'use strict';
/*************************************************************************
## alias Plugin

The alias module lets players and server admins create their own
per-player or global custom in-game command aliases.

### Examples

To set a command alias which is only visible to the current player
(per-player alias)...

    /jsp alias set cw = time set {1} ; weather {2}

... Creates a new custom command only usable by the player who set
it called `cw` (short for set Clock and Weather) which when invoked...

    /cw 4000 sun

... will perform the following commands...

    /time set 4000
    /weather sun

Aliases can use paramters as above. On the right hand side of the `=`, the 
`{1}` refers to the first parameter provided with the `cw` alias, `{2}`
refers to the second parameter and so on. So `cw 4000 sun` is converted to 
`time set 4000` and `weather sun`. 

To set a global command alias usable by all (only operators can create
such an alias)...

    /jsp alias global stormy = time 18000; weather storm

To remove an alias ...

    /jsp alias remove cw

... removes the 'cw' alias from the appropriate alias map.

To get a list of aliases currently defined...

    /jsp alias list

To get help on the `jsp alias` command:

    /jsp alias help

Aliases can be used at the in-game prompt by players or in the server
console.  Aliases will not be able to avail of command autocompletion
(pressing the TAB key will have no effect).

***/

var _usage = "\
/jsp alias set {alias} = {comand-1} ;{command-2}\n \
/jsp alias global {alias} = {command-1} ; {command-2}\n \
/jsp alias list\n \
/jsp alias remove {alias}\n \
Create a new alias : \n \
/jsp alias set cw = time set {1} ; weather {2}\n \
Execute the alias : \n \
/cw 4000 sun \n \
...is the same as '/time set 4000' and '/weather sun'";
/*
  persist aliases
*/
var _store = {
  players: {},
  global: {}
};
/*
  turns 'cw = time set {1} ; weather {2}' into {cmd: 'cw', aliases: ['time set {1}', 'weather {2}']}
  _processParams is a private function which takes an array of parameters
  used for the 'set' and 'global' options.
*/
var _processParams = function(params){
  var paramStr = params.join(' '),
    eqPos = paramStr.indexOf('='),
    aliasCmd = paramStr.substring(0,eqPos).trim(),
    aliasValue = paramStr.substring(eqPos+1).trim();
  return { 
    cmd: aliasCmd, 
    aliases: aliasValue.split(/\s*;\s*/) 
  };
};

var _set = function(params, player){
  var playerAliases = _store.players[player.name];
  if (!playerAliases){
    playerAliases = {};
  }
  var o = _processParams(params);
  playerAliases[o.cmd] = o.aliases;
  _store.players[player.name] = playerAliases;
  player.sendMessage("Alias '" + o.cmd + "' created.");
};

var _remove = function(params, player){
  if (_store.players[player.name] &&
      _store.players[player.name][params[0]]){
    delete _store.players[player.name][params[0]];
    player.sendMessage("Alias '" + params[0] + "' removed.");
  }
  else{
    player.sendMessage("Alias '" + params[0] + "' does not exist.");
  }
  if (player.op){
    if (_store.global[params[0]])
      delete _store.global[params[0]];
  }
};

var _global = function(params, player){
  if (!player.op){
    player.sendMessage("Only operators can set global aliases. " + 
                       "You need to be an operator to perform this command.");
    return;
  }
  var o = _processParams(params);
  _store.global[o.cmd] = o.aliases;
  player.sendMessage("Global alias '" + o.cmd + "' created.");
};

var _list = function(params, player){
  var alias = 0;
  try { 
    if (_store.players[player.name]){
      player.sendMessage("Your aliases:");
      for (alias in _store.players[player.name]){
        player.sendMessage(alias + " = " + 
                           JSON.stringify(_store.players[player.name][alias]));
      }
    }else{
      player.sendMessage("You have no player-specific aliases.");
    }
    player.sendMessage("Global aliases:");
    for (alias in _store.global){
      player.sendMessage(alias + " = " + JSON.stringify(_store.global[alias]) );
    }
  }catch(e){
    console.error("Error in list function: " + e.message);
    throw e;
  }
};
var _help = function(params, player){
  player.sendMessage('Usage:\n' + _usage);
};

var alias = plugin('alias', {
  store:  _store,
  set:    _set,
  global: _global,
  remove: _remove,
  list:   _list,
  help:   _help
}, true );

var aliasCmd = command('alias', function( params, invoker ) {
  var operation = params[0], 
    fn;
  if (!operation){
    invoker.sendMessage('Usage:\n' + _usage);
    return;
  }
  /*
   wph 20140122 this is kind of dumb but Nashorn has some serious problems 
   accessing object properties by array index notation
   in JRE8 alias[operation] returns null - definitely a bug in Nashorn.
   */
  for (var key in alias){
    if (key == operation){
      fn = alias[key];
      fn(params.slice(1),invoker);
      return;
    }
  }
  invoker.sendMessage('Usage:\n' + _usage);
});

var _intercept = function( msg, invoker, exec)
{
  if (msg.trim().length == 0)
    return false;
  var msgParts = msg.split(' '),
    command = msg.match(/^\/*([^\s]+)/)[1],
    template = [], isAlias = false, cmds = [],
    commandObj,
    filledinCommand;
  
  if (_store.global[command]){
    template = _store.global[command];
    isAlias = true;
  }
  /*
   allows player-specific aliases to override global aliases
   */
  if (_store.players[invoker] &&
      _store.players[invoker][command])
  {
    template = _store.players[invoker][command];
    isAlias = true;
  }
  for (var i = 0;i < template.length; i++)
  {
    filledinCommand = template[i].replace(/{([0-9]+)}/g, function (match,index){ 
      index = parseInt(index,10);
      if (msgParts[index])
	return msgParts[index];
      else
	return match;
    });
    cmds.push(filledinCommand);
  }
  
  for (var i = 0; i< cmds.length; i++){
    exec(cmds[i]);
  }
  return isAlias;

};
/*
  Intercept all command processing and replace with aliased commands if the 
  command about to be issued matches an alias.
*/
events.on('player.PlayerCommandPreprocessEvent', function(listener,evt){
  var invoker = evt.player;
  var exec = function(cmd){ invoker.performCommand(cmd);};
  var isAlias = _intercept(''+evt.message, ''+invoker.name, exec);
  if (isAlias)
    evt.cancelled = true;
});
/* define a 'void' command because ServerCommandEvent can't be canceled */
command('void',function(){});

events.on('server.ServerCommandEvent', function(listener,evt){
  var invoker = evt.sender;
  var exec = function(cmd){ invoker.server.dispatchCommand(invoker, cmd); };
  var isAlias = _intercept(''+evt.command, ''+ invoker.name, exec);
  if (isAlias)
    evt.command = 'jsp void';
});