Add readonly keyword to write-once class properties

Related to #1183.

The readonly keyword helps us to enforce that fundamental properties
of a class do not change (such as the ID of a player, sector, account,
etc.). Once they are defined, they cannot be defined again.

Readonly properties that are passed into the constructor should also
use constructor promotion to further simplify their definition.

Additional notes:

* For attributes that are objects, readonly does _not_ mean constant.
  That is, while the object cannot be overwritten, its internal state
  can still be modified.

* For readonly properties that have an associated getter function, we
  can (and should) remove the getter and simply make the property
  public. This is logically equivalent, but with less overhead. We do
  not do this here because it is a massive change.

src/lib/Default/AbstractSmrAccount.php

@@ -33,8 +33,8 @@ abstract class AbstractSmrAccount {
 	];
 
 	protected Smr\Database $db;
+	protected readonly string $SQL;
 
-	protected int $account_id;
 	protected string $login;
 	protected string $passwordHash;
 	protected string $email;
@@ -74,7 +74,6 @@ abstract class AbstractSmrAccount {
 	protected string $friendlyColour;
 	protected string $neutralColour;
 	protected string $enemyColour;
-	protected string $SQL;
 
 	protected bool $npc;
 
@@ -202,14 +201,13 @@ public static function getUserScoreCaseStatement(Smr\Database $db): array {
 		return ['CASE' => $case, 'IN' => implode(',', $userRankingTypes)];
 	}
 
-	protected function __construct(int $accountID) {
+	protected function __construct(protected readonly int $accountID) {
 		$this->db = Smr\Database::getInstance();
 		$this->SQL = 'account_id = ' . $this->db->escapeNumber($accountID);
 		$dbResult = $this->db->read('SELECT * FROM account WHERE ' . $this->SQL . ' LIMIT 1');
 
 		if ($dbResult->hasRecord()) {
 			$dbRecord = $dbResult->record();
-			$this->account_id = $dbRecord->getInt('account_id');
 
 			$this->login = $dbRecord->getField('login');
 			$this->passwordHash = $dbRecord->getField('password');
@@ -353,7 +351,7 @@ public function updateIP(): void {
 
 		// save...first make sure there isn't one for these keys (someone could double click and get error)
 		$this->db->replace('account_has_ip', [
-			'account_id' => $this->db->escapeNumber($this->account_id),
+			'account_id' => $this->db->escapeNumber($this->accountID),
 			'time' => $this->db->escapeNumber(Smr\Epoch::time()),
 			'ip' => $this->db->escapeString($curr_ip),
 			'host' => $this->db->escapeString($host),
@@ -510,7 +508,7 @@ public function getReferrer(): SmrAccount {
 	public function log(int $log_type_id, string $msg, int $sector_id = 0): void {
 		if ($this->isLoggingEnabled()) {
 			$this->db->insert('account_has_logs', [
-				'account_id' => $this->db->escapeNumber($this->account_id),
+				'account_id' => $this->db->escapeNumber($this->accountID),
 				'microtime' => $this->db->escapeMicrotime(Smr\Epoch::microtime()),
 				'log_type_id' => $this->db->escapeNumber($log_type_id),
 				'message' => $this->db->escapeString($msg),
@@ -661,7 +659,7 @@ public function equals(self $other): bool {
 	}
 
 	public function getAccountID(): int {
-		return $this->account_id;
+		return $this->accountID;
 	}
 
 	/**

src/lib/Default/AbstractSmrLocation.php

@@ -7,9 +7,8 @@ class AbstractSmrLocation {
 	protected static array $CACHE_SECTOR_LOCATIONS = [];
 
 	protected Smr\Database $db;
-	protected string $SQL;
+	protected readonly string $SQL;
 
-	protected int $typeID;
 	protected string $name;
 	protected ?string $processor;
 	protected string $image;
@@ -114,9 +113,12 @@ public static function getLocation(int $locationTypeID, bool $forceUpdate = fals
 		return self::$CACHE_LOCATIONS[$locationTypeID];
 	}
 
