"use client";

import * as React from "react";

const TOAST_LIMIT = 1;
const TOAST_REMOVE_DELAY = 1000000;

type ToastVariant = "default" | "destructive";

interface ToastData {
  id: string;
  title?: string;
  description?: string;
  variant?: ToastVariant;
  open: boolean;
  onOpenChange: (open: boolean) => void;
}

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(): string {
  count = (count + 1) % Number.MAX_SAFE_INTEGER;
  return count.toString();
}

type ActionType = typeof actionTypes;

type Action =
  | {
      type: ActionType["ADD_TOAST"];
      toast: ToastData;
    }
  | {
      type: ActionType["UPDATE_TOAST"];
      toast: Partial<ToastData>;
    }
  | {
      type: ActionType["DISMISS_TOAST"];
      toastId?: string;
    }
  | {
      type: ActionType["REMOVE_TOAST"];
      toastId?: string;
    };

interface State {
  toasts: ToastData[];
}

const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>();

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":
      return {
        ...state,
        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
      };

    case "UPDATE_TOAST":
      return {
        ...state,
        toasts: state.toasts.map((t) =>
          t.id === action.toast.id ? { ...t, ...action.toast } : t,
        ),
      };

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

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

const listeners: Array<(state: State) => void> = [];

let memoryState: State = { toasts: [] };

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

interface ToastInput {
  title?: string;
  description?: string;
  variant?: ToastVariant;
}

function toast(input: ToastInput) {
  const id = genId();

  const update = (props: Partial<ToastData>) =>
    dispatch({ type: "UPDATE_TOAST", toast: { ...props, id } });

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

  dispatch({
    type: "ADD_TOAST",
    toast: {
      ...input,
      id,
      open: true,
      onOpenChange: (open: boolean) => {
        if (!open) dismiss();
      },
    },
  });

  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);
      }
    };
  }, [state]);

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

export { useToast, toast };
export type { ToastData, ToastVariant };
