Merge pull request #15 from boltcard/ln-addr

Ln addr

create_db.sql

@@ -25,6 +25,7 @@ CREATE TABLE cards (
 	one_time_code CHAR(32) NOT NULL DEFAULT '',
 	one_time_code_expiry TIMESTAMPTZ DEFAULT NOW() + INTERVAL '1 DAY',
 	one_time_code_used CHAR(1) NOT NULL DEFAULT 'Y',
+	allow_negative_balance CHAR(1) NOT NULL DEFAULT 'N',
 	PRIMARY KEY(card_id)
 );
 

database.go

@@ -8,7 +8,7 @@ import (
 	"os"
 )
 
-type Card struct {
+type card struct {
 	card_id                    int
 	card_guid                  string
 	k0_auth_key                string
@@ -22,11 +22,12 @@ type Card struct {
 	lnurlw_enable              string
 	tx_limit_sats              int
 	day_limit_sats             int
-	lnurlp_enable		string
+	lnurlp_enable              string
-	email_address		string
+	email_address              string
-	email_enable		string
+	email_enable               string
 	one_time_code              string
 	card_name                  string
+	allow_negative_balance     string
 }
 
 type payment struct {
@@ -36,6 +37,14 @@ type payment struct {
 	paid_flag       string
 }
 
+type transaction struct {
+	card_id         int
+	tx_id           int
+	tx_type         string
+	tx_amount_msats int
+	tx_time         string
+}
+
 func db_open() (*sql.DB, error) {
 
 	// get connection string from environment variables
@@ -55,9 +64,9 @@ func db_open() (*sql.DB, error) {
 	return db, nil
 }
 
-func db_get_new_card(one_time_code string) (*Card, error) {
+func db_get_new_card(one_time_code string) (*card, error) {
 
-	c := Card{}
+	c := card{}
 
 	db, err := db_open()
 	if err != nil {
@@ -191,7 +200,7 @@ func db_get_card_id_for_r_hash(r_hash string) (int, error) {
 	return card_id, nil
 }
 
-func db_get_cards_blank_uid() ([]Card, error) {
+func db_get_cards_blank_uid() ([]card, error) {
 
 	// open the database
 
@@ -217,17 +226,17 @@ func db_get_cards_blank_uid() ([]Card, error) {
 
 	// prepare the results
 
-	var cards []Card
+	var cards []card
 
 	// Loop through rows, using Scan to assign column data to struct fields.
 	for rows.Next() {
-		var card Card
+		var c card
-		err := rows.Scan(&card.card_id, &card.k2_cmac_key)
+		err := rows.Scan(&c.card_id, &c.k2_cmac_key)
 
 		if err != nil {
 			return cards, err
 		}
-		cards = append(cards, card)
+		cards = append(cards, c)
 	}
 
 	err = rows.Err()
@@ -262,9 +271,9 @@ func db_update_card_uid_ctr(card_id int, uid string, ctr uint32) error {
 	return nil
 }
 
-func db_get_card_from_uid(card_uid string) (*Card, error) {
+func db_get_card_from_uid(card_uid string) (*card, error) {
 
-	c := Card{}
+	c := card{}
 
 	db, err := db_open()
 	if err != nil {
@@ -293,9 +302,9 @@ func db_get_card_from_uid(card_uid string) (*Card, error) {
 	return &c, nil
 }
 
-func db_get_card_from_card_id(card_id int) (*Card, error) {
+func db_get_card_from_card_id(card_id int) (*card, error) {
 
-	c := Card{}
+	c := card{}
 
 	db, err := db_open()
 	if err != nil {
@@ -303,10 +312,11 @@ func db_get_card_from_card_id(card_id int) (*Card, error) {
 	}
 	defer db.Close()
 
