import { useState, useEffect } from 'react';
import { Link, useLocation } from 'react-router-dom';
import { useTranslation } from 'react-i18next';
import { useProjectStore } from '../../store/useProjectStore';
import { ShareModal } from './ShareModal';
import { LanguageSwitcher } from './LanguageSwitcher';
import { useLocalizedHref, useCurrentLocale } from '../../i18n/useLocalizedNavigate';
import { blogUrlFor } from '../../i18n/path';
import { trackVisitGitHub, trackVisitDiscord } from '../../utils/analytics';
import type { AutoSaveState } from '../../hooks/useAutoSaveProject';
import './LanguageSwitcher.css';

const GITHUB_URL = 'https://github.com/davidmonterocrespo24/velxio';
const DISCORD_URL = 'https://discord.gg/3mARjJrh4E';

interface AppHeaderProps {
  /** Optional auto-save state — when set, renders a save status indicator. */
  autoSave?: AutoSaveState;
}

const SAVE_STATUS_COPY: Record<AutoSaveState['status'], { label: string; color: string }> = {
  idle: { label: 'Saved', color: '#7d8590' },
  dirty: { label: 'Unsaved changes', color: '#f0883e' },
  saving: { label: 'Saving…', color: '#3fb950' },
  saved: { label: 'Saved', color: '#3fb950' },
  error: { label: 'Save failed', color: '#f85149' },
};

const AutoSaveIndicator: React.FC<{ state: AutoSaveState }> = ({ state }) => {
  const meta = SAVE_STATUS_COPY[state.status];
  const tip =
    state.status === 'error' && state.errorMessage
      ? `Auto-save failed: ${state.errorMessage}`
      : state.lastSavedAt
        ? `Last saved ${new Date(state.lastSavedAt).toLocaleTimeString()}`
        : 'Auto-save ready';
  return (
    <div
      title={tip}
      style={{
        display: 'flex',
        alignItems: 'center',
        gap: 6,
        padding: '4px 10px',
        fontSize: 12,
        color: meta.color,
        userSelect: 'none',
      }}
    >
      <span
        style={{
          width: 7,
          height: 7,
          borderRadius: '50%',
          background: meta.color,
          opacity: state.status === 'saving' ? 0.7 : 1,
          animation: state.status === 'saving' ? 'velxio-pulse 1s ease-in-out infinite' : 'none',
        }}
      />
      <span>{meta.label}</span>
    </div>
  );
};

export const AppHeader: React.FC<AppHeaderProps> = ({ autoSave }) => {
  const location = useLocation();
  const currentProject = useProjectStore((s) => s.currentProject);
  const [menuOpen, setMenuOpen] = useState(false);
  const [showShareModal, setShowShareModal] = useState(false);
  const { t } = useTranslation();
  const localize = useLocalizedHref();
  const currentLocale = useCurrentLocale();

  // Close mobile menu on route change
  useEffect(() => {
    setMenuOpen(false);
  }, [location.pathname]);

  // Tauri desktop: skip the header entirely. The marketing nav was
  // already hidden, but the strip itself was still painting an empty
  // black bar over the editor. Brand/auto-save/share/auth-slot all
  // live elsewhere in desktop: title bar shows "Velxio Desktop", the
  // native menubar has File/Edit/View/Help, auto-save is a Pro cloud
  // feature (desktop saves to .vlx), share generates a velxio.dev URL
  // that doesn't apply to a desktop session, and the license flow
  // owns its own DesktopWelcomePage.
  if (import.meta.env.VITE_DESKTOP) {
    return null;
  }

  const isActive = (path: string) =>
    location.pathname === localize(path) ? ' header-nav-link-active' : '';

  return (
    <header className="app-header">
      <div className="header-content">
        <div className="header-left">
          {/* Brand */}
          <div className="header-brand">
            <svg
              width="20"
              height="20"
              viewBox="0 0 24 24"
              fill="none"
              stroke="#0071e3"
              strokeWidth="2"
              strokeLinecap="round"
              strokeLinejoin="round"
            >
              <rect x="5" y="5" width="14" height="14" rx="2" />
              <rect x="9" y="9" width="6" height="6" />
              <path d="M9 1v4M15 1v4M9 19v4M15 19v4M1 9h4M1 15h4M19 9h4M19 15h4" />
            </svg>
            <Link to={localize('/')} style={{ textDecoration: 'none', color: 'inherit' }}>
              <span className="header-title">Velxio</span>
            </Link>
          </div>

