import * as TKUnit from "../../tk-unit";
import { isAndroid } from "@nativescript/core/platform";
import { _resetRootView } from "@nativescript/core/application/";
import { Frame, NavigationEntry } from "@nativescript/core/ui/frame";
import { Page } from "@nativescript/core/ui/page";
// import { TabView, TabViewItem } from "@nativescript/core/ui/tab-view";
import { BottomNavigation, TabContentItem, TabStrip, TabStripItem } from "@nativescript/core/ui/bottom-navigation";

function waitUntilNavigatedToMaxTimeout(pages: Page[], action: Function) {
    const maxTimeout = 8;
    let completed = 0;
    function navigatedTo(args) {
        args.object.page.off("navigatedTo", navigatedTo);
        completed++;
    }

    pages.forEach(page => page.on("navigatedTo", navigatedTo));
    action();
    TKUnit.waitUntilReady(() => completed === pages.length, maxTimeout);
}

function waitUntilTabViewReady(page: Page, action: Function) {
    action();

    if (isAndroid) {
        TKUnit.waitUntilReady(() => page.frame._currentEntry.fragment.isAdded());
    } else {
        TKUnit.waitUntilReady(() => page.isLoaded);
    }
}

function createPage(i: number) {
    const page = new Page();
    page.id = `Tab${i} Frame${i} Page${i}`;

    return page;
}

function createFrame(i: number, page: Page) {
    const frame = new Frame();
    frame.navigate(() => page);
    frame.id = `Tab${i} Frame${i}`;

    return frame;
}

function createTabItem(i: number, frame: Frame) {
    const tabEntry = new TabContentItem();
    // tabEntry.title = "Tab " + i;
    tabEntry.content = frame;
    tabEntry["index"] = i;

    return tabEntry;
}

function createTabItemsWithFrames(count: number) {
    const items = [];

    for (var i = 0; i < count; i++) {
        const page = createPage(i);
        const frame = createFrame(i, page);
        const tabItem = createTabItem(i, frame);

        items.push({ page, frame, tabItem });
    }

    return items;
}

function createTabStrip(count: number): TabStrip {
    const items = new Array<TabStripItem>();
    for (let i = 0; i < count; i++) {
        let tabStripEntry = new TabStripItem();
        tabStripEntry.title = "Tab " + i;
        items.push(tabStripEntry);
    }

    const tabStrip = new TabStrip();
    tabStrip.items = items;

    return tabStrip;
}

export function test_frame_topmost_matches_selectedIndex() {
    const items = createTabItemsWithFrames(3);
    const tabView = new BottomNavigation();
    tabView.items = items.map(item => item.tabItem);
    tabView.tabStrip = createTabStrip(3);

    // iOS cannot preload tab items
    // Android preloads 1 tab item to the sides by default
    // set this to 0, so that both platforms behave the same.
    // tabView.androidOffscreenTabLimit = 0;

    const entry: NavigationEntry = {
        create: () => tabView
    };

    waitUntilNavigatedToMaxTimeout([items[0].page], () => _resetRootView(entry));
    TKUnit.assertEqual(Frame.topmost().id, "Tab0 Frame0");

    waitUntilNavigatedToMaxTimeout([items[1].page], () => tabView.selectedIndex = 1);
    TKUnit.assertEqual(Frame.topmost().id, "Tab1 Frame1");
}

export function test_no_preloading_on_index_change() {
    let actualEventsRaised = [];

    function resetActualEventsRaised() {
        for (var i = 0; i < actualEventsRaised.length; i++) {
            actualEventsRaised[i] = [];
        }
    }

    function attachEventHandlers(i: number, item) {
        actualEventsRaised.push([]);

        const page = item.page;
        page.on(Page.loadedEvent, () => actualEventsRaised[i].push(`${page.id} loaded`));
        page.on(Page.unloadedEvent, () => actualEventsRaised[i].push(`${page.id} unloaded`));
        page.on(Page.navigatingToEvent, () => actualEventsRaised[i].push(`${page.id} navigatingTo`));
        page.on(Page.navigatingFromEvent, () => actualEventsRaised[i].push(`${page.id} navigatingFrom`));
        page.on(Page.navigatedToEvent, () => actualEventsRaised[i].push(`${page.id} navigatedTo`));
        page.on(Page.navigatedFromEvent, () => actualEventsRaised[i].push(`${page.id} navigatedFrom`));

        const frame = item.frame;
        frame.on(Frame.loadedEvent, () => actualEventsRaised[i].push(`${frame.id} loaded`));
        frame.on(Frame.unloadedEvent, () => actualEventsRaised[i].push(`${frame.id} unloaded`));
    }

    const items = createTabItemsWithFrames(3);

    items.forEach((item, i) => {
        attachEventHandlers(i, item);
    });

    const tabView = new BottomNavigation();
    tabView.items = items.map(item => item.tabItem);
    tabView.tabStrip = createTabStrip(3);

    const entry: NavigationEntry = {
        create: () => tabView
    };

    waitUntilNavigatedToMaxTimeout([items[0].page], () => _resetRootView(entry));

    const expectedEventsRaisedAfterTabCreated = [
        [
            "Tab0 Frame0 loaded",
            "Tab0 Frame0 Page0 navigatingTo",
            "Tab0 Frame0 Page0 loaded",
            "Tab0 Frame0 Page0 navigatedTo",
        ],
        [],
        []
    ];

    TKUnit.assertDeepEqual(actualEventsRaised, expectedEventsRaisedAfterTabCreated);

    resetActualEventsRaised();
    waitUntilNavigatedToMaxTimeout([items[2].page], () => tabView.selectedIndex = 2);

    const expectedEventsRaisedAfterSelectThirdTab = [
        [
            "Tab0 Frame0 Page0 unloaded",
            "Tab0 Frame0 unloaded",
        ],
        [],
        [
            "Tab2 Frame2 loaded",
            "Tab2 Frame2 Page2 navigatingTo",
            "Tab2 Frame2 Page2 loaded",
            "Tab2 Frame2 Page2 navigatedTo"
        ]
    ];

    TKUnit.assertDeepEqual(actualEventsRaised, expectedEventsRaisedAfterSelectThirdTab);

    resetActualEventsRaised();

    waitUntilTabViewReady(items[0].page, () => tabView.selectedIndex = 0);

    const expectedEventsRaisedAfterReturnToFirstTab = [
        [
            "Tab0 Frame0 Page0 loaded",
            "Tab0 Frame0 loaded",
        ],
        [],
        [
            "Tab2 Frame2 Page2 unloaded",
            "Tab2 Frame2 unloaded",
        ]
    ];

    TKUnit.assertDeepEqual(actualEventsRaised, expectedEventsRaisedAfterReturnToFirstTab);
}

export function tearDownModule() {
    const page = new Page();
    const frame = new Frame();
    frame.navigate(() => page);

    const entry: NavigationEntry = {
        create: () => frame
    };

    waitUntilNavigatedToMaxTimeout([page], () => _resetRootView(entry));
}