'use strict';

exports = module.exports = {
    add,
    get,
    del,
    list
};

const assert = require('assert'),
    BoxError = require('./boxerror.js'),
    collectd = require('./collectd.js'),
    debug = require('debug')('box:volumes'),
    ejs = require('ejs'),
    eventlog = require('./eventlog.js'),
    fs = require('fs'),
    path = require('path'),
    safe = require('safetydance'),
    services = require('./services.js'),
    uuid = require('uuid'),
    volumedb = require('./volumedb.js');

const COLLECTD_CONFIG_EJS = fs.readFileSync(__dirname + '/collectd/volume.ejs', { encoding: 'utf8' });
const NOOP_CALLBACK = function (error) { if (error) debug(error); };

function validateName(name) {
    assert.strictEqual(typeof name, 'string');

    if (!/^[-\w^&'@{}[\],$=!#().%+~ ]+$/.test(name)) return new BoxError(BoxError.BAD_FIELD, 'Invalid name');

    return null;
}

function validateHostPath(hostPath) {
    assert.strictEqual(typeof hostPath, 'string');

    if (path.normalize(hostPath) !== hostPath) return new BoxError(BoxError.BAD_FIELD, 'hostPath must contain a normalized path', { field: 'hostPath' });
    if (!path.isAbsolute(hostPath)) return new BoxError(BoxError.BAD_FIELD, 'backupFolder must be an absolute path', { field: 'hostPath' });

    if (hostPath === '/') return new BoxError(BoxError.BAD_FIELD, 'hostPath cannot be /', { field: 'hostPath' });

    if (!hostPath.endsWith('/')) hostPath = hostPath + '/'; // ensure trailing slash for the prefix matching to work
    const allowedPaths = [ '/mnt/', '/media/', '/srv/', '/opt/' ];

    if (!allowedPaths.some(p => hostPath.startsWith(p))) return new BoxError(BoxError.BAD_FIELD, 'hostPath must be under /mnt, /media, /opt or /srv', { field: 'hostPath' });

    const stat = safe.fs.lstatSync(hostPath);
    if (!stat) return new BoxError(BoxError.BAD_FIELD, 'hostPath does not exist. Please create it on the server first', { field: 'hostPath' });
    if (!stat.isDirectory()) return new BoxError(BoxError.BAD_FIELD, 'hostPath is not a directory', { field: 'hostPath' });

    return null;
}

function add(name, hostPath, auditSource, callback) {
    assert.strictEqual(typeof name, 'string');
    assert.strictEqual(typeof hostPath, 'string');
    assert.strictEqual(typeof auditSource, 'object');
    assert.strictEqual(typeof callback, 'function');

    let error = validateName(name);
    if (error) return callback(error);

    error = validateHostPath(hostPath);
    if (error) return callback(error);

    const id = uuid.v4();

    volumedb.add(id, name, hostPath, function (error) {
        if (error) return callback(error);

        eventlog.add(eventlog.ACTION_VOLUME_ADD, auditSource, { id, name, hostPath });
        services.rebuildService('sftp', NOOP_CALLBACK);

        const collectdConf = ejs.render(COLLECTD_CONFIG_EJS, { volumeId: id, hostPath });
        collectd.addProfile(id, collectdConf, NOOP_CALLBACK);

        callback(null, id);
    });
}

function get(id, callback) {
    assert.strictEqual(typeof id, 'string');
    assert.strictEqual(typeof callback, 'function');

    volumedb.get(id, function (error, result) {
        if (error) return callback(error);

        callback(null, result);
    });
}

function list(callback) {
    assert.strictEqual(typeof callback, 'function');

    volumedb.list(function (error, result) {
        if (error) return callback(error);

        return callback(null, result);
    });
}

function del(volume, auditSource, callback) {
    assert.strictEqual(typeof volume, 'object');
    assert.strictEqual(typeof auditSource, 'object');
    assert.strictEqual(typeof callback, 'function');

    volumedb.del(volume.id, function (error) {
        if (error) return callback(error);

        eventlog.add(eventlog.ACTION_VOLUME_REMOVE, auditSource, { volume });
        services.rebuildService('sftp', NOOP_CALLBACK);
        collectd.removeProfile(volume.id, NOOP_CALLBACK);

        return callback(null);
    });
}