const messagesEl = document.querySelector("#messages");
const statusEl = document.querySelector("#connection-status");
const chatForm = document.querySelector("#chat-form");
const userMessage = document.querySelector("#user-message");
const systemPrompts = document.querySelector("#system-prompts");
const preMessages = document.querySelector("#pre-messages");
const preMessageTemplate = document.querySelector("#pre-message-template");
const toolList = document.querySelector("#tool-list");

let socket = null;
let activeAssistant = null;
let runStartedAt = 0;
let firstTokenAt = 0;

document.querySelector("#add-system-prompt").addEventListener("click", () => {
  const textarea = document.createElement("textarea");
  textarea.className = "system-prompt";
  textarea.rows = 4;
  systemPrompts.append(textarea);
});

document.querySelector("#add-pre-message").addEventListener("click", () => {
  preMessages.append(preMessageTemplate.content.cloneNode(true));
});

chatForm.addEventListener("submit", (event) => {
  event.preventDefault();
  runDebugSession();
});

loadTools();

async function loadTools() {
  try {
    const response = await fetch("/api/tools");
    if (!response.ok) {
      throw new Error(`Tool API failed: ${response.status}`);
    }
    renderTools(await response.json());
  } catch (error) {
    toolList.textContent = "Failed to load tools";
  }
}

function renderTools(tools) {
  toolList.textContent = "";
  if (!tools.length) {
    toolList.textContent = "No tools available";
    return;
  }

  tools.forEach((tool) => {
    const label = document.createElement("label");
    label.className = "checkbox";
    label.title = tool.description || tool.name;

    const checkbox = document.createElement("input");
    checkbox.type = "checkbox";
    checkbox.className = "tool-toggle";
    checkbox.value = tool.name;
    checkbox.checked = true;

    label.append(checkbox, ` ${tool.name}`);
    toolList.append(label);
  });
}

function runDebugSession() {
  closeSocket();
  resetRun();

  socket = new WebSocket(wsUrl());
  socket.addEventListener("open", () => {
    statusEl.textContent = "Streaming";
    runStartedAt = performance.now();
    socket.send(JSON.stringify(buildRequest()));
  });
  socket.addEventListener("message", (event) => {
    handleServerMessage(JSON.parse(event.data));
  });
  socket.addEventListener("close", () => {
    statusEl.textContent = "Idle";
    updateElapsed();
  });
  socket.addEventListener("error", () => {
    appendLog("error", "WebSocket connection failed");
  });
}

function buildRequest() {
  return {
    user_message: userMessage.value,
    system_prompts: [...document.querySelectorAll(".system-prompt")]
      .map((input) => input.value.trim())
      .filter(Boolean),
    pre_messages: [...document.querySelectorAll(".pre-message")]
      .map((row) => ({
        role: row.querySelector(".pre-role").value,
        content: row.querySelector(".pre-content").value.trim(),
      }))
      .filter((message) => message.content),
    chat_agent: {
      model: document.querySelector("#model").value.trim(),
      temperature: Number(document.querySelector("#temperature").value),
      max_tokens: Number(document.querySelector("#max-tokens").value),
    },
    event_agent: {
      enabled_tools: selectedTools(),
      max_event_loops: Number(document.querySelector("#max-event-loops").value),
    },
  };
}

function selectedTools() {
  return [...toolList.querySelectorAll(".tool-toggle:checked")].map(
    (input) => input.value,
  );
}

function handleServerMessage(message) {
  if (message.type === "session_started") {
    appendLog("session", "Session started");
    return;
  }
  if (message.type === "message_delta") {
    appendAssistantDelta(message.content || "");
    return;
  }
  if (message.type === "usage") {
    updateUsage(message.usage || {});
    return;
  }
  if (message.type === "event") {
    appendLog("event", `${message.event.name}: ${JSON.stringify(message.event.arguments)}`);
    return;
  }
  if (message.type === "tool_result") {
    appendLog("tool", message.message.content);
    return;
  }
  if (message.type === "error") {
    appendLog("error", message.message);
    return;
  }
  if (message.type === "done") {
    appendLog("session", "Done");
    closeSocket();
  }
}

function appendAssistantDelta(content) {
  if (!firstTokenAt) {
    firstTokenAt = performance.now();
    document.querySelector("#stat-ttft").textContent = `${Math.round(firstTokenAt - runStartedAt)}ms`;
  }
  if (!activeAssistant) {
    activeAssistant = document.createElement("div");
    activeAssistant.className = "message assistant";
    messagesEl.append(activeAssistant);
  }
  activeAssistant.textContent += content;
  updateElapsed();
  messagesEl.scrollTop = messagesEl.scrollHeight;
}

function appendLog(kind, content) {
  const item = document.createElement("div");
  item.className = `message ${kind}`;
  item.textContent = content;
  messagesEl.append(item);
  messagesEl.scrollTop = messagesEl.scrollHeight;
}

function updateUsage(usage) {
  document.querySelector("#stat-tokens").textContent = usage.total_tokens || 0;
  document.querySelector("#stat-cached").textContent = usage.cached_tokens || 0;
}

function updateElapsed() {
  if (!runStartedAt) {
    return;
  }
  document.querySelector("#stat-elapsed").textContent = `${Math.round(performance.now() - runStartedAt)}ms`;
}

function resetRun() {
  activeAssistant = null;
  runStartedAt = 0;
  firstTokenAt = 0;
  messagesEl.textContent = "";
  document.querySelector("#stat-tokens").textContent = "0";
  document.querySelector("#stat-cached").textContent = "0";
  document.querySelector("#stat-ttft").textContent = "-";
  document.querySelector("#stat-elapsed").textContent = "-";
}

function closeSocket() {
  if (socket && socket.readyState < WebSocket.CLOSING) {
    socket.close();
  }
}

function wsUrl() {
  const protocol = window.location.protocol === "https:" ? "wss:" : "ws:";
  return `${protocol}//${window.location.host}/ws/debug`;
}