/// <summary>
/// 获取与给定的 <see cref="ProblemSortKey"/> 值相对应的排序成员定义。
/// </summary>
/// <param name="key">排序键。</param>
/// <returns>排序成员定义。</returns>
/// <exception cref="ArgumentException">给定的 <see cref="ProblemSortKey"/> 值无效。</exception>
public static FieldDefinition <Problem> GetField(this ProblemSortKey key)
{
LambdaExpression selector;
switch (key)
{
case ProblemSortKey.ArchiveId:
selector = (Expression <Func <Problem, int?> >)(p => p.ArchiveId);
break;
case ProblemSortKey.CreationTime:
selector = (Expression <Func <Problem, DateTime> >)(p => p.CreationTime);
break;
case ProblemSortKey.LastUpdateTime:
selector = (Expression <Func <Problem, DateTime> >)(p => p.LastUpdateTime);
break;
case ProblemSortKey.Difficulty:
selector = (Expression <Func <Problem, int> >)(p => p.Difficulty);
break;
case ProblemSortKey.TotalSubmissions:
selector = (Expression <Func <Problem, int> >)(p => p.TotalSubmissions);
break;
case ProblemSortKey.AcceptedSubmissions:
selector = (Expression <Func <Problem, int> >)(p => p.AcceptedSubmissions);
break;
case ProblemSortKey.TotalAttemptedUsers:
selector = (Expression <Func <Problem, int> >)(p => p.TotalAttemptedUsers);
break;
case ProblemSortKey.TotalSolvedUsers:
selector = (Expression <Func <Problem, int> >)(p => p.TotalSolvedUsers);
break;
case ProblemSortKey.LastSubmissionTime:
selector = (Expression <Func <Problem, DateTime> >)(p => p.LastSubmissionTime);
break;
default:
throw new ArgumentException("Invalid sort key for problems: " + key, nameof(key));
}
return(new ExpressionFieldDefinition <Problem>(selector));
}
public async Task <PaginatedListActionResult <ProblemListInfo> > GetProblemList(
[FromQuery] ProblemSortKey by = ProblemSortKey.ArchiveId,
[FromQuery] bool descend = false,
[FromQuery][Page] int page = 0,
[FromQuery][ItemsPerPage] int itemsPerPage = 20)
{
var findPipeline = new ProblemFindPipeline(new ProblemFilterBuilder().InArchive(true))
{
SortKey = by,
SortByDescending = descend,
Pagination = new Pagination(page, itemsPerPage)
};
var findResult = await _repo.Problems.FindManyAsync(findPipeline);
var models = findResult.ResultSet.Select(p => _mapper.Map <Problem, ProblemListInfo>(p));
return(findResult.TotalCount, models);
}
public async Task <PaginatedListActionResult <ProblemListInfo> > GetProblems(
[FromQuery] ProblemSortKey by = ProblemSortKey.CreationTime,
[FromQuery] bool descend = true,
[FromQuery][Range(0, int.MaxValue)] int page = 0,
[FromQuery][Range(1, int.MaxValue)] int itemsPerPage = 20)
{
var findPipeline = new ProblemFindPipeline(ProblemFilterBuilder.Empty)
{
SortKey = by,
SortByDescending = descend,
Pagination = new Pagination(page, itemsPerPage)
};
var findResult = await _repo.Problems.FindManyAsync(findPipeline);
var models = findResult.ResultSet.Select(e => _mapper.Map <Problem, ProblemListInfo>(e));
return(findResult.TotalCount, models);
}
