public RulesEvaluationResult Evaluate(RuleApiModel rule, RawMessage message)
{
var result = new RulesEvaluationResult();
if (GroupContainsDevice(message.DeviceId, rule.GroupId))
{
logger.Debug($"Evaluating rule {rule.Description} for device {message.DeviceId} with {rule.Conditions.Count()} conditions", () => { });
var descriptions = new List <string>();
foreach (var c in rule.Conditions)
{
var eval = EvaluateCondition(c, message);
// perf: all conditions must match, break as soon as one doesn't
if (!eval.Match)
{
return(result);
}
descriptions.Add(eval.Message);
}
result.Match = true;
result.Message = string.Join("; ", descriptions);
}
else
{
logger.Debug($"Skipping rule {rule.Description} because device {message.DeviceId} doesn't belong to group {rule.GroupId}", () => { });
}
return(result);
}
private RulesEvaluationResult EvaluateCondition(
ConditionApiModel condition,
RawMessage message)
{
var r = new RulesEvaluationResult();
var field = condition.Field;
object value;
if (!message.PayloadData.TryGetValue(field, out value))
{
logger.Debug($"Message payload doesn't contain field {field}", () => { });
return(r);
}
OperatorLogic logic;
if (!OperatorLogicLookup.TryGetValue(condition.Operator.ToLowerInvariant(), out logic))
{
logger.Error("Unknown operator", () => new { condition });
return(r);
}
switch (Type.GetTypeCode(value.GetType()))
{
case TypeCode.SByte:
case TypeCode.Byte:
case TypeCode.Int16:
case TypeCode.UInt16:
case TypeCode.Int32:
case TypeCode.UInt32:
case TypeCode.Int64:
case TypeCode.UInt64:
case TypeCode.Single:
case TypeCode.Double:
case TypeCode.Decimal:
{
var actualValue = Convert.ToDouble(value);
var threshold = Convert.ToDouble(condition.Value);
logger.Debug($"Field {field}, Value {actualValue}, Operator {condition.Operator}, Threshold {threshold}", () => { });
if (logic.DoubleTestFunc(actualValue, threshold))
{
r.Match = true;
r.Message = string.Format(logic.Message, field, actualValue, threshold);
}
}
break;
case TypeCode.String:
{
var actualValue = value.ToString();
var threshold = condition.Value;
logger.Debug($"Field {field}, Value '{actualValue}', Operator {condition.Operator}, Threshold '{threshold}'", () => { });
if (logic.StringTestFunc(actualValue, threshold))
{
r.Match = true;
r.Message = string.Format(logic.Message, field, actualValue, threshold);
}
}
break;
default:
logger.Error($"Unknown type for `{field}` value sent by device {message.DeviceId}", () => { });
break;
}
return(r);
}