'use client';

import {
  createContext,
  useCallback,
  useContext,
  useEffect,
  useMemo,
  useState,
} from 'react';
import { useTranslations } from 'next-intl';
import { CheckCircle2, AlertTriangle, Info, X } from 'lucide-react';

type ToastKind = 'success' | 'error' | 'info';

interface Toast {
  id: number;
  kind: ToastKind;
  message: string;
}

interface ToastContextValue {
  toast: (message: string, kind?: ToastKind) => void;
  success: (message: string) => void;
  error: (message: string) => void;
  info: (message: string) => void;
}

const ToastContext = createContext<ToastContextValue | undefined>(undefined);

const KIND_CLASSES: Record<ToastKind, string> = {
  success: 'bg-emerald-50 text-emerald-900 ring-emerald-200',
  error: 'bg-red-50 text-red-900 ring-red-200',
  info: 'bg-slate-50 text-slate-900 ring-slate-200',
};

const KIND_ICON = {
  success: CheckCircle2,
  error: AlertTriangle,
  info: Info,
} as const;

export function ToastProvider({ children }: { children: React.ReactNode }) {
  const tCommon = useTranslations('common');
  const [toasts, setToasts] = useState<Toast[]>([]);

  const dismiss = useCallback((id: number) => {
    setToasts((prev) => prev.filter((t) => t.id !== id));
  }, []);

  const toast = useCallback(
    (message: string, kind: ToastKind = 'info') => {
      const id = Date.now() + Math.random();
      setToasts((prev) => [...prev, { id, kind, message }]);
      setTimeout(() => dismiss(id), 4500);
    },
    [dismiss],
  );

  const value = useMemo<ToastContextValue>(
    () => ({
      toast,
      success: (m) => toast(m, 'success'),
      error: (m) => toast(m, 'error'),
      info: (m) => toast(m, 'info'),
    }),
    [toast],
  );

  return (
    <ToastContext.Provider value={value}>
      {children}
      <div
        aria-live="polite"
        aria-atomic="true"
        className="pointer-events-none fixed bottom-4 right-4 z-50 flex w-full max-w-sm flex-col gap-2"
      >
        {toasts.map((t) => {
          const Icon = KIND_ICON[t.kind];
          return (
            <div
              key={t.id}
              role={t.kind === 'error' ? 'alert' : 'status'}
              className={`pointer-events-auto flex items-start gap-2 rounded-xl p-3 text-sm shadow-lg ring-1 ${KIND_CLASSES[t.kind]}`}
            >
              <Icon className="mt-0.5 h-4 w-4 flex-none" aria-hidden />
              <span className="flex-1">{t.message}</span>
              <button
                type="button"
                onClick={() => dismiss(t.id)}
                className="flex h-5 w-5 items-center justify-center rounded hover:bg-black/5"
                aria-label={tCommon('close')}
              >
                <X className="h-3.5 w-3.5" aria-hidden />
              </button>
            </div>
          );
        })}
      </div>
    </ToastContext.Provider>
  );
}

export function useToast(): ToastContextValue {
  const ctx = useContext(ToastContext);
  if (!ctx) {
    // Graceful fallback in case a consumer renders outside the provider
    return {
      toast: () => undefined,
      success: () => undefined,
      error: () => undefined,
      info: () => undefined,
    };
  }
  return ctx;
}

// Re-export for callers that want a hook-less ergonomic check.
export function useToastMount() {
  const [mounted, setMounted] = useState(false);
  useEffect(() => setMounted(true), []);
  return mounted;
}