package main
import (
"bytes"
"flag"
"fmt"
"image/png"
"io"
"log"
"net/http"
"regexp"
"strings"
"github.com/davecgh/go-spew/spew"
"github.com/stapelberg/qrbill"
_ "net/http/pprof"
)
func ifEmpty(s, alternative string) string {
if s == "" {
return alternative
}
return s
}
func qrchFromRequest(r *http.Request) *qrbill.QRCH {
return &qrbill.QRCH{
CdtrInf: qrbill.QRCHCdtrInf{
IBAN: ifEmpty(r.FormValue("criban"), "CH0209000000870913543"),
Cdtr: qrbill.Address{
AdrTp: qrbill.AddressTypeStructured,
Name: ifEmpty(r.FormValue("crname"), "Legalize it!"),
StrtNmOrAdrLine1: ifEmpty(r.FormValue("craddr1"), "Quellenstrasse 25"),
BldgNbOrAdrLine2: ifEmpty(r.FormValue("craddr2"), ""),
PstCd: ifEmpty(r.FormValue("crpost"), "8005"),
TwnNm: ifEmpty(r.FormValue("crcity"), "Zürich"),
Ctry: ifEmpty(r.FormValue("crcountry"), "CH"),
},
},
CcyAmt: qrbill.QRCHCcyAmt{
Amt: "",
Ccy: "CHF",
},
UltmtDbtr: qrbill.Address{
AdrTp: qrbill.AddressTypeStructured,
Name: ifEmpty(r.FormValue("udname"), "Michael Stapelberg"),
StrtNmOrAdrLine1: ifEmpty(r.FormValue("udaddr1"), "Brahmsstrasse 21"),
BldgNbOrAdrLine2: ifEmpty(r.FormValue("udaddr2"), ""),
PstCd: ifEmpty(r.FormValue("udpost"), "8003"),
TwnNm: ifEmpty(r.FormValue("udcity"), "Zürich"),
Ctry: ifEmpty(r.FormValue("udcountry"), "CH"),
},
RmtInf: qrbill.QRCHRmtInf{
Tp: "NON", // Reference type
Ref: "", // Reference
AddInf: qrbill.QRCHRmtInfAddInf{
Ustrd: ifEmpty(r.FormValue("message"), "Spende 6141"),
},
},
}
}
var fieldNameRe = regexp.MustCompile(`
( )*([^:]+):`)
var stringLiteralRe = regexp.MustCompile(`"([^"]*)"`)
func qrHandler(format string) http.Handler {
if format != "png" &&
format != "svg" &&
format != "txt" &&
format != "html" {
log.Fatalf("BUG: format must be either png, svg, txt or html")
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
prefix := "[" + r.RemoteAddr + "]"
log.Printf("%s handling request for %s", prefix, r.URL.Path)
defer log.Printf("%s done: %s", prefix, r.URL.Path)
qrch := qrchFromRequest(r)
bill, err := qrch.Encode()
if err != nil {
log.Print(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
var b []byte
switch format {
case "png":
code, err := bill.EncodeToImage()
if err != nil {
log.Print(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
var buf bytes.Buffer
if err := png.Encode(&buf, code); err != nil {
log.Print(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
b = buf.Bytes()
w.Header().Add("Content-Type", "image/png")
case "svg":
var err error
b, err = bill.EncodeToSVG()
if err != nil {
log.Print(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Add("Content-Type", "image/svg+xml")
case "txt":
w.Header().Add("Content-Type", "text/plain; charset=utf-8")
spew.Fdump(w, qrch.Fill())
case "html":
w.Header().Add("Content-Type", "text/html; charset=utf-8")
fmt.Fprintf(w, `
QR Bill HTML Debug Page
`)
sp := spew.Sdump(qrch.Fill())
sp = strings.ReplaceAll(sp, "\n", "
")
sp = strings.ReplaceAll(sp, " ", " ")
sp = stringLiteralRe.ReplaceAllStringFunc(sp, func(stringLiteral string) string {
return `` + stringLiteral + ""
})
sp = fieldNameRe.ReplaceAllStringFunc(sp, func(fieldName string) string {
return `` + fieldName + ""
})
fmt.Fprintf(w, "%s", sp)
}
// TODO: add cache control headers
if _, err := io.Copy(w, bytes.NewReader(b)); err != nil {
log.Print(err)
return
}
})
}
func logic() error {
var listen = flag.String("listen", "localhost:9933", "[host]:port to listen on")
flag.Parse()
http.Handle("/qr.png", qrHandler("png"))
http.Handle("/qr.svg", qrHandler("svg"))
http.Handle("/qr.txt", qrHandler("txt"))
http.Handle("/qr.html", qrHandler("html"))
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.Error(w, "not found", http.StatusNotFound)
return
}
w.Header().Add("Content-Type", "text/html; charset=utf-8")
// TODO: add explanation for how to construt a URL
// e.g. for usage in filemaker web view
fmt.Fprintf(w, "")
fmt.Fprintf(w, `- PNG referenz: qr.png`+"\n")
fmt.Fprintf(w, `
- SVG scalable: qr.svg`+"\n")
fmt.Fprintf(w, `
- debug: qr.txt`+"\n")
})
log.Printf("listening on http://%s", *listen)
return http.ListenAndServe(*listen, nil)
}
func main() {
if err := logic(); err != nil {
log.Fatal(err)
}
}
