initial commit

lnurlw_callback.go

@@ -0,0 +1,142 @@
+package main
+
+import (
+	decodepay "github.com/fiatjaf/ln-decodepay"
+	log "github.com/sirupsen/logrus"
+	"net/http"
+	"os"
+)
+
+func lnurlw_callback(w http.ResponseWriter, req *http.Request) {
+
+	url := req.URL.RequestURI()
+	log.WithFields(log.Fields{"url": url}).Debug("cb request")
+
+	// check k1 value
+	params_k1, ok := req.URL.Query()["k1"]
+
+	if !ok || len(params_k1[0]) < 1 {
+		log.WithFields(log.Fields{"url": url}).Debug("k1 not found")
+		return
+	}
+
+	param_k1 := params_k1[0]
+
+	p, err := db_get_payment_k1(param_k1)
+	if err != nil {
+		log.WithFields(log.Fields{"url": url, "k1": param_k1}).Warn(err)
+		return
+	}
+
+	// check that payment has not been made
+	if p.paid_flag != "N" {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("payment already made")
+		return
+	}
+
+	// check if lnurlw_request has timed out
+	lnurlw_timeout, err := db_check_lnurlw_timeout(p.card_payment_id)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+	if lnurlw_timeout == true {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("lnurlw request has timed out")
+		return
+	}
+
+	params_pr, ok := req.URL.Query()["pr"]
+	if !ok || len(params_pr[0]) < 1 {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn("pr field not found")
+		return
+	}
+
+	param_pr := params_pr[0]
+	bolt11, _ := decodepay.Decodepay(param_pr)
+
+	// record the lightning invoice
+	err = db_update_payment_invoice(p.card_payment_id, param_pr, bolt11.MSatoshi)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+
+	log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Debug("checking payment rules")
+
+	// check if we are only sending funds to a defined test node
+	testnode := os.Getenv("LN_TESTNODE")
+	if testnode != "" && bolt11.Payee != testnode {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("rejected as not the defined test node")
+		return
+	}
+
+	// check amount limits
+
+	invoice_sats := int(bolt11.MSatoshi / 1000)
+
+	day_total_sats, err := db_get_card_totals(p.card_id)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+
+	c, err := db_get_card_from_card_id(p.card_id)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+
+	if invoice_sats > c.tx_limit_sats {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("invoice_sats: ", invoice_sats)
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("tx_limit_sats: ", c.tx_limit_sats)
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("over tx_limit_sats!")
+		return
+	}
+
+	if day_total_sats+invoice_sats > c.day_limit_sats {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("invoice_sats: ", invoice_sats)
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("day_total_sats: ", day_total_sats)
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("day_limit_sats: ", c.day_limit_sats)
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("over day_limit_sats!")
+		return
+	}
+
+	log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("paying invoice")
+
+	// update paid_flag so we only attempt payment once
+	err = db_update_payment_paid(p.card_payment_id)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+
+	// https://github.com/fiatjaf/lnurl-rfc/blob/luds/03.md
+	//
+	// LN SERVICE sends a {"status": "OK"} or
+	// {"status": "ERROR", "reason": "error details..."}
+	//  JSON response and then attempts to pay the invoices asynchronously.
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	jsonData := []byte(`{"status":"OK"}`)
+	w.Write(jsonData)
+
+	payment_status, failure_reason, err := pay_invoice(param_pr)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+
+	if failure_reason != "FAILURE_REASON_NONE" {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("payment failure reason : ", failure_reason)
+	}
+
+	log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("payment status : ", payment_status)
+
+	// store result in database
+	err = db_update_payment_status(p.card_payment_id, payment_status, failure_reason)
+	if err != nil {
+		log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+		return
+	}
+}