fix: correct offset for insertion after start

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - MPD Patch functionality with new `/patch_ttl` URL configuration
+- nowDate query parameter as an alternative to nowMS for MPD and patch
 
 ### Fixed
 

cmd/livesim2/app/handler_livesim.go

@@ -45,9 +45,18 @@ func (s *Server) livesimHandlerFunc(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	nowDate := q.Get("nowDate")
+	if nowDate != "" {
+		nowMS, err = getMSFromDate(nowDate)
+		if err != nil {
+			http.Error(w, "bad date query", http.StatusBadRequest)
+			return
+		}
+	}
+
 	publishTime := q.Get("publishTime")
 	if publishTime != "" {
-		nowMS, err = getMSFromPublishTime(publishTime)
+		nowMS, err = getMSFromDate(publishTime)
 		if err != nil {
 			http.Error(w, "bad publishTime query", http.StatusBadRequest)
 			return
@@ -155,10 +164,10 @@ func getNowMS(nowMSValue string) (nowMS int, err error) {
 	return int(time.Now().UnixMilli()), nil
 }
 
-// getMSFromPublishTime returns a nowMS value based on publishTime (+1ms).
+// getMSFromDate returns a nowMS value based on date (+1ms).
 // The extra millisecond is there to ensure that the corresponding manifest
 // can be generated
-func getMSFromPublishTime(publishTimeValue string) (nowMS int, err error) {
+func getMSFromDate(publishTimeValue string) (nowMS int, err error) {
 	t, err := time.Parse(time.RFC3339, publishTimeValue)
 	if err != nil {
 		return -1, err

cmd/livesim2/app/handler_patch.go

@@ -29,25 +29,23 @@ func (r *rec) Header() http.Header {
 
 // patchHandlerFunc returns an MPD patch
 func (s *Server) patchHandlerFunc(w http.ResponseWriter, r *http.Request) {
+	origQuery := r.URL.RawQuery
 	q := r.URL.Query()
 	publishTime := q.Get("publishTime")
 	if publishTime == "" {
 		slog.Warn("publishTime query is required, but not provided in patch request")
 		http.Error(w, "publishTime query is required", http.StatusBadRequest)
 	}
 	old := &rec{}
-	origPath := r.URL.Path
-	origQuery := r.URL.RawQuery
-
-	newPath := strings.Replace(origPath, ".mpp", ".mpd", 1)
-	newPath = strings.TrimPrefix(newPath, "/patch")
-	r.URL.Path = newPath
-	newQuery := removeQuery(origQuery, "nowMS")
-	r.URL.RawQuery = newQuery
+	oldQuery := removeQuery(origQuery, "nowMS")
+	oldQuery = removeQuery(oldQuery, "nowDate")
+	mpdPath := mpdPathFromPatchPath(r.URL.Path)
+	r.URL.Path = mpdPath
+	r.URL.RawQuery = oldQuery
 	s.livesimHandlerFunc(old, r)
 
 	new := &rec{}
-	newQuery = removeQuery(origQuery, "publishTime")
+	newQuery := removeQuery(origQuery, "publishTime")
 	r.URL.RawQuery = newQuery
 	s.livesimHandlerFunc(new, r)
 
@@ -73,6 +71,12 @@ func (s *Server) patchHandlerFunc(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusOK)
 }
 
+func mpdPathFromPatchPath(patchPath string) string {
+	mpdPath := strings.Replace(patchPath, ".mpp", ".mpd", 1)
+	//TODO. Handle a possible set prefix before patch
+	return strings.TrimPrefix(mpdPath, "/patch")
+}
+
 func removeQuery(query, key string) string {
 	q := strings.Split(query, "&")
 	for i, kv := range q {

cmd/livesim2/app/handler_patch_test.go

@@ -10,7 +10,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-var wantedPatch = `<?xml version="1.0" encoding="UTF-8"?>
+var wantedPatchSegTimelineTime = `<?xml version="1.0" encoding="UTF-8"?>
 <Patch xmlns="urn:mpeg:dash:schema:mpd-patch:2020" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd-patch:2020 DASH-MPD-PATCH.xsd" mpdId="base" originalPublishTime="2024-04-02T15:50:56Z" publishTime="2024-04-02T15:52:40Z">
   <replace sel="/MPD/@publishTime">2024-04-02T15:52:40Z</replace>
   <replace sel="/MPD/PatchLocation[1]">
@@ -27,6 +27,28 @@ var wantedPatch = `<?xml version="1.0" encoding="UTF-8"?>
 </Patch>
 `
 
