const fs = require("fs");
const childProcess = require("child_process");
const fork = require("./debugFork");
const paths = require("./paths");

const dirname = paths.baseDir;

function getRunningPid(callback) {
    fs.readFile(paths.pidfile, {encoding: 'utf-8'}, (err, pid) => {
        if (err)
            return callback(err);
        pid = parseInt(pid, 10);
        try {
           process.kill(pid, 0);
           callback(null, pid);
        }
        catch (e) {
            callback(e);
        }
    });
}

function start(options) {
    if (options.dev) {
        process.env.NODE_ENV = 'development';
        fork(paths.loader, ['--no-daemon', '--no-silent'], {
            env: process.env,
            cwd: dirname,
            stdio: 'inherit'
        });
        return;
    }
    if (options.log) {
        console.log('\n' + [
            'Starting MFFBot with logging output'.bold,
            'Hit '.red + 'CTRL-C'.bold + 'to exit'.red,
            'The MFFBot will continue to run in the background',
            'Use "' + './mffbot stop'.yellow + '" to stop the MFFBot'
        ].join('\n'));
    }
    else if (!options.silent) {
        console.log('\n' + [
            'Starting MFFBot'.bold,
            '\t"' + './mffbot stop'.yellow + '" to stop the MFFBot',
            '\t"' + './mffbot log'.yellow + '" to view log output',
            '\t"' + './mffbot help'.yellow + '" for more commands\n'.reset
        ].join('\n'));
    }

    // Spawn a new MFFBot process
    const child = fork(paths.loader, process.argv.slice(3), {
        env: process.env,
        cwd: dirname
    });
    if (options.log) {
        childProcess.spawn('tail', ['-F', './logs/output.log'], {
            cwd: dirname,
            stdio: 'inherit'
        });
    }

    return child;
}

function stop() {
    getRunningPid((err, pid) => {
       if(!err) {
           process.kill(pid, 'SIGTERM');
           console.log('Stopping MFFBot. GoodBye!');
       }
       else {
           console.log('MFFBot is already stopped.');
       }
    });
}

function restart(options) {
    getRunningPid((err, pid) => {
        if(!err) {
            console.log('\nRestarting MFFBot'.bold);
            process.kill(pid, 'SIGTERM');
            options.silent = true;
            start(options);
        }
        else {
            console.warn("MFFBot couldn't be restarted, as a running instance couldn't be found");
        }
    });
}

function status() {
    getRunningPid((err, pid) => {
       if(!err) {
           console.log('\n' + [
               'MFFBot Running '.bold + ('(pid ' + pid.toString() + ')').cyan,
               '\t"' + './mffbot stop'.yellow + '" to stop the MFFBot',
               '\t"' + './mffbot log'.yellow + '" to view log output',
               '\t"' + './mffbot restart'.yellow + '" to restart MFFBot'
           ].join('\n'));
       }
       else {
           console.log('\nMFFBot is not running'.bold);
           console.log('\t"' + './mffbot start'.yellow + '" to launch the MFFBot\n'.reset)
       }
    });
}

function log() {
    console.log('\nHit '.red + 'CTRL-C'.bold + ' to exit\n'.red + '\n'.reset);
    childProcess.spawn('tail', ['-F', './logs/output.log'], {
        cwd: dirname,
        stdio: 'inherit'
    });
}

exports.start = start;
exports.stop = stop;
exports.restart = restart;
exports.status = status;
exports.log = log;