package main

import (
	"database/sql"
	"fmt"
	"log"
	"os"

	"github.com/go-sql-driver/mysql"
)

var db *sql.DB

type Album struct {
	ID       int64
	Title    string
	Artist   string
	Price    float32
	Quantity int64
}

func main() {
	// Capture connection properties.
	cfg := mysql.Config{
		User:   os.Getenv("DBUSER"),
		Passwd: os.Getenv("DBPASS"),
		Net:    "tcp",
		Addr:   "127.0.0.1:3306",
		DBName: "recordings",
	}
	// Get a database handle.
	var err error
	db, err = sql.Open("mysql", cfg.FormatDSN())
	if err != nil {
		log.Fatal(err)
	}

	pingErr := db.Ping()
	if pingErr != nil {
		log.Fatal(pingErr)
	}
	fmt.Println("Connected!")

	// Hard-code ID 2 here to test the query.
	alb, err := albumByID(2)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("Album found: %v\n", alb)
}

// albumByID queries for the album with the specified ID.
func albumByID(id int64) (Album, error) {
	// An album to hold data from the returned row.
	var alb Album

	row := db.QueryRow("SELECT * FROM album WHERE id = ?", id)
	if err := row.Scan(&alb.ID, &alb.Title, &alb.Artist, &alb.Price, &alb.Quantity); err != nil {
		if err == sql.ErrNoRows {
			return alb, fmt.Errorf("albumsById %d: no such album", id)
		}
		return alb, fmt.Errorf("albumsById %d: %v", id, err)
	}
	return alb, nil
}