import { useEffect, useState } from 'react';
import Link from 'next/link';
import { useTheme } from '../../lib/theme-context';

/**
 * TopSearchBar — the top horizontal chrome strip from the operator's
 * redesign-v2 mockup.
 *
 * Layout: prominent search input on the left (with magnifier + Cmd+K
 * hint pill), then 3 right-side widgets — notification bell (with red
 * badge when there are unread items), mail/inbox icon, and a compact
 * user-menu chip (avatar + name + chevron).
 *
 * Mounted globally inside <Layout> for authenticated users; renders
 * as a no-op `null` for unauthenticated visitors (the public landing
 * uses its own marketing header).
 *
 * Props:
 *   user                       { username, email, avatar_url, ... }
 *   notificationCount          number  — drives the bell badge; 0 hides it
 *   onOpenCommandPalette       () => void  — fires when user clicks the
 *                              search input or presses ⌘K (the global
 *                              keydown listener lives in <Layout>).
 *
 * Implementation notes:
 *   - The search input is intentionally read-only-ish: clicking or
 *     focusing it opens the CommandPaletteModal instead of typing
 *     inline. This matches Linear / Notion / Vercel's pattern and
 *     avoids two competing search affordances on the page.
 *   - The "Cmd+K" hint adapts to the user's platform: ⌘K on Mac,
 *     Ctrl+K elsewhere. Detection is best-effort via navigator.platform
 *     and gracefully defaults to ⌘ on the server (matches the Mac
 *     audience's default expectation).
 *   - User menu (avatar + name + chevron) opens a real dropdown
 *     (see <UserMenu> below) with Profile, Settings, Admin (when
 *     applicable), Help & Support, Theme toggle, and Logout. The
 *     Help and Theme entries moved here from the desktop sidebar's
 *     bottom icon row 2026-06-04 per operator feedback.
 */
function isMacPlatform() {
  if (typeof window === 'undefined' || !window.navigator) return true;
  return /Mac|iPhone|iPad|iPod/.test(window.navigator.platform);
}

/**
 * UserMenu — the dropdown that opens from the top-right avatar chip.
 *
 * Hosts the canonical authenticated-user menu items (Profile, Settings,
 * Admin Panel for admins, Help & Support, Theme toggle, Logout). The
 * Help and Theme entries moved here 2026-06-04 per operator feedback
 * ("move the help and theme toggle into the profile drop-down") — the
 * sidebar's bottom icon row is gone for authenticated users now, so
 * this menu is the canonical entry point for both.
 *
 * The Theme entry is a button (not a Link) because toggling theme is
 * a side-effect with no destination route. Clicking it flips the
 * theme AND closes the menu, matching the "act and dismiss" feel of
 * the other items. Profile / Settings / Admin / Support / Logout are
 * Links and close the menu on click via onClick.
 *
 * a11y:
 *   - The trigger button has aria-haspopup="menu" + aria-expanded.
 *   - The dropdown is role="menu" with menuitem children.
 *   - Escape closes; click-outside closes.
 *   - The focus model is intentionally simple (no roving tabindex);
 *     each menuitem is in the natural tab order so Tab/Shift+Tab
 *     navigates between them — matches the existing sidebar
 *     UserProfileDropdown's pattern (Layout.js).
 */
function UserMenu({ user }) {
  const { theme, toggleTheme } = useTheme();
  const [open, setOpen] = useState(false);

  useEffect(() => {
    if (!open) return undefined;
    const onKeyDown = (event) => {
      if (event.key === 'Escape') {
        setOpen(false);
      }
    };
    document.addEventListener('keydown', onKeyDown);
    return () => document.removeEventListener('keydown', onKeyDown);
  }, [open]);

  const initial = (user.username || user.email || 'U').charAt(0).toUpperCase();
  const displayName =
    user.username || user.email?.split('@')[0] || 'Account';
  const isAdmin = user?.role === 'admin';

  const close = () => setOpen(false);

