Alerting: move getNewState to EvalContext

This fix alert state update when several evaluation attempts are needed

Signed-off-by: Thibault Chataigner <t.chataigner@criteo.com>

pkg/services/alerting/eval_context.go

@@ -112,3 +112,34 @@ func (c *EvalContext) GetRuleUrl() (string, error) {
 		return fmt.Sprintf(urlFormat, m.GetFullDashboardUrl(ref.Uid, ref.Slug), c.Rule.PanelId, c.Rule.OrgId), nil
 	}
 }
+
+func (c *EvalContext) GetNewState() m.AlertStateType {
+	if c.Error != nil {
+		c.log.Error("Alert Rule Result Error",
+			"ruleId", c.Rule.Id,
+			"name", c.Rule.Name,
+			"error", c.Error,
+			"changing state to", c.Rule.ExecutionErrorState.ToAlertState())
+
+		if c.Rule.ExecutionErrorState == m.ExecutionErrorKeepState {
+			return c.PrevAlertState
+		}
+		return c.Rule.ExecutionErrorState.ToAlertState()
+
+	} else if c.Firing {
+		return m.AlertStateAlerting
+
+	} else if c.NoDataFound {
+		c.log.Info("Alert Rule returned no data",
+			"ruleId", c.Rule.Id,
+			"name", c.Rule.Name,
+			"changing state to", c.Rule.NoDataState.ToAlertState())
+
+		if c.Rule.NoDataState == m.NoDataKeepState {
+			return c.PrevAlertState
+		}
+		return c.Rule.NoDataState.ToAlertState()
+	}
+
+	return m.AlertStateOK
+}