/*
    Copyright (c) 2014 Google Inc. All rights reserved.

    Use of this source code is governed by the MIT License, available in this package's LICENSE file
    or at http://opensource.org/licenses/MIT.
 */
const path = require('path');

function resolvePaths({filepath}, paths) {
    if (!paths) {
        return [];
    }

    return paths.slice(0).map(p => path.resolve(filepath, p));
}

function requirePaths(parentModule, opts) {
    const result = {
        before: [],
        after: []
    };

    if (!parentModule) {
        return result;
    }

    if (Array.isArray(opts)) {
        result.before = resolvePaths(parentModule, opts);
    } else {
        result.before = resolvePaths(parentModule, opts.before);
        result.after = resolvePaths(parentModule, opts.after);
    }

    return result;
}

exports.before = function before(targetPath, parentModule, opts) {
    const resolvedPaths = requirePaths(parentModule, opts);

    return `module.paths = ${JSON.stringify(resolvedPaths.before)}.concat(module.paths)` +
        `.concat(${JSON.stringify(resolvedPaths.after)}); `;
};

exports.after = function after() {
    return '';
};