import { compileStringAsync } from "sass";
import { pathToFileURL } from "node:url";
import type { Loader, LoaderFile } from "../../contracts/index.ts";
import { compileCss, type CompileOptions } from "./compiler.ts";

export interface SassLoaderOptions extends CompileOptions {
	/** Directory scanned by the Sass integration, relative to the project root. */
	dir?: string;
	/** Extra directories searched by Sass `@use` and `@import`. */
	loadPaths?: string[];
}

/**
 * Compiles Sass to CSS and then runs it through STCSS. This lets a project
 * move Sass files over incrementally while keeping one CSS output path.
 */
export function sassLoader(options: SassLoaderOptions = {}): Loader {
	return {
		name: "sass",
		extensions: [".scss", ".sass"],
		async load(file: LoaderFile) {
			const result = await compileStringAsync(file.source, {
				url: pathToFileURL(file.path),
				loadPaths: options.loadPaths,
			});
			return { data: {}, content: compileCss(result.css, options) };
		},
	};
}