From 39b89fc404e1a6b715bf363ff788a2036cda4efa Mon Sep 17 00:00:00 2001
From: yash <yash.shatilov@gmail.com>
Date: Wed, 25 Feb 2026 20:55:10 +0300
Subject: [PATCH] user usecases & repository methods

---
 internal/entities/user.go              |  9 +++++
 internal/repository/postgresql/user.go | 46 ++++++++++++++++++++++++++
 internal/repository/repository.go      | 13 ++++++++
 internal/usecase/usecase.go            | 19 +++++++++++
 internal/usecase/user.go               | 38 +++++++++++++++++++++
 5 files changed, 125 insertions(+)
 create mode 100644 internal/entities/user.go
 create mode 100644 internal/repository/repository.go
 create mode 100644 internal/usecase/usecase.go
 create mode 100644 internal/usecase/user.go

diff --git a/internal/entities/user.go b/internal/entities/user.go
new file mode 100644
index 0000000..0d91e98
--- /dev/null
+++ b/internal/entities/user.go
@@ -0,0 +1,9 @@
+package entities
+
+type UserID string
+type TelegramID int64
+
+type User struct {
+	ID         UserID
+	TelegramID TelegramID
+}
diff --git a/internal/repository/postgresql/user.go b/internal/repository/postgresql/user.go
index 4e9a54a..d548d4c 100644
--- a/internal/repository/postgresql/user.go
+++ b/internal/repository/postgresql/user.go
@@ -1 +1,47 @@
 package postgresql
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
+)
+
+const saveUserQuery = "insert into users(telegram_id) values ($1) returning id"
+
+func (p *Postgresql) SaveUser(ctx context.Context, user *entities.User) (entities.UserID, error) {
+	var id entities.UserID
+
+	err := p.db.QueryRow(ctx, saveUserQuery, user.TelegramID).Scan(&id)
+	if err != nil {
+		return "", fmt.Errorf("failed to exec saveUserQuery: %w", err)
+	}
+
+	return id, nil
+}
+
+const getUserByIDQuery = "select id, telegram_id from users where id = $1"
+
+func (p *Postgresql) UserByID(ctx context.Context, id entities.UserID) (*entities.User, error) {
+	var user entities.User
+
+	err := p.db.QueryRow(ctx, getUserByIDQuery, id).Scan(&user.ID, &user.TelegramID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to exec getUserByIDQuery: %w", err)
+	}
+
+	return &user, nil
+}
+
+const getUserByTelegramIDQuery = "select id, telegram_id from users where telegram_id = $1"
+
+func (p *Postgresql) UserByTelegramID(ctx context.Context, tgID entities.TelegramID) (*entities.User, error) {
+	var user entities.User
+
+	err := p.db.QueryRow(ctx, getUserByTelegramIDQuery, tgID).Scan(&user.ID, &user.TelegramID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to exec getUserByTelegramIDQuery: %w", err)
+	}
+
+	return &user, nil
+}
diff --git a/internal/repository/repository.go b/internal/repository/repository.go
new file mode 100644
index 0000000..dd8d9c5
--- /dev/null
+++ b/internal/repository/repository.go
@@ -0,0 +1,13 @@
+package repository
+
+import (
+	"context"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
+)
+
+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)
+}
diff --git a/internal/usecase/usecase.go b/internal/usecase/usecase.go
new file mode 100644
index 0000000..dd03a22
--- /dev/null
+++ b/internal/usecase/usecase.go
@@ -0,0 +1,19 @@
+package usecase
+
+import (
+	"log/slog"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/repository"
+)
+
+type Usecase struct {
+	log     *slog.Logger
+	storage repository.Storage
+}
+
+func New(log *slog.Logger, storage repository.Storage) *Usecase {
+	return &Usecase{
+		log:     log,
+		storage: storage,
+	}
+}
diff --git a/internal/usecase/user.go b/internal/usecase/user.go
new file mode 100644
index 0000000..a48d12f
--- /dev/null
+++ b/internal/usecase/user.go
@@ -0,0 +1,38 @@
+package usecase
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.computernetthings.ru/yash/crypto_alert_bot/internal/entities"
+)
+
+func (uc *Usecase) RegisterNewUser(ctx context.Context, user *entities.User) error {
+	_, err := uc.storage.SaveUser(ctx, user)
+	if err != nil {
+		uc.log.Error("failed to register new user", "user", user, "err", err)
+		return fmt.Errorf("failed to register new user: %w", err)
+	}
+
+	return nil
+}
+
+func (uc *Usecase) UserByID(ctx context.Context, userID entities.UserID) (*entities.User, error) {
+	user, err := uc.storage.UserByID(ctx, userID)
+	if err != nil {
+		uc.log.Error("failed to get user by id", "user_id", userID, "err", err)
+		return nil, fmt.Errorf("failed to get user by id: %w", err)
+	}
+
+	return user, nil
+}
+
+func (uc *Usecase) UserByTgID(ctx context.Context, telegramID entities.TelegramID) (*entities.User, error) {
+	user, err := uc.storage.UserByTelegramID(ctx, telegramID)
+	if err != nil {
+		uc.log.Error("failed to get user by telegram id", "tg_id", telegramID, "err", err)
+		return nil, fmt.Errorf("failed to get user by telegram id: %w", err)
+	}
+
+	return user, nil
+}