(() => {
  const ws = new WebSocket(`ws://${location.host}/ws`);

  const clientTabs = document.getElementById("client-tabs");
  const clientPanels = document.getElementById("client-panels");
  const cardTemplate = document.getElementById("client-card-template");
  const tabTemplate = document.getElementById("client-tab-template");
  const addClientBtn = document.getElementById("add-client");
  const leftTabServer = document.getElementById("left-tab-server");
  const leftTabSystem = document.getElementById("left-tab-system");
  const leftPaneServer = document.getElementById("left-pane-server");
  const leftPaneSystem = document.getElementById("left-pane-system");
  const clients = new Map();
  const closedTabs = new Set();
  let activeClient = null;

  function append(target, text, stream, severity) {
    const pane = document.getElementById(target);
    if (!pane) return;
    const line = document.createElement("div");
    line.className = [stream || "stdout", severity].filter(Boolean).join(" ");
    line.textContent = text;
    pane.appendChild(line);
    pane.scrollTop = pane.scrollHeight;
  }

  function appendStatus(text) {
    append("system-log", text, "status");
  }

  function setLeftTab(name) {
    const serverActive = name === "server";
    leftTabServer.classList.toggle("active", serverActive);
    leftTabSystem.classList.toggle("active", !serverActive);
    leftPaneServer.hidden = !serverActive;
    leftPaneSystem.hidden = serverActive;
  }

  function parseClientId(process) {
    if (!process.startsWith("client-")) return null;
    const raw = process.slice("client-".length);
    if (!/^\d+$/.test(raw)) return null;
    return Number(raw);
  }

  async function closeClient(process) {
    const id = parseClientId(process);
    if (id == null) return;
    await fetch(`/api/clients/${id}`, { method: "DELETE" });
    removeClient(process);
    closedTabs.add(process);
  }

  function setActiveClient(process) {
    activeClient = process;
    for (const [name, meta] of clients.entries()) {
      const active = name === process;
      meta.tab.classList.toggle("active", active);
      meta.panel.classList.toggle("active", active);
      meta.panel.hidden = !active;
    }
  }

  function removeClient(process) {
    const meta = clients.get(process);
    if (!meta) return;
    meta.tab.remove();
    meta.panel.remove();
    clients.delete(process);

    if (activeClient === process) {
      const next = clients.keys().next();
      if (!next.done) setActiveClient(next.value);
      else activeClient = null;
    }
  }

  function closeTab(process) {
    const meta = clients.get(process);
    if (!meta) return;
    meta.tab.remove();
    meta.panel.remove();
    clients.delete(process);
    closedTabs.add(process);

    if (activeClient === process) {
      const next = clients.keys().next();
      if (!next.done) setActiveClient(next.value);
      else activeClient = null;
    }
  }

  function ensureClient(process) {
    if (closedTabs.has(process)) return;
    if (clients.has(process)) return;

    const tabClone = tabTemplate.content.cloneNode(true);
    const tab = tabClone.querySelector(".client-tab");
    const tabSelect = tabClone.querySelector(".client-tab-select");
    tabSelect.textContent = process;

    const cardClone = cardTemplate.content.cloneNode(true);
    const panel = cardClone.querySelector(".client-card");
    const name = cardClone.querySelector(".client-name");
    const stdout = cardClone.querySelector(".client-stdout");
    const stderr = cardClone.querySelector(".client-stderr");
    const closeTabBtn = cardClone.querySelector(".btn-close-tab");
    const killBtn = cardClone.querySelector(".btn-kill");

    name.textContent = process;
    stdout.id = `${process}-stdout`;
    stderr.id = `${process}-stderr`;
    panel.hidden = true;

    tabSelect.addEventListener("click", () => setActiveClient(process));
    closeTabBtn.addEventListener("click", async () => closeClient(process));
    killBtn.addEventListener("click", async () => closeClient(process));

    clientTabs.appendChild(tabClone);
    clientPanels.appendChild(cardClone);
    clients.set(process, { tab, panel });

    if (!activeClient) {
      setActiveClient(process);
    }
  }

  function appendToProcess(process, stream, text) {
    const safeStream = stream === "stderr" ? "stderr" : "stdout";
    let severity = "";
    if (safeStream === "stderr") {
      const lower = text.toLowerCase();
      if (lower.startsWith("[") && lower.includes("] ")) {
        const idx = lower.indexOf("] ");
        const raw = lower.slice(idx + 2).trimStart();
        if (raw.startsWith("error")) severity = "stderr-error";
        else if (raw.startsWith("warning")) severity = "stderr-warning";
        else severity = "stderr-default";
      } else if (lower.startsWith("error")) {
        severity = "stderr-error";
      } else if (lower.startsWith("warning")) {
        severity = "stderr-warning";
      } else {
        severity = "stderr-default";
      }
    }
    append(`${process}-${safeStream}`, text, stream, severity);
  }

  addClientBtn.addEventListener("click", async () => {
    const res = await fetch("/api/clients", { method: "POST" });
    if (!res.ok) return;
    const payload = await res.json();
    if (payload && payload.name) {
      closedTabs.delete(payload.name);
      ensureClient(payload.name);
      setActiveClient(payload.name);
    }
  });

  leftTabServer.addEventListener("click", () => setLeftTab("server"));
  leftTabSystem.addEventListener("click", () => setLeftTab("system"));
  setLeftTab("server");

  ws.onopen = () => {
    appendStatus("[orchestrator/status] websocket connected");
  };

  ws.onmessage = (event) => {
    const msg = JSON.parse(event.data);
    const line = `[${msg.process}/${msg.stream}] ${msg.line}`;
    if (msg.process === "server") {
      appendToProcess("server", msg.stream, line);
      return;
    }
    if (msg.process.startsWith("client-")) {
      closedTabs.delete(msg.process);
      ensureClient(msg.process);
      appendToProcess(msg.process, msg.stream, line);
      return;
    }
    appendStatus(line);
  };

  ws.onclose = () => {
    appendStatus("[orchestrator/status] websocket disconnected");
  };
})();