"use client";

import * as React from "react";
import type { ToastActionElement, ToastProps } from "@/components/ui/toast";

const TOAST_LIMIT = 1;
const TOAST_REMOVE_DELAY = 1000000; // your existing delay (exit animation window)
const TOAST_DEFAULT_DURATION = 4000; // <— new: default auto-close

type ToasterToast = ToastProps & {
  id: string;
  title?: React.ReactNode;
  description?: React.ReactNode;
  action?: ToastActionElement;
  duration?: number; // <— new
};

const actionTypes = {
  ADD_TOAST: "ADD_TOAST",
  UPDATE_TOAST: "UPDATE_TOAST",
  DISMISS_TOAST: "DISMISS_TOAST",
  REMOVE_TOAST: "REMOVE_TOAST",
} as const;

let count = 0;
function genId() {
  count = (count + 1) % Number.MAX_SAFE_INTEGER;
  return count.toString();
}

type ActionType = typeof actionTypes;
type Action =
  | { type: ActionType["ADD_TOAST"]; toast: ToasterToast }
  | {
      type: ActionType["UPDATE_TOAST"];
      toast: Partial<ToasterToast> & { id: string };
    }
  | { type: ActionType["DISMISS_TOAST"]; toastId?: ToasterToast["id"] }
  | { type: ActionType["REMOVE_TOAST"]; toastId?: ToasterToast["id"] };

interface State {
  toasts: ToasterToast[];
}

const listeners: Array<(state: State) => void> = [];
let memoryState: State = { toasts: [] };

// Timers:
// - toastTimeouts: removal after closing (your existing behavior)
// - autoDismissTimeouts: auto-close after duration (new)
const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>(); // remove-after-delay
const autoDismissTimeouts = new Map<string, ReturnType<typeof setTimeout>>(); // auto-dismiss

function clearAutoDismiss(id: string) {
  const t = autoDismissTimeouts.get(id);
  if (t) {
    clearTimeout(t);
    autoDismissTimeouts.delete(id);
  }
}

function scheduleAutoDismiss(id: string, duration?: number) {
  const d = duration ?? TOAST_DEFAULT_DURATION;
  // Infinity or <=0 disables auto-dismiss
  if (!isFinite(d) || d <= 0) return;
  clearAutoDismiss(id);
  const t = setTimeout(() => {
    dispatch({ type: "DISMISS_TOAST", toastId: id });
  }, d);
  autoDismissTimeouts.set(id, t);
}

const addToRemoveQueue = (toastId: string) => {
  if (toastTimeouts.has(toastId)) return;
  const timeout = setTimeout(() => {
    toastTimeouts.delete(toastId);
    dispatch({ type: "REMOVE_TOAST", toastId });
  }, TOAST_REMOVE_DELAY);
  toastTimeouts.set(toastId, timeout);
};

export const reducer = (state: State, action: Action): State => {
  switch (action.type) {
    case "ADD_TOAST": {
      // Note: auto-dismiss scheduling handled by the public toast() helper
      return {
        ...state,
        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
      };
    }

    case "UPDATE_TOAST": {
      // If duration changes, reschedule auto-dismiss for that toast id
      if (action.toast.id && "duration" in action.toast) {
        scheduleAutoDismiss(action.toast.id, action.toast.duration);
      }
      return {
        ...state,
        toasts: state.toasts.map((t) =>
          t.id === action.toast.id ? { ...t, ...action.toast } : t
        ),
      };
    }

    case "DISMISS_TOAST": {
      const { toastId } = action;

      // Clear auto-dismiss timers for affected toasts
      if (toastId) {
        clearAutoDismiss(toastId);
      } else {
        // dismiss all
        state.toasts.forEach((t) => clearAutoDismiss(t.id));
      }

      // Queue removal after exit animation
      if (toastId) {
        addToRemoveQueue(toastId);
      } else {
        state.toasts.forEach((t) => addToRemoveQueue(t.id));
      }

      return {
        ...state,
        toasts: state.toasts.map((t) =>
          t.id === toastId || toastId === undefined ? { ...t, open: false } : t
        ),
      };
    }

    case "REMOVE_TOAST": {
      if (action.toastId === undefined) {
        // Remove all; clear timers
        state.toasts.forEach((t) => {
          clearAutoDismiss(t.id);
          const rt = toastTimeouts.get(t.id);
          if (rt) {
            clearTimeout(rt);
            toastTimeouts.delete(t.id);
          }
        });
        return { ...state, toasts: [] };
      }
      // Remove one; clear timers
      clearAutoDismiss(action.toastId);
      const rt = toastTimeouts.get(action.toastId);
      if (rt) {
        clearTimeout(rt);
        toastTimeouts.delete(action.toastId);
      }

      return {
        ...state,
        toasts: state.toasts.filter((t) => t.id !== action.toastId),
      };
    }
  }
};

function dispatch(action: Action) {
  memoryState = reducer(memoryState, action);
  listeners.forEach((l) => l(memoryState));
}

type Toast = Omit<ToasterToast, "id">;

function toast(props: Toast) {
  const id = genId();

  const update = (next: ToasterToast) =>
    dispatch({ type: "UPDATE_TOAST", toast: { ...next, id } });

  const dismiss = () => dispatch({ type: "DISMISS_TOAST", toastId: id });

  // add toast as open and wire onOpenChange to dismiss
  dispatch({
    type: "ADD_TOAST",
    toast: {
      ...props,
      id,
      open: true,
      onOpenChange: (open) => {
        if (!open) dismiss();
      },
    },
  });

  // schedule auto-dismiss using provided duration (or default)
  scheduleAutoDismiss(id, props.duration);

  return { id, dismiss, update };
}

function useToast() {
  const [state, setState] = React.useState<State>(memoryState);

  React.useEffect(() => {
    listeners.push(setState);
    return () => {
      const index = listeners.indexOf(setState);
      if (index > -1) listeners.splice(index, 1);
    };
  }, []); // <— fix: don’t re-register on every state change

  return {
    ...state,
    toast,
    dismiss: (toastId?: string) => dispatch({ type: "DISMISS_TOAST", toastId }),
  };
}

export { useToast, toast };