storage.go

package main

import (
	"database/sql"

	_ "github.com/lib/pq"
)

type Storage interface {
	CreateAccount(*Account) (*Account, error)
	DeleteAccount(int) error
	UpdateAccount(*Account) error
	GetAccounts() ([]*Account, error)
	GetAccountById(int) (*Account, error)
}

type PostgresStore struct {
	db *sql.DB
}

func NewPostgresStore() (*PostgresStore, error) {
	connStr := "user=postgres dbname=postgres password=gobank sslmode=disable"
	db, err := sql.Open("postgres", connStr)
	if err != nil {
		return nil, err
	}

	if err := db.Ping(); err != nil {
		return nil, err
	}

	return &PostgresStore{
		db: db,
	}, nil
}

func (s *PostgresStore) Init() error {
	return s.createAccountTable()
}

func (s *PostgresStore) createAccountTable() error {
	query := `CREATE TABLE IF NOT EXISTS account (
		id SERIAL PRIMARY KEY,
		first_name VARCHAR(100),
		last_name VARCHAR(100),
		number SERIAL,
		balance SERIAL,
		created_at TIMESTAMP
	)`

	_, err := s.db.Exec(query)
	return err
}

func (s *PostgresStore) CreateAccount(acc *Account) (*Account, error) {
	account := &Account{}

	stmt, err := s.db.Prepare(`INSERT INTO account 
	(first_name, last_name, number, balance, created_at)
	VALUES	
	($1, $2, $3, $4, $5)
	RETURNING * 
	`)
	defer stmt.Close()
	if err != nil {
		return nil, err
	}

	err = stmt.QueryRow(acc.FirstName, acc.LastName, acc.Number, acc.Balance, acc.CreatedAt).Scan(&account.ID, &account.FirstName, &account.LastName, &account.Number, &account.Balance, &account.CreatedAt)
	if err != nil {
		return nil, err
	}

	return account, nil
}
func (s *PostgresStore) DeleteAccount(id int) error {
	return nil
}
func (s *PostgresStore) UpdateAccount(*Account) error {
	return nil
}
func (s *PostgresStore) GetAccountById(id int) (*Account, error) {
	return nil, nil
}
func (s *PostgresStore) GetAccounts() ([]*Account, error) {
	rows, err := s.db.Query("SELECT * FROM account")
	if err != nil {
		return nil, err
	}
	accounts := []*Account{}
	for rows.Next() {
		account := &Account{}
		err := rows.Scan(
			&account.ID,
			&account.FirstName,
			&account.LastName,
			&account.Number,
			&account.Balance,
			&account.CreatedAt)
		if err != nil {
			return nil, err
		}

		accounts = append(accounts, account)
	}

	return accounts, nil
}