bsb

#!/usr/bin/env node
//@ts-check
"use strict";

/* This script is supposed to be running in project root directory
 * It matters since we need read .sourcedirs(location)
 * and its content are file/directories with regard to project root
 */

var child_process = require('child_process')
var os = require('os');

var bsconfig = 'bsconfig.json'
var bsb_exe = __filename + ".exe"

var LAST_SUCCESS_BUILD_STAMP = 0

// All clients of type MiniWebSocket
/**
 * @type {any[]}
 */
var wsClients = []
var watch_mode = false
var verbose = false
/**
 * @type {string | undefined}
 */
var postBuild = undefined
var useWebSocket = false
var webSocketPort = 9999

/**
 * @returns {string}
 */
function getDateAsString(){
    var n = new Date()
    return n.getHours() + ":" + n.getMinutes() + ":" + n.getSeconds()
}
/**
 * @time{[number,number]}
 */
var startTime 
function updateStartTime(){
    startTime = process.hrtime()
    return ''
}
function updateFinishTime(){
    var diff = process.hrtime(startTime)
    return diff[0] * 1e9 + diff[1]
}
/**
 * 
 * @param {*} str 
 */
function dlog(str){
    if(verbose){
        console.log(str)
    }
}
function notifyClients() {
    wsClients = wsClients.filter(x => !x.closed && !x.socket.destroyed )
    var wsClientsLen = wsClients.length
    dlog(`Alive sockets number: ${wsClientsLen}`)    
    var data = JSON.stringify(
                    {
                        LAST_SUCCESS_BUILD_STAMP: LAST_SUCCESS_BUILD_STAMP
                    }
                )
    for (var i = 0; i < wsClientsLen; ++ i ) {
        // in reverse order, the last pushed get notified earlier
        var client = wsClients[wsClientsLen - i - 1] 
        if (!client.closed) {
            client.sendText(data)
        }
    }
}

function setUpWebSocket() {
    var WebSocket = require('./minisocket.js').MiniWebSocket
    var id = setInterval(notifyClients, 3000)
    require('http').createServer()
        .on('upgrade', function (req, socket, upgradeHead) {
            dlog("connection opened");
            var ws = new WebSocket(req, socket, upgradeHead);
            socket.on("error",function (err){
                dlog(`Socket Error ${err}`)
            })
            wsClients.push(ws)
        })
        .on('error', function (err) {
            console.error(err)
            process.exit(2)
        })
        .listen(webSocketPort, "localhost");
}



/**
 * @type {string[]}
 */
var delegate_args = []
var process_argv = process.argv
for (var i = 2; i < process_argv.length; ++i) {
    var current = process_argv[i]
    if (current === '-build-success') {
        // TODO boundary safety check
        // Not really needed
        postBuild = process_argv[++i]
    } else if (current === "-ws") {
        var portNumber = parseInt(process_argv[++i])
        dlog(`WebSocket port number: ${portNumber}`)
        if (!isNaN (portNumber )){
            webSocketPort = portNumber
        }
        useWebSocket = true

    } else {
        delegate_args.push(current)
        if (current === '-w') {
            watch_mode = true
        } else if (current === "-verbose") {
            verbose = true

        }
    }
}


if(
    process.env.NINJA_ANSI_FORCED === undefined 
  ){

    if(require ('tty').isatty(1)){
        process.env.NINJA_ANSI_FORCED = '1'
    }
    
} else {
    dlog(`NINJA_ANSI_FORCED: "${process.env.NINJA_ANSI_FORCED}"`)
}

// Note the watch mode flag `-w` is not very useful to bsb.exe
// A trick is played that for such flags `bsb.exe -make-world -w`
// it will exit ignoreing `-make-world` since it will be triggered
// again in bsb
// The following process atm only spawned `bsb.exe` directly
try {
    child_process.execFileSync(bsb_exe, delegate_args, { stdio: 'inherit' })
} catch (e) {
    if (e.code === "ENOENT") {
        // when bsb is actually not found
        console.error(String(e))
        process.exit(2)
    }
    if (!watch_mode) {
        process.exit(2)
    }
}

if (watch_mode) {
    var fs = require('fs')
    var path = require('path')
    if (useWebSocket) {
        setUpWebSocket()
    }
    // for column one based error message
    var cwd = process.cwd()
    var lockFileName = path.join(cwd, ".bsb.lock")
    /**
     * @type {[string,string][]}
     */
    var reasons_to_rebuild = [];