  const menuItems = [
    { id: 'profile', label: 'Profile', href: '/profile', icon: 'user' },
    { id: 'settings', label: 'Settings', href: '/settings', icon: 'settings' },
    ...(isAdmin
      ? [{ id: 'admin', label: 'Admin Panel', href: '/admin', icon: 'admin' }]
      : []),
    { id: 'support', label: 'Help & Support', href: '/support', icon: 'support' },
  ];

  const renderIcon = (name) => {
    const iconProps = {
      className: 'h-4 w-4 flex-shrink-0',
      fill: 'none',
      stroke: 'currentColor',
      viewBox: '0 0 24 24',
      'aria-hidden': true,
    };
    switch (name) {
      case 'user':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z" />
          </svg>
        );
      case 'settings':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z" />
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
          </svg>
        );
      case 'admin':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m5.618-4.016A11.955 11.955 0 0112 2.944a11.955 11.955 0 01-8.618 3.04A12.02 12.02 0 003 9c0 5.591 3.824 10.29 9 11.622 5.176-1.332 9-6.03 9-11.622 0-1.042-.133-2.052-.382-3.016z" />
          </svg>
        );
      case 'support':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M8.228 9c.549-1.165 2.03-2 3.772-2 2.21 0 4 1.343 4 3 0 1.4-1.278 2.575-3.006 2.907-.542.104-.994.54-.994 1.093m0 3h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
          </svg>
        );
      case 'logout':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M17 16l4-4m0 0l-4-4m4 4H7m6 4v1a3 3 0 01-3 3H6a3 3 0 01-3-3V7a3 3 0 013-3h4a3 3 0 013 3v1" />
          </svg>
        );
      case 'sun':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 3v1m0 16v1m9-9h-1M4 12H3m15.364 6.364l-.707-.707M6.343 6.343l-.707-.707m12.728 0l-.707.707M6.343 17.657l-.707.707M16 12a4 4 0 11-8 0 4 4 0 018 0z" />
          </svg>
        );
      case 'moon':
        return (
          <svg {...iconProps}>
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M20.354 15.354A9 9 0 018.646 3.646 9.003 9.003 0 0012 21a9.003 9.003 0 008.354-5.646z" />
          </svg>
        );
      default:
        return null;
    }
  };

  return (
    <div className="relative">
      <button
        type="button"
        onClick={() => setOpen((prev) => !prev)}
        className="flex items-center gap-2 pl-2 pr-3 py-1.5 rounded-xl transition-colors focus:outline-none focus:ring-2 nav-item-hover"
        style={{
          color: 'var(--text-primary)',
          '--tw-ring-color': 'var(--accent-ember)',
        }}
        aria-haspopup="menu"
        aria-expanded={open}
        aria-label="Account menu"
      >
        <div
          className="w-8 h-8 rounded-full flex items-center justify-center text-sm font-bold flex-shrink-0"
          style={{
            background:
              'linear-gradient(135deg, rgb(255, 140, 30) 0%, rgb(216, 67, 21) 100%)',
            color: 'rgb(255, 255, 255)',
            boxShadow:
              '0 1px 4px rgba(255, 110, 0, 0.40), inset 0 1px 0 rgba(255,255,255,0.20)',
          }}
          aria-hidden="true"
        >
          {initial}
        </div>
        <span className="hidden md:inline text-sm font-medium truncate max-w-[10rem]">
          {displayName}
        </span>
        <svg
          className={`hidden md:inline h-4 w-4 flex-shrink-0 transition-transform duration-200 ${
            open ? 'rotate-180' : ''
          }`}
          fill="none"
          stroke="currentColor"
          viewBox="0 0 24 24"
          aria-hidden="true"
        >
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
        </svg>
      </button>

