Add support for creating a fun image with text (including the amount of satoshis)

Makefile

@@ -1,6 +1,8 @@
 PKG := github.com/michael1011/lightningtip
 
-GOBUILD := go build -v
+# Enable image support via ImageMagicks MagickWand API. Requires MagickWand C API to be installed
+# IMAGICK := -tags imagick
+GOBUILD := go build -v ${IMAGICK}
 GOINSTALL := go install -v
 
 GO_BIN := ${GOPATH}/bin

README.md

@@ -35,10 +35,14 @@ That's it! The only two things you need to take care about is keeping the LND no
 
 First of all make sure [Golang](https://golang.org/) and [Dep](https://github.com/golang/dep) are both correctly installed. Golang version 1.10 or newer is recommended.
 
+If you want to return a picture, make sure you install ImageMagick MagickWand C API. For examnple (Ubuntu/Debian): sudo apt-get install libmagickwand-dev
+
+To enable it, edit Makefile and enable the line with IMAGICK : = -tags imagick 
 ```
 go get -d github.com/michael1011/lightningtip
 cd $GOPATH/src/github.com/michael1011/lightningtip
 
+
 make && make install
 ```
 

backends/backend.go

@@ -11,7 +11,7 @@ type Backend interface {
 	Connect() error
 
 	// The amount is denominated in satoshis and the expiry in seconds
-	GetInvoice(description string, amount int64, expiry int64) (invoice string, rHash string, err error)
+	GetInvoice(description string, amount int64, expiry int64) (invoice string, rHash string, picture string, err error)
 
 	InvoiceSettled(rHash string) (settled bool, err error)
 

backends/lnd.go

@@ -8,6 +8,7 @@ import (
 	"io/ioutil"
 
 	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/michael1011/lightningtip/image"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
@@ -64,7 +65,7 @@ func (lnd *LND) Connect() error {
 }
 
 // GetInvoice gets and invoice from a node
-func (lnd *LND) GetInvoice(message string, amount int64, expiry int64) (invoice string, rHash string, err error) {
+func (lnd *LND) GetInvoice(message string, amount int64, expiry int64) (invoice string, rHash string, picture string, err error) {
 	var response *lnrpc.AddInvoiceResponse
 
 	response, err = lnd.client.AddInvoice(lnd.ctx, &lnrpc.Invoice{
@@ -74,10 +75,10 @@ func (lnd *LND) GetInvoice(message string, amount int64, expiry int64) (invoice
 	})
 
 	if err != nil {
-		return "", "", err
+		return "", "", "", err
 	}
 
-	return response.PaymentRequest, hex.EncodeToString(response.RHash), err
+	return response.PaymentRequest, hex.EncodeToString(response.RHash), image.GetImagePath(hex.EncodeToString(response.RHash)), err
 }
 
 // InvoiceSettled checks if an invoice is settled by looking it up
@@ -93,7 +94,7 @@ func (lnd *LND) InvoiceSettled(rHash string) (settled bool, err error) {
 	if err != nil {
 		return false, err
 	}
-
+	_ = image.GenerateImage(hex.EncodeToString(invoice.RHash), invoice.AmtPaid)
 	return invoice.Settled, err
 }
 
@@ -128,6 +129,8 @@ func (lnd *LND) SubscribeInvoices(publish PublishInvoiceSettled, rescan RescanPe
 			}
 
 			if invoice.Settled {
+				_ = image.GenerateImage(hex.EncodeToString(invoice.RHash), invoice.AmtPaid)
+				log.Debug("Payment request settled: ", invoice.PaymentRequest)
 				go publish(invoice.PaymentRequest)
 			}
 

