import { Context } from 'runed';
import { createActiveDom } from '$uix/adom';
import type {
	AppOptions,
	AppDom,
	AppLangs,
	AppNums,
	AppMoney,
	AppDates,
	AppUnits,
	AppPresentation,
	AppLogger,
	Direction,
	DateOrder,
	HourCycle
} from './types';
import { fallbackDom, fallbackLangs, fallbackPresentation, consoleLogger } from './defaults';

/**
 * App — root service compositor.
 *
 * Holds references to all domain services. Owns no preferences directly —
 * each service owns its own state. App provides convenience getters/setters
 * that delegate to the appropriate service.
 *
 * All services that depend on locale receive `langs` at construction and
 * subscribe to `onLocaleChange` internally. When locale changes, each
 * recalculates its defaults unless the user has set an explicit override.
 */
export class App {
	// ── Services ────────────────────────────────────────────────────────
	readonly dom: AppDom;
	readonly langs: AppLangs;
	readonly nums: AppNums | undefined;
	readonly money: AppMoney | undefined;
	readonly dates: AppDates | undefined;
	readonly units: AppUnits | undefined;
	readonly presentation: AppPresentation;
	readonly logger: AppLogger;

	constructor(opts: AppOptions) {
		this.dom = opts.dom ?? createActiveDom();
		this.langs = opts.langs;
		this.nums = opts.nums;
		this.money = opts.money;
		this.dates = opts.dates;
		this.units = opts.units;
		this.presentation = opts.presentation;
		this.logger = opts.logger ?? consoleLogger;
	}

	// ── Convenience getters (delegate to services) ──────────────────────

	get currency(): string | undefined {
		return this.money?.getCurrency();
	}

	get dateOrder(): DateOrder | undefined {
		return this.dates?.getDateOrder();
	}

	get hourCycle(): HourCycle | undefined {
		return this.dates?.getHourCycle();
	}

	get theme(): string {
		return this.presentation.getTheme();
	}

	get mode(): 'light' | 'dark' {
		return this.presentation.getMode();
	}

	// ── Convenience setters (delegate to services) ──────────────────────

	setLocale(locale: string) {
		this.langs.setLocale(locale);
	}

	setCurrency(currency: string) {
		this.money?.setCurrency(currency);
	}

	setDir(dir: Direction | 'auto') {
		this.presentation.setDir(dir);
	}

	setTheme(theme: string) {
		this.presentation.setTheme(theme);
	}

	setMode(mode: 'light' | 'dark' | 'auto') {
		this.presentation.setMode(mode);
	}

	// ── Static distribution methods ─────────────────────────────────────

	static create(opts: AppOptions): App {
		const app = new App(opts);
		return _ctx.set(app);
	}

	static get(): App {
		return _ctx.getOr(_fallback);
	}

	static require(): App {
		const app = _ctx.getOr(null as unknown as App);
		if (!app) {
			throw new Error(
				'[app] No App found. Make sure this component is rendered inside a App.create() scope.'
			);
		}
		return app;
	}
}

// ── Module-level context ────────────────────────────────────────────────────

const _ctx = new Context<App>('App');

/**
 * Fallback App used when no <App> ancestor exists.
 * Only provides core services (langs, presentation, logger).
 * Optional services (nums, money, dates, units) are undefined —
 * components must handle their absence gracefully.
 */
const _fallback = new App({
	dom: fallbackDom,
	langs: fallbackLangs,
	presentation: fallbackPresentation,
	logger: consoleLogger
});