init; project structure & bybit provider

internal/bot/telegram/telegram.go

@@ -0,0 +1 @@
+package telegram

internal/config/config.go

@@ -0,0 +1,45 @@
+package config
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/ilyakaznacheev/cleanenv"
+)
+
+type Config struct {
+	Logger    Logger `yaml:"logger"`
+	Providers struct {
+		Bybit Bybit `yaml:"bybit"`
+	} `yaml:"providers"`
+}
+
+type Logger struct {
+	ServiceName string `yaml:"service_name" env-required:"true"` // service name for printing in logs
+	Encoding    string `yaml:"encoding" env-default:"json"`      // console/json
+	Level       string `yaml:"level" env-default:"info"`         // debug/info/warn/error
+}
+
+type Bybit struct {
+	BaseURL string `yaml:"base_url" env-default:"https://api.bybit.com"` // bybit api url
+}
+
+// MustLoad returns config or panic.
+func MustLoad() *Config {
+	configPath := os.Getenv("CONFIG_PATH")
+	if configPath == "" {
+		panic("CONFIG_PATH is not set")
+	}
+	// check if file exists
+	if _, err := os.Stat(configPath); os.IsNotExist(err) {
+		panic(fmt.Sprintf("config file does not exist: %s", configPath))
+	}
+
+	var cfg Config
+	// read config
+	if err := cleanenv.ReadConfig(configPath, &cfg); err != nil {
+		panic(fmt.Errorf("cannot read config: %w", err))
+	}
+
+	return &cfg
+}

internal/entities/pair.go

@@ -0,0 +1,6 @@
+package entities
+
+type Pair struct {
+	BaseCurrency  string // base currency of the pair. e.g. BTC.
+	QuoteCurrency string // quote currency of the pair. e.g. USDT.
+}

internal/entities/price.go

@@ -0,0 +1,10 @@
+package entities
+
+import "github.com/shopspring/decimal"
+
+type Price struct {
+	Ask    decimal.Decimal // limit seller / market buyer. ask > bid.
+	Bid    decimal.Decimal // limit buyer / market seller. bid < ask.
+	Spread decimal.Decimal // delta between ask and bid.
+	Pair   Pair            // trading pair
+}

internal/logger/logger.go

@@ -0,0 +1,54 @@
+package logger
+
+import (
+	"crypto_alert_bot/internal/config"
+	"fmt"
+	"log/slog"
+	"os"
+
+	prettyLogger "github.com/charmbracelet/log"
+)
+
+var levelAdapter = map[string]slog.Level{
+	"debug": slog.LevelDebug,
+	"info":  slog.LevelInfo,
+	"warn":  slog.LevelWarn,
+	"error": slog.LevelError,
+}
+
+const (
+	encodingConsole = "console"
+	encodingJSON    = "json"
+)
+
+const (
+	serviceNameKey = "service_name"
+)
+
+func NewAppLogger(cfg *config.Logger) *slog.Logger {
+	var log *slog.Logger
+	// select log level
+	level, ok := levelAdapter[cfg.Level]
+	if !ok {
+		panic(fmt.Errorf("logger level not correct: %s", level))
+	}
+	// make handler
+	switch cfg.Encoding {
+	case encodingConsole:
+		handler := prettyLogger.NewWithOptions(os.Stdout, prettyLogger.Options{
+			Level:           prettyLogger.Level(level),
+			ReportTimestamp: true,
+			ReportCaller:    true,
+		})
+		log = slog.New(handler)
+	case encodingJSON:
+		handler := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level})
+		log = slog.New(handler)
+	default:
+		panic(fmt.Errorf("logger encoding is not correct: %s", cfg.Encoding))
+	}
+	// add field with service name
+	log = log.With(serviceNameKey, cfg.ServiceName)
+
+	return log
+}

internal/provider/bybit/bybit.go

@@ -0,0 +1,74 @@
+// package bybit provides rates of cryptocurrencies from bybit exchange orderbook.
+package bybit
+
+import (
+	"context"
+	"crypto_alert_bot/internal/config"
+	"crypto_alert_bot/internal/entities"
+	"crypto_alert_bot/internal/provider"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"time"
+
+	"github.com/shopspring/decimal"
+)
+
+const (
+	// mainnetURL  = "https://api.bybit.com"
+	httpTimeout = time.Second * 10
+)
+
+type Bybit struct {
+	log    *slog.Logger
+	cfg    *config.Bybit
+	client *http.Client
+}
+
+func New(log *slog.Logger, cfg *config.Bybit) provider.Provider {
+	return &Bybit{
+		log: log,
+		cfg: cfg,
+		client: &http.Client{
+			Timeout: httpTimeout,
+		},
+	}
+}
+
+func (b *Bybit) symbol(pair *entities.Pair) string {
+	return fmt.Sprintf("%s%s", pair.BaseCurrency, pair.QuoteCurrency)
+}
+
+// Price returns the current price of the pair (base currency / quote currency).
+// e.g. BTC/USDT.
+func (b *Bybit) Price(ctx context.Context, pair entities.Pair) (*entities.Price, error) {
+	// build request
+	req := marketOrderbookReq{
+		Category: categorySpot,
+		Symbol:   b.symbol(&pair),
+	}
+	var resp marketOrderbookResp
+	// make request
+	err := b.makeRequest(ctx, http.MethodGet, "/v5/market/orderbook", req, &resp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make request: %w", err)
+	}
+	// get results
+	if len(resp.A) == 0 || len(resp.B) == 0 {
+		return nil, fmt.Errorf("incorrect response: nil data")
+	}
+	if len(resp.A[0]) != 2 || len(resp.B[0]) != 2 {
+		return nil, fmt.Errorf("incorrect response: nil prices")
+	}
+
+	askPrice := decimal.RequireFromString(resp.A[0][0])
+	bidPrice := decimal.RequireFromString(resp.B[0][0])
+	spread := askPrice.Sub(bidPrice)
+
+	return &entities.Price{
+		Ask:    askPrice,
+		Bid:    bidPrice,
+		Spread: spread,
+		Pair:   pair,
+	}, nil
+}

