// Global toast queue (design: State Management). Toasts outlive route
// changes because AppShell mounts the renderer, so "Zapisz i zamknij" can
// show its toast on the list it returns to.
import { readonly, ref } from 'vue'

export type ToastTone = 'success' | 'danger'

export interface ToastItem {
  id: number
  text: string
  tone: ToastTone
}

/** Auto-dismiss delay in milliseconds (design: about 4 s). */
export const TOAST_TIMEOUT = 4000

const items = ref<ToastItem[]>([])
const timers = new Map<number, ReturnType<typeof setTimeout>>()
let nextId = 1

export const toasts = readonly(items)

export function showToast(text: string, tone: ToastTone = 'success'): number {
  const id = nextId++
  items.value = [...items.value, { id, text, tone }]
  timers.set(
    id,
    setTimeout(() => dismissToast(id), TOAST_TIMEOUT),
  )
  return id
}

export function dismissToast(id: number): void {
  const timer = timers.get(id)
  if (timer !== undefined) {
    clearTimeout(timer)
    timers.delete(id)
  }
  items.value = items.value.filter((item) => item.id !== id)
}

export function clearToasts(): void {
  for (const timer of timers.values()) {
    clearTimeout(timer)
  }
  timers.clear()
  items.value = []
}

export function useToasts() {
  return { toasts, showToast, dismissToast, clearToasts }
}