instrument usecases & repository methods

internal/entities/instrument.go

@@ -1,6 +1,9 @@
 package entities
 
-type Pair struct {
+type InstrumentID string
+
+type Instrument struct {
+	ID            InstrumentID
 	BaseCurrency  string // base currency of the pair. e.g. BTC.
 	QuoteCurrency string // quote currency of the pair. e.g. USDT.
 }

internal/entities/price.go

@@ -3,8 +3,8 @@ package entities
 import "github.com/shopspring/decimal"
 
 type Price struct {
-	Ask    decimal.Decimal // limit seller / market buyer. ask > bid.
+	Ask        decimal.Decimal // limit seller / market buyer. ask > bid.
-	Bid    decimal.Decimal // limit buyer / market seller. bid < ask.
+	Bid        decimal.Decimal // limit buyer / market seller. bid < ask.
-	Spread decimal.Decimal // delta between ask and bid.
+	Spread     decimal.Decimal // delta between ask and bid.
-	Pair   Pair            // trading pair
+	Instrument Instrument      // trading pair
 }

internal/provider/bybit/bybit.go

@@ -36,17 +36,17 @@ func New(log *slog.Logger, cfg *config.Bybit) provider.Provider {
 	}
 }
 
-func (b *Bybit) symbol(pair *entities.Pair) string {
+func (b *Bybit) symbol(pair *entities.Instrument) 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) {
+func (b *Bybit) Price(ctx context.Context, instrument entities.Instrument) (*entities.Price, error) {
 	// build request
 	req := marketOrderbookReq{
 		Category: categorySpot,
-		Symbol:   b.symbol(&pair),
+		Symbol:   b.symbol(&instrument),
 	}
 	var resp marketOrderbookResp
 	// make request
@@ -67,9 +67,9 @@ func (b *Bybit) Price(ctx context.Context, pair entities.Pair) (*entities.Price,
 	spread := askPrice.Sub(bidPrice)
 
 	return &entities.Price{
-		Ask:    askPrice,
+		Ask:        askPrice,
-		Bid:    bidPrice,
+		Bid:        bidPrice,
-		Spread: spread,
+		Spread:     spread,
-		Pair:   pair,
+		Instrument: instrument,
 	}, nil
 }

internal/provider/provider.go

@@ -9,5 +9,5 @@ import (
 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)
+	Price(ctx context.Context, instrument entities.Instrument) (*entities.Price, error)
 }

internal/repository/postgresql/instrument.go

@@ -1 +1,54 @@
 package postgresql
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
+)
+
+const instrumentListQuery = `
+select i.id, c_base.symbol, c_quote.symbol
+from instrument i
+join currency c_base on c_base.id = i.base_currency_id
+join currency c_quote on c_quote.id = i.quoted_currency_id
+order by i.id
+offset $1 limit $2`
+
+func (p *Postgresql) InstrumentList(ctx context.Context, offset, limit int) ([]entities.Instrument, error) {
+	rows, err := p.db.Query(ctx, instrumentListQuery, offset, limit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to exec instrumentListQuery: %w", err)
+	}
+	defer rows.Close()
+
+	var instruments []entities.Instrument
+	for rows.Next() {
+		var inst entities.Instrument
+		if err := rows.Scan(&inst.ID, &inst.BaseCurrency, &inst.QuoteCurrency); err != nil {
+			return nil, fmt.Errorf("failed to scan instrument row: %w", err)
+		}
+		instruments = append(instruments, inst)
+	}
+
+	return instruments, nil
+}
+
+const createInstrumentQuery = `
+insert into instrument(base_currency_id, quoted_currency_id)
+values (
+  (select id from currency where symbol = $1),
+  (select id from currency where symbol = $2)
+)
+returning id`
+
+func (p *Postgresql) CreateInstrument(ctx context.Context, instrument *entities.Instrument) (entities.InstrumentID, error) {
+	var id entities.InstrumentID
+
+	err := p.db.QueryRow(ctx, createInstrumentQuery, instrument.BaseCurrency, instrument.QuoteCurrency).Scan(&id)
+	if err != nil {
+		return "", fmt.Errorf("failed to exec createInstrumentQuery: %w", err)
+	}
+
+	return id, nil
+}

internal/repository/repository.go

@@ -10,4 +10,7 @@ type Storage interface {
 	SaveUser(ctx context.Context, user *entities.User) (entities.UserID, error)
 	UserByID(ctx context.Context, id entities.UserID) (*entities.User, error)
 	UserByTelegramID(ctx context.Context, tgID entities.TelegramID) (*entities.User, error)
+
+	InstrumentList(ctx context.Context, offset, limit int) ([]entities.Instrument, error)
+	CreateInstrument(ctx context.Context, instrument *entities.Instrument) (entities.InstrumentID, error)
 }

internal/usecase/instrument.go

@@ -0,0 +1,28 @@
+package usecase
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
+)
+
+func (uc *Usecase) InstrumentList(ctx context.Context, offset, limit int) ([]entities.Instrument, error) {
+	instruments, err := uc.storage.InstrumentList(ctx, offset, limit)
+	if err != nil {
+		uc.log.Error("failed to list instruments", "offset", offset, "limit", limit, "err", err)
+		return nil, fmt.Errorf("failed to list instruments: %w", err)
+	}
+
+	return instruments, nil
+}
+
+func (uc *Usecase) CreateInstrument(ctx context.Context, instrument *entities.Instrument) (entities.InstrumentID, error) {
+	id, err := uc.storage.CreateInstrument(ctx, instrument)
+	if err != nil {
+		uc.log.Error("failed to create instrument", "instrument", instrument, "err", err)
+		return "", fmt.Errorf("failed to create instrument: %w", err)
+	}
+
+	return id, nil
+}