/// <summary>
/// Takes a collection of <see cref="ICriteria" /> and if they are all
/// <see cref="ITermsCriteria" /> for the same field replaces them with a single
/// <see cref="ITermsCriteria" /> containing all terms for that field.
/// </summary>
/// <param name="criteria">collection of <see cref="ICriteria" /> that might be combined.</param>
/// <returns><see cref="ITermsCriteria" /> containing all terms for that field or null if they can not be combined.</returns>
static ICriteria CombineTermsForSameField(ICollection <ICriteria> criteria)
{
var termCriteria = criteria.OfType <ITermsCriteria>().ToArray();
var areAllSameTerm = termCriteria.Length == criteria.Count &&
termCriteria.Select(f => f.Field).Distinct().Count() == 1 &&
termCriteria.All(f => f.IsOrCriteria);
return(areAllSameTerm
? TermsCriteria.Build(termCriteria[0].Field, termCriteria[0].Member, termCriteria.SelectMany(f => f.Values).Distinct())
: null);
}
JObject Build(TermsCriteria criteria)
{
var termsCriteria = new JObject(
new JProperty(criteria.Field,
new JArray(criteria.Values.Select(x => mapping.FormatValue(criteria.Member, x)).Cast<object>().ToArray())));
if (criteria.ExecutionMode.HasValue)
termsCriteria.Add(new JProperty("execution", criteria.ExecutionMode.GetValueOrDefault().ToString()));
return new JObject(new JProperty(criteria.Name, termsCriteria));
}