import { getCustomIcon } from './custom';
import { searchForIcon } from './modern';
import { warnOnce } from './install-pkg';
import type { IconifyLoaderOptions } from './types';

export const isNode = typeof process < 'u' && typeof process.stdout < 'u';

export async function loadIcon(
	collection: string,
	icon: string,
	options?: IconifyLoaderOptions
): Promise<string | undefined> {
	const custom = options?.customCollections?.[collection];

	if (custom) {
		const result = await getCustomIcon(custom, collection, icon, options);
		if (result) {
			return result;
		}
	}

	if (!isNode) {
		return undefined;
	}

	return await loadNodeBuiltinIcon(collection, icon, options);
}

async function importFsModule(): Promise<typeof import('./fs') | undefined> {
	try {
		return await import('./fs');
	} catch {
		try {
			// cjs environments
			// eslint-disable-next-line @typescript-eslint/no-var-requires
			return require('./fs.js') as Promise<
				typeof import('./fs') | undefined
			>;
		} catch {
			return undefined;
		}
	}
}

async function loadNodeBuiltinIcon(
	collection: string,
	icon: string,
	options?: IconifyLoaderOptions,
	warn = true
): Promise<string | undefined> {
	type IconifyJSON = Parameters<typeof searchForIcon>[0];
	type LoadCollectionFromFS = (
		collection: string,
		autoInstall?: boolean
	) => Promise<IconifyJSON>;
	// eslint-disable-next-line @typescript-eslint/ban-ts-comment
	// @ts-ignore
	const {
		loadCollectionFromFS,
	}: {
		loadCollectionFromFS: LoadCollectionFromFS;
	} = await importFsModule();
	const iconSet = await loadCollectionFromFS(
		collection,
		options?.autoInstall
	);
	if (iconSet) {
		// possible icon names
		const ids = [
			icon,
			icon.replace(/([a-z])([A-Z])/g, '$1-$2').toLowerCase(),
			icon.replace(/([a-z])(\d+)/g, '$1-$2'),
		];
		return await searchForIcon(iconSet, collection, ids, options);
	}

	if (warn) {
		warnOnce(
			`failed to load \`@iconify-json/${collection}\`, have you installed it?`
		);
	}
}