fun fetchEvents()

in jetbrains-core/src/software/aws/toolkits/jetbrains/services/cloudformation/stack/EventsFetcher.kt [30:70]
33 lines of code
5 McCabe index (conditional complexity)

    fun fetchEvents(client: CloudFormationClient, pageToSwitchTo: Page?): Pair<List<StackEvent>, Set<Page>> {
        assert(!SwingUtilities.isEventDispatchThread())

        val pageToFetch: String? = when (pageToSwitchTo) {
            Page.NEXT -> nextPage
            Page.PREVIOUS -> previousPages.lastOrNull()
            else -> currentPage
        }

        val request = DescribeStackEventsRequest.builder().stackName(stackName).nextToken(pageToFetch).build()
        val response = client.describeStackEvents(request)

        when (pageToSwitchTo) {
            Page.NEXT -> currentPage?.let { previousPages.add(it) } // Store current as prev
            Page.PREVIOUS -> if (previousPages.isNotEmpty()) previousPages.removeAt(previousPages.size - 1)
        }
        nextPage = response.nextToken()
        currentPage = pageToFetch

        if (pageToSwitchTo != null) { // page changed, last event is not valid
            lastEventIdOfCurrentPage = null
        }

        val eventsUnprocessed = response.stackEvents()
        val eventsProcessed = when (lastEventIdOfCurrentPage) {
            null -> eventsUnprocessed
            else -> eventsUnprocessed.takeWhile { it.id != lastEventIdOfCurrentPage }
        }
        eventsProcessed.firstOrNull()?.let { lastEventIdOfCurrentPage = it.id }

        val availablePages = mutableSetOf<Page>()

        if (currentPage != null) { // We only can go prev. if current page is not first (not null)
            availablePages.add(Page.PREVIOUS)
        }
        if (nextPage != null) {
            availablePages.add(Page.NEXT)
        }

        return Pair(eventsProcessed, availablePages)
    }