      {open && (
        <>
          {/* Click-outside scrim. fixed inset-0 catches taps anywhere
              outside the menu. z-index sits between the menu (z-30)
              and normal page content. */}
          <div
            className="fixed inset-0 z-20"
            onClick={close}
            aria-hidden="true"
          />
          <div
            role="menu"
            aria-label="Account menu"
            className="glass-panel-strong absolute right-0 top-full mt-2 w-56 rounded-xl z-30 overflow-hidden"
            style={{
              boxShadow:
                'var(--rim-light-inner), var(--ember-rim-subtle), var(--elevation-pronounced)',
            }}
          >
            <div className="py-1">
              {menuItems.map((item) => (
                <Link key={item.id} href={item.href} passHref legacyBehavior>
                  <a
                    role="menuitem"
                    onClick={close}
                    className="flex items-center gap-3 px-3 py-2 text-sm transition-colors nav-item-hover"
                    style={{ color: 'var(--text-primary)' }}
                  >
                    {renderIcon(item.icon)}
                    <span className="font-medium">{item.label}</span>
                  </a>
                </Link>
              ))}

              {/* Theme toggle — button, not Link, because there's no
                  destination route. Closes the menu after toggling to
                  match the act-and-dismiss feel of the other items. */}
              <button
                type="button"
                role="menuitem"
                onClick={() => {
                  toggleTheme();
                  close();
                }}
                className="w-full flex items-center gap-3 px-3 py-2 text-sm transition-colors nav-item-hover"
                style={{ color: 'var(--text-primary)' }}
              >
                {renderIcon(theme === 'light' ? 'moon' : 'sun')}
                <span className="font-medium">
                  {theme === 'light' ? 'Dark mode' : 'Light mode'}
                </span>
              </button>

              {/* Visual divider before the destructive Logout entry. */}
              <div
                role="separator"
                className="my-1 mx-3 h-px"
                style={{ backgroundColor: 'var(--border)' }}
              />

              <Link href="/logout" passHref legacyBehavior>
                <a
                  role="menuitem"
                  onClick={close}
                  className="flex items-center gap-3 px-3 py-2 text-sm transition-colors nav-item-hover"
                  style={{ color: 'var(--accent-ember)' }}
                >
                  {renderIcon('logout')}
                  <span className="font-medium">Logout</span>
                </a>
              </Link>
            </div>
          </div>
        </>
      )}
    </div>
  );
}

export default function TopSearchBar({
  user,
  notificationCount = 0,
  onOpenCommandPalette,
}) {
  const [hovered, setHovered] = useState(false);

  if (!user) return null;

  const isMac = isMacPlatform();
  const shortcutLabel = isMac ? '⌘K' : 'Ctrl+K';

  const openPalette = () => {
    onOpenCommandPalette?.();
  };

