import * as React from "react";
import { Snackbar, Alert, AlertColor } from "@mui/material";

interface ToastState {
  open: boolean;
  message: string;
  severity: AlertColor;
}

interface ToastContextValue {
  showToast: (message: string, severity?: AlertColor) => void;
}

const ToastContext = React.createContext<ToastContextValue | null>(null);

export function ToastProvider({ children }: { children: React.ReactNode }) {
  const [toast, setToast] = React.useState<ToastState>({ open: false, message: "", severity: "success" });
  const timerRef = React.useRef<ReturnType<typeof setTimeout> | null>(null);

  const showToast = React.useCallback((message: string, severity: AlertColor = "success") => {
    if (timerRef.current) clearTimeout(timerRef.current);
    setToast({ open: true, message, severity });
    timerRef.current = setTimeout(() => setToast((t) => ({ ...t, open: false })), 4000);
  }, []);

  const handleClose = (_?: React.SyntheticEvent | Event, reason?: string) => {
    if (reason === "clickaway") return;
    setToast((t) => ({ ...t, open: false }));
  };

  return (
    <ToastContext.Provider value={{ showToast }}>
      {children}
      <Snackbar
        open={toast.open}
        autoHideDuration={4000}
        onClose={handleClose}
        anchorOrigin={{ vertical: "bottom", horizontal: "center" }}
      >
        <Alert severity={toast.severity} onClose={handleClose} sx={{ borderRadius: 2, minWidth: 260 }}>
          {toast.message}
        </Alert>
      </Snackbar>
    </ToastContext.Provider>
  );
}

export function useToast(): ToastContextValue {
  const ctx = React.useContext(ToastContext);
  if (!ctx) throw new Error("useToast must be used within a ToastProvider");
  return ctx;
}