VisitCountPerPage.razor

@using System.Linq.Expressions
@using LinkDotNet.Blog.Domain
@using LinkDotNet.Blog.Infrastructure
@using LinkDotNet.Blog.Infrastructure.Persistence
@using System.Collections.Immutable
@using System.Diagnostics
@using Microsoft.Extensions.Logging
@inject IRepository<BlogPost> BlogPostRepository
@inject IRepository<BlogPostRecord> BlogPostRecordRepository
@inject ILogger<VisitCountPerPage> Logger;

<div class="card">
    <div class="card-header">Blog Post Visit Counter</div>
    <div class="card-body">
        <div class="row">
            <DateRangeSelector FilterChanged="RefreshVisitCount"></DateRangeSelector>
            @if (visitData is not null)
            {
                <p id="total-clicks">@visitData.Sum(c => c.ClickCount) clicks in total</p>
            }
            else
            {
                <p id="total-clicks">Loading...</p>
            }
            <table class="table table-striped table-hover">
                <tbody>
                <tr>
                    <th>Title</th>
                    <th>Clicks</th>
                    <th>Likes</th>
                </tr>
                @if (visitData is not null)
                {
                    @foreach (var date in visitData)
                    {
                        <tr>
                            <td><a class="link" href="blogPost/@date.Id">@date.Title</a></td>
                            <td>@date.ClickCount</td>
                            <td>@date.Likes</td>
                        </tr>
                    }
                }
                else
                {
                    <Loading></Loading>
                }
                </tbody>
            </table>
        </div>
    </div>
</div>

@code {
    private Filter filter = new();
    private IReadOnlyCollection<VisitCountPageData> visitData = [];

    protected override async Task OnInitializedAsync()
    {
        visitData = await LoadBlogPostInformationAsync();
    }

	private static async ValueTask<IPagedList<BlogPostVisitData>> GetRelevantBlogPostsAsync(
		IRepository<BlogPost> blogPostRepository,
		Filter filter)
	{
		Expression<Func<BlogPost, bool>>? blogPostFilter = filter.EndDate.HasValue
			? bp => bp.UpdatedDate.Date <= filter.EndDate.Value.ToDateTime(default)
			: null;

		return await blogPostRepository.GetAllByProjectionAsync(
			s => new BlogPostVisitData(s.Id, s.Title, s.Likes),
			filter: blogPostFilter,
			orderBy: o => o.UpdatedDate);
	}

	private static async Task<IPagedList<BlogPostRecord>> GetRelevantBlogPostRecords(
		IRepository<BlogPostRecord> blogPostRecordRepository,
		Filter filter)
	{
		return await blogPostRecordRepository.GetAllAsync(
			ur => (!filter.StartDate.HasValue || ur.DateClicked >= filter.StartDate)
			      && (!filter.EndDate.HasValue || ur.DateClicked <= filter.EndDate),
			orderBy: o => o.DateClicked);
	}

    private async Task<IReadOnlyCollection<VisitCountPageData>> LoadBlogPostInformationAsync()
    {
	    var stopwatch = Stopwatch.StartNew();

	    var blogPosts = await GetRelevantBlogPostsAsync(BlogPostRepository, filter);
	    var userRecords = await GetRelevantBlogPostRecords(BlogPostRecordRepository, filter);

	    var time = stopwatch.ElapsedMilliseconds;
	    Logger.LogDebug("Retrieving data took {ElapsedMilliseconds}ms", time);

	    var blogPostDictionary = blogPosts.ToDictionary(bp => bp.Id, bp => bp);
	    var loadBlogPostInformation = userRecords
		    .GroupBy(s => s.BlogPostId)
		    .Where(s => blogPostDictionary.ContainsKey(s.Key))
		    .Select(s => new
		    {
			    Count = s.Sum(l => l.Clicks),
			    BlogPost = blogPostDictionary[s.Key]
		    })
		    .OrderByDescending(s => s.Count)
		    .Select(s => new VisitCountPageData
		    {
			    Id = s.BlogPost.Id,
			    Likes = s.BlogPost.Likes,
			    Title = s.BlogPost.Title,
			    ClickCount = s.Count,
		    }).ToImmutableArray();

	    Logger.LogDebug("Processing data took {ElapsedMilliseconds}ms", stopwatch.ElapsedMilliseconds - time);

	    return loadBlogPostInformation;
    }

	private async Task RefreshVisitCount(Filter newBeginning)
    {
        filter = newBeginning;
        visitData = await LoadBlogPostInformationAsync();
    }

	private record struct BlogPostVisitData(string Id, string Title, int Likes);
}