const Unit = require('libflitter/Unit')
const LDAP = require('ldapjs')

class LDAPServerUnit extends Unit {
    static get name() {
        return 'ldap_server'
    }

    static get services() {
        return [...super.services, 'configs', 'express', 'output']
    }

    auth_dn() {
        return this.build_dn(this.config.schema.authentication_base)
    }

    anonymous() {
        return LDAP.parseDN('cn=anonymous')
    }

    build_dn(...parts) {
        parts = parts.flat()
        parts.push(this.config.schema.base_dc)
        return LDAP.parseDN(parts.join(','))
    }

    async go(app) {
        this.config = this.configs.get('ldap:server')
        const server_config = {}

        // If Flitter is configured to use an SSL certificate,
        // use it to enable LDAPS in the server.
        if ( this.express.use_ssl() ) {
            this.output.info('Using configured SSL certificate. The LDAP server will require an ldaps:// connection.')
            server_config.certificate = await this.express.ssl_certificate()
            server_config.key = await this.express.ssl_key()
        }

        this.server = LDAP.createServer(server_config)

        if ( this.config.max_connections ) {
            this.server.maxConnections = this.config.max_connections
        }

        this.output.info(`Will listen on ${this.config.interface}:${this.config.port}`)
        await new Promise((res, rej) => {
            this.server.listen(this.config.port, this.config.interface, () => {
                this.output.success(`LDAP server listening on port ${this.config.port}...`)
                res()
            })
        })
    }

    async cleanup(app) {
        this.server.close()
    }
}

module.exports = exports = LDAPServerUnit