using ErsatzTV.Core.Api.Search;
using ErsatzTV.Core.Interfaces.Search;

namespace ErsatzTV.Application.Search.Queries;

public class GetSearchFieldValuesHandler(ISearchIndex searchIndex)
    : IRequestHandler<GetSearchFieldValues, Option<SearchFieldValuesResponseModel>>
{
    private const int DefaultLimit = 50;
    private const int MaxLimit = 50;

    public async Task<Option<SearchFieldValuesResponseModel>> Handle(
        GetSearchFieldValues request,
        CancellationToken cancellationToken)
    {
        SearchFieldResponseModel field = SearchFieldCatalog.Fields
            .FirstOrDefault(f => f.Name == request.Name);

        if (field is null || field.Type != "text")
        {
            return Option<SearchFieldValuesResponseModel>.None;
        }

        int limit = request.Limit <= 0 ? DefaultLimit : Math.Clamp(request.Limit, 1, MaxLimit);
        List<string> values = await searchIndex.GetFieldValues(request.Name, request.Query, limit);
        return new SearchFieldValuesResponseModel(values);
    }
}