import { glob } from 'glob';
import { Config } from './conf';
import { load_from_dir } from './fs';
import { ColorTheme, themes as builtin_themes, load_theme as load_builtin_theme, validate_theme } from '@doc-utils/color-themes';

export async function load_themes(conf: Config) {
	const themes: Record<string, ColorTheme> = { };

	for (const theme of builtin_themes) {
		themes[theme] = load_builtin_theme(theme);
	}

	if (conf.templates?.themes) {
		const local_themes = await glob(conf.templates.themes + '/**/theme.json');

		for (const theme_path of local_themes) {
			const segments = theme_path.split('/');
			const theme = segments[segments.length - 2];
			themes[theme] = await load_local_theme(conf, theme);
		}
	}

	return themes;
}

export async function load_theme(conf: Config, name: string) {
	if (name.includes('/')) {
		return null;
	}

	const local_theme = await load_local_theme(conf, name);

	if (local_theme) {
		return local_theme;
	}

	return load_builtin_theme(name);
}

export async function load_local_theme(conf: Config, name: string) {
	let json: string;

	try {
		json = await load_from_dir(conf.templates?.themes, `./${name}/theme.json`);
	}
	
	catch (error) {
		return null;
	}

	const theme = JSON.parse(json);
	validate_theme(theme);
	return theme;
}

export function render_theme_css_properties(theme: ColorTheme) {
	return Object
		.entries(theme.colors)
		.map(([ name, color ]) => {
			return `--theme-${name.replace(/_/g, '-')}: ${color};`;
		})
		.join('\n') + '\n';
}