internal/provider/bybit/models.go

@@ -0,0 +1,32 @@
+package bybit
+
+const (
+	categorySpot    string = "spot"
+	categoryLinear  string = "linear"
+	categoryInverse string = "inverse"
+	categoryOption  string = "option"
+)
+
+type marketOrderbookReq struct {
+	// Product type. spot, linear, inverse, option
+	Category string `json:"category"`
+	// Symbol name, like BTCUSDT, uppercase only
+	Symbol string `json:"symbol"`
+	/*
+		Limit size for each bid and ask
+			spot: [1, 200]. Default: 1.
+		  linear&inverse: [1, 500]. Default: 25.
+		  option: [1, 25]. Default: 1.
+	*/
+	Limit *int `json:"limit,omitempty"`
+}
+
+type marketOrderbookResp struct {
+	S   string     `json:"s"`   // Symbol name.
+	A   [][]string `json:"a"`   // Ask, seller. Sorted by price in ascending order. a[0]: Ask price, a[1]: Ask size.
+	B   [][]string `json:"b"`   // Bid, buyer. Sorted by price in descending order. b[0]: Bid price, b[1]: Bid size.
+	Ts  int64      `json:"ts"`  // The timestamp (ms) that the system generates the data.
+	U   int        `json:"u"`   // Update ID, is always in sequence.
+	Seq int        `json:"seq"` // Cross sequence.
+	Cts int64      `json:"cts"` // The timestamp from the matching engine when this orderbook data is produced. It can be correlated with T from public trade channel.
+}

internal/provider/bybit/request.go

@@ -0,0 +1,138 @@
+package bybit
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+)
+
+type response struct {
+	RetCode    int             `json:"retCode"`
+	RetMsg     string          `json:"retMsg"`
+	Result     json.RawMessage `json:"result"`
+	Time       int64           `json:"time"`
+	RetExtInfo json.RawMessage `json:"retExtInfo"`
+}
+
+func (b *Bybit) makeRequest(ctx context.Context, method string, endpoint string, params any, v any) error {
+	// send request
+	var (
+		body []byte
+		err  error
+	)
+
+	switch method {
+	case http.MethodGet:
+		body, err = b.getRequest(ctx, endpoint, params)
+	case http.MethodPost:
+		body, err = b.postRequest(ctx, endpoint, params)
+	default:
+		return fmt.Errorf("method not correct")
+	}
+	if err != nil {
+		return fmt.Errorf("failed to make request: %w", err)
+	}
+
+	b.log.Debug("bybit request", "endpoint", endpoint, "params", params, "body", string(body))
+
+	var resp response
+	if err := json.Unmarshal(body, &resp); err != nil {
+		return fmt.Errorf("failed to parse response: %w", err)
+	}
+
+	if resp.RetCode != 0 {
+		return fmt.Errorf("response not ok: code: %d, msg: %s, info: %s, result: %s", resp.RetCode, resp.RetMsg, resp.RetExtInfo, resp.Result)
+	}
+	if v == nil {
+		return nil
+	}
+	if err := json.Unmarshal(resp.Result, v); err != nil {
+		return fmt.Errorf("failed to parse result: %w", err)
+	}
+
+	return nil
+}
+
+func (b *Bybit) getRequest(ctx context.Context, endPoint string, params any) ([]byte, error) {
+	// params to query
+	queryString := ""
+	if params != nil {
+		b, err := json.Marshal(params)
+		if err != nil {
+			return nil, err
+		}
+		var q map[string]any
+		if err := json.Unmarshal(b, &q); err != nil {
+			return nil, err
+		}
+		query := make(url.Values)
+		for k, v := range q {
+			query.Add(k, fmt.Sprint(v))
+		}
+		queryString = query.Encode()
+	}
+
+	// make request
+	request, err := http.NewRequest("GET", b.cfg.BaseURL+endPoint+"?"+queryString, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make request: %w", err)
+	}
+
+	request = request.WithContext(ctx)
+
+	request.Header.Set("Content-Type", "application/json")
+	// b.setRequestAPIHeaders(request, []byte(queryString))
+
+	// get response
+	response, err := b.client.Do(request)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make request: %w", err)
+	}
+
+	defer response.Body.Close()
+
+	body, err := io.ReadAll(response.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	return body, nil
+}
+
+func (b *Bybit) postRequest(ctx context.Context, endPoint string, params any) ([]byte, error) {
+	// params to json
+	jsonData, err := json.Marshal(params)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal params: %w", err)
+	}
+
+	// make request
+	request, err := http.NewRequest("POST", b.cfg.BaseURL+endPoint, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return nil, fmt.Errorf("failed to make request: %w", err)
+	}
+
+	request = request.WithContext(ctx)
+
+	request.Header.Set("Content-Type", "application/json")
+	// b.setRequestAPIHeaders(request, jsonData)
+
+	// get response
+	response, err := b.client.Do(request)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make request: %w", err)
+	}
+
+	defer response.Body.Close()
+
+	body, err := io.ReadAll(response.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	return body, nil
+}

internal/provider/provider.go

@@ -0,0 +1,12 @@
+package provider
+
+import (
+	"context"
+	"crypto_alert_bot/internal/entities"
+)
+
+type Provider interface {
+	// Price returns the current price of the pair (base currency / quote currency).
+	// e.g. BTC/USDT.
+	Price(ctx context.Context, pair entities.Pair) (*entities.Price, error)
+}