package main

import (
	"database/sql"
	"fmt"
	_ "github.com/jackc/pgx/v4/stdlib"
)

func AddUser(db *sql.DB, name string, email string) (error, int) {
	row := db.QueryRow(`
    INSERT INTO users(name, email)
    VALUES($1, $2)
    RETURNING id;
  `, name, email)
	var id int
	err := row.Scan(&id)
	return err, id
}

func QueryUser(db *sql.DB, id int) (error, string, string) {
	row := db.QueryRow(`
  SELECT name, email
  FROM users
  WHERE id=$1;`, id)
	var name, email string
	err := row.Scan(&name, &email)
	return err, name, email
}

type Order struct {
	ID     int
	UID    int
	Amount int
	Desc   string
}

func AddOrder(db *sql.DB, uid int, amount int, desc string) (error, int) {
	row := db.QueryRow(`
    insert into orders(user_id, amount, description)
    values($1, $2, $3)
    returning id;
  `, uid, amount, desc)
	var id int
	err := row.Scan(&id)
	return err, id
}

func QueryOrders(db *sql.DB, uid int) ([]Order, error) {
	var orders []Order
	rows, err := db.Query(`
    select id, amount, description from orders where user_id=$1
  `, uid)
	if err != nil {
		return orders, err
	}
	defer rows.Close()
	for rows.Next() {
		var order Order
		order.UID = uid
		err := rows.Scan(&order.ID, &order.Amount, &order.Desc)
		if err != nil {
			return orders, err
		}
		orders = append(orders, order)
	}
	err = rows.Err()
	return orders, err
}

func main() {
	db, err := sql.Open("pgx", "host=localhost port=5432 user=baloo  dbname=lenslocked sslmode=disable")
	if err != nil {
		panic(err)
	}
	defer db.Close()
	err = db.Ping()
	if err != nil {
		panic(err)
	}

	fmt.Println("Connected!")
	_, err = db.Exec(`
  create table if not exists users (
    id serial primary key,
    name text,
    email text not null
  );
  create table if not exists orders (
    id serial primary key,
    user_id int not null,
    amount int,
    description text
  );`)
	if err != nil {
		panic(err)
	}
	fmt.Println("Tables created")

	var name string
	var email string

	// Create User
	/*
		name = "Jon Rob Baker"
		email = "demo@user.com"
		err, id := AddUser(db, name, email)
		if err != nil {
			panic(err)
		}
		fmt.Println("User ", id, " created")
	*/

	// Query User
	err, name, email = QueryUser(db, 5)
	if err == sql.ErrNoRows {
		fmt.Println("Error, no rows!")
	}
	if err != nil {
		panic(err)
	}
	fmt.Printf("User information: name=%s, email=%s\n", name, email)

	uid := 5

	// Create fake orders
	/*
		for i := 1; i <= 5; i++ {
			amount := i * 100
			desc := fmt.Sprintf("Fake order #%d", i)
			err, _ := AddOrder(db, uid, amount, desc)
			if err != nil {
				panic(err)
			}
		}
		fmt.Println("Created fake orders")
	*/

	// Query Orders
	orders, err := QueryOrders(db, uid)
	if err != nil {
		panic(err)
	}
	fmt.Println("Orders: ", orders)
}