KeyInfo GetKey()
{
if (this.ApiFilter != null)
{
var keys = Resource.GetRecordInfo(typeof(TRecord)).Keys;
var maxKeySegmentCount = keys.Max(k => k.Segments.Count);
IEnumerable <KeyInfo> enabledKeys = keys, remainedKeys = new KeyInfo[0];
var enabledKeyList = new List <KeyInfo>();
var priorityList = new List <uint>();
var fields = this.ApiFilter
.SelectMany(filter => filter.GetFields().Select(field => new {
State = filter.State,
Field = field
}))
.GroupBy(f => f.Field)
.Select(g => new {
Field = g.Key,
Priority = GetPriority(g.Select(f => f.State))
});
for (var i = 0; i < maxKeySegmentCount; i++)
{
uint priority = 0;
foreach (var key in enabledKeys)
{
var field = fields.SingleOrDefault(f => f.Field == key.Segments[i].Field);
if (field != null)
{
if (field.Priority == priority)
{
enabledKeyList.Add(key);
}
else if (field.Priority > priority)
{
priority = field.Priority;
enabledKeyList.Clear();
enabledKeyList.Add(key);
}
}
}
if (enabledKeyList.Count == 0)
{
if (remainedKeys.Count() == 0)
{
remainedKeys = enabledKeys.Where(k => i == k.Segments.Count - 1).ToArray();
}
enabledKeys = enabledKeys.Where(k => i != k.Segments.Count - 1).ToArray();
}
else if (enabledKeyList.Count == 1)
{
return(enabledKeyList[0]);
}
else if (enabledKeyList.Count > 1)
{
enabledKeys = enabledKeyList.Where(k => i != k.Segments.Count - 1).ToArray();
remainedKeys = enabledKeyList.Where(k => i == k.Segments.Count - 1).ToArray();
}
enabledKeyList.Clear();
priorityList.Add(priority);
}
if (priorityList.Any(p => p != 0))
{
return(remainedKeys.FirstOrDefault() ?? enabledKeys.FirstOrDefault());
}
else
{
return(null);
}
}
return(null);
}
