const SyncConnector = require('./sync-connector');
const nthash = require('smbhash').nthash;
const ldap = require('./ldapjs-extra');
const crypto = require('crypto');

class SyncLdap extends SyncConnector {
    async init() {
        let ldapConfig = await this.$.LdapConfig.findOne({
            fields: [
                'server',
                'rdn',
                'password',
                'userDn',
                'groupDn'
            ]
        });
        if (!ldapConfig) return false;

        let client = ldap.createClient({
            url: ldapConfig.server
        });
        await client.bind(ldapConfig.rdn, ldapConfig.password);

        Object.assign(this, {
            ldapConfig,
            client
        });
        return true;
    }

    async deinit() {
        if (this.client)
            await this.client.unbind();
    }

    async sync(info, userName, password) {
        let {
            ldapConfig,
            client,
            accountConfig
        } = this;

        let {user} = info;

        let res = await client.search(ldapConfig.userDn, {
            scope: 'sub',
            attributes: ['userPassword', 'sambaNTPassword'],
            filter: `&(uid=${userName})`
        });

        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.userDn}`;
            await client.del(dn);
        } catch (e) {
            if (e.name !== 'NoSuchObjectError') throw e;
        }

        if (!info.hasAccount) {
            if (oldUser)
                console.log(` -> '${userName}' removed from LDAP`);
            return;
        }

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

        let dn = `uid=${userName},${ldapConfig.userDn}`;
        let newEntry = {
            uid: userName,
            objectClass: [
                'inetOrgPerson',
                'posixAccount',
                'sambaSamAccount'
            ],
            cn: nickname,
            displayName: nickname,
            givenName: nameArgs[0],
            sn,
            mail: info.corporateMail,
            preferredLanguage: user.lang,
            homeDirectory: `${accountConfig.homedir}/${userName}`,
            loginShell: accountConfig.shell,
            uidNumber: info.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 client.add(dn, newEntry);
    }

    async syncGroups(info, userName) {
        let {
            ldapConfig,
            client
        } = this;

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

        if (!info.hasAccount) return;

        reqs = [];
        for (let role of info.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(client.modify(dn, change));
        }
        await Promise.all(reqs);
    }

    async getUsers(usersToSync) {
        let {
            ldapConfig,
            client
        } = this;

        let res = await client.search(ldapConfig.userDn, {
            scope: 'sub',
            attributes: ['uid'],
            filter: `uid=*`
        });

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

    async syncRoles() {
        let {
            $,
            ldapConfig,
            client,
            accountConfig
        } = this;

        // Delete roles

        let opts = {
            scope: 'sub',
            attributes: ['dn'],
            filter: 'objectClass=posixGroup'
        };
        let res = await client.search(ldapConfig.groupDn, opts);

        let reqs = [];
        await new Promise((resolve, reject) => {
            res.on('error', err => {
                if (err.name === 'NoSuchObjectError')
                    err = new Error(`Object '${ldapConfig.groupDn}' does not exist`);
                reject(err);
            });
            res.on('searchEntry', e => {
                reqs.push(client.del(e.object.dn));
            });
            res.on('end', resolve);
        });
        await Promise.all(reqs);

        // Recreate roles

        let roles = await $.Role.find({
            fields: ['id', 'name', 'description']
        });
        let roleRoles = await $.RoleRole.find({
            fields: ['role', 'inheritsFrom']
        });
        let roleMap = toMap(roleRoles, e => {
            return {key: e.inheritsFrom, val: e.role};
        });

        let accounts = await $.UserAccount.find({
            fields: ['id'],
            include: {
                relation: 'user',
                scope: {
                    fields: ['name', 'roleFk'],
                    where: {active: true}
                }
            }
        });
        let accountMap = toMap(accounts, e => {
            let user = e.user();
            if (!user) return;
            return {key: user.roleFk, val: user.name};
        });

        reqs = [];
        for (let role of roles) {
            let newEntry = {
                objectClass: ['top', 'posixGroup'],
                cn: role.name,
                description: role.description,
                gidNumber: accountConfig.idBase + role.id
            };

            let memberUid = [];
            for (let subrole of roleMap.get(role.id) || [])
                memberUid = memberUid.concat(accountMap.get(subrole) || []);

            if (memberUid.length) {
                memberUid.sort((a, b) => a.localeCompare(b));
                newEntry.memberUid = memberUid;
            }

            let dn = `cn=${role.name},${ldapConfig.groupDn}`;
            reqs.push(client.add(dn, newEntry));
        }
        await Promise.all(reqs);
    }
}

SyncConnector.connectors.push(SyncLdap);
module.exports = SyncLdap;

function toMap(array, fn) {
    let map = new Map();
    for (let item of array) {
        let keyVal = fn(item);
        if (!keyVal) continue;
        let key = keyVal.key;
        if (!map.has(key)) map.set(key, []);
        map.get(key).push(keyVal.val);
    }
    return map;
}