"use client";

import Link from "next/link";
import { usePathname, useRouter } from "next/navigation";
import { cn } from "@/lib/utils";
import { motion } from "framer-motion";
import {
  LayoutDashboard, ArrowRightLeft, BarChart2, Wallet, Target,
  MessageSquare, Settings, LogOut, Zap, Shield, Sparkles,
  Activity, CreditCard, Sun, Moon, Globe,
} from "lucide-react";
import { useAuthStore } from "@/lib/stores/authStore";
import { useThemeStore } from "@/lib/stores/themeStore";
import { useLanguageStore, LANGUAGES, Language } from "@/lib/stores/languageStore";
import { useState } from "react";

export function Sidebar() {
  const pathname = usePathname();
  const router = useRouter();
  const { logout } = useAuthStore();
  const { theme, toggle } = useThemeStore();
  const { language, setLanguage, t } = useLanguageStore();
  const [showLang, setShowLang] = useState(false);

  const navigation = [
    { key: "overview",      href: "/",             icon: LayoutDashboard },
    { key: "transactions",  href: "/transactions",  icon: ArrowRightLeft },
    { key: "payments",      href: "/payments",      icon: CreditCard,    badge: "NEW" },
    { key: "analytics",     href: "/analytics",     icon: BarChart2 },
    { key: "simulator",     href: "/simulator",     icon: Zap },
    { key: "loans",         href: "/loans",         icon: Wallet },
    { key: "goals",         href: "/goals",         icon: Target },
    { key: "ai_assistant",  href: "/chat",          icon: MessageSquare, badge: "AI" },
    { key: "security",      href: "/security",      icon: Shield },
    { key: "system_status", href: "/status",        icon: Activity },
    { key: "settings",      href: "/settings",      icon: Settings },
  ];

  const handleLogout = () => { logout(); router.replace("/login"); };

  const isLight = theme === "light";

  return (
    <div
      className="flex h-full w-60 flex-col overflow-y-auto border-r text-sm backdrop-blur-2xl transition-colors duration-300"
      style={{
        background: "var(--sidebar-bg)",
        borderColor: "var(--border)",
        color: "var(--fg)",
      }}
    >
      {/* ── Logo ─────────────────────────────────────────────────────────────── */}
      <div
        className="flex h-16 shrink-0 items-center gap-2.5 px-5 border-b"
        style={{ borderColor: "var(--border)" }}
      >
        <div className="flex h-8 w-8 items-center justify-center rounded-xl bg-gradient-to-br from-emerald-400 to-cyan-500 shadow-lg shadow-emerald-500/20">
          <Sparkles className="h-4 w-4 text-white" />
        </div>
        <div>
          <h1 className="text-base font-bold leading-tight" style={{ color: "var(--fg)" }}>
            BankBot
          </h1>
          <p className="text-[10px] text-emerald-500 leading-tight">AI Finance</p>
        </div>
      </div>

      {/* ── Nav ──────────────────────────────────────────────────────────────── */}
      <div className="flex flex-1 flex-col justify-between px-3 py-4">
        <nav className="space-y-0.5">
          {navigation.map((item) => {
            const isActive = pathname === item.href;
            return (
              <Link
                key={item.key}
                href={item.href}
                className={cn(
                  "group relative flex items-center rounded-xl px-3 py-2.5 font-medium transition-all duration-200",
                  isActive
                    ? ""
                    : isLight
                      ? "hover:bg-black/5"
                      : "hover:bg-white/5"
                )}
                style={{
                  color: isActive
                    ? "var(--fg)"
                    : "var(--fg-subtle)",
                }}
              >
                {/* Active background pill */}
                {isActive && (
                  <motion.div
                    layoutId="activeNav"
                    className={cn(
                      "absolute inset-0 rounded-xl border",
                      isLight
                        ? "bg-emerald-50 border-emerald-200/80"
                        : "bg-white/10 border-white/10"
                    )}
                    transition={{ type: "spring", bounce: 0.2, duration: 0.4 }}
                  />
                )}
                {/* Active left accent */}
                {isActive && (
                  <div className="absolute left-0 top-1/2 -translate-y-1/2 h-5 w-0.5 rounded-full bg-emerald-500" />
                )}

                <item.icon
                  className={cn(
                    "relative mr-3 h-4 w-4 flex-shrink-0 transition-colors",
                    isActive
                      ? "text-emerald-500"
                      : isLight
                        ? "text-slate-400 group-hover:text-slate-600"
                        : "text-zinc-500 group-hover:text-zinc-300"
                  )}
                />
                <span className="relative flex-1">{t(item.key)}</span>

