// Copyright (c) 2026 Gordon Bolton. MIT License.

import { state, SPLASH_MIN_MS } from '../state.js';
import { checkAuthentication, handleLogin as apiHandleLogin, handleLogout as apiHandleLogout } from '../api.js';
import { startSSE, stopSSE } from '../sse.js';
import { stopHistoryRefresh, clearHistory, startHistoryRefresh } from './history.js';
import { closeStatusPanel } from './statusPanel.js';

export function fadeOutLogin() {
  return new Promise(resolve => {
    const login = document.getElementById('login-container');
    login.classList.add('fade-out');
    login.addEventListener('transitionend', () => {
      login.classList.add('hidden');
      login.classList.remove('fade-out');
      resolve();
    }, { once: true });
  });
}

export function showSplash() {
  const splash = document.getElementById('splash-screen');
  splash.classList.remove('hidden');
  splash.style.opacity = '1';
  splash.classList.remove('fade-out');
}

export function dismissSplash(startTime) {
  return new Promise(resolve => {
    const elapsed = Date.now() - (startTime || 0);
    const remaining = Math.max(0, SPLASH_MIN_MS - elapsed);
    setTimeout(() => {
      const splash = document.getElementById('splash-screen');
      splash.classList.add('fade-out');
      // Fallback: resolve after transition duration + buffer in case
      // transitionend never fires (e.g. display was toggled in same frame)
      const TRANSITION_MS = 400;
      const fallback = setTimeout(() => {
        splash.classList.add('hidden');
        resolve();
      }, TRANSITION_MS + 100);
      splash.addEventListener('transitionend', () => {
        clearTimeout(fallback);
        splash.classList.add('hidden');
        resolve();
      }, { once: true });
    }, remaining);
  });
}

export async function checkAuthenticationAndInit() {
  const splashStart = Date.now();
  try {
    const result = await checkAuthentication();
    if (result.authenticated) {
      showDashboard();
      showLoading();
      startSSE();
      await dismissSplash(splashStart);
    } else {
      await dismissSplash(splashStart);
      showLogin();
    }
  } catch (err) {
    console.error('Authentication check failed:', err);
    await dismissSplash(splashStart);
    showLogin();
  }
}

export async function handleLogin(e) {
  e.preventDefault();
  
  const username = document.getElementById('username').value;
  const password = document.getElementById('password').value;
  const rememberMe = document.getElementById('remember-me').checked;
  
  try {
    const result = await apiHandleLogin(username, password, rememberMe);
    
    if (result.success) {
      // Fade out login, then show splash while opening SSE stream.
      // requestAnimationFrame ensures the browser paints the splash at
      // opacity:1 before dismissSplash adds fade-out, so the CSS
      // transition fires and transitionend is guaranteed.
      await fadeOutLogin();
      showSplash();
      await new Promise(r => requestAnimationFrame(() => requestAnimationFrame(r)));
      showDashboard();
      showLoading();
      const splashStart = Date.now();
      startSSE();
      await dismissSplash(splashStart);
    } else {
      showLoginError(result.error || 'Login failed');
    }
  } catch (err) {
    showLoginError('Login failed. Please try again.');
    console.error(err);
  }
}

export async function handleLogoutClick() {
  try {
    stopSSE();
    stopHistoryRefresh();
    if (state.statusRefreshHandle) { clearInterval(state.statusRefreshHandle); state.statusRefreshHandle = null; }
    await apiHandleLogout();
    state.currentUser = null;
    clearHistory();
    showLogin();
  } catch (err) {
    console.error('Logout failed:', err);
  }
}

export function showLogin() {
  document.getElementById('login-container').classList.remove('hidden');
  document.getElementById('dashboard-container').classList.add('hidden');
  hideLoginError();
}

export function showDashboard() {
  document.getElementById('login-container').classList.add('hidden');
  document.getElementById('dashboard-container').classList.remove('hidden');
  document.getElementById('currentUser').textContent = state.currentUser.name || '-';
  // Always start with status panel hidden (guards against stale display value on re-login)
  const sp = document.getElementById('status-panel');
  sp.classList.add('hidden');
  // Also hide webhooks-section to keep them in sync (both show/hide together)
  const webhooksSection = document.getElementById('webhooks-section');
  if (webhooksSection) webhooksSection.classList.add('hidden');
  const adminControls = document.getElementById('admin-controls');
  if (state.isAdmin) {
    adminControls.classList.remove('hidden');
  } else {
    adminControls.classList.add('hidden');
  }
  // Note: webhooks-section visibility is controlled by toggleStatusPanel()
  // Initialise days input from saved value
  const daysInput = document.getElementById('history-days');
  if (daysInput) daysInput.value = state.historyDays;
  startHistoryRefresh();
}

export function showLoginError(message) {
  const errorDiv = document.getElementById('login-error');
  errorDiv.textContent = message;
  errorDiv.classList.remove('hidden');
}

export function hideLoginError() {
  const errorDiv = document.getElementById('login-error');
  errorDiv.classList.add('hidden');
}

export function showError(message) {
  const errorDiv = document.getElementById('error-message');
  errorDiv.textContent = message;
  errorDiv.classList.remove('hidden');
}

export function hideError() {
  const errorDiv = document.getElementById('error-message');
  errorDiv.classList.add('hidden');
}

export function showLoading() {
  const loading = document.getElementById('loading');
  loading.classList.remove('hidden');
}

export function hideLoading() {
  const loading = document.getElementById('loading');
  loading.classList.add('hidden');
}