angular.module('fr.infiniteScrollCtrl', [])

.service('infiniteScrollCtrl', ['$window', '$http', '$compile', function ($window, $http, $compile) {
    return function (scope, element) {
        try {
            scope.currentPage = parseInt($window.location.href.match(/\/page\/(\d+)/)[1], 10);
        } catch (e) {
            scope.currentPage = 1;
        }

        scope.loadMoreEnabled = true;
        scope.infiniteScrollDisabled = true;
        scope.pagesScrolled = 0;

        scope.enableInfiniteScroll = function () {
            scope.infiniteScrollDisabled = false;
        };

        scope.infiniteScroll = function () {
            // Disable infinite scroll until we load the next page.
            scope.infiniteScrollDisabled = true;

            // Let others know that posts are loading.
            scope.postsLoading = true;

            scope.infiniteScrollError = null;

            // Load the page.
            $http.get(DataStore.postsEndpointUrl + '?page=' + (scope.currentPage + 1)
				+ ((DataStore.currentStage) ? '&stageTree=' + DataStore.currentStage.tree : '')
				+ ((DataStore.legendary) ? '&legendary=1' : '')
				+ ((DataStore.search) ? '&q=' + encodeURIComponent(DataStore.search) : '')
            )

            .then(function (response) {
                // Increment current page.
                scope.currentPage++;

                // Increment number of pages scrolled.
                scope.pagesScrolled++;

                // Append the newly loaded content.
                element.append($compile(response.data)(scope));

                // If we did not scroll more than 15 pages.
                if (scope.pagesScrolled < 15) {
                    // Re-enabled infinite scroll
                    scope.infiniteScrollDisabled = false;

                    // Disable "Load more" button. Assumes that the button is no longer needed because infinite scroll is now enabled.
                    scope.loadMoreEnabled = false;
                }
                // If we scrolled more than 15 pages.
                else {
                    // Re-enable "Load more" button.
                    scope.loadMoreEnabled = true;

                    // Reset pages scrolled count.
                    scope.pagesScrolled = 0;
                }

                // Let everyone know that posts finished loading.
                scope.postsLoading = false;

                // Track the page view in Google analytics.
                ga('send', 'event', 'InfiniteScroll', 'Loaded', $window.location.href, scope.currentPage);

                // history.replaceState({}, '', '/page/' + scope.currentPage);
            })

            .catch(function (response) {
                scope.postsLoading = false;

                if (response.status === 404) {
                    scope.loadMoreEnabled = false;
                }

                if (response.status === 429) {
                    // eslint-disable-next-line prefer-destructuring
                    scope.infiniteScrollError = response.data.errors[0];
                }
            });
        };
    };
}]);