'use client';

import { createContext, useContext, useState, useCallback, useRef, useEffect } from 'react';
import { CheckCircle2, AlertTriangle, Info, X, AlertCircle } from 'lucide-react';

type ToastType = 'success' | 'error' | 'warning' | 'info';

interface Toast {
  id: string;
  message: string;
  type: ToastType;
  duration?: number;
}

interface ConfirmOptions {
  title: string;
  message: string;
  confirmLabel?: string;
  cancelLabel?: string;
  danger?: boolean;
}

interface ToastContextType {
  toast: (message: string, type?: ToastType, duration?: number) => void;
  confirm: (options: ConfirmOptions) => Promise<boolean>;
}

const ToastContext = createContext<ToastContextType | null>(null);

export function useToast() {
  const ctx = useContext(ToastContext);
  if (!ctx) throw new Error('useToast must be used within ToastProvider');
  return ctx;
}

const icons: Record<ToastType, React.ReactNode> = {
  success: <CheckCircle2 className="w-5 h-5 text-emerald-500" />,
  error: <AlertCircle className="w-5 h-5 text-red-500" />,
  warning: <AlertTriangle className="w-5 h-5 text-amber-500" />,
  info: <Info className="w-5 h-5 text-blue-500" />,
};

const bgColors: Record<ToastType, string> = {
  success: 'bg-emerald-50 border-emerald-200',
  error: 'bg-red-50 border-red-200',
  warning: 'bg-amber-50 border-amber-200',
  info: 'bg-blue-50 border-blue-200',
};

export function ToastProvider({ children }: { children: React.ReactNode }) {
  const [toasts, setToasts] = useState<Toast[]>([]);
  const [confirmState, setConfirmState] = useState<{
    options: ConfirmOptions;
    resolve: (value: boolean) => void;
  } | null>(null);

  const toast = useCallback((message: string, type: ToastType = 'info', duration = 4000) => {
    const id = Math.random().toString(36).slice(2) + Date.now().toString(36);
    setToasts(prev => [...prev, { id, message, type, duration }]);
    if (duration > 0) {
      setTimeout(() => {
        setToasts(prev => prev.filter(t => t.id !== id));
      }, duration);
    }
  }, []);

  const confirm = useCallback((options: ConfirmOptions): Promise<boolean> => {
    return new Promise((resolve) => {
      setConfirmState({ options, resolve });
    });
  }, []);

  const handleConfirm = (result: boolean) => {
    confirmState?.resolve(result);
    setConfirmState(null);
  };

  const removeToast = (id: string) => {
    setToasts(prev => prev.filter(t => t.id !== id));
  };

  return (
    <ToastContext.Provider value={{ toast, confirm }}>
      {children}

      {/* Toast Container */}
      <div className="fixed top-4 right-4 z-[100] space-y-3 pointer-events-none" style={{ maxWidth: '400px' }}>
        {toasts.map((t) => (
          <div
            key={t.id}
            className={`pointer-events-auto flex items-start gap-3 p-4 rounded-xl border shadow-lg backdrop-blur-sm ${bgColors[t.type]} animate-slide-in`}
          >
            <div className="flex-shrink-0 mt-0.5">{icons[t.type]}</div>
            <p className="text-sm font-medium text-slate-800 flex-1">{t.message}</p>
            <button onClick={() => removeToast(t.id)} className="flex-shrink-0 text-slate-400 hover:text-slate-600 transition">
              <X className="w-4 h-4" />
            </button>
          </div>
        ))}
      </div>

      {/* Confirm Modal */}
      {confirmState && (
        <div className="fixed inset-0 bg-slate-900/60 backdrop-blur-sm flex items-center justify-center z-[110] p-4 animate-fade-in">
          <div className="bg-white rounded-2xl shadow-2xl max-w-md w-full p-8 animate-scale-in">
            <div className={`w-12 h-12 rounded-full flex items-center justify-center mb-4 ${confirmState.options.danger ? 'bg-red-100' : 'bg-blue-100'}`}>
              {confirmState.options.danger
                ? <AlertTriangle className="w-6 h-6 text-red-600" />
                : <Info className="w-6 h-6 text-blue-600" />
              }
            </div>
            <h3 className="text-lg font-bold text-slate-900 mb-2">{confirmState.options.title}</h3>
            <p className="text-sm text-slate-600 mb-8">{confirmState.options.message}</p>
            <div className="flex justify-end gap-3">
              <button
                onClick={() => handleConfirm(false)}
                className="px-5 py-2.5 rounded-lg text-slate-600 font-medium hover:bg-slate-100 transition"
              >
                {confirmState.options.cancelLabel || 'Abbrechen'}
              </button>
              <button
                onClick={() => handleConfirm(true)}
                className={`px-5 py-2.5 rounded-lg font-medium text-white shadow-sm transition ${confirmState.options.danger ? 'bg-red-600 hover:bg-red-700' : 'bg-indigo-600 hover:bg-indigo-700'}`}
              >
                {confirmState.options.confirmLabel || 'Bestätigen'}
              </button>
            </div>
          </div>
        </div>
      )}
    </ToastContext.Provider>
  );
}