-	sqlStatement := `SELECT card_id, k2_cmac_key, uid,` +
+	sqlStatement := `SELECT card_id, k2_cmac_key, uid, ` +
-		` last_counter_value, lnurlw_request_timeout_sec,` +
+		`last_counter_value, lnurlw_request_timeout_sec, ` +
-		` lnurlw_enable, tx_limit_sats, day_limit_sats, email_enable, email_address` +
+		`lnurlw_enable, tx_limit_sats, day_limit_sats, ` +
-		` FROM cards WHERE card_id=$1;`
+		`email_enable, email_address, card_name, ` +
+		`allow_negative_balance FROM cards WHERE card_id=$1;`
 	row := db.QueryRow(sqlStatement, card_id)
 	err = row.Scan(
 		&c.card_id,
@@ -318,7 +328,9 @@ func db_get_card_from_card_id(card_id int) (*Card, error) {
 		&c.tx_limit_sats,
 		&c.day_limit_sats,
 		&c.email_enable,
-		&c.email_address)
+		&c.email_address,
+		&c.card_name,
+		&c.allow_negative_balance)
 	if err != nil {
 		return &c, err
 	}
@@ -584,3 +596,90 @@ func db_get_card_totals(card_id int) (int, error) {
 
 	return day_total_sats, nil
 }
+
+func db_get_card_txs(card_id int, max_txs int) ([]transaction, error) {
+	// open the database
+
+	db, err := db_open()
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer db.Close()
+
+	// query the database
+
+	sqlStatement := `SELECT card_id, ` +
+		`card_payments.card_payment_id AS tx_id, 'payment' AS tx_type, ` +
+		`amount_msats as tx_amount_msats, ` +
+		`TO_CHAR(payment_status_time, 'DD/MM/YYYY HH:MI:SS') AS tx_time ` +
+		`FROM card_payments WHERE card_id = $1 AND payment_status != 'FAILED' ` +
+		`AND payment_status != '' ` +
+		`AND amount_msats != 0 UNION SELECT card_id, card_receipts.card_receipt_id AS tx_id, ` +
+		`'receipt' AS tx_type, amount_msats as tx_amount_msats, ` +
+		`TO_CHAR(receipt_status_time, 'DD/MM/YYYY HH:MI:SS') AS tx_time ` +
+		`FROM card_receipts WHERE card_id = $1 ` +
+		`AND receipt_status = 'SETTLED' ORDER BY tx_time DESC LIMIT $2`
+
+	rows, err := db.Query(sqlStatement, card_id, max_txs)
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer rows.Close()
+
+	// prepare the results
+
+	var transactions []transaction
+
+	// Loop through rows, using Scan to assign column data to struct fields.
+	for rows.Next() {
+		var t transaction
+		err := rows.Scan(&t.card_id, &t.tx_id, &t.tx_type, &t.tx_amount_msats, &t.tx_time)
+
+		if err != nil {
+			return transactions, err
+		}
+		transactions = append(transactions, t)
+	}
+
+	err = rows.Err()
+
+	if err != nil {
+		return transactions, err
+	}
+
+	return transactions, nil
+}
+
+func db_get_card_total_sats(card_id int) (int, error) {
+
+	db, err := db_open()
+	if err != nil {
+		return 0, err
+	}
+
+	card_total_msats := 0
+
+	sqlStatement := `SELECT SUM(tx_amount_msats) FROM (SELECT card_id, ` +
+		`card_payments.card_payment_id AS tx_id, 'payment' AS tx_type, ` +
+		`-amount_msats as tx_amount_msats, payment_status_time AS tx_time ` +
+		`FROM card_payments WHERE card_id = $1 AND payment_status != 'FAILED' ` +
+		`AND payment_status != '' ` +
+		`AND amount_msats != 0 UNION SELECT card_id, card_receipts.card_receipt_id AS tx_id, ` +
+		`'receipt' AS tx_type, amount_msats as tx_amount_msats, ` +
+		`receipt_status_time AS tx_time FROM card_receipts WHERE card_id = $1 ` +
+		`AND receipt_status = 'SETTLED' ORDER BY tx_time) AS transactions;`
+
+	row := db.QueryRow(sqlStatement, card_id)
+	err = row.Scan(&card_total_msats)
+	if err != nil {
+		return 0, err
+	}
+
+	card_total_sats := card_total_msats / 1000
+
+	return card_total_sats, nil
+}

email.go

@@ -8,8 +8,83 @@ import (
 	"github.com/aws/aws-sdk-go/service/ses"
 	log "github.com/sirupsen/logrus"
 	"os"
+	"strconv"
+	"strings"
 )
 
