1 files changed, 76 insertions, 8 deletions
diff --git a/official_climb/matcher.go b/official_climb/matcher.go
index faf51a7..00f7e9b 100644
--- a/official_climb/matcher.go
+++ b/official_climb/matcher.go
@@ -20,16 +20,84 @@ type MatchedClimb struct {
 // coordinates: both the start and end coordinates must be within radiusM of a
 // route point, and the matched start point must precede the matched end point.
 func MatchClimb(route []geodist.Coord, official OfficialClimb, radiusM float64) (MatchedClimb, bool) {
-	if math.IsNaN(radiusM) || math.IsInf(radiusM, 0) || radiusM <= 0 {
+	matches := MatchClimbs(route, official, radiusM)
+	if len(matches) == 0 {
 		return MatchedClimb{}, false
 	}
-	startIndex, startDistance := geo.Nearest(route, official.StartCoord)
-	endIndex, endDistance := geo.Nearest(route, official.EndCoord)
-	if startDistance > radiusM || endDistance > radiusM {
-		return MatchedClimb{}, false
+	return matches[0], true
+}
+
+// MatchClimbs returns all non-overlapping occurrences of an official climb on
+// a route. Each occurrence is defined by a start and end point both within
+// radiusM, with start strictly before end and direction preserved. Loops are
+// handled by clustering contiguous approaches into single candidates and pairing
+// each start cluster with the first end cluster inside its lap window.
+func MatchClimbs(route []geodist.Coord, official OfficialClimb, radiusM float64) []MatchedClimb {
+	if math.IsNaN(radiusM) || math.IsInf(radiusM, 0) || radiusM <= 0 {
+		return nil
 	}
-	if startIndex >= endIndex {
-		return MatchedClimb{}, false
+	if len(route) == 0 {
+		return nil
+	}
+	startClusters := clustersInRadius(route, official.StartCoord, radiusM)
+	endClusters := clustersInRadius(route, official.EndCoord, radiusM)
+	if len(startClusters) == 0 || len(endClusters) == 0 {
+		return nil
+	}
+	matches := make([]MatchedClimb, 0)
+	for i, start := range startClusters {
+		nextStartIdx := len(route)
+		if i+1 < len(startClusters) {
+			nextStartIdx = startClusters[i+1].Index
+		}
+		var matchedEnd *clusterCandidate
+		for j := range endClusters {
+			end := &endClusters[j]
+			if end.Index > start.Index && end.Index < nextStartIdx {
+				matchedEnd = end
+				break
+			}
+		}
+		if matchedEnd == nil {
+			continue
+		}
+		matches = append(matches, MatchedClimb{
+			OfficialClimb: official,
+			StartIndex:    start.Index,
+			EndIndex:      matchedEnd.Index,
+		})
+	}
+	return matches
+}
+
+type clusterCandidate struct {
+	Index    int
+	Distance float64
+}
+
+func clustersInRadius(route []geodist.Coord, target geodist.Coord, radiusM float64) []clusterCandidate {
+	candidates := make([]clusterCandidate, 0)
+	inCluster := false
+	bestIndex := 0
+	bestDistance := 0.0
+	for idx, coord := range route {
+		dist := geo.DistanceM(coord, target)
+		if dist <= radiusM {
+			if !inCluster {
+				inCluster = true
+				bestIndex = idx
+				bestDistance = dist
+			} else if dist < bestDistance {
+				bestIndex = idx
+				bestDistance = dist
+			}
+		} else if inCluster {
+			candidates = append(candidates, clusterCandidate{Index: bestIndex, Distance: bestDistance})
+			inCluster = false
+		}
+	}
+	if inCluster {
+		candidates = append(candidates, clusterCandidate{Index: bestIndex, Distance: bestDistance})
 	}
-	return MatchedClimb{OfficialClimb: official, StartIndex: startIndex, EndIndex: endIndex}, true
+	return candidates
 }