import { __decorate, __metadata } from "tslib";
import { Injectable } from '@angular/core';
import { NavigationEnd, Router } from '@angular/router';
import { filter, pairwise, startWith, map } from 'rxjs/operators';
import { getPathPartOfUrl } from '../menu/url-matching-helpers';
/**
 * This service determines whether we should scroll the layout back to top.
 * This occurs when the page is changed, so when current url PATH is not equal to the previous one.
 *
 *  TODO: this is most likely a temporary solutions as recently Angular introduces ViewportScroll
 *  and scroll restoration process
 */
var NbRestoreScrollTopHelper = /** @class */ (function () {
    function NbRestoreScrollTopHelper(router) {
        this.router = router;
    }
    NbRestoreScrollTopHelper.prototype.shouldRestore = function () {
        var _this = this;
        return this.router.events
            .pipe(startWith(null), filter(function (event) { return event === null || event instanceof NavigationEnd; }), pairwise(), map(function (_a) {
            var prev = _a[0], current = _a[1];
            return _this.pageChanged(prev, current);
        }), filter(function (res) { return !!res; }));
    };
    NbRestoreScrollTopHelper.prototype.pageChanged = function (prev, current) {
        return !prev || getPathPartOfUrl(prev.url) !== getPathPartOfUrl(current.url);
    };
    NbRestoreScrollTopHelper = __decorate([
        Injectable(),
        __metadata("design:paramtypes", [Router])
    ], NbRestoreScrollTopHelper);
    return NbRestoreScrollTopHelper;
}());
export { NbRestoreScrollTopHelper };
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