Improve input handling and add option to start http.Server to show the result

2 files changed, 106 insertions, 60 deletions

diff --git a/challenge-165/pokgopun/go/ch-1.go b/challenge-165/pokgopun/go/ch-1.go
index cace8187e2..d8caec8cf2 100644
--- a/challenge-165/pokgopun/go/ch-1.go
+++ b/challenge-165/pokgopun/go/ch-1.go
@@ -3,28 +3,37 @@
 
 go run ch-1.go
 
-Enter 'x1,y1' for a point or 'x1,y1,x2,y2' for a line, or '0' to end this
+Enter 'x1,y1' for a point or 'x1,y1,x2,y2' for a line, or 'done' when done
 53,10
 53,10,23,30
 23,30
-0
+done
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
 <svg height="60.000000" width="106.000000" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
 	<g id="lines" stroke="#369" stroke-width="4"><line x1="53.000000" x2="23.000000" y1="10.000000" y2="30.000000" /></g><g fill="#f73" id="points"><circle cx="53.000000" cy="10.000000" r="3" /><circle cx="23.000000" cy="30.000000" r="3" /></g></svg>
 
-### Pass points and line data via STDIN and output to file ch-1.svg:
+### Pass point and line data via STDIN and output to file ch-1.svg:
+
+echo -e "53,10\n53,10,23,30\n23,30" | go run ch-1.go ch-1.svg
+
+### Pass point and line data via STDIN and start http.Server at localhost:8080 to show the result:
+
+go run ch-2.go | go run ch-1.go :8080
 
-echo -e "53,10\n53,10,23,30\n23,30\n0" | go run ch-1.go ch-1.svg
 */
 package main
 
 import (
 	"bufio"
+	"bytes"
 	"fmt"
 	"io"
 	"log"
+	"net/http"
 	"os"
+	"regexp"
+	"time"
 )
 
 type point struct{ x, y float64 }
@@ -54,54 +63,89 @@ func (svg *Svg) updateHW() {
 	}
 }
 
-func (svg *Svg) input() {
-	var x1, y1, x2, y2 float64
-	guide := "Enter 'x1,y1' for a point or 'x1,y1,x2,y2' for a line, or '0' to end this"
-	//fmt.Println(guide)
-	for {
-		n, err := fmt.Scanf("%f,%f,%f,%f\n", &x1, &y1, &x2, &y2)
-		//fmt.Println("n =>", n, "err =>", err)
-		switch n {
-		case 2:
-			svg.points = append(svg.points, point{x1, y1})
-		case 4:
-			svg.lines = append(svg.lines, line{point{x1, y1}, point{x2, y2}})
-		default:
-			if err == io.EOF || n == 1 && x1 == 0 {
-				goto done
+func (svg *Svg) input(r io.Reader) {
+	var (
+		x1, y1, x2, y2 float64
+		text           string
+	)
+	guide := "Enter 'x1,y1' for a point or 'x1,y1,x2,y2' for a line, or 'done' when done"
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		text = scanner.Text()
+		if text == "done" {
+			break
+		} else {
+			n, err := fmt.Sscanf(text, "%f,%f,%f,%f\n", &x1, &y1, &x2, &y2)
+			if err != nil {
+				_, err := fmt.Sscanf(text, "%f,%f\n", &x1, &y1)
+				if err != nil {
+					fmt.Fprintln(os.Stderr, guide)
+					continue
+				}
+			}
+			if n == 4 {
+				svg.lines = append(svg.lines, line{point{x1, y1}, point{x2, y2}})
+			} else {
+				svg.points = append(svg.points, point{x1, y1})
 			}
-			fmt.Fprintln(os.Stderr, guide)
-			continue
 		}
-		//fmt.Println("svg =>", svg)
 	}
-done:
+	svg.updateHW()
 }
-func main() {
-	w := bufio.NewWriter(os.Stdout)
-	if len(os.Args) > 1 {
-		f, err := os.Create(os.Args[1])
-		if err != nil {
-			log.Fatal(err)
-		}
-		defer f.Close()
-		w = bufio.NewWriter(f)
-	}
-	var data Svg
-	data.input()
-	data.updateHW()
-	//fmt.Println(data.height, data.width)
-	fmt.Fprintf(w, `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+func (svg Svg) output(w io.Writer) {
+	bw := bufio.NewWriter(w)
+	fmt.Fprintf(bw, `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
 <svg height="%f" width="%f" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
-	<g id="lines" stroke="#369" stroke-width="4">`, data.height*2, data.width*2)
-	for _, l := range data.lines {
-		fmt.Fprintf(w, `<line x1="%f" x2="%f" y1="%f" y2="%f" />`, l.start.x, l.end.x, l.start.y, l.end.y)
+	<g id="lines" stroke="#369" stroke-width="4">`, svg.height*2, svg.width*2)
+	for _, l := range svg.lines {
+		fmt.Fprintf(bw, `<line x1="%f" x2="%f" y1="%f" y2="%f" />`, l.start.x, l.end.x, l.start.y, l.end.y)
 	}
-	w.WriteString(`</g><g fill="#f73" id="points">`)
-	for _, p := range data.points {
-		fmt.Fprintf(w, `<circle cx="%f" cy="%f" r="3" />`, p.x, p.y)
+	bw.WriteString(`</g><g fill="#f73" id="points">`)
+	for _, p := range svg.points {
+		fmt.Fprintf(bw, `<circle cx="%f" cy="%f" r="3" />`, p.x, p.y)
 	}
-	w.WriteString(`</g></svg>`)
-	w.Flush()
+	bw.WriteString(`</g></svg>`)
+	bw.Flush()
+}
+
+func (svg Svg) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	buf := bytes.NewBuffer([]byte{})
+	svg.output(buf)
+	w.Write(buf.Bytes())
+	//w.Write([]byte(fmt.Sprint(time.Now())))
+}
+
+func main() {
+	var data Svg
+	data.input(os.Stdin)
+	if len(os.Args) > 1 {
+		out := os.Args[1]
+		if regexp.MustCompile(`^:\d+$`).MatchString(out) {
+			s := http.Server{
+				Addr:         out,
+				ReadTimeout:  30 * time.Second,
+				WriteTimeout: 90 * time.Second,
+				IdleTimeout:  120 * time.Second,
+				Handler:      data,
+			}
+			fmt.Printf("Start http.Server at localhost%s to show the result\n", out)
+			err := s.ListenAndServe()
+			if err != nil {
+				if err != http.ErrServerClosed {
+					panic(err)
+				}
+			}
+		} else {
+			w, err := os.Create(out)
+			if err != nil {
+				log.Fatal(err)
+			}
+			defer w.Close()
+			data.output(w)
+		}
+	} else {
+		data.output(os.Stdout)
+	}
+
 }
diff --git a/challenge-165/pokgopun/go/ch-2.go b/challenge-165/pokgopun/go/ch-2.go
index a3d0d9c451..93c868bc33 100644
--- a/challenge-165/pokgopun/go/ch-2.go
+++ b/challenge-165/pokgopun/go/ch-2.go
@@ -1,8 +1,12 @@
 /*
-### To pipe output to ch1.go to create svg file
+### Pass output to ch-1.go to create svg file
 
