1 files changed, 155 insertions, 0 deletions
diff --git a/graph.go b/graph.go
new file mode 100644
index 0000000..955abbd
--- /dev/null
+++ b/graph.go
@@ -0,0 +1,155 @@
+package bookpipeline
+
+import (
+	"fmt"
+	"io"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-chart/drawing"
+)
+
+const maxticks = 40
+const goodCutoff = 70
+const mediumCutoff = 65
+const badCutoff = 60
+
+type Conf struct {
+	Path, Code string
+	Conf       float64
+}
+
+type GraphConf struct {
+	Pgnum, Conf float64
+}
+
+func createLine(xvalues []float64, y float64, c drawing.Color) chart.ContinuousSeries {
+	var yvalues []float64
+	for range xvalues {
+		yvalues = append(yvalues, y)
+	}
+	return chart.ContinuousSeries{
+		XValues: xvalues,
+		YValues: yvalues,
+		Style: chart.Style{
+			StrokeColor: c,
+		},
+	}
+}
+
+func Graph(confs map[string]*Conf, bookname string, w io.Writer) error {
+	// Organise confs to sort them by page
+	var graphconf []GraphConf
+	for _, conf := range confs {
+		name := filepath.Base(conf.Path)
+		var numend int
+		numend = strings.Index(name, "_")
+		if numend == -1 {
+			numend = strings.Index(name, ".")
+		}
+		pgnum, err := strconv.ParseFloat(name[0:numend], 64)
+		if err != nil {
+			continue
+		}
+		var c GraphConf
+		c.Pgnum = pgnum
+		c.Conf = conf.Conf
+		graphconf = append(graphconf, c)
+	}
+	sort.Slice(graphconf, func(i, j int) bool { return graphconf[i].Pgnum < graphconf[j].Pgnum })
+
+	// Create main xvalues and yvalues, annotations and ticks
+	var xvalues, yvalues []float64
+	var annotations []chart.Value2
+	var ticks []chart.Tick
+	tickevery := len(graphconf) / maxticks
+	if tickevery < 1 {
+		tickevery = 1
+	}
+	for i, c := range graphconf {
+		xvalues = append(xvalues, c.Pgnum)
+		yvalues = append(yvalues, c.Conf)
+		if c.Conf < goodCutoff {
+			annotations = append(annotations, chart.Value2{Label: fmt.Sprintf("%.0f", c.Pgnum), XValue: c.Pgnum, YValue: c.Conf})
+		}
+		if i%tickevery == 0 {
+			ticks = append(ticks, chart.Tick{c.Pgnum, fmt.Sprintf("%.0f", c.Pgnum)})
+		}
+	}
+	// make last tick the final page
+	final := graphconf[len(graphconf)-1]
+	ticks[len(ticks)-1] = chart.Tick{final.Pgnum, fmt.Sprintf("%.0f", final.Pgnum)}
+	mainSeries := chart.ContinuousSeries{
+		XValues: xvalues,
+		YValues: yvalues,
+	}
+
+	// Create lines
+	goodCutoffSeries := createLine(xvalues, goodCutoff, chart.ColorAlternateGreen)
+	mediumCutoffSeries := createLine(xvalues, mediumCutoff, chart.ColorOrange)
+	badCutoffSeries := createLine(xvalues, badCutoff, chart.ColorRed)
+
+	// Create lines marking top and bottom 10% confidence
+	sort.Slice(graphconf, func(i, j int) bool { return graphconf[i].Conf < graphconf[j].Conf })
+	lowconf := graphconf[int(len(graphconf)/10)].Conf
+	highconf := graphconf[int((len(graphconf)/10)*9)].Conf
+	yvalues = []float64{}
+	for range graphconf {
+		yvalues = append(yvalues, lowconf)
+	}
+	minSeries := &chart.ContinuousSeries{
+		Style: chart.Style{
+			StrokeColor:     chart.ColorAlternateGray,
+			StrokeDashArray: []float64{5.0, 5.0},
+		},
+		XValues: xvalues,
+		YValues: yvalues,
+	}
+	yvalues = []float64{}
+	for _ = range graphconf {
+		yvalues = append(yvalues, highconf)
+	}
+	maxSeries := &chart.ContinuousSeries{
+		Style: chart.Style{
+			StrokeColor:     chart.ColorAlternateGray,
+			StrokeDashArray: []float64{5.0, 5.0},
+		},
+		XValues: xvalues,
+		YValues: yvalues,
+	}
+
+	graph := chart.Chart{
+		Title:      bookname,
+		Width:      3840,
+		Height:     2160,
+		XAxis: chart.XAxis{
+			Name:      "Page number",
+			Range: &chart.ContinuousRange{
+				Min: 0.0,
+			},
+			Ticks: ticks,
+		},
+		YAxis: chart.YAxis{
+			Name:      "Confidence",
+			Range: &chart.ContinuousRange{
+				Min: 0.0,
+				Max: 100.0,
+			},
+		},
+		Series: []chart.Series{
+			mainSeries,
+			minSeries,
+			maxSeries,
+			goodCutoffSeries,
+			mediumCutoffSeries,
+			badCutoffSeries,
+			chart.AnnotationSeries{
+				Annotations: annotations,
+			},
+		},
+	}
+	return graph.Render(chart.PNG, w)
+}