config.go

@@ -13,6 +13,7 @@ import (
 	"github.com/jessevdk/go-flags"
 	"github.com/michael1011/lightningtip/backends"
 	"github.com/michael1011/lightningtip/database"
+	"github.com/michael1011/lightningtip/image"
 	"github.com/michael1011/lightningtip/notifications"
 	"github.com/michael1011/lightningtip/version"
 	"github.com/op/go-logging"
@@ -50,6 +51,20 @@ const (
 	defaultSTMPSSL      = false
 	defaultSTMPUser     = ""
 	defaultSTMPPassword = ""
+
+	defaultImageDir             = ""
+	defaultImageURLDir          = ""
+	defaultImageFile            = ""
+	defaultImageTextBeforeAmt   = "I paid a random dude"
+	defaultImageTextAfterAmt    = "satoshis with Lightning Network"
+	defaultImageTextSecondLine  = "but all I got was this picture of his dog."
+	defaultImageTextFirstLineX  = 25
+	defaultImageTextFirstLineY  = 165
+	defaultImageTextSecondLineX = 25
+	defaultImageTextSecondLineY = 365
+	defaultImageTextColor       = "black"
+	defaultImageTextFont        = "Verdana-Bold-Italic"
+	defaultImageTextSize        = 150
 )
 
 type helpOptions struct {
@@ -78,7 +93,8 @@ type config struct {
 	ReconnectInterval int64 `long:"reconnectinterval" description:"Reconnect interval to LND in seconds"`
 	KeepAliveInterval int64 `long:"keepaliveinterval" description:"Send a dummy request to LND to prevent timeouts "`
 
-	LND *backends.LND `group:"LND" namespace:"lnd"`
+	LND   *backends.LND `group:"LND" namespace:"lnd"`
+	Image *image.Image  `group:"Image" namespace:"image"`
 
 	Mail *notifications.Mail `group:"Mail" namespace:"mail"`
 
@@ -117,6 +133,22 @@ func initConfig() {
 			MacaroonFile: getDefaultMacaroon(),
 		},
 
+		Image: &image.Image{
+			ImageDir:             defaultImageDir,
+			ImageURLDir:          defaultImageURLDir,
+			ImageFile:            defaultImageFile,
+			ImageTextBeforeAmt:   defaultImageTextBeforeAmt,
+			ImageTextAfterAmt:    defaultImageTextAfterAmt,
+			ImageTextSecondLine:  defaultImageTextSecondLine,
+			ImageTextFirstLineX:  defaultImageTextFirstLineX,
+			ImageTextFirstLineY:  defaultImageTextFirstLineY,
+			ImageTextSecondLineX: defaultImageTextSecondLineX,
+			ImageTextSecondLineY: defaultImageTextSecondLineY,
+			ImageTextColor:       defaultImageTextColor,
+			ImageTextFont:        defaultImageTextFont,
+			ImageTextSize:        defaultImageTextSize,
+		},
+
 		Mail: &notifications.Mail{
 			Recipient: defaultRecipient,
 			Sender:    defaultSender,
@@ -133,6 +165,9 @@ func initConfig() {
 	parser.Parse()
 
 	errFile := flags.IniParse(cfg.ConfigFile, &cfg)
+	if cfg.Image.ImageDir != "" {
+		image.SetImageCfg(*cfg.Image)
+	}
 
 	// If the user just wants to see the version initializing everything else is irrelevant
 	if cfg.Help.ShowVersion {

frontend/lightningTip.js

@@ -1,6 +1,6 @@
 // Edit this variable if you are not running LightningTip on the same domain or IP address as your webserver or not on port 8081
 // Don't forget the "/" at the end!
-var requestUrl = window.location.protocol + "//" + window.location.hostname + ":8081/";
+var requestUrl = window.location.protocol + "//" + window.location.hostname + "/tiprest/";
 
 // To prohibit multiple requests at the same time
 var requestPending = false;
@@ -69,7 +69,7 @@ function getInvoice() {
 
                                 console.log("Starting listening for invoice to get settled");
 
-                                listenInvoiceSettled(json.RHash);
+                                listenInvoiceSettled(json.RHash, json.Picture);
 
                                 invoice = json.Invoice;
 
@@ -135,7 +135,7 @@ function getInvoice() {
 
 }
 
-function listenInvoiceSettled(rHash) {
+function listenInvoiceSettled(rHash, picture) {
     try {
         var eventSrc = new EventSource(requestUrl + "eventsource");
 
@@ -145,7 +145,7 @@ function listenInvoiceSettled(rHash) {
 
                 eventSrc.close();
 