-	protected function __construct(int $locationTypeID, Smr\DatabaseRecord $dbRecord = null) {
+	protected function __construct(
+		protected readonly int $typeID,
+		Smr\DatabaseRecord $dbRecord = null
+	) {
 		$this->db = Smr\Database::getInstance();
-		$this->SQL = 'location_type_id = ' . $this->db->escapeNumber($locationTypeID);
+		$this->SQL = 'location_type_id = ' . $this->db->escapeNumber($typeID);
 
 		if ($dbRecord === null) {
 			$dbResult = $this->db->read('SELECT * FROM location_type WHERE ' . $this->SQL . ' LIMIT 1');
@@ -127,12 +129,11 @@ protected function __construct(int $locationTypeID, Smr\DatabaseRecord $dbRecord
 		$locationExists = $dbRecord !== null;
 
 		if ($locationExists) {
-			$this->typeID = $dbRecord->getInt('location_type_id');
 			$this->name = $dbRecord->getField('location_name');
 			$this->processor = $dbRecord->getField('location_processor');
 			$this->image = $dbRecord->getField('location_image');
 		} else {
-			throw new Exception('Cannot find location: ' . $locationTypeID);
+			throw new Exception('Cannot find location: ' . $typeID);
 		}
 	}
 

src/lib/Default/AbstractSmrPlayer.php

@@ -19,10 +19,8 @@ abstract class AbstractSmrPlayer {
 	protected static array $CACHE_PLAYERS = [];
 
 	protected Smr\Database $db;
-	protected string $SQL;
+	protected readonly string $SQL;
 
-	protected int $accountID;
-	protected int $gameID;
 	protected string $playerName;
 	protected int $playerID;
 	protected int $sectorID;
@@ -199,7 +197,11 @@ public static function getPlayerByPlayerName(string $playerName, int $gameID, bo
 		throw new Smr\Exceptions\PlayerNotFound('Player Name not found.');
 	}
 
-	protected function __construct(int $gameID, int $accountID, Smr\DatabaseRecord $dbRecord = null) {
+	protected function __construct(
+		protected readonly int $gameID,
+		protected readonly int $accountID,
+		Smr\DatabaseRecord $dbRecord = null
+	) {
 		$this->db = Smr\Database::getInstance();
 		$this->SQL = 'account_id = ' . $this->db->escapeNumber($accountID) . ' AND game_id = ' . $this->db->escapeNumber($gameID);
 
@@ -213,8 +215,6 @@ protected function __construct(int $gameID, int $accountID, Smr\DatabaseRecord $
 			throw new Smr\Exceptions\PlayerNotFound('Invalid accountID: ' . $accountID . ' OR gameID: ' . $gameID);
 		}
 
-		$this->accountID = $accountID;
-		$this->gameID = $gameID;
 		$this->playerName = $dbRecord->getField('player_name');
 		$this->playerID = $dbRecord->getInt('player_id');
 		$this->sectorID = $dbRecord->getInt('sector_id');

src/lib/Default/AbstractSmrPort.php

@@ -30,9 +30,8 @@ class AbstractSmrPort {
 	public const RAZE_PAYOUT = 0.75; // fraction of base payout for razing
 
 	protected Smr\Database $db;
+	protected readonly string $SQL;
 
-	protected int $gameID;
-	protected int $sectorID;
 	protected int $shields;
 	protected int $combatDrones;
 	protected int $armour;
@@ -53,8 +52,6 @@ class AbstractSmrPort {
 	protected int $cachedTime;
 	protected bool $cacheIsValid = true;
 
-	protected string $SQL;
-
 	protected bool $hasChanged = false;
 	protected bool $isNew = false;
 
@@ -119,7 +116,11 @@ public static function getBaseExperience(int $cargo, int $distance): float {
 		return ($cargo / 13) * $distance;
 	}
 
-	protected function __construct(int $gameID, int $sectorID, Smr\DatabaseRecord $dbRecord = null) {
+	protected function __construct(
+		protected readonly int $gameID,
+		protected readonly int $sectorID,
+		Smr\DatabaseRecord $dbRecord = null
+	) {
 		$this->cachedTime = Smr\Epoch::time();
 		$this->db = Smr\Database::getInstance();
 		$this->SQL = 'sector_id = ' . $this->db->escapeNumber($sectorID) . ' AND game_id = ' . $this->db->escapeNumber($gameID);
@@ -132,8 +133,6 @@ protected function __construct(int $gameID, int $sectorID, Smr\DatabaseRecord $d
 		}
 		$this->isNew = $dbRecord === null;
 