                {item.badge && (
                  <span
                    className={cn(
                      "relative ml-auto rounded-md px-1.5 py-0.5 text-[9px] font-bold uppercase tracking-wide border",
                      item.badge === "AI"
                        ? "bg-emerald-500/15 text-emerald-500 border-emerald-500/30"
                        : "bg-blue-500/15 text-blue-500 border-blue-500/30"
                    )}
                  >
                    {item.badge}
                  </span>
                )}
              </Link>
            );
          })}
        </nav>

        {/* ── Bottom controls ───────────────────────────────────────────────── */}
        <div
          className="space-y-1 pt-4 border-t"
          style={{ borderColor: "var(--border)" }}
        >
          {/* AI Shield status */}
          <div
            className={cn(
              "flex items-center gap-2.5 rounded-xl px-3 py-2.5 border",
              isLight
                ? "bg-emerald-50 border-emerald-200/80"
                : "bg-emerald-500/5 border-emerald-500/10"
            )}
          >
            <div className="h-1.5 w-1.5 rounded-full bg-emerald-400 animate-pulse flex-shrink-0" />
            <div className="flex-1 min-w-0">
              <p className="text-xs font-medium text-emerald-500 leading-tight">
                {t("ai_shield")}
              </p>
              <p
                className="text-[10px] leading-tight truncate"
                style={{ color: "var(--fg-subtle)" }}
              >
                {t("all_normal")}
              </p>
            </div>
          </div>

          {/* Theme toggle */}
          <button
            onClick={toggle}
            className={cn(
              "flex w-full items-center rounded-xl px-3 py-2.5 font-medium transition-all duration-200",
              isLight ? "hover:bg-black/5" : "hover:bg-white/5"
            )}
            style={{ color: "var(--fg-muted)" }}
          >
            {isLight
              ? <Sun className="mr-3 h-4 w-4 text-amber-500" />
              : <Moon className="mr-3 h-4 w-4 text-indigo-400" />}
            {isLight ? t("theme_light") : t("theme_dark")}
          </button>

          {/* Language switcher */}
          <div className="relative">
            <button
              onClick={() => setShowLang(!showLang)}
              className={cn(
                "flex w-full items-center rounded-xl px-3 py-2.5 font-medium transition-all duration-200",
                isLight ? "hover:bg-black/5" : "hover:bg-white/5",
                showLang && (isLight ? "bg-black/5" : "bg-white/5")
              )}
              style={{ color: "var(--fg-muted)" }}
            >
              <Globe className="mr-3 h-4 w-4" />
              <span className="flex-1 text-left">{LANGUAGES[language].native}</span>
              <span className="text-base leading-none">{LANGUAGES[language].flag}</span>
            </button>

            {showLang && (
              <motion.div
                initial={{ opacity: 0, y: 4, scale: 0.97 }}
                animate={{ opacity: 1, y: 0, scale: 1 }}
                exit={{ opacity: 0, y: 4, scale: 0.97 }}
                transition={{ duration: 0.15 }}
                className="absolute bottom-full left-0 right-0 mb-1.5 rounded-xl border overflow-hidden shadow-2xl z-50"
                style={{
                  background: isLight ? "white" : "#18181b",
                  borderColor: "var(--border-strong)",
                  boxShadow: isLight
                    ? "0 8px 32px rgba(15,23,42,0.12)"
                    : "0 8px 32px rgba(0,0,0,0.5)",
                }}
              >
                {(Object.entries(LANGUAGES) as [Language, typeof LANGUAGES[Language]][]).map(
                  ([code, info]) => (
                    <button
                      key={code}
                      onClick={() => { setLanguage(code); setShowLang(false); }}
                      className={cn(
                        "flex w-full items-center gap-3 px-3 py-2.5 text-sm transition-colors",
                        language === code
                          ? isLight
                            ? "bg-emerald-50 text-emerald-700"
                            : "bg-emerald-500/10 text-emerald-400"
                          : isLight
                            ? "text-slate-600 hover:bg-slate-50"
                            : "text-zinc-300 hover:bg-white/5"
                      )}
                    >
                      <span className="text-base leading-none">{info.flag}</span>
                      <span className="flex-1 text-left font-medium">{info.native}</span>
                      <span
                        className="text-xs"
                        style={{ color: "var(--fg-subtle)" }}
                      >
                        {info.label}
                      </span>
                      {language === code && (
                        <span className="ml-1 text-emerald-500 text-xs">✓</span>
                      )}
                    </button>
                  )
                )}
              </motion.div>
            )}
          </div>

          {/* Sign out */}
          <button
            onClick={handleLogout}
            className={cn(
              "flex w-full items-center rounded-xl px-3 py-2.5 font-medium transition-all duration-200",
              isLight
                ? "text-slate-500 hover:bg-red-50 hover:text-red-600"
                : "text-zinc-500 hover:bg-red-500/10 hover:text-red-400"
            )}
          >
            <LogOut className="mr-3 h-4 w-4 flex-shrink-0" />
            {t("sign_out")}
          </button>
        </div>
      </div>
    </div>
  );
}