import { _decorator, Button, Component, Label, Node } from 'cc';
import { App } from '../../app/App';

const { ccclass, property } = _decorator;

/**
 * The lobby, per LOBBY.md: one button that starts a game, and — since the save
 * module is already keeping them — the player's record.
 *
 * It owns no game logic. Starting a match is reported to `MainFlow` through
 * `onStartRequested`, which keeps the lobby ignorant of what a match even is.
 */
@ccclass('LobbyScreen')
export class LobbyScreen extends Component {
    @property(Label)
    playedLabel: Label | null = null;

    @property(Label)
    wonLabel: Label | null = null;

    @property(Label)
    lostLabel: Label | null = null;

    @property(Label)
    streakLabel: Label | null = null;

    @property(Node)
    statsPanel: Node | null = null;

    @property(Button)
    newGameButton: Button | null = null;

    /** Set by `MainFlow`. */
    onStartRequested: (() => void) | null = null;

    onLoad(): void {
        // Clicks are subscribed here rather than through the scene's clickEvents
        // list: the wiring stays visible in the source, and a renamed handler
        // becomes a compile error instead of a button that silently does nothing.
        this.newGameButton?.node.on(Button.EventType.CLICK, this.startGame, this);
    }

    onDestroy(): void {
        this.newGameButton?.node.off(Button.EventType.CLICK, this.startGame, this);
    }

    onEnable(): void {
        this.refresh();
    }

    /** Re-reads the saved statistics. Called whenever the lobby comes back into view. */
    refresh(): void {
        if (!App.exists) {
            return;
        }
        const stats = App.instance.stats;

        setText(this.playedLabel, `${stats.played}`);
        setText(this.wonLabel, `${stats.won}`);
        setText(this.lostLabel, `${stats.lost}`);
        setText(this.streakLabel, stats.bestStreak > 0
            ? `${stats.streak} (best ${stats.bestStreak})`
            : `${stats.streak}`);

        // Nothing to show before the first game — an empty table of zeroes is
        // worse than no table at all.
        if (this.statsPanel) {
            this.statsPanel.active = stats.played > 0;
        }
    }

    /** Wired to the New Game button in the scene. */
    startGame(): void {
        this.onStartRequested?.();
    }
}

function setText(label: Label | null, text: string): void {
    if (label) {
        label.string = text;
    }
}