'use strict';

exports = module.exports = {
    start,
    status,

    DEFAULT_MEMORY_LIMIT: 256 * 1024 * 1024
};

const apps = require('./apps.js'),
    assert = require('assert'),
    blobs = require('./blobs.js'),
    BoxError = require('./boxerror.js'),
    debug = require('debug')('box:sftp'),
    docker = require('./docker.js'),
    hat = require('./hat.js'),
    infra = require('./infra_version.js'),
    paths = require('./paths.js'),
    safe = require('safetydance'),
    settings = require('./settings.js'),
    services = require('./services.js'),
    shell = require('./shell.js'),
    system = require('./system.js'),
    volumes = require('./volumes.js');

async function ensureKeys() {
    const sftpPrivateKey = await blobs.get(blobs.SFTP_PRIVATE_KEY);
    const sftpPublicKey = await blobs.get(blobs.SFTP_PUBLIC_KEY);

    if (!sftpPrivateKey || !sftpPublicKey) {
        debug('ensureSecrets: generating new sftp keys');
        if (!safe.child_process.execSync(`ssh-keygen -m PEM -t rsa -f "${paths.SFTP_KEYS_DIR}/ssh_host_rsa_key" -q -N ""`)) throw new BoxError(BoxError.OPENSSL_ERROR, `Could not generate sftp ssh keys: ${safe.error.message}`);
        const newSftpPublicKey = safe.fs.readFileSync(paths.SFTP_PUBLIC_KEY_FILE);
        await blobs.set(blobs.SFTP_PUBLIC_KEY, newSftpPublicKey);
        const newSftpPrivateKey = safe.fs.readFileSync(paths.SFTP_PRIVATE_KEY_FILE);
        await blobs.set(blobs.SFTP_PRIVATE_KEY, newSftpPrivateKey);
    } else {
        if (!safe.fs.writeFileSync(paths.SFTP_PUBLIC_KEY_FILE, sftpPublicKey)) throw new BoxError(BoxError.FS_ERROR, `Could not save sftp public key: ${safe.error.message}`);
        if (!safe.fs.writeFileSync(paths.SFTP_PRIVATE_KEY_FILE, sftpPrivateKey, { mode: 0o600 })) throw new BoxError(BoxError.FS_ERROR, `Could not save sftp private key: ${safe.error.message}`);
    }
}

async function start(existingInfra) {
    assert.strictEqual(typeof existingInfra, 'object');

    debug('start: re-creating container');

    const servicesConfig = await settings.getServicesConfig();
    const serviceConfig = servicesConfig['sftp'] || {};
    const tag = infra.images.sftp.tag;
    const memoryLimit = serviceConfig.memoryLimit || exports.DEFAULT_MEMORY_LIMIT;
    const memory = await system.getMemoryAllocation(memoryLimit);
    const cloudronToken = hat(8 * 128);

    await ensureKeys();

    const resolvedAppDataDir = safe.fs.realpathSync(paths.APPS_DATA_DIR);
    if (!resolvedAppDataDir) throw new BoxError(BoxError.FS_ERROR, `Could not resolve apps data dir: ${safe.error.message}`);

    const dataDirs = [{ hostDir: resolvedAppDataDir, mountDir: '/mnt/appsdata' }];

    // custom app data directories
    const allApps = await apps.list();
    for (const app of allApps) {
        if (!app.manifest.addons['localstorage'] || !app.storageVolumeId) continue;

        const hostDir = await apps.getStorageDir(app), mountDir = `/mnt/app-${app.id}`; // see also sftp:userSearchSftp
        if (!safe.fs.existsSync(hostDir)) { // this can fail if external mount does not have permissions for yellowtent user
            // do not create host path when cloudron is restoring. this will then create dir with root perms making restore logic fail
            debug(`Ignoring app data dir ${hostDir} for ${app.id} since it does not exist`);
            continue;
        }

        dataDirs.push({ hostDir, mountDir });
    }

    // volume directories
    dataDirs.push({ hostDir: '/mnt/volumes', mountDir: '/mnt/volumes' }); // managed volumes
    const allVolumes = await volumes.list();
    for (const volume of allVolumes) {
        if (volume.hostPath.startsWith('/mnt/volumes/')) continue; // skip managed volume

        if (!safe.fs.existsSync(volume.hostPath)) {
            debug(`Ignoring volume host path ${volume.hostPath} since it does not exist`);
            continue;
        }

        dataDirs.push({ hostDir: volume.hostPath, mountDir: `/mnt/volume-${volume.id}` });
    }

    // mail data dir
    const resolvedMailDataDir = safe.fs.realpathSync(paths.MAIL_DATA_DIR);
    if (!resolvedMailDataDir) throw new BoxError(BoxError.FS_ERROR, `Could not resolve mail data dir: ${safe.error.message}`);
    dataDirs.push({ hostDir: resolvedMailDataDir, mountDir: '/mnt/maildata' });

    const readOnly = !serviceConfig.recoveryMode ? '--read-only' : '';
    const cmd = serviceConfig.recoveryMode ? '/bin/bash -c \'echo "Debug mode. Sleeping" && sleep infinity\'' : '';

    const mounts = dataDirs.map(v => `-v "${v.hostDir}:${v.mountDir}"`).join(' ');
    const runCmd = `docker run --restart=always -d --name="sftp" \
                --hostname sftp \
                --net cloudron \
                --net-alias sftp \
                --log-driver syslog \
                --log-opt syslog-address=udp://127.0.0.1:2514 \
                --log-opt syslog-format=rfc5424 \
                --log-opt tag=sftp \
                -m ${memory} \
                --memory-swap ${memoryLimit} \
                --dns 172.18.0.1 \
                --dns-search=. \
                -p 222:22 \
                ${mounts} \
                -e CLOUDRON_SFTP_TOKEN="${cloudronToken}" \
                -v "${paths.SFTP_KEYS_DIR}:/etc/ssh:ro" \
                --label isCloudronManaged=true \
                ${readOnly} -v /tmp -v /run "${tag}" ${cmd}`;

    // ignore error if container not found (and fail later) so that this code works across restarts
    await shell.promises.exec('stopSftp', 'docker stop sftp || true');
    await shell.promises.exec('removeSftp', 'docker rm -f sftp || true');
    await shell.promises.exec('startSftp', runCmd);
}

async function status() {
    const [error, container] = await safe(docker.inspect('sftp'));
    if (error && error.reason === BoxError.NOT_FOUND) return { status: services.SERVICE_STATUS_STOPPED };
    if (error) throw error;

    const result = await docker.memoryUsage('sftp');

    const status = container.State.Running
        ? (container.HostConfig.ReadonlyRootfs ? services.SERVICE_STATUS_ACTIVE : services.SERVICE_STATUS_STARTING)
        : services.SERVICE_STATUS_STOPPED;

    return {
        status,
        memoryUsed: result.memory_stats.usage,
        memoryPercent: parseInt(100 * result.memory_stats.usage / result.memory_stats.limit)
    };
}