 go run ch-2.go | go run ch-1.go ch-2.svg
 
+### Pass output to ch-1.go and start http.Server at localhost:8080 to show the result:
+
+go run ch-2.go | go run ch-1.go :8080
+
 */
 package main
 
@@ -11,7 +15,7 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"regexp"
+	"strings"
 )
 
 func main() {
@@ -24,18 +28,24 @@ func main() {
 			215,136 153,137 390,104 100,180  76,188  77,181  69,195  92,186
 			275,96  250,147  34,174 213,134 186,129 189,154 361,82  363,89`
 	/**/
-	var ds struct{ count, x, y, sumx, sumy, sumxx, sumxy, m, b, x1, x2, y1, y2 float64 }
+	var ds struct {
+		count, x, y, sumx, sumy, sumxx, sumxy, m, b, x1, x2, y1, y2 float64
+		xy                                                          string
+	}
 	_, err := fmt.Sscanf(rawin, "%f,%f %f,%f", &ds.x1, &ds.y1, &ds.x2, &ds.y2)
 	if err != nil {
 		log.Fatal(err)
 	}
 	w := bufio.NewWriter(os.Stdout)
-	for _, v := range regexp.MustCompile(`\d+,\d+`).FindAllString(rawin, -1) {
-		_, err := fmt.Sscanf(v, "%f,%f", &ds.x, &ds.y)
+	scanner := bufio.NewScanner(strings.NewReader(rawin))
+	scanner.Split(bufio.ScanWords)
+	for scanner.Scan() {
+		ds.xy = scanner.Text()
+		_, err := fmt.Sscanf(ds.xy, "%f,%f", &ds.x, &ds.y)
 		if err != nil {
 			log.Fatal(err)
 		}
-		fmt.Fprintln(w, v)
+		fmt.Fprintln(w, ds.xy)
 		ds.count++
 		ds.sumx += ds.x
 		ds.sumy += ds.y
@@ -47,14 +57,6 @@ func main() {
 		if ds.x2 < ds.x {
 			ds.x2 = ds.x
 		}
-		/*
-			if ds.y1 > ds.y {
-				ds.y1 = ds.y
-			}
-			if ds.y2 < ds.y {
-				ds.y2 = ds.y
-			}
-		*/
 	}
 	ds.m = (ds.count*ds.sumxy - ds.sumx*ds.sumy) / (ds.count*ds.sumxx - ds.sumx*ds.sumx)
 	ds.b = (ds.sumy - ds.m*ds.sumx) / ds.count