chore: reorganize and rewrite

address.go

@@ -0,0 +1,124 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// AddressInfo represents information about a given address.
+type AddressInfo struct {
+	Address             string
+	Nickname            string
+	BalanceSat          int
+	PreviousBalanceSat  int
+	BalanceFiat         string
+	PreviousBalanceFiat string
+	Currency            string
+	TXCount             int
+}
+
+// GetIdentifier returns the address of the AddressInfo variable.
+func (a AddressInfo) GetIdentifier() string {
+	return a.Address
+}
+
+// GetNickname returns the nickname of the AddressInfo variable.
+func (a AddressInfo) GetNickname() string {
+	return a.Nickname
+}
+
+// Update updates the database with the AddressInfo variable.
+func (a AddressInfo) Update(w Watcher) error {
+	tx := w.DB.Model(&AddressInfo{}).
+		Where(&AddressInfo{Address: a.Address, Nickname: a.Nickname}).
+		Updates(&a)
+	if tx.RowsAffected != 1 {
+		return fmt.Errorf("%d rows affected", tx.RowsAffected)
+	}
+	return nil
+}
+
+const (
+	addressMessageTemplate = `**Address Balance Changed**
+Nickname: {{ .Nickname }}
+Address: {{ .Address }}
+Previous Balance (satoshis): {{ .PreviousBalanceSat }}
+Previous Balance ({{ .Currency }}): {{ .PreviousBalanceFiat }}
+Transactions: {{ .TXCount }}
+New Balance (satoshis): {{ .BalanceSat }}
+New Balance ({{ .Currency }}): {{ .BalanceFiat }}
+`
+)
+
+// WatchAddress takes a btcapi config and a nickname:address string. It
+// checks the database for a previous address summary and compares the
+// previous balance to the current balance. If they are different,
+// it calls Watcher.SendNotification.
+func (w Watcher) WatchAddress(nickAddress string) {
+	for {
+		nickname := strings.Split(nickAddress, ":")[0]
+		address := strings.Split(nickAddress, ":")[1]
+
+		var oldAddressInfo AddressInfo
+		w.DB.Model(&AddressInfo{}).
+			Where(&AddressInfo{Address: address, Nickname: nickname}).
+			Scan(&oldAddressInfo)
+
+		// Insert blank AddressInfo if none was found
+		if (oldAddressInfo == AddressInfo{}) {
+			oldAddressInfo = w.CreateNewAddressInfo(address, nickname)
+		}
+
+		addressSummary, err := w.BTCAPI.AddressSummary(address)
+		if err != nil {
+			log.Errorf("error calling btcapi: %v", err)
+		}
+
+		balanceFiat, err := w.ConvertBalance(addressSummary.TXHistory.BalanceSat)
+		if err != nil {
+			log.Errorf("unable to convert balance of %d to %s, err: %v", addressSummary.TXHistory.BalanceSat, w.Currency, err)
+		}
+		addressInfo := AddressInfo{
+			Address:             address,
+			Nickname:            nickname,
+			BalanceSat:          addressSummary.TXHistory.BalanceSat,
+			BalanceFiat:         strconv.FormatFloat(balanceFiat, 'f', 2, 64),
+			Currency:            strings.ToUpper(w.Currency),
+			PreviousBalanceSat:  oldAddressInfo.BalanceSat,
+			PreviousBalanceFiat: oldAddressInfo.BalanceFiat,
+			TXCount:             addressSummary.TXHistory.TXCount,
+		}
+
+		if addressInfo.BalanceSat != oldAddressInfo.BalanceSat {
+			log.Debugf("\"%s\" (%s) balance updated from %d to %d sats", nickname, address, oldAddressInfo.BalanceSat, addressInfo.BalanceSat)
+			w.UpdateInfo(addressInfo)
+			w.SendNotification(addressInfo, addressMessageTemplate)
+		}
+		time.Sleep(time.Duration(int(time.Second) * w.SleepInterval))
+	}
+}
+
+// CreateNewAddressInfo creates an AddressInfo database entry for a new
+// address & nickname combination.
+func (w Watcher) CreateNewAddressInfo(address string, nickname string) AddressInfo {
+	log.Warnf("previous address information for \"%s\" (%s) was not found, database will be updated", nickname, address)
+	addressInfo := AddressInfo{
+		Address:             address,
+		Nickname:            nickname,
+		BalanceSat:          0,
+		BalanceFiat:         "0.0",
+		Currency:            w.Currency,
+		PreviousBalanceSat:  0,
+		PreviousBalanceFiat: "0.0",
+		TXCount:             0,
+	}
+	tx := w.DB.Model(&AddressInfo{}).Create(&addressInfo)
+	if tx.RowsAffected != 1 {
+		log.Errorf("%d rows affected creating address info for \"%s\" (%s)", tx.RowsAffected, nickname, address)
+	}
+	return addressInfo
+}

btc.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ConvertBalance takes a balance in satoshis and returns the equivalent
+// balance in the currency specified by Watcher.Currency
+func (w Watcher) ConvertBalance(balanceSat int) (float64, error) {
+	price, err := w.BTCAPI.Price()
+	if err != nil {
+		return 0.0, fmt.Errorf("error calling btcapi: %v", err)
+	}
+
+	balanceFiat := 0.0
+	currency := strings.ToUpper(w.Currency)
+	bitcoinBalance := float64(balanceSat) / float64(SatsPerBitcoin)
+	switch currency {
+	case "EUR":
+		balanceFiat = price.EUR * bitcoinBalance
+	case "GBP":
+		balanceFiat = price.GBP * bitcoinBalance
+	case "XAU":
+		balanceFiat = price.XAU * bitcoinBalance
+	default:
+		balanceFiat = price.USD * bitcoinBalance
+	}
+	return balanceFiat, nil
+}