src/hooks/use-toast.ts

import * as React from "react"

const TOAST_LIMIT = 1
const TOAST_REMOVE_DELAY = 1000000

type ToasterToast = {
  id: string
  title?: React.ReactNode
  description?: React.ReactNode
  action?: React.ReactElement
  open?: boolean
  onOpenChange?: (open: boolean) => void
  variant?: "default" | "destructive"
}

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 Action =
  | { type: typeof actionTypes.ADD_TOAST; toast: ToasterToast }
  | { type: typeof actionTypes.UPDATE_TOAST; toast: Partial<ToasterToast> }
  | { type: typeof actionTypes.DISMISS_TOAST; toastId?: string }
  | { type: typeof actionTypes.REMOVE_TOAST; toastId?: string }

interface State {
  toasts: ToasterToast[]
}

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: actionTypes.REMOVE_TOAST, toastId })
  }, TOAST_REMOVE_DELAY)
  toastTimeouts.set(toastId, timeout)
}

export 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) addToRemoveQueue(toastId)
      else state.toasts.forEach((t) => addToRemoveQueue(t.id))
      return { ...state, toasts: state.toasts.map((t) => (toastId == null || t.id === toastId ? { ...t, open: false } : t)) }
    }
    case actionTypes.REMOVE_TOAST:
      return { ...state, toasts: action.toastId == null ? [] : 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))
}

type Toast = Omit<ToasterToast, "id">

function toast({ ...props }: Toast) {
  const id = genId()
  const update = (props: ToasterToast) => dispatch({ type: actionTypes.UPDATE_TOAST, toast: { ...props, id } })
  const dismiss = () => dispatch({ type: actionTypes.DISMISS_TOAST, toastId: id })
  dispatch({ type: actionTypes.ADD_TOAST, toast: { ...props, id, open: true, onOpenChange: (open) => { if (!open) dismiss() } } })
  return { id, dismiss, update }
}

function useToast() {
  const [state, setState] = React.useState<State>(memoryState)
  React.useEffect(() => {
    listeners.push(setState)
    return () => { const i = listeners.indexOf(setState); if (i > -1) listeners.splice(i, 1) }
  }, [state])
  return { ...state, toast, dismiss: (toastId?: string) => dispatch({ type: actionTypes.DISMISS_TOAST, toastId }) }
}

export { useToast, toast }