.error(e);
          }
        }
      };

      const parser = createParser(onParse);
      if (res.body) {
        for await (const chunk of res.body) {
          if (isFinished) {
            return;
          }
          parser.feed(decoder.decode(chunk as Buffer));
        }
      }
    },