public static async Task <IssuesPagedList> CreateAsync(
IQueryable <GeminiIssueEntity> source,
IssuesQueryParameters issuesQueryParameters,
CancellationToken token)
{
var count = source.Count();
var requestedIssuePagination = MetaIssuePagination.ParsePagination(issuesQueryParameters);
int pageNumber = 0;
List <GeminiIssueEntity> items;
if (requestedIssuePagination != null)
{
pageNumber = Math.Max(1, requestedIssuePagination.PageNumber);
items = await GetPageAsync(source, issuesQueryParameters.PageSize, pageNumber, token).ConfigureAwait(false);
}
else
{
items = await source.Take(issuesQueryParameters.PageSize).ToListAsync(token).ConfigureAwait(false);
}
var meta = new MetaIssuePagination
{
PageNumber = pageNumber,
PageSize = issuesQueryParameters.PageSize,
CheckSum = CreateCheckSum(issuesQueryParameters)
};
return(new IssuesPagedList(items, count, meta));
}
public static string Create(MetaIssuePagination metaIssuePagination, int totalPages, PageDirection pageDirection)
{
var pageNumber = metaIssuePagination.PageNumber;
if (pageDirection == PageDirection.Next)
{
if (metaIssuePagination.PageNumber >= totalPages)
{
return(string.Empty);
}
pageNumber++;
}
else if (pageDirection == PageDirection.Previous)
{
if (metaIssuePagination.PageNumber < 1)
{
return(string.Empty);
}
pageNumber--;
}
var meta = new MetaIssuePagination
{
CheckSum = metaIssuePagination.CheckSum,
PageNumber = pageNumber,
PageSize = metaIssuePagination.PageSize
};
var json = JsonSerializer.Serialize(meta);
return(Base64Encode(json));
}
private static IssuePagination CreateIssuePagination(int count, MetaIssuePagination metaIssuePagination)
{
var totalPages = (int)Math.Ceiling(count / (double)metaIssuePagination.PageSize);
var issuePagination = new IssuePagination
{
Count = count,
CurrentPage = MetaIssuePagination.Create(metaIssuePagination, totalPages, PageDirection.Current),
NextPage = MetaIssuePagination.Create(metaIssuePagination, totalPages, PageDirection.Next),
PreviousPage = MetaIssuePagination.Create(metaIssuePagination, totalPages, PageDirection.Previous),
TotalPages = totalPages
};
return(issuePagination);
}
IssuesPagedList(List <GeminiIssueEntity> items, int count, MetaIssuePagination metaIssuePagination)
{
IssuePagination = CreateIssuePagination(count, metaIssuePagination);
AddRange(items);
}