From 11689ed8424cdd6d4c47b3e6f8e07177ab98665b Mon Sep 17 00:00:00 2001
From: DanB <danb@cgrates.org>
Date: Fri, 21 Sep 2018 21:05:24 +0200
Subject: [PATCH] Diameter data provider with support for group filters

---
 agents/libdmt.go      | 43 +++++++++++++++++++++++++++++++++++++++++--
 agents/libdmt_test.go | 21 +++++++++++++++++++--
 config/rsrparser.go   |  5 +++++
 3 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/agents/libdmt.go b/agents/libdmt.go
index 7e074f49f..1e499f112 100644
--- a/agents/libdmt.go
+++ b/agents/libdmt.go
@@ -151,14 +151,53 @@ func (dP *diameterDP) FieldAsInterface(fldPath []string) (data interface{}, err
 		return nil, err
 	}
 	err = nil // cancel previous err
+	// lastPath can contain selector inside
+	lastPath := fldPath[len(fldPath)-1]
+	var slctr *config.RSRParser
+	if splt := strings.Split(lastPath, "["); len(splt) != 1 {
+		lastPath = splt[0]
+		if splt[1][len(splt[1])-1:] != "]" {
+			return nil, fmt.Errorf("filter rule <%s> needs to end in ]", splt[1])
+		}
+		fltrStr := splt[1][:len(splt[1])-1] // also strip the last ]
+		if slctr, err = config.NewRSRParser(fltrStr, true); err != nil {
+			return nil, err
+		}
+	}
+	pathIface := utils.SliceStringToIface(fldPath)
+	if slctr != nil { // last path was having selector inside before
+		pathIface[len(pathIface)-1] = lastPath
+	}
 	var avps []*diam.AVP
 	if avps, err = dP.m.FindAVPsWithPath(
-		utils.SliceStringToIface(fldPath), dict.UndefinedVendorID); err != nil {
+		pathIface, dict.UndefinedVendorID); err != nil {
 		return nil, err
 	} else if len(avps) == 0 {
 		return nil, utils.ErrNotFound
 	}
-	if data, err = diamAVPAsIface(avps[0]); err != nil {
+	slectedIdx := 0 // by default we select AVP[0]
+	if len(avps) != 1 && slctr != nil {
+		pathIface[len(pathIface)-1] = slctr.AttrName() // search for AVPs which are having common path but different end element
+		fltrAVPs, err := dP.m.FindAVPsWithPath(pathIface, dict.UndefinedVendorID)
+		if err != nil {
+			return nil, err
+		} else if len(fltrAVPs) == 0 || len(fltrAVPs) != len(avps) {
+			return nil, utils.ErrFilterNotPassingNoCaps
+		}
+		for k, fAVP := range fltrAVPs {
+			if dataAVP, err := diamAVPAsIface(fAVP); err != nil {
+				return nil, err
+			} else if _, err := slctr.ParseValue(dataAVP); err != nil { // filter not passing
+				if err != utils.ErrFilterNotPassingNoCaps {
+					return nil, err
+				}
+				continue // filter not passing, not really error
+			} else {
+				slectedIdx = k // filter passing, found our match, select the index of AVP to return
+			}
+		}
+	}
+	if data, err = diamAVPAsIface(avps[slectedIdx]); err != nil {
 		return nil, err
 	}
 	dP.cache.Set(fldPath, data, false)
diff --git a/agents/libdmt_test.go b/agents/libdmt_test.go
index 32cd025a9..830064e84 100644
--- a/agents/libdmt_test.go
+++ b/agents/libdmt_test.go
@@ -44,6 +44,17 @@ func TestDPFieldAsInterface(t *testing.T) {
 			}),
 		},
 	})
+	m.NewAVP("Subscription-Id", avp.Mbit, 0, &diam.GroupedAVP{
+		AVP: []*diam.AVP{
+			diam.NewAVP(450, avp.Mbit, 0, datatype.Enumerated(0)),             // Subscription-Id-Type
+			diam.NewAVP(444, avp.Mbit, 0, datatype.UTF8String("33708000003")), // Subscription-Id-Data
+		}})
+	m.NewAVP("Subscription-Id", avp.Mbit, 0, &diam.GroupedAVP{
+		AVP: []*diam.AVP{
+			diam.NewAVP(450, avp.Mbit, 0, datatype.Enumerated(1)),              // Subscription-Id-Type
+			diam.NewAVP(444, avp.Mbit, 0, datatype.UTF8String("208708000003")), // Subscription-Id-Data
+		}})
+
 	dP := newDADataProvider(m)
 	eOut := interface{}("simuhuawei;1449573472;00002")
 	if out, err := dP.FieldAsInterface([]string{"Session-Id"}); err != nil {
@@ -57,8 +68,14 @@ func TestDPFieldAsInterface(t *testing.T) {
 	} else if eOut != out {
 		t.Errorf("Expecting: %v, received: %v", eOut, out)
 	}
-	eOut = interface{}(uint32(33))
-	if out, err := dP.FieldAsInterface([]string{"Requested-Service-Unit", "CC-Money", "Currency-Code"}); err != nil {
+	eOut = interface{}("208708000003") // with filter on second group item
+	if out, err := dP.FieldAsInterface([]string{"Subscription-Id", "Subscription-Id-Data[~Subscription-Id-Type(1)]"}); err != nil {
+		t.Error(err)
+	} else if eOut != out {
+		t.Errorf("Expecting: %v, received: %v", eOut, out)
+	}
+	eOut = interface{}("33708000003")
+	if out, err := dP.FieldAsInterface([]string{"Subscription-Id", "Subscription-Id-Data"}); err != nil {
 		t.Error(err)
 	} else if eOut != out {
 		t.Errorf("Expecting: %v, received: %v", eOut, out)
diff --git a/config/rsrparser.go b/config/rsrparser.go
index 4892224cf..175aca5c0 100644
--- a/config/rsrparser.go
+++ b/config/rsrparser.go
@@ -207,6 +207,11 @@ type RSRParser struct {
 	filters    utils.RSRFilters         // The value to compare when used as filter
 }
 
+// AttrName exports the attribute name of the RSRParser
+func (prsr *RSRParser) AttrName() string {
+	return prsr.attrName
+}
+
 // Compile parses Rules string and repopulates other fields
 func (prsr *RSRParser) Compile() (err error) {
 	var newPrsr *RSRParser