115 lines
4 KiB
C#
115 lines
4 KiB
C#
using Dapper;
|
|
using Femto.Common.Infrastructure.DbConnection;
|
|
using Femto.Modules.Blog.Application.Queries.GetPosts.Dto;
|
|
using MediatR;
|
|
|
|
namespace Femto.Modules.Blog.Application.Queries.GetPosts;
|
|
|
|
public class GetPostsQueryHandler(IDbConnectionFactory connectionFactory)
|
|
: IRequestHandler<GetPostsQuery, GetPostsQueryResult>
|
|
{
|
|
public async Task<GetPostsQueryResult> Handle(
|
|
GetPostsQuery query,
|
|
CancellationToken cancellationToken
|
|
)
|
|
{
|
|
using var conn = connectionFactory.GetConnection();
|
|
|
|
var orderBy = query.Direction is GetPostsDirection.Backward ? "desc" : "asc";
|
|
var pageFilter = query.Direction is GetPostsDirection.Backward ? "<=" : ">=";
|
|
var username = query.Author;
|
|
var authorGuid = query.AuthorId;
|
|
var cursor = query.From;
|
|
var showPrivate = query.CurrentUserId is not null;
|
|
|
|
// lang=sql
|
|
var sql = $$"""
|
|
with page as (
|
|
select blog.post.*, blog.author.username as Username, blog.author.id as AuthorId
|
|
from blog.post
|
|
inner join blog.author on blog.author.id = blog.post.author_id
|
|
where (@username is null or blog.author.username = @username)
|
|
and (@showPrivate or blog.post.is_public = true)
|
|
and (@authorGuid is null or blog.author.id = @authorGuid)
|
|
and (@cursor is null or blog.post.id {{pageFilter}} @cursor)
|
|
order by blog.post.id {{orderBy}}
|
|
limit @amount
|
|
)
|
|
select
|
|
page.id as PostId,
|
|
page.content as Content,
|
|
blog.post_media.url as MediaUrl,
|
|
blog.post_media.width as MediaWidth,
|
|
blog.post_media.height as MediaHeight,
|
|
page.posted_on as PostedOn,
|
|
page.Username,
|
|
page.AuthorId
|
|
from page
|
|
left join blog.post_media on blog.post_media.post_id = page.id
|
|
order by page.id {{orderBy}}
|
|
""";
|
|
|
|
var result = await conn.QueryAsync<QueryResult>(
|
|
sql,
|
|
new
|
|
{
|
|
username,
|
|
authorGuid,
|
|
cursor,
|
|
// load an extra one to take for the cursor
|
|
amount = query.Amount + 1,
|
|
showPrivate,
|
|
}
|
|
);
|
|
|
|
var rows = result.ToList();
|
|
|
|
var posts = rows.GroupBy(row => row.PostId)
|
|
.Select(group =>
|
|
{
|
|
var postId = group.Key;
|
|
var post = group.First();
|
|
var media = group
|
|
.Select(row =>
|
|
{
|
|
if (row.MediaUrl is not null)
|
|
{
|
|
return new PostMediaDto(
|
|
new Uri(row.MediaUrl),
|
|
row.MediaHeight,
|
|
row.MediaHeight
|
|
);
|
|
}
|
|
else
|
|
return null;
|
|
})
|
|
.OfType<PostMediaDto>()
|
|
.ToList();
|
|
return new PostDto(
|
|
postId,
|
|
post.Content,
|
|
media,
|
|
post.PostedOn,
|
|
new PostAuthorDto(post.AuthorId, post.Username)
|
|
);
|
|
})
|
|
.ToList();
|
|
|
|
var next = rows.Count >= query.Amount ? rows.LastOrDefault()?.PostId : null;
|
|
|
|
return new GetPostsQueryResult(posts, next);
|
|
}
|
|
|
|
internal class QueryResult
|
|
{
|
|
public Guid PostId { get; set; }
|
|
public string Content { get; set; }
|
|
public string? MediaUrl { get; set; }
|
|
public string? MediaType { get; set; }
|
|
public int? MediaWidth { get; set; }
|
|
public int? MediaHeight { get; set; }
|
|
public DateTimeOffset PostedOn { get; set; }
|
|
public Guid AuthorId { get; set; }
|
|
public string Username { get; set; }
|
|
}
|
|
}
|