    /**
     * watchers are held so that we close it later
     */
    var watchers = [];

    function onUncaughtException (err){
        console.error("Uncaught Exception", err)
        process.exit(1)
    }
    function onExit() {
        try {
            fs.unlinkSync(lockFileName)
        } catch (err) {

        }
        process.exit(2)
    }

    /**
     * @return {boolean}
     */
    function acquireLockFile() {
        try {
            // We use [~perm:0o664] rather than our usual default perms, [0o666], because
            // lock files shouldn't rely on the umask to disallow tampering by other.        
            var fd = fs.openSync(lockFileName, 'wx', 0o664)
            try {
                fs.writeFileSync(fd, String(process.pid), 'ascii')
                fs.closeSync(fd)
            } catch (err) {

            }

            process.on('exit', onExit)
            // Ctrl+C
            process.on('SIGINT', onExit)
            // kill pid
            process.on('SIGUSR1', onExit)
            process.on('SIGUSR2', onExit)
            process.on('SIGTERM', onExit)
            process.on('SIGHUP', onExit)
            process.on('uncaughtException', onUncaughtException)
            process.stdin.on('close', onExit)
            // close when stdin stops
            if (os.platform() !== "win32") {
                process.stdin.on('end', onExit)
                process.stdin.resume()
            }

            return true
        } catch (exn) {
            return false
        }
    }

    var is_building = false;
    function releaseBuild() {
        is_building = false
    }
    function acquireBuild() {
        if (is_building) {
            return false
        }
        else {
            is_building = true
            return true
        }
    }
    var sourcedirs = path.join('lib', 'bs', '.sourcedirs.json')
    var watch_generated = []

    function watch_build(watch_config) {
        var watch_files = watch_config.dirs
        watch_generated = watch_config.generated
        // close and remove all unused watchers
        watchers = watchers.filter(function (watcher) {
            if (watcher.dir === bsconfig) {
                return true;
            } else if (watch_files.indexOf(watcher.dir) < 0) {
                dlog(`${watcher.dir} is no longer watched`);
                watcher.watcher.close();
                return false
            } else {
                return true;
            }
        })

        // adding new watchers
        for (var i = 0; i < watch_files.length; ++i) {
            var dir = watch_files[i]
            if (!watchers.find(function (watcher) { return watcher.dir === dir })) {
                dlog(`watching dir ${dir} now`)
                var watcher = fs.watch(dir, on_change);
                watchers.push({ dir: dir, watcher: watcher })
            } else {
                // console.log(dir, 'already watched')
            }
        }
    };


    /**
     * 
     * @param {string} eventType 
     * @param {string} fileName 
     */
    function validEvent(eventType, fileName) {
        // Return true if filename is nil, filename is only provided on Linux, macOS, Windows, and AIX.
        // On other systems, we just have to assume that any change is valid.
        // This could cause problems if source builds (generating js files in the same directory) are supported. 
        if (!fileName)
            return true;

        return !(fileName === '.merlin' ||
            fileName.endsWith('.js') ||
            watch_generated.indexOf(fileName) >= 0 ||
            fileName.endsWith('.swp')
        )
    }
    /**
     * @return {boolean}
     */
    function needRebuild() {
        return reasons_to_rebuild.length != 0
    }
    var error_is_tty = process.stderr.isTTY
    var std_is_tty = process.stdout.isTTY
    function logFinish(code) {
        if (std_is_tty) {
            if (code === 0) {
                console.log("\x1b[36m>>>> Finish compiling\x1b[0m", Math.floor(updateFinishTime()/1e6),"mseconds")
            } else {
                console.log("\x1b[1;31m>>>> Finish compiling(exit: " + code + ")\x1b[0m")
            }
        } else {
            if (code === 0) {
                console.log(">>>> Finish compiling")
            } else {
                console.log(">>>> Finish compiling(exit: " + code + ")")
            }

