AlertingNG: Split into several packages (#31719)

* AlertingNG: Split into several packages

* Move AlertQuery to models

pkg/services/ngalert/models/instance_labels.go

@@ -0,0 +1,105 @@
+package models
+
+import (
+	// nolint:gosec
+	"crypto/sha1"
+	"encoding/json"
+	"fmt"
+	"sort"
+
+	"github.com/grafana/grafana-plugin-sdk-go/data"
+)
+
+// InstanceLabels is an extension to data.Labels with methods
+// for database serialization.
+type InstanceLabels data.Labels
+
+// FromDB loads labels stored in the database as json tuples into InstanceLabels.
+// FromDB is part of the xorm Conversion interface.
+func (il *InstanceLabels) FromDB(b []byte) error {
+	tl := &tupleLabels{}
+	err := json.Unmarshal(b, tl)
+	if err != nil {
+		return err
+	}
+	labels, err := tupleLablesToLabels(*tl)
+	if err != nil {
+		return err
+	}
+	*il = labels
+	return nil
+}
+
+// ToDB is not implemented as serialization is handled with manual SQL queries).
+// ToDB is part of the xorm Conversion interface.
+func (il *InstanceLabels) ToDB() ([]byte, error) {
+	// Currently handled manually in sql command, needed to fulfill the xorm
+	// converter interface it seems
+	return []byte{}, fmt.Errorf("database serialization of alerting ng Instance labels is not implemented")
+}
+
+// StringAndHash returns a the json representation of the labels as tuples
+// sorted by key. It also returns the a hash of that representation.
+func (il *InstanceLabels) StringAndHash() (string, string, error) {
+	tl := labelsToTupleLabels(*il)
+
+	b, err := json.Marshal(tl)
+	if err != nil {
+		return "", "", fmt.Errorf("can not gereate key for alert instance due to failure to encode labels: %w", err)
+	}
+
+	h := sha1.New()
+	if _, err := h.Write(b); err != nil {
+		return "", "", err
+	}
+
+	return string(b), fmt.Sprintf("%x", h.Sum(nil)), nil
+}
+
+// The following is based on SDK code, copied for now
+
+// tupleLables is an alternative representation of Labels (map[string]string) that can be sorted
+// and then marshalled into a consistent string that can be used a map key. All tupleLabel objects
+// in tupleLabels should have unique first elements (keys).
+type tupleLabels []tupleLabel
+
+// tupleLabel is an element of tupleLabels and should be in the form of [2]{"key", "value"}.
+type tupleLabel [2]string
+
+// Sort tupleLabels by each elements first property (key).
+func (t *tupleLabels) sortBtKey() {
+	if t == nil {
+		return
+	}
+	sort.Slice((*t)[:], func(i, j int) bool {
+		return (*t)[i][0] < (*t)[j][0]
+	})
+}
+
+// labelsToTupleLabels converts Labels (map[string]string) to tupleLabels.
+func labelsToTupleLabels(l InstanceLabels) tupleLabels {
+	if l == nil {
+		return nil
+	}
+	t := make(tupleLabels, 0, len(l))
+	for k, v := range l {
+		t = append(t, tupleLabel{k, v})
+	}
+	t.sortBtKey()
+	return t
+}
+
+// tupleLabelsToLabels converts tupleLabels to Labels (map[string]string), erroring if there are duplicate keys.
+func tupleLablesToLabels(tuples tupleLabels) (InstanceLabels, error) {
+	if tuples == nil {
+		return nil, nil
+	}
+	labels := make(map[string]string)
+	for _, tuple := range tuples {
+		if key, ok := labels[tuple[0]]; ok {
+			return nil, fmt.Errorf("duplicate key '%v' in lables: %v", key, tuples)
+		}
+		labels[tuple[0]] = tuple[1]
+	}
+	return labels, nil
+}