import {
  setKefuWidgetConfig,
  type KefuWidgetHostConfig,
} from "@/lib/kefu-widget-config"

type HostBridgeOptions = {
  onInit?: () => void
  onOpen?: () => void
  onMinimize?: () => void
  onMaximizedChange?: (isMaximized: boolean) => void
}

const INIT_MESSAGE_TYPE = "cs-agent:init"
const OPEN_MESSAGE_TYPE = "cs-agent:open"
const MINIMIZE_MESSAGE_TYPE = "cs-agent:minimize"
const MAXIMIZED_MESSAGE_TYPE = "cs-agent:maximized"
const READY_MESSAGE_TYPE = "cs-agent:ready"
const REQUEST_MINIMIZE_MESSAGE_TYPE = "cs-agent:request-minimize"
const REQUEST_CLOSE_MESSAGE_TYPE = "cs-agent:request-close"
const REQUEST_TOGGLE_MAXIMIZE_MESSAGE_TYPE = "cs-agent:request-toggle-maximize"

export function bindKefuHostBridge(options: HostBridgeOptions = {}) {
  if (typeof window === "undefined") {
    return () => undefined
  }

  if (window.parent && window.parent !== window) {
    window.parent.postMessage({ type: READY_MESSAGE_TYPE }, "*")
  }

  const handleMessage = (event: MessageEvent) => {
    const data = event.data as
      | {
          type?: string
          payload?: KefuWidgetHostConfig | { isMaximized?: boolean }
        }
      | undefined
    if (!data?.type) {
      return
    }

    if (data.type === INIT_MESSAGE_TYPE && data.payload) {
      setKefuWidgetConfig(data.payload as KefuWidgetHostConfig)
      options.onInit?.()
      return
    }

    if (data.type === OPEN_MESSAGE_TYPE) {
      options.onOpen?.()
      return
    }

    if (data.type === MINIMIZE_MESSAGE_TYPE) {
      options.onMinimize?.()
      return
    }

    if (data.type === MAXIMIZED_MESSAGE_TYPE) {
      const payload = data.payload as { isMaximized?: boolean } | undefined
      options.onMaximizedChange?.(Boolean(payload?.isMaximized))
    }
  }

  window.addEventListener("message", handleMessage)
  return () => window.removeEventListener("message", handleMessage)
}

function postToParent(type: string) {
  if (typeof window === "undefined") {
    return
  }
  if (window.parent && window.parent !== window) {
    window.parent.postMessage({ type }, "*")
  }
}

export function requestKefuHostMinimize() {
  postToParent(REQUEST_MINIMIZE_MESSAGE_TYPE)
}

export function requestKefuHostClose() {
  postToParent(REQUEST_CLOSE_MESSAGE_TYPE)
}

export function requestKefuHostToggleMaximize() {
  postToParent(REQUEST_TOGGLE_MAXIMIZE_MESSAGE_TYPE)
}
