var Q = require("q");

var _ = require("hr.utils");

var Model = require("hr.model");

var logger = require("hr.logger")("command");

var keyboard = require("../utils/keyboard");

var ARGS = {

'number': parseInt

};

var Command = Model.extend({

defaults: {

// Unique id for the command

id: null,

// Title for the command

title: null,

// Run command

run: function(context) {},

// Context needed for the command

context: [],

// Arguments

arguments: [],

// Keyboard shortcuts

shortcuts: [],

// Hidden from command palette

hidden: false,

// Disabled (not runnable)

enabled: true

},

// Constructor

initialize: function() {

Command.__super__.initialize.apply(this, arguments);

this.justRun = function(e) {

if (e) e.preventDefault();

this.run({}, e);

}.bind(this);

this.listenTo(this, "change:shortcuts", this.bindKeyboard);

this.listenTo(this, "destroy", this.unbindKeyboard);

this.bindKeyboard();

},

// Unbind keyboard shortcuts

unbindKeyboard: function() {

if (!this._shortcuts) return;

keyboard.unbind(this._shortcuts, this, this.justRun);

},

// Bind keyboard shortcuts

bindKeyboard: function() {

this.unbindKeyboard();

this._shortcuts = _.clone(this.get("shortcuts", []));

keyboard.bind(this._shortcuts, this.justRun, this);

},

// Run a command

run: function(args, origin) {

var that = this;

// Check context

if (!this.isRunnable()) return Q();

logger.log("Run", this.get("id"));

return Q()

.then(function() {

return that.get("run").apply(that, [ args || {}, that.collection.context, origin ]);

})

.fail(function(err) {

logger.exception("Command failed", err);

});

},

// Shortcut text

shortcutText: function() {

return keyboard.toText(this.get("shortcuts"));

},

// Valid context

hasValidContext: function() {

var context = this.get("context") || [];

var currentContext = _.keys(this.collection.context);

return _.difference(context, currentContext).length == 0;

},

// Valid a command name against this command and return a match score

resolve: function(cmd) {

var score = 0;

var parts = cmd.split(".");

var thisParts = this.get("id").split(".");

_.each(parts, function(part, i) {

if (!thisParts[i]) return false;

var r = new RegExp(thisParts[i]);

if (part.match(r) == null) {

return false;

}

score = score + 1;

});

if (score < thisParts.length) return 0;

return (score/parts.length) + (score/thisParts.length);

},

// Check if command is runnable

isRunnable: function() {

return this.hasValidContext() && this.get("enabled");

}

});

module.exports = Command;