'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'),
    path = require('path'),
    paths = require('./paths.js'),
    safe = require('safetydance'),
    services = require('./services.js'),
    shell = require('./shell.js'),
    volumes = require('./volumes.js');

async function ensureKeys() {
    for (const keyType of [ 'rsa', 'ed25519' ]) {
        const privateKey = await blobs.get(`sftp_${keyType}_private_key`);
        const publicKey = await blobs.get(`sftp_${keyType}_public_key`);
        const publicKeyFile = path.join(paths.SFTP_KEYS_DIR, `ssh_host_${keyType}_key.pub`);
        const privateKeyFile = path.join(paths.SFTP_KEYS_DIR, `ssh_host_${keyType}_key`);

        if (!privateKey || !publicKey) {
            debug(`ensureSecrets: generating new sftp keys of type ${keyType}`);
            safe.fs.unlinkSync(publicKeyFile);
            safe.fs.unlinkSync(privateKeyFile);
            const [error] = await safe(shell.exec('ensureKeys', `ssh-keygen -m PEM -t ${keyType} -f ${paths.SFTP_KEYS_DIR}/ssh_host_${keyType}_key -q -N ""`, { shell: '/bin/bash' }));
            if (error) throw new BoxError(BoxError.OPENSSL_ERROR, `Could not generate sftp ${keyType} keys: ${error.message}`);
            const newPublicKey = safe.fs.readFileSync(publicKeyFile);
            await blobs.set(`sftp_${keyType}_public_key`, newPublicKey);
            const newPrivateKey = safe.fs.readFileSync(privateKeyFile);
            await blobs.set(`sftp_${keyType}_private_key`, newPrivateKey);
        } else {
            if (!safe.fs.writeFileSync(publicKeyFile, publicKey)) throw new BoxError(BoxError.FS_ERROR, `Could not save sftp public ${keyType} key: ${safe.error.message}`);
            if (!safe.fs.writeFileSync(privateKeyFile, privateKey, { mode: 0o600 })) throw new BoxError(BoxError.FS_ERROR, `Could not save sftp private ${keyType} key: ${safe.error.message}`);
        }
    }
}

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

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

    const serviceConfig = await services.getServiceConfig('sftp');
    const image = infra.images.sftp;
    const memoryLimit = serviceConfig.memoryLimit || exports.DEFAULT_MEMORY_LIMIT;
    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 (hostDir === null || !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=unix://${paths.SYSLOG_SOCKET_FILE} \
                --log-opt syslog-format=rfc5424 \
                --log-opt tag=sftp \
                -m ${memoryLimit} \
                --memory-swap -1 \
                -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 ${image} ${cmd}`;

    debug('startSftp: stopping and deleting previous sftp container');
    await docker.stopContainer('sftp');
    await docker.deleteContainer('sftp');

    debug('startSftp: starting sftp container');
    await shell.exec('startSftp', runCmd, { shell: '/bin/bash' });
}

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;

    const stats = result.memory_stats || { usage: 0, limit: 1 };

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