-		$this->gameID = $gameID;
-		$this->sectorID = $sectorID;
 		if (!$this->isNew) {
 			$this->shields = $dbRecord->getInt('shields');
 			$this->combatDrones = $dbRecord->getInt('combat_drones');

src/lib/Default/SmrAlliance.php

@@ -5,10 +5,8 @@ class SmrAlliance {
 	protected static array $CACHE_ALLIANCES = [];
 
 	protected Smr\Database $db;
-	protected string $SQL;
+	protected readonly string $SQL;
 
-	protected int $gameID;
-	protected int $allianceID;
 	protected string $allianceName;
 	protected ?string $description;
 	protected string $password;
@@ -73,11 +71,11 @@ public static function getAllianceByName(string $name, int $gameID, bool $forceU
 		throw new Smr\Exceptions\AllianceNotFound('Alliance name not found');
 	}
 
-	protected function __construct(int $allianceID, int $gameID) {
+	protected function __construct(
+		protected readonly int $allianceID,
+		protected readonly int $gameID
+	) {
 		$this->db = Smr\Database::getInstance();
-
-		$this->allianceID = $allianceID;
-		$this->gameID = $gameID;
 		$this->SQL = 'alliance_id=' . $this->db->escapeNumber($allianceID) . ' AND game_id=' . $this->db->escapeNumber($gameID);
 
 		if ($allianceID != 0) {

src/lib/Default/SmrEnhancedWeaponEvent.php

@@ -8,11 +8,7 @@ class SmrEnhancedWeaponEvent {
 	protected const GRACE_PERIOD = 3600; // 1 hour
 	protected const DURATION = 21600; // 6 hours
 
-	protected int $gameID;
-	protected int $sectorID;
-	protected int $locationTypeID;
-	protected int $expires;
-	protected SmrWeapon $weapon;
+	protected readonly SmrWeapon $weapon;
 
 	/**
 	 * Return all the valid events for the given location in a sector.
@@ -114,12 +110,15 @@ private static function getEventFromDatabase(Smr\DatabaseRecord $dbRecord): self
 		);
 	}
 
-	protected function __construct(int $gameID, int $weaponTypeID, int $locationTypeID, int $sectorID, int $expires, bool $bonusAccuracy, bool $bonusDamage) {
-		$this->gameID = $gameID;
-		$this->locationTypeID = $locationTypeID;
-		$this->sectorID = $sectorID;
-		$this->expires = $expires;
-
+	protected function __construct(
+		protected readonly int $gameID,
+		protected readonly int $weaponTypeID,
+		protected readonly int $locationTypeID,
+		protected readonly int $sectorID,
+		protected readonly int $expires,
+		bool $bonusAccuracy,
+		bool $bonusDamage
+	) {
 		$this->weapon = SmrWeapon::getWeapon($weaponTypeID);
 		$this->weapon->setBonusDamage($bonusDamage);
 		$this->weapon->setBonusAccuracy($bonusAccuracy);

src/lib/Default/SmrForce.php

@@ -18,11 +18,8 @@ class SmrForce {
 	public const MAX_SDS = 5;
 
 	protected Smr\Database $db;
-	protected string $SQL;
+	protected readonly string $SQL;
 
-	protected int $ownerID;
-	protected int $sectorID;
-	protected int $gameID;
 	protected int $combatDrones = 0;
 	protected int $scoutDrones = 0;
 	protected int $mines = 0;
@@ -103,7 +100,12 @@ public static function tidyUpForces(SmrGalaxy $galaxyToTidy): void {
 		}
 	}
 
-	protected function __construct(int $gameID, int $sectorID, int $ownerID, Smr\DatabaseRecord $dbRecord = null) {
+	protected function __construct(
+		protected readonly int $gameID,
+		protected readonly int $sectorID,
+		protected readonly int $ownerID,
+		Smr\DatabaseRecord $dbRecord = null
+	) {
 		$this->db = Smr\Database::getInstance();
 		$this->SQL = 'game_id = ' . $this->db->escapeNumber($gameID) . '
 		              AND sector_id = ' . $this->db->escapeNumber($sectorID) . '
@@ -117,9 +119,6 @@ protected function __construct(int $gameID, int $sectorID, int $ownerID, Smr\Dat
 		}
 		$this->isNew = $dbRecord === null;
 
