var _      = require('lodash');
var logger = require('./logger.js').getInstance();

module.exports = {
    getTarget: getTarget
};

function getTarget(req, config) {
    var newTarget;
    var router = config.router;

    if (_.isPlainObject(router)) {
        newTarget = getTargetFromProxyTable(req, router);
    } else if (_.isFunction(router)) {
        newTarget = router(req);
    }

    return newTarget;
}

function getTargetFromProxyTable(req, table) {
    var result;
    var host = req.headers.host;
    var path = req.url;

    var hostAndPath = host + path;

    _.forIn(table, function(value, key) {
        if (containsPath(key)) {

            if (hostAndPath.indexOf(key) > -1) {    // match 'localhost:3000/api'
                result = table[key];
                logger.debug('[HPM] Router table match: "%s"', key);
                return false;
            }
        } else {

            if (key === host) {                     // match 'localhost:3000'
                result = table[key];
                logger.debug('[HPM] Router table match: "%s"', host);
                return false;
            }

        }

    });

    return result;
}

function containsPath(v) {
    return v.indexOf('/') > -1;
}