+func send_balance_email(recipient_email string, card_id int) {
+
+	c, err := db_get_card_from_card_id(card_id)
+	if err != nil {
+		log.Warn(err.Error())
+		return
+	}
+
+	card_total_sats, err := db_get_card_total_sats(card_id)
+	if err != nil {
+		log.Warn(err.Error())
+		return
+	}
+
+	email_max_txs, err := strconv.Atoi(os.Getenv("EMAIL_MAX_TXS"))
+	if err != nil {
+		log.Warn(err.Error())
+		return
+	}
+
+	txs, err := db_get_card_txs(card_id, email_max_txs+1)
+	if err != nil {
+		log.Warn(err.Error())
+		return
+	}
+
+	subject := c.card_name + " balance = " + strconv.Itoa(card_total_sats) + " sats"
+
+	// add transactions to the email body
+
+	var html_body_sb strings.Builder
+	var text_body_sb strings.Builder
+
+	html_body_sb.WriteString("<!DOCTYPE html><html><head><style> table, " +
+		"th, td { border: 1px solid black; border-collapse: collapse; } " +
+		"</style></head><body>")
+
+	html_body_sb.WriteString("<h3>transactions</h3><table><tr><th>date</th><th>action</th><th>amount</th>")
+	text_body_sb.WriteString("transactions\n\n")
+
+	for i, tx := range txs {
+
+		if i < email_max_txs {
+			html_body_sb.WriteString(
+				"<tr>" +
+					"<td>" + tx.tx_time + "</td>" +
+					"<td>" + tx.tx_type + "</td>" +
+					"<td style='text-align:right'>" + strconv.Itoa(tx.tx_amount_msats/1000) + "</td>" +
+					"</tr>")
+		} else {
+			html_body_sb.WriteString(
+				"<tr>" +
+					"<td style='text-align:center'> ... </td>" +
+					"<td style='text-align:center'> ... </td>" +
+					"<td style='text-align:center'> ... </td>" +
+					"</tr>")
+		}
+
+		text_body_sb.WriteString(tx.tx_type +
+			" " + strconv.Itoa(tx.tx_amount_msats/1000))
+	}
+
+	html_body_sb.WriteString("</table></body></html>")
+
+	html_body := html_body_sb.String()
+	text_body := text_body_sb.String()
+
+	send_email(recipient_email,
+		subject,
+		html_body,
+		text_body)
+}
+
 // https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/ses-example-send-email.html
 
 func send_email(recipient string, subject string, htmlBody string, textBody string) {

lightning.go

@@ -182,7 +182,7 @@ func monitor_invoice_state(r_hash []byte) () {
 		return
 	}
 
-	go send_email(c.email_address, "bolt card receipt", "html body", "text body")
+	go send_balance_email(c.email_address, card_id)
 
 	return
 }
@@ -278,7 +278,7 @@ func pay_invoice(card_payment_id int, invoice string) {
 		return
 	}
 
-	go send_email(c.email_address, "bolt card payment", "html body", "text body")
+	go send_balance_email(c.email_address, card_id)
 
 	return
 }

lnurlw_callback.go

@@ -9,12 +9,12 @@ import (
 
 func lnurlw_callback(w http.ResponseWriter, req *http.Request) {
 
-        env_host_domain := os.Getenv("HOST_DOMAIN")
+	env_host_domain := os.Getenv("HOST_DOMAIN")
-        if req.Host != env_host_domain {
+	if req.Host != env_host_domain {
-                log.Warn("wrong host domain")
+		log.Warn("wrong host domain")
-                write_error(w)
+		write_error(w)
-                return
+		return
-        }
+	}
 
 	url := req.URL.RequestURI()
 	log.WithFields(log.Fields{"url": url}).Debug("cb request")
@@ -120,6 +120,24 @@ func lnurlw_callback(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
+	// check the card balance if marked as 'must stay above zero' (default)
+	//  i.e. cards.allow_negative_balance == 'N'
+
+	if c.allow_negative_balance != "Y" {
+		card_total, err := db_get_card_total_sats(p.card_id)
+		if err != nil {
+			log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn(err)
+			write_error(w)
+			return
+		}
+
+		if card_total-invoice_sats < 0 {
+			log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Warn("not enough balance")
+			write_error(w)
+			return
+		}
+	}
+
 	log.WithFields(log.Fields{"card_payment_id": p.card_payment_id}).Info("paying invoice")
 
 	// update paid_flag so we only attempt payment once
@@ -138,7 +156,7 @@ func lnurlw_callback(w http.ResponseWriter, req *http.Request) {
 
 	go pay_invoice(p.card_payment_id, param_pr)
 
-	log.Debug("sending 'status OK' response");
+	log.Debug("sending 'status OK' response")
 
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)