"use client";

import { useEffect, useRef, useState } from "react";
import { useRouter } from "next/navigation";
import GroupDropdown from "@/components/group-dropdown";
import { useAuthContext } from "@/hooks/auth-context";
import { useGroupsContext } from "@/hooks/groups-context";

export default function Navbar() {
  const router = useRouter();
  const { checkSession, logout } = useAuthContext();
  const { activeGroupId } = useGroupsContext();
  const [inviteModalCode, setInviteModalCode] = useState<string | null>(null);
  const [inviteCopied, setInviteCopied] = useState(false);
  const [hideNavbar, setHideNavbar] = useState(false);
  const [userMenuOpen, setUserMenuOpen] = useState(false);
  const [userEmail, setUserEmail] = useState<string | null>(null);
  const userMenuRef = useRef<HTMLDivElement | null>(null);

  async function handleCopyInvite() {
    if (!inviteModalCode) return;

    await navigator.clipboard.writeText(inviteModalCode);
    setInviteCopied(true);
  }

  async function handleLogout() {
    await logout();
    setUserMenuOpen(false);
    router.push("/login");
  }

  useEffect(() => {
    let active = true;
    async function loadUser() {
      const user = await checkSession();
      if (active) setUserEmail(user?.email || null);
    }
    loadUser();
    return () => {
      active = false;
    };
  }, [checkSession]);

  useEffect(() => {
    function handleClickOutside(event: MouseEvent) {
      if (!userMenuOpen || !userMenuRef.current) return;
      if (!userMenuRef.current.contains(event.target as Node))
        setUserMenuOpen(false);
    }
    document.addEventListener("mousedown", handleClickOutside);
    return () => document.removeEventListener("mousedown", handleClickOutside);
  }, [userMenuOpen]);

  useEffect(() => {
    if (!inviteModalCode) return;
    function handleKeyDown(event: KeyboardEvent) {
      if (event.key === "Escape") setInviteModalCode(null);
    }
    window.addEventListener("keydown", handleKeyDown);
    return () => window.removeEventListener("keydown", handleKeyDown);
  }, [inviteModalCode]);

  useEffect(() => {
    let lastY = window.scrollY;
    function onScroll() {
      const current = window.scrollY;
      const diff = current - lastY;
      if (Math.abs(diff) < 6) return;
      if (current <= 8) {
        setHideNavbar(false);
      } else if (diff > 0) {
        setHideNavbar(true);
      } else {
        setHideNavbar(false);
      }
      lastY = current;
    }
    window.addEventListener("scroll", onScroll, { passive: true });
    return () => window.removeEventListener("scroll", onScroll);
  }, []);

  return (
    <>
      <header className={`sticky top-0 z-40 border-b border-accent-weak bg-app backdrop-blur transition-transform duration-200 ${hideNavbar ? "-translate-y-full" : "translate-y-0"}`}>
        <div className="mx-auto flex max-w-5xl items-center justify-between px-4 py-2.5">
          <div className="flex items-center gap-2">
            <button
              type="button"
              className="flex h-9 w-9 items-center justify-center overflow-hidden rounded-xl border border-accent bg-panel hover:border-accent-strong"
              aria-label="Settings"
              onClick={() => {
                if (activeGroupId) router.push("/groups/settings");
                else router.push("/");
              }}
            >
              <img src="/icons/navbar-settings.png" alt="" className="h-full w-full rounded-lg object-cover" />
            </button>
            <div className="hidden sm:block text-sm font-semibold">Fiddy</div>
          </div>

          <GroupDropdown
            onInviteCode={code => {
              setInviteModalCode(code);
              setInviteCopied(false);
            }}
          />

          <div className="relative" ref={userMenuRef}>
            <button
              type="button"
              aria-label="User menu"
              onClick={() => setUserMenuOpen(prev => !prev)}
              className="flex h-9 w-9 items-center justify-center rounded-full border border-accent-weak bg-panel text-sm text-muted hover:border-accent"
            >
              <span className="text-base">👤</span>
            </button>
            {userMenuOpen ? (
              <div className="absolute right-0 mt-2 w-48 rounded-xl border border-accent-weak bg-panel p-3 text-sm shadow-lg">
                <div className="text-xs text-soft">Signed in as</div>
                <div className="mt-1 truncate text-sm font-semibold text-[color:var(--color-text)]">
                  {userEmail || "User"}
                </div>
                <div className="my-3 h-px divider" />
                <button
                  type="button"
                  className="w-full rounded-lg btn-outline-accent px-3 py-2 text-xs font-semibold"
                  onClick={() => {
                    setUserMenuOpen(false);
                    if (activeGroupId) router.push("/groups/settings");
                    else router.push("/");
                  }}
                >
                  Settings
                </button>
                <button
                  type="button"
                  className="mt-2 w-full rounded-lg border border-red-400/60 bg-red-500/10 px-3 py-2 text-xs font-semibold text-red-200"
                  onClick={handleLogout}
                >
                  Logout
                </button>
              </div>
            ) : null}
          </div>
        </div>
      </header>
      {inviteModalCode ? (
        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 px-4 py-6 overflow-y-auto">
          <div
            className="w-full max-w-sm rounded-2xl border border-accent-weak bg-panel p-5 shadow-xl max-h-[90vh]"
            onKeyDown={event => {
              if (event.key === "Escape") setInviteModalCode(null);
            }}
            role="dialog"
            tabIndex={-1}
          >
            <div className="text-lg font-semibold">Invite code</div>
            <p className="mt-2 text-sm text-muted">
              Share this code to invite members. You can view it later in group settings.
            </p>
            <div className="mt-4 rounded-lg border border-accent-weak bg-surface px-3 py-2 text-center text-lg tracking-widest">
              {inviteModalCode}
            </div>
            <div className="mt-4 flex items-center gap-2">
              <button
                type="button"
                className="flex-1 rounded-lg btn-accent px-3 py-2 text-sm font-semibold"
                onClick={handleCopyInvite}
              >
                {inviteCopied ? "Copied" : "Copy code"}
              </button>
              <button
                type="button"
                className="flex-1 rounded-lg btn-outline-accent px-3 py-2 text-sm font-semibold"
                onClick={() => setInviteModalCode(null)}
              >
                Close
              </button>
            </div>
          </div>
        </div>
      ) : null}
    </>
  );
}