          {/* Main nav links (web only). The Tauri desktop build hides
              this nav and surfaces the equivalent actions via the
              native menubar (see pro/desktop/src-tauri/src/menu.rs in
              velxio-prod). VITE_DESKTOP is the env flag the Tauri
              build sets — main.tsx already uses it to gate the @pro
              overlay, same pattern here. */}
          {!import.meta.env.VITE_DESKTOP && (
          <nav className={'header-nav-links' + (menuOpen ? ' header-nav-open' : '')}>
            <Link to={localize('/')} className={'header-nav-link' + isActive('/')}>
              {t('header.nav.home')}
            </Link>
            <Link to={localize('/docs')} className={'header-nav-link' + isActive('/docs')}>
              {t('header.nav.documentation')}
            </Link>
            <Link to={localize('/examples')} className={'header-nav-link' + isActive('/examples')}>
              {t('header.nav.examples')}
            </Link>
            <Link to={localize('/editor')} className={'header-nav-link' + isActive('/editor')}>
              {t('header.nav.editor')}
            </Link>
            <Link to={localize('/about')} className={'header-nav-link' + isActive('/about')}>
              {t('header.nav.about')}
            </Link>
            <Link to={localize('/pricing')} className={'header-nav-link' + isActive('/pricing')}>
              {t('header.nav.pricing')}
            </Link>
            <Link to={localize('/classroom')} className={'header-nav-link' + isActive('/classroom')}>
              {t('header.nav.classroom', 'For schools')}
            </Link>
            <Link
              to={localize('/account/desktop-install')}
              className={'header-nav-link' + isActive('/account/desktop-install')}
            >
              {t('header.nav.download')}
            </Link>
            <a
              href={blogUrlFor(currentLocale)}
              className="header-nav-link"
              rel="noopener"
            >
              {t('header.nav.blog')}
            </a>
            <a
              href={GITHUB_URL}
              target="_blank"
              rel="noopener noreferrer"
              className="header-nav-link"
              onClick={trackVisitGitHub}
            >
              <svg
                width="14"
                height="14"
                viewBox="0 0 24 24"
                fill="currentColor"
                style={{ flexShrink: 0 }}
              >
                <path d="M12 2C6.477 2 2 6.484 2 12.021c0 4.428 2.865 8.185 6.839 9.504.5.092.682-.217.682-.482 0-.237-.009-.868-.013-1.703-2.782.605-3.369-1.342-3.369-1.342-.454-1.154-1.11-1.462-1.11-1.462-.908-.62.069-.608.069-.608 1.003.07 1.531 1.032 1.531 1.032.892 1.53 2.341 1.088 2.91.832.092-.647.35-1.088.636-1.338-2.22-.253-4.555-1.113-4.555-4.951 0-1.093.39-1.988 1.029-2.688-.103-.253-.446-1.272.098-2.65 0 0 .84-.27 2.75 1.026A9.564 9.564 0 0 1 12 6.844a9.59 9.59 0 0 1 2.504.337c1.909-1.296 2.747-1.026 2.747-1.026.546 1.378.202 2.397.1 2.65.64.7 1.028 1.595 1.028 2.688 0 3.848-2.338 4.695-4.566 4.944.359.309.678.919.678 1.852 0 1.336-.012 2.415-.012 2.743 0 .267.18.578.688.48C19.138 20.203 22 16.447 22 12.021 22 6.484 17.523 2 12 2z" />
              </svg>
              {t('header.nav.github')}
            </a>
            <a
              href={DISCORD_URL}
              target="_blank"
              rel="noopener noreferrer"
              className="header-nav-link header-nav-discord"
              onClick={trackVisitDiscord}
            >
              <svg
                width="14"
                height="14"
                viewBox="0 0 24 24"
                fill="currentColor"
                style={{ flexShrink: 0 }}
              >
                <path d="M20.317 4.37a19.791 19.791 0 0 0-4.885-1.515.074.074 0 0 0-.079.037c-.21.375-.444.864-.608 1.25a18.27 18.27 0 0 0-5.487 0 12.64 12.64 0 0 0-.617-1.25.077.077 0 0 0-.079-.037A19.736 19.736 0 0 0 3.677 4.37a.07.07 0 0 0-.032.027C.533 9.046-.32 13.58.099 18.057c.002.022.015.043.032.053a19.9 19.9 0 0 0 5.993 3.03.078.078 0 0 0 .084-.028 14.09 14.09 0 0 0 1.226-1.994.076.076 0 0 0-.041-.106 13.107 13.107 0 0 1-1.872-.892.077.077 0 0 1-.008-.128 10.2 10.2 0 0 0 .372-.292.074.074 0 0 1 .077-.01c3.928 1.793 8.18 1.793 12.062 0a.074.074 0 0 1 .078.01c.12.098.246.198.373.292a.077.077 0 0 1-.006.127 12.299 12.299 0 0 1-1.873.892.077.077 0 0 0-.041.107c.36.698.772 1.362 1.225 1.993a.076.076 0 0 0 .084.028 19.839 19.839 0 0 0 6.002-3.03.077.077 0 0 0 .032-.054c.5-5.177-.838-9.674-3.549-13.66a.061.061 0 0 0-.031-.03zM8.02 15.33c-1.183 0-2.157-1.085-2.157-2.419 0-1.333.956-2.419 2.157-2.419 1.21 0 2.176 1.096 2.157 2.42 0 1.333-.956 2.418-2.157 2.418zm7.975 0c-1.183 0-2.157-1.085-2.157-2.419 0-1.333.955-2.419 2.157-2.419 1.21 0 2.176 1.096 2.157 2.42 0 1.333-.946 2.418-2.157 2.418z" />
              </svg>
              {t('header.nav.discord')}
            </a>
          </nav>
          )}
        </div>

