"use client";

import { useState, useEffect, useCallback } from "react";
import { useAuth } from "@/lib/auth";
import { useTheme } from "./ThemeProvider";
import Link from "next/link";
import { useRouter } from "next/navigation";

export default function Header() {
  const { user, logout, token } = useAuth();
  const { theme, toggleTheme } = useTheme();
  const router = useRouter();
  const [drawerOpen, setDrawerOpen] = useState(false);

  function handleLogout() {
    logout();
    router.push("/login");
    setDrawerOpen(false);
  }

  const closeDrawer = useCallback(() => setDrawerOpen(false), []);
  const openDrawer = useCallback(() => setDrawerOpen(true), []);

  // Close drawer on escape
  useEffect(() => {
    if (!drawerOpen) return;
    function handleKey(e: KeyboardEvent) {
      if (e.key === "Escape") closeDrawer();
    }
    document.addEventListener("keydown", handleKey);
    document.body.style.overflow = "hidden";
    return () => {
      document.removeEventListener("keydown", handleKey);
      document.body.style.overflow = "";
    };
  }, [drawerOpen, closeDrawer]);

  return (
    <>
      <header className="sticky top-0 z-50 bg-white/80 dark:bg-gray-950/80 backdrop-blur-md border-b border-gray-200 dark:border-gray-800">
        <div className="max-w-4xl mx-auto px-4 h-14 flex items-center justify-between">
          {/* Left: Logo + title */}
          <Link href="/tasks" className="flex items-center gap-2">
            <div className="w-8 h-8 bg-blue-600 rounded-lg flex items-center justify-center">
              <svg className="w-4 h-4 text-white" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2.5}>
                <path strokeLinecap="round" strokeLinejoin="round" d="M5 13l4 4L19 7" />
              </svg>
            </div>
            <span className="text-lg font-bold tracking-tight hidden sm:inline">Task Team</span>
          </Link>

          {/* Right: Desktop controls */}
          <div className="hidden sm:flex items-center gap-2">
            <button
              onClick={toggleTheme}
              className="p-2.5 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-w-[44px] min-h-[44px] flex items-center justify-center"
              aria-label="Přepnout téma"
            >
              {theme === "dark" ? (
                <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <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>
              ) : (
                <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <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>
              )}
            </button>

            {token && user ? (
              <div className="flex items-center gap-2">
                <button
                  onClick={openDrawer}
                  className="w-7 h-7 bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-300 rounded-full flex items-center justify-center text-xs font-bold cursor-pointer hover:ring-2 hover:ring-blue-400 transition-all"
                >
                  {(user.name || user.email || "?").charAt(0).toUpperCase()}
                </button>
                <span className="text-sm text-muted max-w-[120px] truncate">
                  {user.name || user.email}
                </span>
                <button
                  onClick={handleLogout}
                  className="text-sm px-3 py-1.5 rounded-lg border border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors min-h-[44px] flex items-center"
                >
                  Odhlásit
                </button>
              </div>
            ) : (
              <Link
                href="/login"
                className="text-sm px-4 py-2 rounded-lg bg-blue-600 text-white hover:bg-blue-700 transition-colors min-h-[44px] flex items-center"
              >
                Přihlásit
              </Link>
            )}
          </div>

          {/* Right: Mobile - avatar + hamburger both open drawer */}
          <div className="flex sm:hidden items-center gap-1">
            {token && user && (
              <button
                onClick={openDrawer}
                className="w-8 h-8 bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-300 rounded-full flex items-center justify-center text-xs font-bold cursor-pointer"
                aria-label="Otevřít menu"
              >
                {(user.name || user.email || "?").charAt(0).toUpperCase()}
              </button>
            )}
            <button
              onClick={openDrawer}
              className="p-2.5 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-w-[44px] min-h-[44px] flex items-center justify-center"
              aria-label="Menu"
            >
              <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
                <path strokeLinecap="round" strokeLinejoin="round" d="M4 6h16M4 12h16M4 18h16" />
              </svg>
            </button>
          </div>
        </div>
      </header>

      {/* Mobile slide-out drawer */}
      {drawerOpen && (
        <div className="fixed inset-0 z-[60]">
          {/* Backdrop */}
          <div
            className="absolute inset-0 bg-black/50 backdrop-blur-sm animate-fadeIn"
            onClick={closeDrawer}
          />