-		$this->gameID = $gameID;
-		$this->ownerID = $ownerID;
-		$this->sectorID = $sectorID;
 		if (!$this->isNew) {
 			$this->combatDrones = $dbRecord->getInt('combat_drones');
 			$this->scoutDrones = $dbRecord->getInt('scout_drones');

src/lib/Default/SmrGalaxy.php

@@ -10,10 +10,8 @@ class SmrGalaxy {
 	public const TYPES = [self::TYPE_RACIAL, self::TYPE_NEUTRAL, self::TYPE_PLANET];
 
 	protected Smr\Database $db;
-	protected string $SQL;
+	protected readonly string $SQL;
 
-	protected int $gameID;
-	protected int $galaxyID;
 	protected string $name;
 	protected int $width;
 	protected int $height;
@@ -23,7 +21,7 @@ class SmrGalaxy {
 	protected int $startSector;
 
 	protected bool $hasChanged = false;
-	protected bool $isNew = false;
+	protected bool $isNew;
 
 	public static function clearCache(): void {
 		self::$CACHE_GALAXIES = [];
@@ -68,7 +66,12 @@ public static function createGalaxy(int $gameID, int $galaxyID): self {
 		return self::$CACHE_GALAXIES[$gameID][$galaxyID];
 	}
 
-	protected function __construct(int $gameID, int $galaxyID, bool $create = false, Smr\DatabaseRecord $dbRecord = null) {
+	protected function __construct(
+		protected readonly int $gameID,
+		protected readonly int $galaxyID,
+		bool $create = false,
+		Smr\DatabaseRecord $dbRecord = null
+	) {
 		$this->db = Smr\Database::getInstance();
 		$this->SQL = 'game_id = ' . $this->db->escapeNumber($gameID) . '
 		              AND galaxy_id = ' . $this->db->escapeNumber($galaxyID);
@@ -81,8 +84,6 @@ protected function __construct(int $gameID, int $galaxyID, bool $create = false,
 		}
 		$this->isNew = $dbRecord === null;
 
-		$this->gameID = $gameID;
-		$this->galaxyID = $galaxyID;
 		if (!$this->isNew) {
 			$this->name = $dbRecord->getField('galaxy_name');
 			$this->width = $dbRecord->getInt('width');

src/lib/Default/SmrGame.php

@@ -6,7 +6,6 @@ class SmrGame {
 
 	protected Smr\Database $db;
 
-	protected int $gameID;
 	protected string $name;
 	protected string $description;
 	protected int $joinTime;
@@ -81,13 +80,15 @@ public static function createGame(int $gameID): self {
 		return self::$CACHE_GAMES[$gameID];
 	}
 
-	protected function __construct(int $gameID, bool $create = false) {
+	protected function __construct(
+		protected readonly int $gameID,
+		bool $create = false
+	) {
 		$this->db = Smr\Database::getInstance();
 
 		$dbResult = $this->db->read('SELECT * FROM game WHERE game_id = ' . $this->db->escapeNumber($gameID) . ' LIMIT 1');
 		if ($dbResult->hasRecord()) {
 			$dbRecord = $dbResult->record();
-			$this->gameID = $dbRecord->getInt('game_id');
 			$this->name = $dbRecord->getField('game_name');
 			$this->description = $dbRecord->getField('game_description');
 			$this->joinTime = $dbRecord->getInt('join_time');
@@ -105,9 +106,7 @@ protected function __construct(int $gameID, bool $create = false) {
 			$this->allianceMaxVets = $dbRecord->getInt('alliance_max_vets');
 			$this->startingCredits = $dbRecord->getInt('starting_credits');
 		} elseif ($create === true) {
-			$this->gameID = $gameID;
 			$this->isNew = true;
-			return;
 		} else {
 			throw new Smr\Exceptions\GameNotFound('No such game: ' . $gameID);
 		}

src/lib/Default/SmrInvitation.php

@@ -5,12 +5,12 @@
  */
 class SmrInvitation {
 
-	private int $allianceID;
-	private int $gameID;
-	private int $receiverAccountID;
-	private int $senderAccountID;
-	private int $messageID;
-	private int $expires;
+	private readonly int $allianceID;
+	private readonly int $gameID;
+	private readonly int $receiverAccountID;
+	private readonly int $senderAccountID;
+	private readonly int $messageID;
+	private readonly int $expires;
 
 	public static function send(int $allianceID, int $gameID, int $receiverAccountID, int $senderAccountID, int $messageID, int $expires): void {
 		$db = Smr\Database::getInstance();