import {
  setReplyTo,
  getThreads,
  addNotice,
  updateUser,
  getGroupedUsers,
  getMyId,
  getUsers,
  getFocused,
  setFocused,
  clearFocused,
} from "./data.js";
import { renderChat } from "./render.js";
import { initWebSocket } from "./wsModule.js";

document.addEventListener("DOMContentLoaded", () => {
  const chat = document.getElementById("chat");
  const inputContainer = document.getElementById("inputContainer");
  const rootButton = document.getElementById("rootButton");
  const sendButton = document.getElementById("sendButton");
  const input = document.getElementById("messageInput");
  const usersList = document.getElementById("userList");
  const nameInput = document.getElementById("nameInput");
  const nameButton = document.getElementById("nameButton");

  chat.style.display = "";
  inputContainer.style.display = "flex";

  const defaultName = "Anon";
  const MAX_NAME_LEN = 31;

  const { socket, sendMessage, sendName } = initWebSocket(
    defaultName,
    chat,
    inputContainer,
    usersList,
  );

  // Renames.
  nameButton.addEventListener("click", () => {
    const newName = nameInput.value.trim() || defaultName;
    if (newName.length > MAX_NAME_LEN) {
      addNotice(
        `<span class="err">Name may be at most ${MAX_NAME_LEN} characters.</span>`,
      );
      renderChat(chat, inputContainer);
      nameInput.focus();
      return;
    }

    sendName(newName);
    updateUser(getMyId(), newName);
    const groups = getGroupedUsers();
    usersList.innerHTML = "Online: " + groups.join(", ");

    nameInput.value = "";
    nameInput.placeholder = `Name: ${newName}`;
    input.focus();
  });

  // Enter to set name.
  nameInput.addEventListener("keydown", (e) => {
    if (e.key === "Enter") nameButton.click();
  });

  // Button to send.
  sendButton.addEventListener("click", () => {
    const text = input.value.trim();
    if (!text) return;
    sendMessage(text);
    input.value = "";
    input.focus();
  });

  // Enter to send and escape to go to root.
  input.addEventListener("keydown", (e) => {
    if (e.key === "Enter") {
      sendButton.click();
    } else if (e.key === "Escape") {
      setReplyTo(null);
      input.placeholder = "";
      renderChat(chat, inputContainer);
      input.focus();
    }
  });

  // Click message to reply.
  chat.addEventListener("click", (e) => {
    const msgDiv = e.target.closest(".msg");
    if (!msgDiv) return;
    const id = Number(msgDiv.dataset.id);
    if (!isFinite(id)) return;
    const threads = getThreads();
    const author = threads.get(id)?.username;
    setReplyTo(id);
    setFocused(id);
    input.placeholder = author ? `Replying to @${author}` : "";
    renderChat(chat, inputContainer);
    input.focus();
  });

  // Go back to root.
  rootButton.addEventListener("click", () => {
    setReplyTo(null);
    clearFocused();
    input.placeholder = "";
    renderChat(chat, inputContainer);
    input.focus();
  });

  // Global Escape handler: clear reply context, focus input, and clear focused message.
  document.addEventListener("keydown", (e) => {
    if (e.key === "Escape") {
      setReplyTo(null);
      clearFocused();
      input.placeholder = "";
      renderChat(chat, inputContainer);
      input.focus();
    }
  });

  // Arrow key navigation for focused messages (also sets reply target).
  document.addEventListener("keydown", (e) => {
    if (e.key === "ArrowDown" || e.key === "ArrowUp") {
      const msgs = Array.from(chat.querySelectorAll("div.msg"));
      if (!msgs.length) return;
      let idx = msgs.findIndex(
        (div) => Number(div.dataset.id) === getFocused(),
      );
      if (idx === -1) {
        idx = e.key === "ArrowDown" ? -1 : msgs.length;
      }
      idx =
        e.key === "ArrowDown"
          ? Math.min(msgs.length - 1, idx + 1)
          : Math.max(0, idx - 1);
      const newId = Number(msgs[idx].dataset.id);
      setFocused(newId);
      setReplyTo(newId); // Move input box under focused message.
      const threads = getThreads();
      const author = threads.get(newId)?.username;
      input.placeholder = author ? `Replying to @${author}` : "";
      renderChat(chat, inputContainer);
      const newDiv = chat.querySelector(`div[data-id="${newId}"]`);
      if (newDiv) newDiv.scrollIntoView({ block: "nearest" });
    }
  });
});