#!/usr/bin/env node

import { createServer } from "node:http";
import { executeCodexDesktopRefreshHint } from "./codex-desktop-refresh-hint.mjs";
import { detectCodexDesktopIntegration } from "./codex-desktop-integration-probe.mjs";

const subscribers = new Set();
const recentEvents = [];
let nextEventId = 1;

function parsePort(value) {
  const parsed = Number.parseInt(String(value ?? ""), 10);
  return Number.isFinite(parsed) && parsed >= 0 ? parsed : 4318;
}

function readRequestBody(request) {
  return new Promise((resolve, reject) => {
    let raw = "";
    request.setEncoding("utf8");
    request.on("data", (chunk) => {
      raw += chunk;
      if (raw.length > 64 * 1024) {
        reject(new Error("CODEX_DESKTOP_REFRESH_HINT_TOO_LARGE"));
        request.destroy();
      }
    });
    request.on("end", () => {
      resolve(raw);
    });
    request.on("error", reject);
  });
}

function writeJson(response, statusCode, payload) {
  response.writeHead(statusCode, {
    "Content-Type": "application/json",
    "Cache-Control": "no-store",
  });
  response.end(`${JSON.stringify(payload)}\n`);
}

function writeSse(response, event) {
  if (event.id !== undefined) {
    response.write(`id: ${event.id}\n`);
  }
  response.write(`event: ${event.event}\n`);
  response.write(`data: ${JSON.stringify(event.data)}\n\n`);
}

function buildSafeRefreshEvent(payload, result) {
  return {
    eventId: nextEventId++,
    eventType: "codex_desktop_refresh",
    receivedAt: new Date().toISOString(),
    targetThreadRef: String(payload?.targetThreadRef || "").trim() || undefined,
    sourceMessageId: String(payload?.sourceMessageId || "").trim() || undefined,
    appName: String(result?.appName || payload?.appName || "Codex").trim() || "Codex",
    refreshMode: String(payload?.refreshMode || "deeplink-reload").trim() || "deeplink-reload",
    status: result?.status,
    deepLink: result?.deepLink,
    detail: result?.detail || result?.error,
  };
}

function publishRefreshEvent(eventData) {
  recentEvents.push(eventData);
  while (recentEvents.length > 50) {
    recentEvents.shift();
  }
  for (const subscriber of subscribers) {
    writeSse(subscriber, {
      id: eventData.eventId,
      event: "codex_desktop_refresh",
      data: eventData,
    });
  }
}

function handleEvents(request, response) {
  if (request.method !== "GET") {
    writeJson(response, 405, { status: "failed", error: "METHOD_NOT_ALLOWED" });
    return;
  }
  response.writeHead(200, {
    "Content-Type": "text/event-stream",
    "Cache-Control": "no-store",
    Connection: "keep-alive",
    "X-Accel-Buffering": "no",
  });
  subscribers.add(response);
  writeSse(response, {
    event: "ready",
    data: {
      ok: true,
      service: "boss-codex-desktop-refresh-bridge",
    },
  });
  const keepAlive = setInterval(() => {
    response.write(": keepalive\n\n");
  }, 15000);
  request.on("close", () => {
    clearInterval(keepAlive);
    subscribers.delete(response);
  });
}

async function handleRefresh(request, response) {
  if (request.method !== "POST") {
    writeJson(response, 405, { status: "failed", error: "METHOD_NOT_ALLOWED" });
    return;
  }

  try {
    const raw = await readRequestBody(request);
    const payload = JSON.parse(raw || "{}");
    const result = await executeCodexDesktopRefreshHint(payload);
    publishRefreshEvent(buildSafeRefreshEvent(payload, result));
    writeJson(response, result.status === "failed" ? 422 : 200, result);
  } catch (error) {
    writeJson(response, 400, {
      status: "failed",
      error: error instanceof Error ? error.message : String(error),
    });
  }
}

const host = process.env.BOSS_CODEX_DESKTOP_BRIDGE_HOST || "127.0.0.1";
const port = parsePort(process.env.BOSS_CODEX_DESKTOP_BRIDGE_PORT);

const server = createServer(async (request, response) => {
  if (request.url === "/health") {
    writeJson(response, 200, {
      ok: true,
      service: "boss-codex-desktop-refresh-bridge",
    });
    return;
  }
  if (request.url === "/api/v1/codex-desktop/events") {
    handleEvents(request, response);
    return;
  }
  if (request.url === "/api/v1/codex-desktop/events/recent") {
    writeJson(response, 200, {
      ok: true,
      events: recentEvents,
    });
    return;
  }
  if (request.url === "/api/v1/codex-desktop/capabilities") {
    try {
      writeJson(response, 200, await detectCodexDesktopIntegration());
    } catch (error) {
      writeJson(response, 500, {
        ok: false,
        error: error instanceof Error ? error.message : String(error),
      });
    }
    return;
  }
  if (request.url === "/api/v1/codex-desktop/refresh") {
    await handleRefresh(request, response);
    return;
  }
  writeJson(response, 404, { status: "failed", error: "NOT_FOUND" });
});

server.listen(port, host, () => {
  const address = server.address();
  process.stdout.write(
    `${JSON.stringify({
      status: "ready",
      service: "boss-codex-desktop-refresh-bridge",
      host: address.address,
      port: address.port,
    })}\n`,
  );
});

process.on("SIGTERM", () => {
  server.close(() => {
    process.exit(0);
  });
});