-                showThankYouScreen();
+                showThankYouScreen(picture);
             }
 
         };
@@ -170,7 +170,7 @@ function listenInvoiceSettled(rHash) {
 
                                 clearInterval(interval);
 
-                                showThankYouScreen();
+                                showThankYouScreen(json.Picture);
                             }
 
                         }
@@ -190,11 +190,14 @@ function listenInvoiceSettled(rHash) {
 
 }
 
-function showThankYouScreen() {
+function showThankYouScreen(picture) {
     var wrapper = document.getElementById("lightningTip");
 
     wrapper.innerHTML = "<p id=\"lightningTipLogo\">⚡</p>";
     wrapper.innerHTML += "<a id='lightningTipFinished'>Thank you for your tip!</a>";
+    if (picture !== "") {
+      wrapper.innerHTML += "<a href=" + picture + "><img height=150 src=" + picture + "></a>";
+    }
 }
 
 function starTimer(duration, element) {
@@ -320,4 +323,4 @@ function divRestorePlaceholder(element) {
     if (element.innerHTML === "<br>" || element.innerHTML === "<div><br></div>") {
         element.innerHTML = "";
     }
-}
+}

image/imageimagick.go

@@ -0,0 +1,73 @@
+// +build imagick
+
+package image
+
+import (
+	"gopkg.in/gographics/imagick.v2/imagick"
+	"strconv"
+)
+
+// Image type for holding configuration
+type Image struct {
+	ImageDir             string  `long:"imagedir" description:"Directory where generated images are placed"`
+	ImageURLDir          string  `long:"imageurldir" description:"The directory part of the URL where browsers will find the images"`
+	ImageFile            string  `long:"imagefile" description:"Full path to the image that will be served"`
+	ImageTextBeforeAmt   string  `long:"imagetextbeforeamt" description:"The text on the first line before the amount"`
+	ImageTextAfterAmt    string  `long:"imagetextafteramt" description:"The text on the first line after the amount"`
+	ImageTextSecondLine  string  `long:"imagetextsecondline" description:"The text on the second line"`
+	ImageTextFirstLineX  float64 `long:"imagetextfirstlinex" description:"X position for start of first line"`
+	ImageTextFirstLineY  float64 `long:"imagetextfirstliney" description:"Y position for start of first line"`
+	ImageTextSecondLineX float64 `long:"imagetextsecondlinex" description:"X position for start of second line"`
+	ImageTextSecondLineY float64 `long:"imagetextsecondliney" description:"Y position for start of second line"`
+	ImageTextColor       string  `long:"imagetextcolor" description:"Text Color"`
+	ImageTextFont        string  `long:"imagetextfont" description:"Text Font"`
+	ImageTextSize        float64 `long:"imagetextsize" description:"Text size (heigth in pixels)"`
+}
+
+// ImageCfg is the Configuration variable
+var ImageCfg Image
+
+// SetImageCfg - Set package configuration from outside package
+func SetImageCfg(Cfg Image) {
+	ImageCfg = Cfg
+}
+
+// GetImagePath - Get the web path for the picture based on the payment hash
+func GetImagePath(rHash string) string {
+	return (ImageCfg.ImageURLDir + "/" + rHash + ".jpg")
+}
+
+// GetImagePath - Get the web path for the picture based on the payment hash
+func GenerateImage(rHash string, Amount int64) string {
+	imagick.Initialize()
+	defer imagick.Terminate()
+	var imerr error
+
+	mw := imagick.NewMagickWand()
+	dw := imagick.NewDrawingWand()
+	pw := imagick.NewPixelWand()
+
+	imerr = mw.ReadImage(ImageCfg.ImageFile)
+	if imerr != nil {
+		panic(imerr)
+	}
+	pw.SetColor(ImageCfg.ImageTextColor)
+	dw.SetFillColor(pw)
+	dw.SetFont(ImageCfg.ImageTextFont)
+	dw.SetFontSize(ImageCfg.ImageTextSize)
+	dw.SetStrokeColor(pw)
+	dw.Annotation(ImageCfg.ImageTextFirstLineX, ImageCfg.ImageTextFirstLineY,
+		ImageCfg.ImageTextBeforeAmt+" "+strconv.FormatInt(Amount, 10)+" "+ImageCfg.ImageTextAfterAmt)
+	dw.Annotation(ImageCfg.ImageTextSecondLineX, ImageCfg.ImageTextSecondLineY, ImageCfg.ImageTextSecondLine)
+	mw.DrawImage(dw)
+	mw.WriteImage(ImageCfg.ImageDir + "/" + rHash + ".jpg")
+	newWidth := uint(250)
+	newHeight := uint(mw.GetImageHeight() * newWidth / mw.GetImageWidth())
+	imerr = mw.ResizeImage(newWidth, newHeight, imagick.FILTER_LANCZOS, 1)
+	if imerr != nil {
+		panic(imerr)
+	}
+	mw.WriteImage("/var/www/lnd/tips/" + rHash + ".jpg_small.jpg")
+
+	return GetImagePath(rHash)
+}

