const ldap = require('../../util/ldapjs-extra');
const nthash = require('smbhash').nthash;
const ssh = require('node-ssh');
const crypto = require('crypto');

module.exports = Self => {
    Self.remoteMethod('sync', {
        description: 'Synchronizes the user with the other user databases',
        accepts: [
            {
                arg: 'userName',
                type: 'string',
                description: 'The user name',
                required: true
            }, {
                arg: 'password',
                type: 'string',
                description: 'The password'
            }
        ],
        http: {
            path: `/:userName/sync`,
            verb: 'PATCH'
        }
    });

    Self.sync = async function(userName, password) {
        let $ = Self.app.models;

        let user = await $.Account.findOne({
            fields: ['id'],
            where: {name: userName}
        });
        let isSync = !await $.UserSync.exists(userName);

        if (user && isSync) return;

        let sync = await Self.syncInit();
        try {
            await Self.doSync(sync, userName, password);
        } finally {
            await Self.syncDeinit(sync);
        }
    };

    Self.syncInit = async function() {
        let $ = Self.app.models;

        let accountConfig = await $.AccountConfig.findOne({
            fields: ['homedir', 'shell', 'idBase']
        });
        let mailConfig = await $.MailConfig.findOne({
            fields: ['domain']
        });

        // LDAP

        let ldapClient;
        let ldapConfig = await $.LdapConfig.findOne({
            fields: ['host', 'rdn', 'password', 'baseDn', 'groupDn']
        });

        if (ldapConfig) {
            ldapClient = ldap.createClient({
                url: `ldap://${ldapConfig.host}:389`
            });

            let ldapPassword = Buffer
                .from(ldapConfig.password, 'base64')
                .toString('ascii');
            await ldapClient.bind(ldapConfig.rdn, ldapPassword);
        }

        // Samba

        let sambaClient;
        let sambaConfig = await $.SambaConfig.findOne({
            fields: ['host', 'sshUser', 'sshPass']
        });

        if (sambaConfig) {
            let sshPassword = Buffer
                .from(sambaConfig.sshPass, 'base64')
                .toString('ascii');

            sambaClient = new ssh.NodeSSH();
            await sambaClient.connect({
                host: sambaConfig.host,
                username: sambaConfig.sshUser,
                password: sshPassword
            });
        }

        return {
            accountConfig,
            mailConfig,
            ldapConfig,
            ldapClient,
            sambaClient
        };
    };

    Self.syncDeinit = async function(sync) {
        // FIXME: Cannot disconnect, hangs on undind() call
        // if (sync.ldapClient)
        //     await sync.ldapClient.unbind();

        if (sync.sambaClient)
            await sync.sambaClient.dispose();
    };

    Self.doSync = async function(sync, userName, password) {
        let $ = Self.app.models;
        let {
            accountConfig,
            mailConfig,
            ldapConfig,
            ldapClient,
            sambaClient
        } = sync;

        // Skip conflicting users
        if (!userName || ['administrator', 'root'].indexOf(userName.toLowerCase()) >= 0)
            return;

        let user = await $.Account.findOne({
            where: {name: userName},
            fields: [
                'id',
                'nickname',
                'email',
                'lang',
                'roleFk',
                'sync',
                'active',
                'created',
                'bcryptPassword',
                'updated'
            ],
            include: {
                relation: 'roles',
                scope: {
                    include: {
                        relation: 'inherits',
                        scope: {
                            fields: ['name']
                        }
                    }
                }
            }
        });

        let extraParams;
        let hasAccount = false;

        if (user) {
            extraParams = {
                corporateMail: `${userName}@${mailConfig.domain}`,
                uidNumber: accountConfig.idBase + user.id
            };

            hasAccount = user.active
                && await $.UserAccount.exists(user.id);
        }

        // Database

        if (user && user.active) {
            let bcryptPassword = password
                ? $.User.hashPassword(password)
                : user.bcryptPassword;

            await $.Account.upsertWithWhere({id: user.id},
                {bcryptPassword}
            );

            let appUser = {
                id: user.id,
                username: userName,
                email: user.email,
                created: user.created,
                updated: user.updated
            };
            if (bcryptPassword)
                appUser.password = bcryptPassword;

            if (await $.user.exists(user.id))
                await $.user.replaceById(user.id, appUser);
            else if (bcryptPassword)
                await $.user.upsert(appUser);
        } else
            await $.user.destroyAll({username: userName});

        // SIP

        if (hasAccount && password) {
            await Self.rawSql('CALL pbx.sip_setPassword(?, ?)',
                [user.id, password]
            );
        }

