From 7296cfb425ce6aa14320bb9291be4b370a2e56a3 Mon Sep 17 00:00:00 2001
From: Vadym Popov <me@vpopov.org>
Date: Sun, 12 Aug 2018 16:12:37 +0300
Subject: [PATCH] channeldb: add payment statuses: ground, in flight, completed

---
 channeldb/payments.go | 96 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/channeldb/payments.go b/channeldb/payments.go
index 0e5f47b9..aa880b0b 100644
--- a/channeldb/payments.go
+++ b/channeldb/payments.go
@@ -3,6 +3,7 @@ package channeldb
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"io"
 
 	"github.com/coreos/bbolt"
@@ -17,8 +18,64 @@ var (
 	// which is a monotonically increasing uint64.  BoltDB's sequence
 	// feature is used for generating monotonically increasing id.
 	paymentBucket = []byte("payments")
+
+	// paymentStatusBucket is the name of the bucket within the database that
+	// stores the status of a payment indexed by the payment's preimage.
+	paymentStatusBucket = []byte("payment-status")
 )
 
+// PaymentStatus represent current status of payment
+type PaymentStatus byte
+
+const (
+	// StatusGrounded is status where payment is initiated and received
+	// an intermittent failure
+	StatusGrounded PaymentStatus = 0
+
+	// StatusInFlight is status where payment is initiated, but a response
+	// has not been received
+	StatusInFlight PaymentStatus = 1
+
+	// StatusCompleted is status where payment is initiated and complete
+	// a payment successfully
+	StatusCompleted PaymentStatus = 2
+)
+
+// Bytes returns status as slice of bytes
+func (ps PaymentStatus) Bytes() []byte {
+	return []byte{byte(ps)}
+}
+
+// FromBytes sets status from slice of bytes
+func (ps *PaymentStatus) FromBytes(status []byte) error {
+	if len(status) != 1 {
+		return errors.New("payment status is empty")
+	}
+
+	switch PaymentStatus(status[0]) {
+	case StatusGrounded, StatusInFlight, StatusCompleted:
+		*ps = PaymentStatus(status[0])
+	default:
+		return errors.New("unknown payment status")
+	}
+
+	return nil
+}
+
+// String returns readable representation of payment status
+func (ps PaymentStatus) String() string {
+	switch ps {
+	case StatusGrounded:
+		return "Grounded"
+	case StatusInFlight:
+		return "In Flight"
+	case StatusCompleted:
+		return "Completed"
+	default:
+		return "Unknown"
+	}
+}
+
 // OutgoingPayment represents a successful payment between the daemon and a
 // remote node. Details such as the total fee paid, and the time of the payment
 // are stored.
@@ -129,6 +186,45 @@ func (db *DB) DeleteAllPayments() error {
 	})
 }
 
+// UpdatePaymentStatus sets status for outgoing/finished payment to store status in
+// local database.
+func (db *DB) UpdatePaymentStatus(paymentHash [32]byte, status PaymentStatus) error {
+	return db.Batch(func(tx *bolt.Tx) error {
+		paymentStatuses, err := tx.CreateBucketIfNotExists(paymentStatusBucket)
+		if err != nil {
+			return err
+		}
+
+		return paymentStatuses.Put(paymentHash[:], status.Bytes())
+	})
+}
+
+// FetchPaymentStatus returns payment status for outgoing payment
+// if status of the payment isn't found it set to default status "StatusGrounded".
+func (db *DB) FetchPaymentStatus(paymentHash [32]byte) (PaymentStatus, error) {
+	// default status for all payments that wasn't recorded in database
+	paymentStatus := StatusGrounded
+
+	err := db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(paymentStatusBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		paymentStatusBytes := bucket.Get(paymentHash[:])
+		if paymentStatusBytes == nil {
+			return nil
+		}
+
+		return paymentStatus.FromBytes(paymentStatusBytes)
+	})
+	if err != nil {
+		return StatusGrounded, err
+	}
+
+	return paymentStatus, nil
+}
+
 func serializeOutgoingPayment(w io.Writer, p *OutgoingPayment) error {
 	var scratch [8]byte