import { ESLint } from "eslint";
import userscripts from "eslint-plugin-userscripts";

export interface LintOptions {
    fix?: boolean;
    isHomepageAllowed?: boolean;
    spaces?: number;
}

export interface LintResult {
    error: string;
    headers: string;
}

/**
 * @summary lints generated userscript headers
 * @param metadataBlock generated headers to lint
 * @param options lint configuration
 */
export const lintHeaders = async (metadataBlock: string, options: LintOptions = {}): Promise<LintResult> => {
    const { fix = false, isHomepageAllowed = false, spaces = 4 } = options;

    const eslint = new ESLint({
        baseConfig: {
            plugins: { userscripts },
            rules: {
                ...userscripts.configs.recommended.rules,
                "userscripts/align-attributes": ["error", spaces],
                "userscripts/use-homepage-and-url": isHomepageAllowed ? "error" : "off",
                "userscripts/filename-user": "off",
            },
        },
        overrideConfigFile: true,
        fix,
    });

    const results = await eslint.lintText(metadataBlock);

    const [{ output }] = results;

    const formatter = await eslint.loadFormatter("stylish");

    return {
        error: await formatter.format(results),
        headers: fix && output ? output : metadataBlock,
    };
};