cmus-bundler/daemon.js

cmus player plugin manager

var spawn = require("child_process").spawn;
var fs = require("fs");
var exec_async = require("child_process").exec;
var execFile = require("child_process").execFile;
var net = require("net");
var colors = require("colors/safe");

var Socket = require("./socket");
var Server = Socket.Server;
var delete_socket = Socket.delete_socket;
var logger = require("./logger")(process.argv[3] === "debug" ? process.argv.slice(4) : ["info"]);


var children = [];
var state = {
  "variables": {},
  "status_programs": [],
  "queue": []
};

  
function init(){

  process.on('exit', function(){
    children.forEach(function(child){
      process.kill(-child.pid);
    });
  })

  var cmus_remote = spawn("cmus-remote", []);

  cmus_remote.stdout.on("data", function (data) {
    logger("stdout: " + data, "stdout");
  });

  cmus_remote.stderr.on("data", function (data) {
    logger("stderr: " + data, "warning");
    logger("graceful shutdown", "info");

    children.forEach(function(child){
      child.kill();
    });

    delete_socket(function(){
      logger("deleting socket", "info");
      process.exit(0);
    });

  });

  cmus_remote.on("close", function (code) {
    logger("child process exited with code " + code, "info");

    //copypaste!
    children.forEach(function(child){
      child.kill();
    });

    delete_socket(function(){
      logger("deleting socket", "info");
      process.exit(0);
    });

  });

  setInterval(function(){
    cmus_remote.stdin.write("\n");
  }, 1000);

  Server()
    .then(on_message)
    .run()

  logger("daemon started\n", "info");
}

function on_message(message, cb){

    state.queue.push(message.join(" "));

    switch(message[0]){
      case "set":
        logger("setting variable " + message[1] + ": " + message[2], message[0]);
        state.variables[message[1]] = message[2];
        cb("ok");
        break;
      case "get":
        cb(JSON.stringify(state));
        break;
      case "call":
        run_plugin(
          message.slice(1),
          {cwd: PLUGINS_DIR},
          function(stdout){
            logger("got from program: " + stdout, "call");
            cb("ok");
          },
          function(error_message){
            logger("program failed: " + error_message, "call");
            cb("ok");
          }
        );
        logger("calling " + message[1] + "; arguments: " + message.slice(2).join(", "), message[0]);
        break;
      case "plugin":
      case "theme":
        logger("installing " + message[0] + ": " + message[1], message[0]);
        cb("ok");
        break;
      case "status_program":
        logger("setting status program: " + message[1] + ", arguments: " + message.slice(2), message[0]);
        state.status_programs.push(message[1] !== "cmd" ? message[1] : message.slice(1));
        cb("ok");
        break;
      case "status":
        logger("got status: " + message.join(" "), message[0]);

        state.status_programs.forEach(function(status_program){
          run_plugin(
            [].concat(status_program).concat(message),
            {env: state.variables},
            function(stdout){
              logger("got from status program " + status_program + ": " + stdout, "plugin");
            },
            function(error_message){
              logger("status program " + status_program + " failed. error:\n" + error_message + "\n", "plugin");
            }
          );
        });
      
        cb("ok");
        break;
      default:
        logger("unknown command: " + message.join(" "), "unknown");
        cb("ok");
    }
}

function run_plugin(cmd_array, options, success_callback, error_callback){
  if(cmd_array[0] === "cmd"){
    options.detached = true;
    var child_process = spawn('/bin/sh', ['-c'].concat(cmd_array.slice(1)), options);
    child_process.stdout.on('data', function (data) {});

    child_process.stderr.on('data', function (data) {});

    child_process.on('close', function (code) {
      success_callback && success_callback();
    });
  } else {
    var script_name = PLUGINS_DIR + "/" + cmd_array[0];
    var child_process = execFile(script_name, cmd_array.slice(1), options, function(error, stdout, stderr){
      if (error !== null && error_callback) {
        error_callback(error.stack);
        child_process.kill();
      } else {
        success_callback && success_callback(stdout);
      }
    });
  }

  children.push(child_process);
}

function lookup_self(command, ifyes_callback, ifno_callback){
  exec_async("which cmus-bundler", function(error, stdout, stderr){
    var bundler_path;
    if (error !== null) {
      bundler_path = module.parent.filename;
    } else {
      bundler_path = stdout.replace("\n", "");
    }
    process.nextTick(function(){
      exec_async("pgrep -f \"^node " + bundler_path + " " + command + "\"", function(error, stdout, stderr){
        if (error !== null) {
          ifno_callback();
        } else {
          ifyes_callback();
        }
      });
    });
  });
}



module.exports = {
  run_plugin: run_plugin,
  init: function(){
    lookup_self(
      "install",
      function(){
        console.log("install running");
      },
      init
    )
  },
  lookup: lookup_self
}