          {/* Drawer panel */}
          <div className="absolute right-0 top-0 bottom-0 w-72 bg-white dark:bg-gray-900 shadow-2xl animate-slideInRight">
            {/* Close button */}
            <div className="flex items-center justify-between p-4 border-b border-gray-200 dark:border-gray-800">
              <span className="font-semibold text-lg">Menu</span>
              <button
                onClick={closeDrawer}
                className="p-2 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 min-w-[44px] min-h-[44px] flex items-center justify-center"
                aria-label="Zavřít menu"
              >
                <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
                  <path strokeLinecap="round" strokeLinejoin="round" d="M6 18L18 6M6 6l12 12" />
                </svg>
              </button>
            </div>

            {/* User info */}
            {token && user && (
              <div className="p-4 border-b border-gray-200 dark:border-gray-800">
                <div className="flex items-center gap-3">
                  <div className="w-10 h-10 bg-blue-100 dark:bg-blue-900/30 text-blue-700 dark:text-blue-300 rounded-full flex items-center justify-center text-sm font-bold">
                    {(user.name || user.email || "?").charAt(0).toUpperCase()}
                  </div>
                  <div className="min-w-0">
                    <p className="font-medium text-sm truncate">{user.name || "Uživatel"}</p>
                    <p className="text-xs text-muted truncate">{user.email}</p>
                  </div>
                </div>
              </div>
            )}

            {/* Menu items */}
            <div className="p-2 space-y-1">
              <Link
                href="/tasks"
                onClick={closeDrawer}
                className="flex items-center gap-3 px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-h-[48px]"
              >
                <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                  <path strokeLinecap="round" strokeLinejoin="round" d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2" />
                </svg>
                <span className="text-sm font-medium">Úkoly</span>
              </Link>

              <Link
                href="/calendar"
                onClick={closeDrawer}
                className="flex items-center gap-3 px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-h-[48px]"
              >
                <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                  <path strokeLinecap="round" strokeLinejoin="round" d="M8 7V3m8 4V3m-9 8h10M5 21h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v12a2 2 0 002 2z" />
                </svg>
                <span className="text-sm font-medium">Kalendář</span>
              </Link>

              <Link
                href="/chat"
                onClick={closeDrawer}
                className="flex items-center gap-3 px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-h-[48px]"
              >
                <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                  <path strokeLinecap="round" strokeLinejoin="round" d="M8 12h.01M12 12h.01M16 12h.01M21 12c0 4.418-4.03 8-9 8a9.863 9.863 0 01-4.255-.949L3 20l1.395-3.72C3.512 15.042 3 13.574 3 12c0-4.418 4.03-8 9-8s9 3.582 9 8z" />
                </svg>
                <span className="text-sm font-medium">Chat</span>
              </Link>

              <Link
                href="/settings"
                onClick={closeDrawer}
                className="flex items-center gap-3 px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors min-h-[48px]"
              >
                <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                  <path strokeLinecap="round" strokeLinejoin="round" 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 0 001.066 2.573c1.756.426 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 00-2.573 1.066c-.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 00-1.066-2.573c-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" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
                </svg>
                <span className="text-sm font-medium">Nastavení</span>
              </Link>

              {/* Theme toggle */}
              <button
                onClick={() => { toggleTheme(); }}
                className="flex items-center gap-3 px-4 py-3 rounded-lg hover:bg-gray-100 dark:hover:bg-gray-800 transition-colors w-full text-left min-h-[48px]"
              >
                {theme === "dark" ? (
                  <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                    <path strokeLinecap="round" strokeLinejoin="round" 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>
                ) : (
                  <svg className="w-5 h-5 text-muted" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                    <path strokeLinecap="round" strokeLinejoin="round" 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>
                )}
                <span className="text-sm font-medium">
                  {theme === "dark" ? "Světlý režim" : "Tmavý režim"}
                </span>
              </button>
            </div>

            {/* Logout at bottom */}
            {token && (
              <div className="absolute bottom-0 left-0 right-0 p-4 border-t border-gray-200 dark:border-gray-800 safe-area-bottom">
                <button
                  onClick={handleLogout}
                  className="w-full flex items-center justify-center gap-2 px-4 py-3 rounded-lg border border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-800 transition-colors min-h-[48px]"
                >
                  <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                    <path strokeLinecap="round" strokeLinejoin="round" 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>
                  <span className="text-sm font-medium">Odhlásit se</span>
                </button>
              </div>
            )}
          </div>
        </div>
      )}
    </>
  );
}