  return (
    <header
      // Floating-chrome pass 2026-06-04: `md:rounded-2xl` so the bar
      // reads as its own floating chip on desktop (Layout's
      // `md:p-4 md:gap-4` puts visible body gradient on all four sides
      // of it). Mobile keeps square corners since the header runs
      // edge-to-edge there. The shadow stack pairs `rim-light-inner`
      // (subtle top inset highlight kept from the prior pass) with
      // `elevation-ambient` (drop shadow) so it floats over the body
      // gradient. We deliberately did NOT add `rim-light-outer` here:
      // the operator's "remove the divider" feedback from the prior
      // pass applies to any visible 1px edge, and a hairline outer
      // ring would re-introduce one on mobile where the bar abuts
      // content directly.
      className="px-4 sm:px-6 py-3 flex items-center gap-3 sm:gap-4 md:rounded-2xl"
      style={{
        // 2026-06-04 corner-border pass: same gradient-border
        // technique as .glass-panel — the chip's fill clipped to
        // padding-box, with border-box-clipped warm bottom-left +
        // cool top-right radial highlights exposed through a 1px
        // transparent border. The directional outer drop shadows
        // from PR #115 are gone — corner catch-lights only now.
        background:
          'linear-gradient(var(--glass-surface-mid), var(--glass-surface-mid)) padding-box, ' +
          'radial-gradient(at 0% 100%, var(--corner-light-warm) 0%, transparent 42%) border-box, ' +
          'radial-gradient(at 100% 0%, var(--corner-light-cool) 0%, transparent 42%) border-box, ' +
          'var(--chip-border-base) border-box',
        border: '1px solid transparent',
        backdropFilter: 'blur(12px) saturate(180%)',
        WebkitBackdropFilter: 'blur(12px) saturate(180%)',
        boxShadow: 'var(--rim-light-inner), var(--elevation-ambient)',
      }}
    >
      {/* Search affordance — read-only-ish input that opens the
          command palette on click. */}
      <button
        type="button"
        onClick={openPalette}
        onMouseEnter={() => setHovered(true)}
        onMouseLeave={() => setHovered(false)}
        className="flex-1 max-w-2xl flex items-center gap-2 px-4 py-2 rounded-xl text-left transition-colors focus:outline-none focus:ring-2"
        style={{
          backgroundColor: hovered
            ? 'var(--bg-tertiary)'
            : 'var(--input-bg)',
          border: '1px solid var(--input-border)',
          color: 'var(--text-secondary)',
          '--tw-ring-color': 'var(--accent-ember)',
        }}
        aria-label="Open command palette to search"
      >
        <svg
          className="h-5 w-5 flex-shrink-0"
          fill="none"
          stroke="currentColor"
          viewBox="0 0 24 24"
          aria-hidden="true"
        >
          <path
            strokeLinecap="round"
            strokeLinejoin="round"
            strokeWidth={2}
            d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"
          />
        </svg>
        <span className="flex-1 text-sm truncate">
          Search cards, sets, decks, users…
        </span>
        <span
          className="hidden sm:inline-flex items-center gap-0.5 px-2 py-0.5 rounded-md text-xs font-mono"
          style={{
            backgroundColor: 'var(--bg-tertiary)',
            color: 'var(--text-secondary)',
            border: '1px solid var(--border)',
          }}
          aria-hidden="true"
        >
          {shortcutLabel}
        </span>
      </button>

      <div className="flex items-center gap-2 sm:gap-3 flex-shrink-0">
        <button
          type="button"
          className="relative p-2 rounded-xl transition-colors focus:outline-none focus:ring-2 nav-item-hover"
          style={{
            color: 'var(--text-secondary)',
            '--tw-ring-color': 'var(--accent-ember)',
          }}
          aria-label={
            notificationCount > 0
              ? `${notificationCount} unread notifications`
              : 'Notifications'
          }
        >
          <svg
            className="h-5 w-5"
            fill="none"
            stroke="currentColor"
            viewBox="0 0 24 24"
          >
            <path
              strokeLinecap="round"
              strokeLinejoin="round"
              strokeWidth={2}
              d="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6.002 6.002 0 00-4-5.659V5a2 2 0 10-4 0v.341C7.67 6.165 6 8.388 6 11v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9"
            />
          </svg>
          {notificationCount > 0 && (
            <span
              className="absolute -top-0.5 -right-0.5 min-w-[1.25rem] h-5 px-1 rounded-full text-xs font-bold flex items-center justify-center"
              style={{
                backgroundColor: 'rgb(239, 68, 68)',
                color: 'rgb(255, 255, 255)',
                boxShadow: '0 1px 3px rgba(239, 68, 68, 0.5)',
              }}
              aria-hidden="true"
            >
              {notificationCount > 99 ? '99+' : notificationCount}
            </span>
          )}
        </button>

        <Link href="/settings#messages" passHref legacyBehavior>
          <a
            className="p-2 rounded-xl transition-colors focus:outline-none focus:ring-2 nav-item-hover"
            style={{
              color: 'var(--text-secondary)',
              '--tw-ring-color': 'var(--accent-ember)',
            }}
            aria-label="Messages"
          >
            <svg
              className="h-5 w-5"
              fill="none"
              stroke="currentColor"
              viewBox="0 0 24 24"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M3 8l7.89 5.26a2 2 0 002.22 0L21 8M5 19h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z"
              />
            </svg>
          </a>
        </Link>

        <UserMenu user={user} />
      </div>
    </header>
  );
}
