add user models

internal/data/models.go

@@ -6,7 +6,8 @@ import (
 )
 
 var (
-	ErrRecordNotFound = errors.New("record not found")
+	ErrRecordNotFound      = errors.New("record not found")
+	ErrRecordAlreadyExists = errors.New("channel already in database")
 )
 
 // struct Models wraps the models, making them callable
@@ -17,6 +18,11 @@ type Models struct {
 		Get(login string) (*Channel, error)
 		Delete(login string) error
 	}
+	User interface {
+		Insert(channel *Channel) error
+		Get(login string) (*Channel, error)
+		Delete(login string) error
+	}
 }
 
 func NewModels(db *sql.DB) Models {

internal/data/users.go

@@ -0,0 +1,103 @@
+package data
+
+import (
+	"database/sql"
+	"errors"
+	"time"
+)
+
+type User struct {
+	ID       int       `json:"id"`
+	AddedAt  time.Time `json:"-"`
+	Login    string    `json:"login"`
+	TwitchID string    `json:"twitchid"`
+	Level    int       `json:"level"`
+}
+
+type UserModel struct {
+	DB *sql.DB
+}
+
+func (u UserModel) Insert(user *User) error {
+	query := `
+	INSERT INTO users(login, twitchid, level)
+	VALUES ($1, $2, $3)
+	ON CONFLICT (login)
+	DO NOTHING
+	RETURNING id, added_at;
+	`
+
+	args := []interface{}{user.Login, user.TwitchID, 100}
+
+	// Execute the query returning the number of affected rows.
+	result, err := u.DB.Exec(query, args...)
+	if err != nil {
+		return err
+	}
+
+	// Check how many rows were affected.
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+
+	if rowsAffected == 0 {
+		return ErrRecordAlreadyExists
+	}
+
+	return nil
+}
+
+func (u UserModel) Get(login string) (*User, error) {
+	query := `
+	SELECT id, added_at, login, twitchid, level
+	FROM users
+	WHERE login = $1`
+
+	var user User
+
+	err := u.DB.QueryRow(query, login).Scan(
+		&user.ID,
+		&user.AddedAt,
+		&user.Login,
+		&user.TwitchID,
+		&user.Level,
+	)
+
+	if err != nil {
+		switch {
+		case errors.Is(err, sql.ErrNoRows):
+			return nil, ErrRecordNotFound
+		default:
+			return nil, err
+		}
+	}
+
+	return &user, nil
+}
+
+func (u UserModel) Delete(login string) error {
+	// Prepare the statement.
+	query := `
+	DELETE FROM users
+	WHERE login = $1`
+
+	// Execute the query returning the number of affected rows.
+	result, err := u.DB.Exec(query, login)
+	if err != nil {
+		return err
+	}
+
+	// Check how many rows were affected.
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+
+	// We want atleast 1, if it is 0 the entry did not exist.
+	if rowsAffected == 0 {
+		return ErrRecordNotFound
+	}
+
+	return nil
+}

migrations/000002_create_users_table.down.sql

@@ -0,0 +1 @@
+DROP TABLE IF EXISTS users;

migrations/000002_create_users_table.up.sql

@@ -0,0 +1,7 @@
+CREATE TABLE IF NOT EXISTS users (
+   id bigserial PRIMARY KEY,
+   added_at timestamp(0) with time zone NOT NULL DEFAULT NOW(),
+   login text NOT NULL,
+   twitchid text UNIQUE NOT NULL,
+   level integer NOT NULL
+);