MusicServer/database.go

package main

import (
	"context"
	"fmt"
	"github.com/jackc/pgtype"
	"github.com/jackc/pgx/v4/pgxpool"
	"os"
	"time"
)

var dbPool *pgxpool.Pool

func initDB(host string, port int, user string, password string, dbname string) {

	psqlInfo := fmt.Sprintf("host=%s port=%d user=%s "+
		"password=%s dbname=%s sslmode=disable",
		host, port, user, password, dbname)

	fmt.Println(psqlInfo)

	var err error
	dbPool, err = pgxpool.Connect(context.Background(), psqlInfo)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
		os.Exit(1)
	}

	var success string
	err = dbPool.QueryRow(context.Background(), "select 'Successfully connected!'").Scan(&success)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println(success)
}

func closeDb() {
	dbPool.Close()
}

func getGameName(gameId int) string {
	var gameName = ""
	err := dbPool.QueryRow(context.Background(),
		"SELECT game_name FROM game WHERE id = $1", gameId).Scan(&gameName)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		return ""
	}
	return gameName
}

func setGameDeletionDate() {
	_, err := dbPool.Exec(context.Background(),
		"UPDATE game SET deleted=$1", time.Now())
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func clearSongs(gameId int) {
	if gameId == -1 {
		_, err := dbPool.Exec(context.Background(), "DELETE FROM song")
		if err != nil {
			_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
		}
	} else {
		_, err := dbPool.Exec(context.Background(), "DELETE FROM song where game_id=$1", gameId)
		if err != nil {
			_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
		}
	}
}

func clearGames() {
	_, err := dbPool.Exec(context.Background(), "DELETE FROM game")
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func updateGameName(id int, name string, path string) {
	_, err := dbPool.Exec(context.Background(),
		"UPDATE game SET game_name=$1, path=$2, last_changed=$3 WHERE id=$4",
		name, path, time.Now(), id)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func removeDeletionDate(id int) {
	_, err := dbPool.Exec(context.Background(),
		"UPDATE game SET deleted=null WHERE id=$1", id)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func addSong(song SongData) {
	_, err := dbPool.Exec(context.Background(),
		"INSERT INTO song(game_id, song_name, path) VALUES ($1, $2, $3)",
		song.gameId, song.songName, song.path)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func findSongsFromGame(id int) []SongData {
	rows, err := dbPool.Query(context.Background(),
		"SELECT song_name, path, times_played FROM song WHERE game_id = $1", id)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		return nil
	}

	var songDataList []SongData
	for rows.Next() {
		var songName string
		var path string
		var timesPlayed int

		err := rows.Scan(&songName, &path, &timesPlayed)
		if err != nil {
			_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		}

		songDataList = append(songDataList, SongData{
			gameId:      id,
			songName:    songName,
			path:        path,
			timesPlayed: timesPlayed,
		})
	}
	return songDataList
}

func getIdByGameName(name string) int {
	var gameId = -1
	err := dbPool.QueryRow(context.Background(),
		"SELECT id FROM game WHERE game_name = $1", name).Scan(&gameId)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		return -1
	}
	return gameId
}

func insertGame(name string, path string) int {
	gameId := -1
	err := dbPool.QueryRow(context.Background(),
		"INSERT INTO game(game_name, path, added) VALUES ($1, $2, $3) RETURNING id",
		name, path, time.Now()).Scan(&gameId)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		resetGameIdSeq()
		err2 := dbPool.QueryRow(context.Background(),
			"INSERT INTO game(game_name, path, added) VALUES ($1, $2, $3) RETURNING id",
			name, path, time.Now()).Scan(&gameId)
		if err2 != nil {
			_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
			return -1
		}
	}
	return gameId
}

func insertGameWithExistingId(id int, name string, path string) {
	_, err := dbPool.Exec(context.Background(),
		"INSERT INTO game(id, game_name, path, added) VALUES ($1, $2, $3, $4)",
		id, name, path, time.Now())
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func resetGameIdSeq() {
	_, err := dbPool.Query(context.Background(), "SELECT setval('game_id_seq', (SELECT MAX(id) FROM game)+1);")
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func findAllGames() []GameData {
	rows, err := dbPool.Query(context.Background(),
		"SELECT id, game_name, added, deleted, last_changed, path, times_played, last_played, number_of_songs "+
			"FROM game "+
			"ORDER BY game_name")
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
	}
	var gameList []GameData
	for rows.Next() {
		var id, timesPlayed int
		var numberOfSongs pgtype.Int4
		var gameName, path string
		var added, deleted, lastChanged, lastPlayed pgtype.Timestamp
		err := rows.Scan(&id, &gameName, &added, &deleted, &lastChanged, &path, &timesPlayed, &lastPlayed, &numberOfSongs)
		if err != nil {
			_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
		}
		gameList = append(gameList, GameData{
			id:            id,
			gameName:      gameName,
			added:         added.Time,
			deleted:       deleted.Time,
			lastChanged:   lastChanged.Time,
			path:          path,
			timesPlayed:   timesPlayed,
			lastPlayed:    lastPlayed.Time,
			numberOfSongs: numberOfSongs.Int,
		})
	}
	return gameList
}

func addGamePlayed(id int) {
	_, err := dbPool.Exec(context.Background(),
		"UPDATE game SET times_played=times_played+1, last_played=now() WHERE id=$1", id)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func addSongPlayed(id int, name string) {
	_, err := dbPool.Exec(context.Background(),
		"UPDATE song SET times_played=times_played+1 WHERE game_id=$1 AND song_name=$2", id, name)
	if err != nil {
		_, _ = fmt.Fprintf(os.Stderr, "Exec failed: %v\n", err)
	}
}

func testf() {
	rows, dbErr := dbPool.Query(context.Background(), "select game_name from game")
	if dbErr != nil {
		_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", dbErr)
		os.Exit(1)
	}
	for rows.Next() {
		var gameName string
		dbErr = rows.Scan(&gameName)
		if dbErr != nil {
			_, _ = fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", dbErr)
		}
		_, _ = fmt.Fprintf(os.Stderr, "%v\n", gameName)
	}
}