Fix up the summary to log as a table

main.go

@@ -8,7 +8,9 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"regexp"
 	"runtime/debug"
+	"strings"
 	"sync/atomic"
 
 	utils "git.site.quack-lab.dev/dave/cyutils"
@@ -185,14 +187,77 @@ func processInstructions(instructions chan *LinkInstruction) int32 {
 }
 
 func printSummary(fs FileSystem) {
-	lines := fs.SummaryLines()
-	if len(lines) == 0 {
+	records := fs.SummaryRecords()
+	if len(records) == 0 {
 		return
 	}
+
+	header := []string{"RESULT", "OPERATION", "SOURCE", "TARGET", "DETAIL"}
+	widths := make([]int, len(header))
+	for i, h := range header {
+		widths[i] = len(h)
+	}
+
+	type row struct {
+		values []string
+		err    error
+	}
+	rows := make([]row, len(records))
+
+	for i, record := range records {
+		values := []string{
+			record.resultLabel(),
+			record.kindLabel(),
+			FormatSourcePath(record.source),
+			FormatTargetPath(record.target),
+			record.detail(),
+		}
+		rows[i] = row{values: values, err: record.err}
+
+		for j, val := range values {
+			if l := visibleLength(val); l > widths[j] {
+				widths[j] = l
+			}
+		}
+	}
+
 	LogInfo("Summary:")
-	for _, line := range lines {
+	var lineBuilder strings.Builder
+
+	writeSummaryRow(&lineBuilder, header, widths)
+	for _, line := range strings.Split(strings.TrimRight(lineBuilder.String(), "\n"), "\n") {
 		LogInfo("%s", line)
 	}
+
+	for _, r := range rows {
+		lineBuilder.Reset()
+		writeSummaryRow(&lineBuilder, r.values, widths)
+		line := strings.TrimRight(lineBuilder.String(), "\n")
+		LogInfo("%s", line)
+	}
+}
+
+func writeSummaryRow(b *strings.Builder, cols []string, widths []int) {
+	for i, val := range cols {
+		if val == "" {
+			val = "-"
+		}
+		b.WriteString(val)
+		pad := widths[i] - visibleLength(val)
+		if pad < 0 {
+			pad = 0
+		}
+		if i < len(cols)-1 {
+			b.WriteString(strings.Repeat(" ", pad+2))
+		}
+	}
+	b.WriteByte('\n')
+}
+
+var ansiRegexp = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+
+func visibleLength(s string) int {
+	return len(ansiRegexp.ReplaceAllString(s, ""))
 }
 
 func IsPipeInput() bool {