var fs = require("fs"),
    auth = require("basic-auth"),
    md5 = require("apache-md5");
var heads = require("robohydra").heads,
    RoboHydraHead = heads.RoboHydraHead;

function loadPasswords(filePath) {
    var passwordFileContents = fs.readFileSync(filePath).toString();
    var passwords = {};

    passwordFileContents.split("\n").forEach(function(line) {
        var colonIndex = line.indexOf(":");
        var user = line.slice(0, colonIndex),
            pass = line.slice(colonIndex + 1);

        if (user && pass) {
            passwords[user] = pass;
        }
    });

    return passwords;
}

function authHeadForPasswordFile(passwordFilePath) {
    var passwords = loadPasswords(passwordFilePath);

    return new RoboHydraHead({
        name: 'admin-ui-auth',
        path: '/robohydra-admin.*',
        handler: function(req, res, next) {
            var credentials = auth(req) || {};
            var hashedPass = passwords[credentials.name];

            if (passwords.hasOwnProperty(credentials.name) &&
                    md5(credentials.pass, hashedPass) === hashedPass) {
                next(req, res);
                return;
            }

            res.statusCode = 401;
            res.headers['WWW-Authenticate'] = 'Basic realm="example"';
            res.send('Access denied');
        }
    });
}

module.exports.getBodyParts = function(conf) {
    var passwordFilePath = conf.passwordpath || "htpasswd";
    var authHead = authHeadForPasswordFile(passwordFilePath);

    conf.robohydra.registerDynamicHead(authHead, {priority: "admin"});

    return {};
};