        {/* Right: language + share + auth + mobile hamburger */}
        <div className="header-right">
          <LanguageSwitcher />

          {/* Auto-save status — only when a project is loaded and the editor
              page mounted the hook */}
          {autoSave && currentProject && <AutoSaveIndicator state={autoSave} />}

          {/* Share button — visible when a project is loaded */}
          {currentProject && location.pathname === '/editor' && (
            <button
              onClick={() => setShowShareModal(true)}
              style={{
                background: 'transparent',
                border: '1px solid #555',
                borderRadius: 4,
                padding: '4px 10px',
                cursor: 'pointer',
                display: 'flex',
                alignItems: 'center',
                gap: 5,
                color: '#ccc',
                fontSize: 13,
              }}
              title="Share project"
            >
              <svg
                width="14"
                height="14"
                viewBox="0 0 24 24"
                fill="none"
                stroke="currentColor"
                strokeWidth="2"
                strokeLinecap="round"
                strokeLinejoin="round"
              >
                <circle cx="18" cy="5" r="3" />
                <circle cx="6" cy="12" r="3" />
                <circle cx="18" cy="19" r="3" />
                <line x1="8.59" y1="13.51" x2="15.42" y2="17.49" />
                <line x1="15.41" y1="6.51" x2="8.59" y2="10.49" />
              </svg>
              Share
            </button>
          )}

          {/* Auth UI lives in the pro overlay — sign-in/sign-up buttons
              when anonymous, user dropdown when logged in. The overlay's
              mountPro() portals its HeaderAuth component into this slot
              via mountIntoSlot('header-auth'). In OSS without the
              overlay this slot stays empty, which is correct because the
              OSS image has no auth backend either. */}
          <div data-velxio-slot="header-auth" style={{ display: 'contents' }} />

          {/* Mobile hamburger — useless in desktop where the nav it
              would expand is itself hidden. */}
          {!import.meta.env.VITE_DESKTOP && (
            <button
              className="header-hamburger"
              onClick={() => setMenuOpen((v) => !v)}
              aria-label="Toggle menu"
            >
              <span />
              <span />
              <span />
            </button>
          )}
        </div>
      </div>

      {showShareModal && <ShareModal onClose={() => setShowShareModal(false)} />}
    </header>
  );
};