+var wantedPatchSegTimelineNumberWithAddAtEnd = `<?xml version="1.0" encoding="UTF-8"?>
+<Patch xmlns="urn:mpeg:dash:schema:mpd-patch:2020" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd-patch:2020 DASH-MPD-PATCH.xsd" mpdId="base" originalPublishTime="2024-04-16T07:34:38Z" publishTime="2024-04-16T07:34:56Z">
+  <replace sel="/MPD/@publishTime">2024-04-16T07:34:56Z</replace>
+  <replace sel="/MPD/PatchLocation[1]">
+    <PatchLocation ttl="60">/patch/livesim2/patch_60/segtimelinenr_1/testpic_2s/Manifest.mpp?publishTime=2024-04-16T07%3A34%3A56Z</PatchLocation>
+  </replace>
+  <replace sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;1&apos;]/SegmentTemplate/@startNumber">856626417</replace>
+  <remove sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;1&apos;]/SegmentTemplate/SegmentTimeline/S[1]"/>
+  <add sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;1&apos;]/SegmentTemplate/SegmentTimeline" pos="prepend">
+    <S t="82236136032256" d="96256" r="1"/>
+  </add>
+  <add sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;1&apos;]/SegmentTemplate/SegmentTimeline/S[15]" pos="after">
+    <S d="95232"/>
+  </add>
+  <replace sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;2&apos;]/SegmentTemplate/@startNumber">856626417</replace>
+  <remove sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;2&apos;]/SegmentTemplate/SegmentTimeline/S[1]"/>
+  <add sel="/MPD/Period[@id=&apos;P0&apos;]/AdaptationSet[@id=&apos;2&apos;]/SegmentTemplate/SegmentTimeline" pos="prepend">
+    <S t="154192755060000" d="180000" r="30"/>
+  </add>
+</Patch>
+`
+
 func TestPatchHandler(t *testing.T) {
 	cfg := ServerConfig{
 		VodRoot:   "testdata/assets",
@@ -51,7 +73,14 @@ func TestPatchHandler(t *testing.T) {
 			url:               "/patch/livesim2/patch_60/segtimeline_1/testpic_2s/Manifest.mpp?publishTime=2024-04-02T15:50:56Z&nowMS=1712073160000",
 			wantedStatusCode:  http.StatusOK,
 			wantedContentType: "application/dash-patch+xml",
-			wantedBody:        wantedPatch,
+			wantedBody:        wantedPatchSegTimelineTime,
+		},
+		{
+			desc:              "segTimeline",
+			url:               "/patch/livesim2/patch_60/segtimelinenr_1/testpic_2s/Manifest.mpp?publishTime=2024-04-16T07:34:38Z&nowDate=2024-04-16T07:34:56Z",
+			wantedStatusCode:  http.StatusOK,
+			wantedContentType: "application/dash-patch+xml",
+			wantedBody:        wantedPatchSegTimelineNumberWithAddAtEnd,
 		},
 	}
 

pkg/patch/patch.go

@@ -266,7 +266,7 @@ func addLeafListChanges(patchRoot, old, new *etree.Element, elemPath string) err
 					e.CreateAttr("pos", "prepend")
 					e.AddChild(newElem.Copy())
 				} else {
-					addr := calcAddr(newElem, newPos)
+					addr := calcAddr(newElem, newPos-1)
 					e.CreateAttr("sel", fmt.Sprintf("%s/%s", elemPath, addr))
 					e.CreateAttr("pos", "after")
 					e.AddChild(newElem.Copy())