// Per-GameObject data (auto-creates DataManager on first use)
const gem = this.add.sprite(100, 100, 'gem');
gem.setData('value', 50);
gem.setData({ color: 'red', level: 2 });
gem.getData('value');            // 50
gem.getData(['value', 'color']); // [50, 'red']

// Increment / toggle helpers
gem.incData('value', 10);       // value is now 60
gem.incData('value', -5);       // value is now 55 (negative to decrement)
gem.toggleData('active');        // false -> true (starts from false if unset)

// Scene-level data (this.data is a DataManagerPlugin)
this.data.set('score', 0);
this.data.get('score');          // 0
this.data.values.score += 100;   // triggers changedata event

// Global registry (shared across ALL scenes)
this.registry.set('highScore', 9999);
// Any scene can read it:
this.registry.get('highScore');  // 9999

// After set('gold', 100), you can do:
data.values.gold += 50; // emits changedata and changedata-gold
// But you MUST use set() to create a key first -- direct assignment
// to values for a new key will NOT set up the event proxy.

// In a Scene's create():
this.data.set('lives', 3);

// Listen on the scene's event emitter
this.events.on('changedata-lives', (scene, value, previousValue) => {
    console.log('Lives changed from', previousValue, 'to', value);
});

// Scene A sets global data
this.registry.set('currentLevel', 1);

// Scene B reads it
const level = this.registry.get('currentLevel');

// Listen for registry changes (note: events fire on registry.events, NOT this.events)
this.registry.events.on('changedata-currentLevel', (game, value, previousValue) => {
    console.log('Level changed to', value);
});

const player = this.add.sprite(0, 0, 'player');
player.setData('hp', 100);

// Listen directly on the game object
player.on('changedata-hp', (gameObject, value, previousValue) => {
    if (value <= 0) {
        gameObject.destroy();
    }
});

// Single key
sprite.setData('speed', 200);
sprite.getData('speed'); // 200

// Multiple keys at once (object form)
sprite.setData({ speed: 200, direction: 'left', hp: 100 });

// Batch get with destructuring
const [speed, hp] = sprite.getData(['speed', 'hp']);

// Direct values access (read and write after initial set)
sprite.data.values.speed = 300; // emits changedata event
const s = sprite.data.values.speed; // 300

// Listen for ANY data change on a game object
sprite.on('changedata', (gameObject, key, value, previousValue) => {
    console.log(key, 'changed to', value);
});

// Listen for a SPECIFIC key change (preferred -- more efficient)
sprite.on('changedata-hp', (gameObject, value, previousValue) => {
    this.hpBar.setValue(value);
});

// Listen for new data being set (first time only)
sprite.on('setdata', (gameObject, key, value) => {
    console.log('New data key:', key);
});

// Listen for data removal
sprite.on('removedata', (gameObject, key, value) => {
    console.log('Removed:', key, 'was', value);
});

// HUD scene watches for score changes set by the Game scene
// In HUDScene.create():
this.registry.events.on('changedata-score', (game, value) => {
    this.scoreText.setText('Score: ' + value);
});
this.events.once('shutdown', () => {
    this.registry.events.off('changedata-score');
});

// In GameScene.update():
this.registry.set('score', this.score);

// You can store any value type: numbers, strings, booleans, objects, arrays
sprite.setData('inventory', ['sword', 'shield']);
sprite.setData('stats', { str: 10, dex: 8, int: 12 });

// CAUTION: mutating a stored object/array does NOT trigger changedata
const inv = sprite.getData('inventory');
inv.push('potion');
// No event fired! The reference didn't change.

// To trigger the event, re-set the key:
sprite.setData('inventory', [...inv]); // new array reference triggers changedata

// Merge defaults -- only sets keys that don't already exist
sprite.data.merge({ hp: 100, speed: 200, armor: 0 }, false);

// Merge and overwrite existing values
sprite.data.merge(savedState, true);

// Find all keys matching a regex
this.data.set('enemy_1_hp', 50);
this.data.set('enemy_2_hp', 80);
this.data.set('player_hp', 100);

const enemyData = this.data.query(/^enemy_/);
// { enemy_1_hp: 50, enemy_2_hp: 80 }

// Prevent all modifications (set, remove, inc, toggle all become no-ops)
sprite.data.freeze = true;
sprite.setData('hp', 0); // silently ignored
sprite.data.freeze = false;
sprite.setData('hp', 0); // works again

// Also available as a chainable method
sprite.data.setFreeze(true);

// Save to localStorage
function saveGame(scene) {
    const state = scene.data.getAll();
    localStorage.setItem('saveData', JSON.stringify(state));
}

// Restore from localStorage
function loadGame(scene) {
    const raw = localStorage.getItem('saveData');
    if (raw) {
        scene.data.merge(JSON.parse(raw), true);
    }
}

// get() returns a copy for primitives -- modifying the local variable does NOT update the DataManager
let score = this.data.get('score');
score += 10;  // local copy only, DataManager still has the old value

// values provides a live proxy -- assignment triggers CHANGE_DATA event
this.data.values.score += 10;  // updates the DataManager AND emits changedata-score

// For objects, get() returns the stored reference (not a deep copy)
const stats = this.data.get('stats');
stats.hp -= 10; // mutates the stored object but does NOT trigger events
this.data.set('stats', { ...stats }); // re-set with new reference to trigger event

create() {
    const handler = (game, value) => { this.updateHUD(value); };
    this.registry.events.on('changedata-score', handler);
    this.events.once('shutdown', () => {
        this.registry.events.off('changedata-score', handler);
    });
}

this.events.once('shutdown', () => {
    this.data.reset();
});