storage.go

package main

import (
	"database/sql"
	"fmt"

	_ "github.com/lib/pq"
)

type storage interface {
	CreateAccount(*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=axisbank1234 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(50),
		last_name varchar(50),
		number serial,
		balance serial,
		created_at timestamp
	)`

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



func (s *PostgresStore) CreateAccount(acc *Account) error{
	query := `insert into account 
	(first_name, last_name, number, balance, created_at)
	values ($1, $2, $3, $4, $5)`


	resp, err := s.db.Query(
		query, 
		acc.FirstName, 
		acc.LastName, 
		acc.Number, 
		acc.Balance, 
		acc.CreatedAt,
	)

	if err != nil{
		return err
	}


	fmt.Printf("%+v\n", resp)

	return nil
}

func (s *PostgresStore) UpdateAccount(*Account) error{
	return nil
}

func (s *PostgresStore) DeleteAccount(id int) error{
	_, err := s.db.Query("delete from account where id = $1", id)
	return err
}

func (s *PostgresStore) GetAccountByID(id int) (*Account, error){
	rows, err := s.db.Query("select * from account where id = $1", id)

	if err != nil{
		return nil, err
	}
	
	for rows.Next(){
		return scanIntoAccounts(rows)
	}

	return nil, fmt.Errorf("account %d not found", id)
}


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, err := scanIntoAccounts(rows) 

		if err != nil{
			return nil, err
		}

		accounts = append(accounts, account)
	}

	return accounts, nil
}


func scanIntoAccounts(rows *sql.Rows) (*Account, error) {
	account := new(Account)
	err := rows.Scan(
		&account.ID, 
		&account.FirstName, 
		&account.LastName, 
		&account.Number,
		&account.Balance,
		&account.CreatedAt);

	return account, err
}