import * as React from "react";

// Define the ToastActionElement type
export type ToastActionElement = React.ReactElement;

// Define toast types for visual distinction
export type ToastType = "default" | "destructive" | "success" | "warning" | "info";

// Main Toast interface
export interface ToastItem {
  id: string;
  title?: React.ReactNode;
  description?: React.ReactNode;
  action?: ToastActionElement;
  type?: ToastType;
  duration?: number;
  variant?: "default" | "destructive" | "success" | "warning" | "info";
  onOpenChange?: (open: boolean) => void;
  open?: boolean;
}

export type ToasterToast = ToastItem;

// Action types for reducer
const actionTypes = {
  ADD_TOAST: "ADD_TOAST",
  UPDATE_TOAST: "UPDATE_TOAST",
  DISMISS_TOAST: "DISMISS_TOAST",
  REMOVE_TOAST: "REMOVE_TOAST",
} as const;

// Configuration constants
const TOAST_LIMIT = 20;
const TOAST_REMOVE_DELAY = 1000;

// ID generation for toasts
let count = 0;

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

// Action types for the reducer
type ActionType = typeof actionTypes;

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

// State interface
interface State {
  toasts: ToasterToast[];
}

// Track toast timeouts
const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>();

// Reducer for toast state management
const reducer = (state: State, action: Action): State => {
  switch (action.type) {
    case actionTypes.ADD_TOAST:
      return {
        ...state,
        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
      };

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

    case actionTypes.DISMISS_TOAST: {
      const { toastId } = action;

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

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

    case actionTypes.REMOVE_TOAST: {
      const { toastId } = action;

      if (toastId === undefined) {
        return {
          ...state,
          toasts: [],
        };
      }

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

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

// Dispatch function to update state and notify listeners
function dispatch(action: Action) {
  memoryState = reducer(memoryState, action);
  listeners.forEach((listener) => {
    listener(memoryState);
  });
}

// Toast function for creating toasts
type ToastOptions = Omit<ToastItem, "id">;

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

  // Auto-dismiss after duration
  if (props.duration !== Infinity) {
    const timeout = setTimeout(() => {
      dispatch({ type: actionTypes.DISMISS_TOAST, toastId: id });
      
      // Remove after animation completes
      setTimeout(() => {
        dispatch({ type: actionTypes.REMOVE_TOAST, toastId: id });
      }, TOAST_REMOVE_DELAY);
      
      toastTimeouts.delete(id);
    }, props.duration || 5000);
    
    toastTimeouts.set(id, timeout);
  }

  // Methods for the toast
  const update = (props: ToastOptions) => {
    dispatch({
      type: actionTypes.UPDATE_TOAST,
      toast: { ...props, id },
    });
    return id;
  };

  const dismiss = () => {
    dispatch({ type: actionTypes.DISMISS_TOAST, toastId: id });
    
    // Clear any existing timeout
    const timeout = toastTimeouts.get(id);
    if (timeout) {
      clearTimeout(timeout);
      toastTimeouts.delete(id);
    }
    
    // Remove after animation completes
    setTimeout(() => {
      dispatch({ type: actionTypes.REMOVE_TOAST, toastId: id });
    }, TOAST_REMOVE_DELAY);
  };

  // Add the toast to state
  dispatch({
    type: actionTypes.ADD_TOAST,
    toast: {
      ...props,
      id,
      open: true,
      onOpenChange: (open) => {
        if (!open) dismiss();
        props.onOpenChange?.(open);
      },
    },
  });

  return {
    id,
    dismiss,
    update,
  };
}

// Convenience functions for different toast types
toast.default = (props: Omit<ToastOptions, "type">) => toast({ ...props, type: "default" });
toast.destructive = (props: Omit<ToastOptions, "type">) => toast({ ...props, type: "destructive" });
toast.success = (props: Omit<ToastOptions, "type">) => toast({ ...props, type: "success", variant: "success" });
toast.warning = (props: Omit<ToastOptions, "type">) => toast({ ...props, type: "warning" });
toast.info = (props: Omit<ToastOptions, "type">) => toast({ ...props, type: "info" });

// Hook for consuming toasts
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);
      }
    };
  }, []);

  return {
    ...state,
    toast,
    dismiss: (toastId?: string) => {
      dispatch({ type: actionTypes.DISMISS_TOAST, toastId });
      
      if (toastId) {
        const timeout = toastTimeouts.get(toastId);
        if (timeout) {
          clearTimeout(timeout);
          toastTimeouts.delete(toastId);
        }
        
        setTimeout(() => {
          dispatch({ type: actionTypes.REMOVE_TOAST, toastId });
        }, TOAST_REMOVE_DELAY);
      }
    },
  };
}

export { useToast, toast };