1 files changed, 146 insertions, 0 deletions
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..5a2edc6
--- /dev/null
+++ b/main.go
@@ -0,0 +1,146 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"slices"
+
+	"github.com/olekukonko/tablewriter"
+	"github.com/tkrajina/gpxgo/gpx"
+)
+
+func Score(points []gpx.GPXPoint) float64 {
+	distance := Distance(points)
+	if distance == 0 {
+		return 0
+	}
+	// TODO: Expect NullableFloat64
+	slope := (points[len(points)-1].Elevation.Value() - points[0].Elevation.Value()) / distance * 100.0
+
+	return math.Abs(slope) * slope * distance / 1000.0
+}
+
+func Category(score float64) string {
+	switch {
+	case score < 35:
+		return "NO"
+	case score < 80:
+		return "Cat 4"
+	case score < 180:
+		return "Cat 3"
+	case score < 250:
+		return "Cat 2"
+	case score < 600:
+		return "Cat 1"
+	default:
+		return "HC"
+	}
+}
+
+type Climb struct {
+	start int
+	end   int
+}
+
+func (c Climb) Score(points []gpx.GPXPoint) float64 {
+	return Score(points[c.start:c.end])
+}
+
+func BestUpHill(points []gpx.GPXPoint, start int, end int) Climb {
+	bestScore := Score(points[start:end])
+	bestStart := start
+	for i := start; i < end; i++ {
+		score := Score(points[i:end])
+		if score > bestScore {
+			bestStart = i
+			bestScore = score
+		}
+	}
+	bestEnd := end
+	for i := bestStart; i < end; i++ {
+		score := Score(points[bestStart:i])
+		if score > bestScore {
+			bestEnd = i
+			bestScore = score
+		}
+	}
+	return Climb{bestStart, bestEnd}
+}
+
+func BestDownHill(points []gpx.GPXPoint, start int, end int) Climb {
+	bestScore := Score(points[start:end])
+	bestStart := start
+	for i := start; i < end; i++ {
+		score := Score(points[i:end])
+		if score < bestScore {
+			bestStart = i
+			bestScore = score
+		}
+	}
+	bestEnd := end
+	for i := bestStart; i < end; i++ {
+		score := Score(points[bestStart:i])
+		if score < bestScore {
+			bestEnd = i
+			bestScore = score
+		}
+	}
+	return Climb{bestStart, bestEnd}
+}
+
+func Distance(points []gpx.GPXPoint) float64 {
+	distance := 0.0
+	for i, point := range points {
+		if i > 0 {
+			distance += point.Distance2D(&points[i-1])
+		}
+	}
+	return distance
+}
+
+func FindAllClimbs(points []gpx.GPXPoint, start int, end int) []Climb {
+	from := Distance(points[:start])
+	to := from + Distance(points[start:end])
+	fmt.Printf("Searching climbs between %.1fkm and %.1fkm (%d-%d)\n", from/1000, to/1000, start, end)
+	climb := BestUpHill(points, start, end)
+	descent := BestDownHill(points, start, end)
+	climbs := []Climb{}
+
+	if climb.Score(points) < 35 {
+		if descent.Score(points) < -35 {
+			if descent.start > start {
+				climbs = append(climbs, FindAllClimbs(points, start, descent.start)...)
+			}
+			if end > descent.end {
+				climbs = append(climbs, FindAllClimbs(points, descent.end, end)...)
+			}
+		}
+	} else {
+		climbs = append(climbs, climb)
+		if climb.start > start {
+			climbs = append(climbs, FindAllClimbs(points, start, climb.start)...)
+		}
+		if end > climb.end {
+			climbs = append(climbs, FindAllClimbs(points, climb.end, end)...)
+		}
+	}
+
+	return climbs
+}
+
+func main() {
+	example, err := gpx.ParseFile("examples/2022-07-21.Pogacar.gpx")
+	if err != nil {
+		panic(err)
+	}
+	segment := example.Tracks[0].Segments[0]
+	climbs := FindAllClimbs(segment.Points, 0, len(segment.Points)-1)
+	slices.SortFunc(climbs, func(i, j Climb) int { return i.start - j.start })
+	table := tablewriter.NewWriter(os.Stdout)
+	table.SetHeader([]string{"Score", "Distance", "Category", "Slope", "From", "To"})
+	for _, climb := range climbs {
+		table.Append([]string{fmt.Sprintf("%d", int(climb.Score(segment.Points))), fmt.Sprintf("%.1fkm", Distance(segment.Points[climb.start:climb.end])/1000), Category(climb.Score(segment.Points)), fmt.Sprintf("%.1f%%", (segment.Points[climb.end].Elevation.Value()-segment.Points[climb.start].Elevation.Value())/Distance(segment.Points[climb.start:climb.end])*100), fmt.Sprintf("%.1fkm", Distance(segment.Points[:climb.start])/1000), fmt.Sprintf("%.1fkm", Distance(segment.Points[:climb.end])/1000)})
+	}
+	table.Render()
+}