'use strict';

exports = module.exports = {
    sleep: sleep,
    sudo: sudo,
    exec: exec,
    system: system
};

var assert = require('assert'),
    child_process = require('child_process'),
    debug = require('debug')('e2e:shell.js'),
    once = require('once'),
    util = require('util');

var SUDO = '/usr/bin/sudo';

function sleep(timeout) {
    child_process.execSync('sleep ' + timeout);
}

function exec(tag, file, args, options, callback) {
    assert.strictEqual(typeof tag, 'string');
    assert.strictEqual(typeof file, 'string');
    assert(util.isArray(args));

    if (typeof options === 'function') {
        callback = options;
        options = { };
    } else {
        assert.strictEqual(typeof options, 'object');
        assert.strictEqual(typeof callback, 'function');
    }

    callback = once(callback); // exit may or may not be called after an 'error'

    debug(tag + ' execFile: %s %s', file, args.join(' '));

    options.maxBuffer = 10000 * 1024; // in bytes default is 200*1024

    var cp = child_process.spawn(file, args, options);
    cp.stdout.on('data', function (data) {
        debug(tag + ' (stdout): %s', data.toString('utf8'));
    });

    cp.stderr.on('data', function (data) {
        debug(tag + ' (stderr): %s', data.toString('utf8'));
    });

    cp.on('exit', function (code, signal) {
        if (code || signal) debug(tag + ' code: %s, signal: %s', code, signal);

        callback(code === 0 ? null : new Error(util.format('Exited with error %s signal %s', code, signal)));
    });

    cp.on('error', function (error) {
        debug(tag + ' code: %s, signal: %s', error.code, error.signal);
        callback(error);
    });

    return cp;
}

function system(tag, cmd, options, callback) {
    assert.strictEqual(typeof tag, 'string');
    assert.strictEqual(typeof cmd, 'string');

    if (typeof options === 'function') {
        callback = options;
        options = { };
    } else {
        assert.strictEqual(typeof options, 'object');
        assert.strictEqual(typeof callback, 'function');
    }

    debug(tag + ' system: %s %j', cmd, options);

    options.maxBuffer = 10000 * 1024; // in bytes default is 200*1024

    var cp = child_process.exec(cmd, options, function (error, stdout, stderr) {
        if (error) debug(tag + ' (error) ' + error);

        callback(error, stdout, stderr);
    });

    cp.stdout.on('data', function (data) {
        debug(tag + ' (stdout): %s', data.toString('utf8'));
    });

    cp.stderr.on('data', function (data) {
        debug(tag + ' (stderr): %s', data.toString('utf8'));
    });

    return cp;
}

function sudo(tag, args, callback) {
    assert.strictEqual(typeof tag, 'string');
    assert(util.isArray(args));
    assert.strictEqual(typeof callback, 'function');

    // -S makes sudo read stdin for password
    var cp = exec(tag, SUDO, [ '-S' ].concat(args), callback);
    cp.stdin.end();
}