#!/usr/bin/env node

function parseBoolean(value) {
  return String(value || "").trim().toLowerCase() === "true";
}

function sanitizeRefreshEvent(data) {
  return {
    eventId: data?.eventId,
    eventType: data?.eventType,
    receivedAt: data?.receivedAt,
    targetThreadRef: data?.targetThreadRef,
    sourceMessageId: data?.sourceMessageId,
    appName: data?.appName,
    refreshMode: data?.refreshMode,
    status: data?.status,
    deepLink: data?.deepLink,
    detail: data?.detail,
  };
}

function compactUndefinedFields(value) {
  return Object.fromEntries(Object.entries(value).filter(([, item]) => item !== undefined));
}

async function consumeEvents({ eventsUrl, once = false }) {
  const response = await fetch(eventsUrl, {
    headers: {
      Accept: "text/event-stream",
    },
  });
  if (!response.ok || !response.body) {
    throw new Error(`CODEX_DESKTOP_EVENTS_UNAVAILABLE status=${response.status}`);
  }

  const decoder = new TextDecoder();
  const reader = response.body.getReader();
  let buffer = "";
  let currentEvent = {};

  function finishEvent() {
    if (!currentEvent.event || currentEvent.event !== "codex_desktop_refresh") {
      currentEvent = {};
      return false;
    }
    const data = currentEvent.data ? JSON.parse(currentEvent.data) : {};
    process.stdout.write(`${JSON.stringify(compactUndefinedFields(sanitizeRefreshEvent(data)))}\n`);
    currentEvent = {};
    return true;
  }

  function handleLine(line) {
    if (line === "") {
      return finishEvent();
    }
    if (line.startsWith("event:")) {
      currentEvent.event = line.slice("event:".length).trim();
    } else if (line.startsWith("id:")) {
      currentEvent.id = line.slice("id:".length).trim();
    } else if (line.startsWith("data:")) {
      currentEvent.data = `${currentEvent.data || ""}${line.slice("data:".length).trim()}`;
    }
    return false;
  }

  while (true) {
    const { done, value } = await reader.read();
    if (done) {
      break;
    }
    buffer += decoder.decode(value, { stream: true });
    const lines = buffer.split(/\r?\n/);
    buffer = lines.pop() ?? "";
    for (const line of lines) {
      const consumed = handleLine(line);
      if (consumed && once) {
        await reader.cancel();
        return;
      }
    }
  }
}

const eventsUrl =
  String(process.env.BOSS_CODEX_DESKTOP_EVENTS_URL || "").trim() ||
  "http://127.0.0.1:4318/api/v1/codex-desktop/events";

try {
  await consumeEvents({
    eventsUrl,
    once: parseBoolean(process.env.BOSS_CODEX_DESKTOP_EVENTS_ONCE),
  });
} catch (error) {
  process.stderr.write(`${error instanceof Error ? error.message : String(error)}\n`);
  process.exit(1);
}