getting somewhere with db and auth

db/db.go

@@ -0,0 +1,122 @@
+package db
+
+import (
+	"crypto/sha256"
+	"database/sql"
+	"encoding/hex"
+	"errors"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+var db *sql.DB
+
+var (
+	ErrUserExists         = errors.New("username already exists")
+	ErrInvalidCredentials = errors.New("invalid username or password")
+)
+
+func InitDB(dbPath string) error {
+	var err error
+	db, err = sql.Open("sqlite3", dbPath)
+	if err != nil {
+		return err
+	}
+
+	// Create tables if they don't exist
+	_, err = db.Exec(`
+		CREATE TABLE IF NOT EXISTS players (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			username TEXT UNIQUE NOT NULL,
+			password_hash TEXT NOT NULL,
+			created_at DATETIME NOT NULL
+		);
+
+		CREATE TABLE IF NOT EXISTS player_states (
+			player_id INTEGER PRIMARY KEY,
+			x INTEGER NOT NULL,
+			y INTEGER NOT NULL,
+			last_seen DATETIME NOT NULL,
+			FOREIGN KEY(player_id) REFERENCES players(id)
+		);
+	`)
+	return err
+}
+
+func hashPassword(password string) string {
+	hash := sha256.Sum256([]byte(password))
+	return hex.EncodeToString(hash[:])
+}
+
+func RegisterPlayer(username, password string) (int, error) {
+	// Check if username exists
+	var exists bool
+	err := db.QueryRow("SELECT EXISTS(SELECT 1 FROM players WHERE username = ?)", username).Scan(&exists)
+	if err != nil {
+		return 0, err
+	}
+	if exists {
+		return 0, ErrUserExists
+	}
+
+	// Create new player
+	result, err := db.Exec(`
+		INSERT INTO players (username, password_hash, created_at)
+		VALUES (?, ?, ?)`,
+		username, hashPassword(password), time.Now().UTC(),
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	id, err := result.LastInsertId()
+	return int(id), err
+}
+
+func AuthenticatePlayer(username, password string) (int, error) {
+	var id int
+	var storedHash string
+	err := db.QueryRow(`
+		SELECT id, password_hash 
+		FROM players 
+		WHERE username = ?`,
+		username,
+	).Scan(&id, &storedHash)
+
+	if err == sql.ErrNoRows {
+		return 0, ErrInvalidCredentials
+	}
+	if err != nil {
+		return 0, err
+	}
+
+	if storedHash != hashPassword(password) {
+		return 0, ErrInvalidCredentials
+	}
+
+	return id, nil
+}
+
+func SavePlayerState(playerID int, x, y int) error {
+	_, err := db.Exec(`
+		INSERT OR REPLACE INTO player_states (
+			player_id, x, y, last_seen
+		) VALUES (?, ?, ?, ?)`,
+		playerID, x, y, time.Now().UTC(),
+	)
+	return err
+}
+
+func LoadPlayerState(playerID int) (x, y int, err error) {
+	err = db.QueryRow(`
+		SELECT x, y FROM player_states 
+		WHERE player_id = ?`,
+		playerID,
+	).Scan(&x, &y)
+	if err == sql.ErrNoRows {
+		// Return default position for new players
+		return 5, 5, nil
+	}
+	return x, y, err
+}