'use strict';

exports = module.exports = {
    ExternalLdapError: ExternalLdapError,

    testConfig: testConfig,

    sync: sync
};

var assert = require('assert'),
    debug = require('debug')('box:ldapclient'),
    ldap = require('ldapjs'),
    settings = require('./settings.js'),
    util = require('util');

function ExternalLdapError(reason, errorOrMessage) {
    assert.strictEqual(typeof reason, 'string');
    assert(errorOrMessage instanceof Error || typeof errorOrMessage === 'string' || typeof errorOrMessage === 'undefined');

    Error.call(this);
    Error.captureStackTrace(this, this.constructor);

    this.name = this.constructor.name;
    this.reason = reason;
    if (typeof errorOrMessage === 'undefined') {
        this.message = reason;
    } else if (typeof errorOrMessage === 'string') {
        this.message = errorOrMessage;
    } else {
        this.message = 'Internal error';
        this.nestedError = errorOrMessage;
    }
}
util.inherits(ExternalLdapError, Error);
ExternalLdapError.EXTERNAL_ERROR = 'external error';
ExternalLdapError.INTERNAL_ERROR = 'internal error';
ExternalLdapError.INVALID_CREDENTIALS = 'invalid credentials';
ExternalLdapError.BAD_STATE = 'bad state';
ExternalLdapError.BAD_FIELD = 'bad field';
ExternalLdapError.NOT_FOUND = 'not found';

// performs service bind if required
function getClientAndConfig(callback) {
    assert.strictEqual(typeof callback, 'function');

    settings.getExternalLdapConfig(function (error, externalLdapConfig) {
        if (error) return callback(new ExternalLdapError(ExternalLdapError.INTERNAL_ERROR, error));

        var client = ldap.createClient({ url: externalLdapConfig.url });

        if (!externalLdapConfig.bindDn) return callback(null, client);

        client.bind(externalLdapConfig.bindDn, externalLdapConfig.bindPassword, function (error) {
            if (error instanceof ldap.InvalidCredentialsError) return callback(new ExternalLdapError(ExternalLdapError.INVALID_CREDENTIALS));
            if (error) return callback(new ExternalLdapError(ExternalLdapError.EXTERNAL_ERROR, error));

            debug('getClient: successful');

            callback(null, client, externalLdapConfig);
        });
    });
}

function testConfig(config, callback) {
    assert.strictEqual(typeof config, 'object');
    assert.strictEqual(typeof callback, 'function');

    if (!config.url) return callback(new ExternalLdapError(ExternalLdapError.BAD_FIELD, 'url must not be empty'));
    if (!config.baseDn) return callback(new ExternalLdapError(ExternalLdapError.BAD_FIELD, 'basedn must not be empty'));
    if (!config.filter) return callback(new ExternalLdapError(ExternalLdapError.BAD_FIELD, 'filter must not be empty'));

    var client = ldap.createClient({ url: config.url });

    if (!config.bindDn) return callback(null, client);

    client.bind(config.bindDn, config.bindPassword, function (error) {
        if (error instanceof ldap.InvalidCredentialsError) return callback(new ExternalLdapError(ExternalLdapError.INVALID_CREDENTIALS));
        if (error) return callback(new ExternalLdapError(ExternalLdapError.EXTERNAL_ERROR, error));

        var opts = {
            filter: config.filter,
            scope: 'sub'
        };

        client.search(config.baseDn, opts, function (error, result) {
            if (error) return callback(new ExternalLdapError(ExternalLdapError.EXTERNAL_ERROR, error));

            result.on('searchEntry', function (entry) {});
            result.on('error', function (error) { callback(new ExternalLdapError(ExternalLdapError.EXTERNAL_ERROR, error)); });
            result.on('end', function (result) { callback(); });
        });
    });
}

function sync(callback) {
    assert.strictEqual(typeof callback, 'function');

    getClientAndConfig(function (error, client, externalLdapConfig) {
        if (error) return callback(error);

        var opts = {
            filter: externalLdapConfig.filter,
            scope: 'sub'
        };

        client.search(externalLdapConfig.baseDn, opts, function(err, res) {
            assert.ifError(err);

            res.on('searchEntry', function(entry) {
                console.log('entry: ' + JSON.stringify(entry.object));
            });
            res.on('searchReference', function(referral) {
                console.log('referral: ' + referral.uris.join());
            });
            res.on('error', function(err) {
                console.error('error: ' + err.message);
            });
            res.on('end', function(result) {
                console.log('status: ' + result.status);
            });
        });
    });
}