/**
 * Request Analyzer
 * Belongs to Decentraleyes.
 *
 * @author      Thomas Rientjes
 * @since       2014-05-30
 * @license     MPL 2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/.
 */

'use strict';

/**
 * Imports
 */

/**
 * Resource version mappings.
 * @var {object} mappings
 */
var mappings = require('./mappings');

/**
 * Public Methods
 */

function isValidCandidate(httpChannel) {

    if (mappings[httpChannel.URI.host] === undefined) {
        return false;
    }

    return httpChannel.requestMethod === 'GET';
}

function getLocalTarget(channelHost, channelPath) {

    var basePath, hostMappings, resourceMappings, localTarget;

    hostMappings = mappings[channelHost];

    // Ignore mapping files.
    if (channelPath.indexOf('.min.js.map') > -1) {
        return false;
    }

    if (channelPath.indexOf('.min.map') > -1) {
        return false;
    }

    basePath = matchBasePath(hostMappings, channelPath);

    if (!basePath) {
        return false;
    }

    resourceMappings = hostMappings[basePath];
    localTarget = matchResourcePath(resourceMappings, basePath, channelPath);

    if (!localTarget) {
        return false;
    }

    return localTarget;
}

/**
 * Exports
 */

exports.isValidCandidate = isValidCandidate;
exports.getLocalTarget = getLocalTarget;

/**
 * Private Methods
 */

function matchBasePath(hostMappings, channelPath) {

    for (var basePath in hostMappings) {

        if (hostMappings.hasOwnProperty(basePath)) {

            if (channelPath.indexOf(basePath) === 0) {
                return basePath;
            }
        }
    }

    return false;
}

function matchResourcePath(resourceMappings, basePath, channelPath) {

    var resourcePath, versionNumber, resourcePattern;

    resourcePath = channelPath.replace(basePath, '');

    versionNumber = resourcePath.match(/(?:\d{1,2}\.){1,3}\d{1,2}/);
    resourcePattern = resourcePath.replace(versionNumber, '{version}');

    for (var resourceMold in resourceMappings) {

        if (resourceMappings.hasOwnProperty(resourceMold)) {

            if (resourcePattern.indexOf(resourceMold) === 0) {

                var localTarget = {
                    path: resourceMappings[resourceMold].path,
                    type: resourceMappings[resourceMold].type
                };

                // Fill in the appropriate version number.
                localTarget.path = localTarget.path.replace('{version}', versionNumber);

                return localTarget;
            }
        }
    }

    return false;
}