        // LDAP

        if (ldapClient) {
            // Deletes user

            res = await ldapClient.search(ldapConfig.baseDn, {
                scope: 'sub',
                attributes: ['userPassword', 'sambaNTPassword'],
                filter: `&(uid=${userName})(objectClass=inetOrgPerson)`
            });

            let oldUser;
            await new Promise((resolve, reject) => {
                res.on('error', reject);
                res.on('searchEntry', e => oldUser = e.object);
                res.on('end', resolve);
            });

            try {
                let dn = `uid=${userName},${ldapConfig.baseDn}`;
                await ldapClient.del(dn);
            } catch (e) {
                if (e.name !== 'NoSuchObjectError') throw e;
            }

            // Removes user from groups

            res = await ldapClient.search(ldapConfig.groupDn, {
                scope: 'sub',
                attributes: ['dn'],
                filter: `&(memberUid=${userName})(objectClass=posixGroup)`
            });

            let oldGroups = [];
            await new Promise((resolve, reject) => {
                res.on('error', reject);
                res.on('searchEntry', e => oldGroups.push(e.object));
                res.on('end', resolve);
            });

            let reqs = [];
            for (oldGroup of oldGroups) {
                let change = new ldap.Change({
                    operation: 'delete',
                    modification: {memberUid: userName}
                });
                reqs.push(ldapClient.modify(oldGroup.dn, change));
            }
            await Promise.all(reqs);

            if (hasAccount) {
                // Recreates user

                let nickname = user.nickname || userName;
                let nameArgs = nickname.split(' ');
                let sn = nameArgs.length > 1
                    ? nameArgs.splice(1).join(' ')
                    : '-';

                let dn = `uid=${userName},${ldapConfig.baseDn}`;
                let newEntry = {
                    uid: userName,
                    objectClass: [
                        'inetOrgPerson',
                        'posixAccount',
                        'sambaSamAccount'
                    ],
                    cn: nickname,
                    displayName: nickname,
                    givenName: nameArgs[0],
                    sn,
                    mail: extraParams.corporateMail,
                    preferredLanguage: user.lang,
                    homeDirectory: `${accountConfig.homedir}/${userName}`,
                    loginShell: accountConfig.shell,
                    uidNumber: extraParams.uidNumber,
                    gidNumber: accountConfig.idBase + user.roleFk,
                    sambaSID: '-'
                };

                if (password) {
                    let salt = crypto
                        .randomBytes(8)
                        .toString('base64');

                    let hash = crypto.createHash('sha1');
                    hash.update(password);
                    hash.update(salt, 'binary');
                    let digest = hash.digest('binary');

                    let ssha = Buffer
                        .from(digest + salt, 'binary')
                        .toString('base64');

                    Object.assign(newEntry, {
                        userPassword: `{SSHA}${ssha}`,
                        sambaNTPassword: nthash(password)
                    });
                } else if (oldUser) {
                    Object.assign(newEntry, {
                        userPassword: oldUser.userPassword,
                        sambaNTPassword: oldUser.sambaNTPassword
                    });
                }

                for (let prop in newEntry) {
                    if (newEntry[prop] == null)
                        delete newEntry[prop];
                }

                await ldapClient.add(dn, newEntry);

                // Adds user to groups

                let reqs = [];
                for (let role of user.roles()) {
                    let change = new ldap.Change({
                        operation: 'add',
                        modification: {memberUid: userName}
                    });
                    let roleName = role.inherits().name;
                    let dn = `cn=${roleName},${ldapConfig.groupDn}`;
                    reqs.push(ldapClient.modify(dn, change));
                }
                await Promise.all(reqs);
            }
        }

        // Samba

        if (sambaClient) {
            if (hasAccount) {
                try {
                    await sambaClient.exec('samba-tool user create', [
                        userName,
                        '--uid-number', `${extraParams.uidNumber}`,
                        '--mail-address', extraParams.corporateMail,
                        '--random-password'
                    ]);
                } catch (e) {}

                await sambaClient.exec('samba-tool user setexpiry', [
                    userName,
                    '--noexpiry'
                ]);

                if (password) {
                    await sambaClient.exec('samba-tool user setpassword', [
                        userName,
                        '--newpassword', password
                    ]);
                    await sambaClient.exec('samba-tool user enable', [
                        userName
                    ]);
                }

                await sambaClient.exec('mkhomedir_helper', [
                    userName,
                    '0027'
                ]);
            } else {
                try {
                    await sambaClient.exec('samba-tool user disable', [
                        userName
                    ]);
                } catch (e) {}
            }
        }

        // Mark as synchronized

        await $.UserSync.destroyById(userName);
    };
};