feat: pdf

invoice/invoice.go

@@ -0,0 +1,118 @@
+package invoice
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"html/template"
+	"strings"
+
+	"github.com/skip2/go-qrcode"
+)
+
+// Invoice contains all necessary information for the generation of an invoice.
+type Invoice struct {
+	ReceiverIBAN    string `yaml:"receiver_iban" default:"CH44 3199 9123 0008 8901 2"`
+	IsQrIBAN        bool   `yaml:"is_qr_iban" default:"true"`
+	ReceiverName    string `yaml:"receiver_name" default:"Robert Schneider AG"`
+	ReceiverStreet  string `yaml:"receiver_street" default:"Rue du Lac"`
+	ReceiverNumber  string `yaml:"receiver_number" default:"12"`
+	ReceiverZIPCode string `yaml:"receiver_zip_code" default:"2501"`
+	ReceiverPlace   string `yaml:"receiver_place" default:"Biel"`
+	ReceiverCountry string `yaml:"receiver_country" default:"CH"`
+	PayeeName       string `yaml:"payee_name" default:"Pia-Maria Rutschmann-Schnyder"`
+	PayeeStreet     string `yaml:"payee_street" default:"Grosse Marktgasse"`
+	PayeeNumber     string `yaml:"payee_number" default:"28"`
+	PayeeZIPCode    string `yaml:"payee_zip_code" default:"9400"`
+	PayeePlace      string `yaml:"payee_place" default:"Rorschach"`
+	PayeeCountry    string `yaml:"payee_country" default:"CH"`
+	Reference       string `yaml:"reference" default:"21 00000 00003 13947 14300 09017"`
+	AdditionalInfo  string `yaml:"additional_info" default:"Rechnung Nr. 3139 für Gartenarbeiten"`
+	Amount          string `yaml:"amount" default:"3 949.75"`
+	Currency        string `yaml:"currency" default:"CHF"`
+}
+
+func (i Invoice) GetQR() (src string, err error) {
+	content, err := i.qrContent()
+	if err != nil {
+		return
+	}
+	qr, err := qrcode.New(content, qrcode.Medium)
+	if err != nil {
+		return
+	}
+	qr.DisableBorder = true
+	png, err := qr.PNG(512)
+	if err != nil {
+		return
+	}
+	b64 := base64.StdEncoding.EncodeToString(png)
+	src = fmt.Sprintf(`data:image/png;base64,%s`, b64)
+	return
+}
+
+// noPayee returns true if no fields of the payee are set
+func (i Invoice) noPayee() bool {
+	return i.PayeeName == "" && i.PayeeStreet == "" && i.PayeeZIPCode == "" && i.PayeePlace == ""
+}
+
+func (i Invoice) qrContent() (string, error) {
+	qrTpl := `SPC\r
+0200\r
+1\r
+{{ .iban }}\r
+S\r
+{{ .inv.ReceiverName }}\r
+{{ .inv.ReceiverStreet }}\r
+{{ .inv.ReceiverNumber }}\r
+{{ .inv.ReceiverZIPCode }}\r
+{{ .inv.ReceiverPlace }}\r
+{{ .inv.ReceiverCountry }}\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+{{ .amount }}\r
+{{ .inv.Currency }}\r
+{{ .payeeAdrType }}\r
+{{ .inv.PayeeName }}\r
+{{ .inv.PayeeStreet }}\r
+{{ .inv.PayeeNumber }}\r
+{{ .inv.PayeeZIPCode }}\r
+{{ .inv.PayeePlace }}\r
+{{ .inv.PayeeCountry }}\r
+{{ .refType }}\r
+{{ .reference }}\r
+{{ .inv.AdditionalInfo }}\r
+EPD
+`
+	refType := "QRR"
+	if !i.IsQrIBAN {
+		refType = "SCOR"
+	}
+	payeeAdrType := "S"
+	if i.noPayee() {
+		payeeAdrType = ""
+	}
+	data := map[string]any{
+		"inv":          i,
+		"iban":         strings.ReplaceAll(i.ReceiverIBAN, " ", ""),
+		"amount":       strings.ReplaceAll(i.Amount, " ", ""),
+		"payeeAdrType": payeeAdrType,
+		"reference":    strings.ReplaceAll(i.Reference, " ", ""),
+		"refType":      refType,
+	}
+	tpl, err := template.New("qr-content").Parse(qrTpl)
+	if err != nil {
+		return "", fmt.Errorf("error while creating qr template: %s", err)
+	}
+	var buf bytes.Buffer
+	if err := tpl.Execute(&buf, data); err != nil {
+		return "", fmt.Errorf("error while applying data to qr template: %s", err)
+	}
+	rsl := strings.ReplaceAll(buf.String(), "\\r", "\r")
+	return rsl, nil
+}