listen to mempool.space websocket

mempool/mempool.go

@@ -5,7 +5,11 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
+	"net/http"
 	"net/url"
+	"strconv"
+	"time"
 
 	"github.com/gorilla/websocket"
 )
@@ -14,19 +18,27 @@ var (
 	ErrNotWebsocket = errors.New("provided addr was not websocket")
 )
 
+const (
+	WSEndpoint = "api/v1/ws"
+)
+
 type mempool struct {
-	addr string
-	ws   *websocket.Conn
+	baseUrl    string
+	httpClient *http.Client
+	ws         *websocket.Conn
 }
 
-func New(addr string) *mempool {
+func New(baseUrl string, httpClient *http.Client) *mempool {
 	return &mempool{
-		addr: addr,
+		baseUrl: baseUrl,
+		httpClient: &http.Client{
+			Timeout: 5 * time.Second,
+		},
 	}
 }
 
 func (m *mempool) Init() error {
-	u, err := url.Parse(m.addr)
+	u, err := url.Parse(fmt.Sprintf("wss://%s/%s", m.baseUrl, WSEndpoint))
 	if err != nil {
 		return err
 	}
@@ -40,15 +52,93 @@ func (m *mempool) Init() error {
 		return err
 	}
 
+	b, err := json.Marshal(struct {
+		Action string   `json:"action"`
+		Data   []string `json:"data"`
+	}{
+		Action: "want",
+		Data:   []string{"blocks", "stats"},
+	})
+	if err != nil {
+		return err
+	}
+
+	if err = c.WriteMessage(websocket.BinaryMessage, b); err != nil {
+		return err
+	}
+
 	m.ws = c
 	return nil
 }
 
-func (m *mempool) Listen(ctx context.Context, blocks chan Block, errs chan error, done chan struct{}) {
+func (m *mempool) CurrentBlockHeight() (int, error) {
+	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("https://%s/api/blocks/tip/height", m.baseUrl), nil)
+	if err != nil {
+		return 0, err
+	}
+
+	resp, err := m.httpClient.Do(req)
+	if err != nil {
+		return 0, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= http.StatusInternalServerError {
+		return 0, errors.New("server error")
+	}
+
+	if resp.StatusCode >= http.StatusBadRequest {
+		return 0, errors.New("client error")
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return 0, err
+	}
+
+	return strconv.Atoi(string(b))
+}
+
+func (m *mempool) CurrentFees() (int, int, int, error) {
+	req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("https://%s/api/v1/fees/recommended", m.baseUrl), nil)
+	if err != nil {
+		return 0, 0, 0, err
+	}
+
+	resp, err := m.httpClient.Do(req)
+	if err != nil {
+		return 0, 0, 0, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= http.StatusInternalServerError {
+		return 0, 0, 0, err
+	}
+
+	if resp.StatusCode >= http.StatusBadRequest {
+		return 0, 0, 0, err
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return 0, 0, 0, err
+	}
+
+	var data struct {
+		Fastest  int `json:"fastestFee"`
+		HalfHour int `json:"halfHourFee"`
+		Hour     int `json:"hourFee"`
+	}
+
+	err = json.Unmarshal(b, &data)
+	return data.Fastest, data.HalfHour, data.Hour, err
+}
+
+func (m *mempool) Listen(ctx context.Context, messages chan Message, errs chan error, done chan struct{}) {
 	for {
 		select {
 		case <-ctx.Done():
-			close(blocks)
+			close(messages)
 			close(errs)
 			close(done)
 			return
@@ -59,14 +149,14 @@ func (m *mempool) Listen(ctx context.Context, blocks chan Block, errs chan error
 				continue
 			}
 
-			var b Block
-			err = json.Unmarshal(message, &b)
+			var m Message
+			err = json.Unmarshal(message, &m)
 			if err != nil {
 				errs <- err
 				continue
 			}
 
-			blocks <- b
+			messages <- m
 		}
 	}
 }

mempool/models.go

@@ -1,5 +1,29 @@
 package mempool
 
+type Message struct {
+	Block       *Block       `json:"block"`
+	Conversions *Conversions `json:"conversions"`
+	Fees        *Fees        `json:"fees"`
+}
+
 type Block struct {
 	Height int64 `json:"height"`
 }
+
+type Conversions struct {
+	USD int `json:"USD"`
+	EUR int `json:"EUR"`
+	GBP int `json:"GBP"`
+	CAD int `json:"CAD"`
+	CHF int `json:"CHF"`
+	AUD int `json:"AUD"`
+	JPY int `json:"JPY"`
+}
+
+type Fees struct {
+	FastestFee  int `json:"fastestFee"`
+	HalfHourFee int `json:"halfHourFee"`
+	HourFee     int `json:"hourFee"`
+	EconomyFee  int `json:"economyFee"`
+	MinimumFee  int `json:"minimumFee"`
+}