        }
    }
    function logStart() {
        if (std_is_tty) {
            console.log("\x1b[36m>>>> Start compiling\x1b[0m",updateStartTime());
        } else {
            console.log(">>>> Start compiling");
        }

    }
    /**
     * 
     * @param code {number}
     * @param signal {string}
     */
    function build_finished_callback(code, signal) {
        if(code === 0){
            LAST_SUCCESS_BUILD_STAMP = + new Date() ;
            notifyClients()
            if(postBuild){
                dlog(`running postbuild command: ${postBuild}`)
                child_process.exec(postBuild)
            }
        }
        logFinish(code)
        releaseBuild()
        if (needRebuild()) {
            build()
        } else {
            var files = getWatchFiles(sourcedirs);
            watch_build(files)
        }
    }



    /**
     * TODO: how to make it captured by vscode
     * @param output {string}
     * @param highlight {string}
     */
    function error_output(output, highlight) {
        if (error_is_tty && highlight) {
            process.stderr.write(output.replace(highlight, '\x1b[1;31m' + highlight + '\x1b[0m'))
        } else {
            process.stderr.write(output)
        }
    }
    // Note this function filters the error output
    // it relies on the fact that ninja will merege stdout and stderr
    // of the compiler output, if it does not
    // then we should have a way to not filter the compiler output
    function build() {
        if (acquireBuild()) {
            logStart()
            if (reasons_to_rebuild.length === 0) {
                dlog("Rebuilding since just got started")
            } else {
                dlog(`Rebuilding since ${reasons_to_rebuild}`)
            }
            reasons_to_rebuild = [];
            var p = child_process
                .spawn(bsb_exe, [], { stdio: ['inherit', 'inherit', 'pipe'] });
            p.on('exit', build_finished_callback)
            p.stderr
                .setEncoding('utf8')
                // @ts-ignore
                .on('data', function (s) { error_output(s, 'ninja: error') })

        }
    }
    /**
     * 
     * @param {string} event 
     * @param {string} reason 
     */
    function on_change(event, reason) {
        if (validEvent(event, reason)) {
            dlog(`Event ${event} ${reason}`);
            reasons_to_rebuild.push([event, reason])
            if (needRebuild()) {
                if (process.env.BS_WATCH_CLEAR && console.clear) {console.clear()}
                build()
            }
        }

    }
    function getWatchFiles(file) {
        if (fs.existsSync(file)) {
            return JSON.parse(fs.readFileSync(file, 'utf8'))
        } else {
            return { dirs: [], generated: [] }
        }

    }

    /**
     * 
     * @param potential_pid {number}
     */
    function existPid(potential_pid) {
        try {
            return process.kill(potential_pid, 0)
        } catch (err) {
            return false
        }
    }

    // Initialization and get locker file
    while (true) {
        if (acquireLockFile()) {
            break;
        } else {
            var potential_pid;
            try {
                var content = fs.readFileSync(lockFileName, 'ascii')
                potential_pid = parseInt(content)
            } catch (err) {
                // ignore   
            }
            var validPid = potential_pid !== undefined && !isNaN(potential_pid)

            if (validPid && !existPid(potential_pid)) {
                console.log('Stale file detected : ', lockFileName)
                try {
                    fs.unlinkSync(lockFileName)
                } catch (err) {

                }
                console.log('Retry:')
                continue;
            } else {

                error_output('Error: could not acquire lockfile', 'Error')
                console.error(lockFileName)

                console.log('Could be another process running in the background',
                    '\nEither kill that process or delete the staled lock')
                if (validPid) {
                    console.error('Try run command: ', '`kill ', potential_pid, ' || rm -f .bsb.lock`')
                }
                process.exit(2)
            }
        }
    }
    watchers.push({ watcher: fs.watch(bsconfig, on_change), dir: bsconfig });
    build()

}