image/imagenone.go

@@ -0,0 +1,39 @@
+// +build !imagick
+// Stubs to make code compile and behave same if it has image supportr or not.
+
+package image
+
+// Image type for holding configuration
+type Image struct {
+	ImageDir             string  `long:"imagedir" description:"Directory where generated images are placed"`
+	ImageURLDir          string  `long:"imageurldir" description:"The directory part of the URL where browsers will find the images"`
+	ImageFile            string  `long:"imagefile" description:"Full path to the image that will be served"`
+	ImageTextBeforeAmt   string  `long:"imagetextbeforeamt" description:"The text on the first line before the amount"`
+	ImageTextAfterAmt    string  `long:"imagetextafteramt" description:"The text on the first line after the amount"`
+	ImageTextSecondLine  string  `long:"imagetextsecondline" description:"The text on the second line"`
+	ImageTextFirstLineX  float64 `long:"imagetextfirstlinex" description:"X position for start of first line"`
+	ImageTextFirstLineY  float64 `long:"imagetextfirstliney" description:"Y position for start of first line"`
+	ImageTextSecondLineX float64 `long:"imagetextsecondlinex" description:"X position for start of second line"`
+	ImageTextSecondLineY float64 `long:"imagetextsecondliney" description:"Y position for start of second line"`
+	ImageTextColor       string  `long:"imagetextcolor" description:"Text Color"`
+	ImageTextFont        string  `long:"imagetextfont" description:"Text Font"`
+	ImageTextSize        float64 `long:"imagetextsize" description:"Text size (heigth in pixels)"`
+}
+
+// ImageCfg is the Configuration variable
+var ImageCfg Image
+
+// SetImageCfg - Set package configuration from outside package
+func SetImageCfg(Cfg Image) {
+	ImageCfg = Cfg
+}
+
+// GetImagePath - Get the web path for the picture based on the payment hash
+func GetImagePath(rHash string) string {
+	return ("")
+}
+
+// GenerateImage - Generate a picture from hash and amount
+func GenerateImage(rHash string, Amount int64) string {
+	return ("")
+}

lightningtip.go

@@ -50,6 +50,7 @@ type invoiceRequest struct {
 type invoiceResponse struct {
 	Invoice string
 	RHash   string
+	Picture string
 	Expiry  int64
 }
 
@@ -319,7 +320,7 @@ func getInvoiceHandler(writer http.ResponseWriter, request *http.Request) {
 
 		if err == nil {
 			if body.Amount != 0 {
-				invoice, paymentHash, err := backend.GetInvoice(body.Message, body.Amount, cfg.TipExpiry)
+				invoice, paymentHash, picture, err := backend.GetInvoice(body.Message, body.Amount, cfg.TipExpiry)
 
 				if err == nil {
 					logMessage := "Created invoice with amount of " + strconv.FormatInt(body.Amount, 10) + " satoshis"
@@ -346,6 +347,7 @@ func getInvoiceHandler(writer http.ResponseWriter, request *http.Request) {
 					writer.Write(marshalJSON(invoiceResponse{
 						Invoice: invoice,
 						RHash:   paymentHash,
+						Picture: picture,
 						Expiry:  cfg.TipExpiry,
 					}))