/**
 * elFinder command prototype
 *
 * @type  elFinder.command
 * @author  Dmitry (dio) Levashov
 */
elFinder.prototype.command = function(fm) {

	/**
	 * elFinder instance
	 *
	 * @type  elFinder
	 */
	this.fm = fm;
	
	/**
	 * Command name, same as class name
	 *
	 * @type  String
	 */
	this.name = '';
	
	/**
	 * Command icon class name with out 'elfinder-button-icon-'
	 * Use this.name if it is empty
	 *
	 * @type  String
	 */
	this.className = '';

	/**
	 * Short command description
	 *
	 * @type  String
	 */
	this.title = '';
	
	/**
	 * Linked(Child) commands name
	 * They are loaded together when tthis command is loaded.
	 * 
	 * @type  Array
	 */
	this.linkedCmds = [];
	
	/**
	 * Current command state
	 *
	 * @example
	 * this.state = -1; // command disabled
	 * this.state = 0;  // command enabled
	 * this.state = 1;  // command active (for example "fullscreen" command while elfinder in fullscreen mode)
	 * @default -1
	 * @type  Number
	 */
	this.state = -1;
	
	/**
	 * If true, command can not be disabled by connector.
	 * @see this.update()
	 *
	 * @type  Boolen
	 */
	this.alwaysEnabled = false;
	
	/**
	 * If true, this means command was disabled by connector.
	 * @see this.update()
	 *
	 * @type  Boolen
	 */
	this._disabled = false;
	
	this.disableOnSearch = false;
	
	this.updateOnSelect = true;
	
	/**
	 * elFinder events defaults handlers.
	 * Inside handlers "this" is current command object
	 *
	 * @type  Object
	 */
	this._handlers = {
		enable  : function() { this.update(void(0), this.value); },
		disable : function() { this.update(-1, this.value); },
		'open reload load sync'    : function() { 
			this._disabled = !(this.alwaysEnabled || this.fm.isCommandEnabled(this.name));
			this.update(void(0), this.value)
			this.change(); 
		}
	};
	
	/**
	 * elFinder events handlers.
	 * Inside handlers "this" is current command object
	 *
	 * @type  Object
	 */
	this.handlers = {}
	
	/**
	 * Shortcuts
	 *
	 * @type  Array
	 */
	this.shortcuts = [];
	
	/**
	 * Command options
	 *
	 * @type  Object
	 */
	this.options = {ui : 'button'};
	
	/**
	 * Prepare object -
	 * bind events and shortcuts
	 *
	 * @return void
	 */
	this.setup = function(name, opts) {
		var self = this,
			fm   = this.fm, i, s, sc, cb;

		this.name      = name;
		this.title     = fm.messages['cmd'+name] ? fm.i18n('cmd'+name)
		               : ((this.extendsCmd && fm.messages['cmd'+this.extendsCmd]) ? fm.i18n('cmd'+this.extendsCmd) : name), 
		this.options   = $.extend({}, this.options, opts);
		this.listeners = [];

		if (opts.shortcuts) {
			if (typeof opts.shortcuts === 'function') {
				sc = opts.shortcuts(this.fm, this.shortcuts);
			} else if (Array.isArray(opts.shortcuts)) {
				sc = opts.shortcuts;
			}
			this.shortcuts = sc || [];
		}

		if (this.updateOnSelect) {
			this._handlers.select = function() { this.update(void(0), this.value); }
		}

		$.each($.extend({}, self._handlers, self.handlers), function(cmd, handler) {
			fm.bind(cmd, $.proxy(handler, self));
		});

		for (i = 0; i < this.shortcuts.length; i++) {
			s = this.shortcuts[i];
			cb = s.callback || self.exec;
			s.callback = function() {
				var enabled, checks = {};
				if (fm.searchStatus.state < 2) {
					enabled = fm.isCommandEnabled(self.name);
				} else {
					$.each(fm.selected(), function(i, h) {
						if (fm.optionsByHashes[h]) {
							checks[h] = true;
						} else {
							$.each(fm.volOptions, function(id) {
								if (!checks[id] && h.indexOf(id) === 0) {
									checks[id] = true;
									return false;
								}
							});
						}
					});
					$.each(checks, function(h) {
						enabled = fm.isCommandEnabled(self.name, h);
						if (! enabled) {
							return false;
						}
					});
				}
				if (enabled) {
					cb.call(self);
				}
			};
			!s.description && (s.description = this.title);
			fm.shortcut(s);
		}

		if (this.disableOnSearch) {
			fm.bind('search searchend', function(e) {
				self._disabled = e.type === 'search'? true : ! (this.alwaysEnabled || fm.isCommandEnabled(name));
				self.update(void(0), self.value);
			});
		}

		this.init();
	}

	/**
	 * Command specific init stuffs
	 *
	 * @return void
	 */
	this.init = function() { }

	/**
	 * Exec command
	 *
	 * @param  Array         target files hashes
	 * @param  Array|Object  command value
	 * @return $.Deferred
	 */
	this.exec = function(files, opts) { 
		return $.Deferred().reject(); 
	}
	
	/**
	 * Return true if command disabled.
	 *
	 * @return Boolen
	 */
	this.disabled = function() {
		return this.state < 0;
	}
	
	/**
	 * Return true if command enabled.
	 *
	 * @return Boolen
	 */
	this.enabled = function() {
		return this.state > -1;
	}
	
	/**
	 * Return true if command active.
	 *
	 * @return Boolen
	 */
	this.active = function() {
		return this.state > 0;
	}
	
	/**
	 * Return current command state.
	 * Must be overloaded in most commands
	 *
	 * @return Number
	 */
	this.getstate = function() {
		return -1;
	}
	
	/**
	 * Update command state/value
	 * and rize 'change' event if smth changed
	 *
	 * @param  Number  new state or undefined to auto update state
	 * @param  mixed   new value
	 * @return void
	 */
	this.update = function(s, v) {
		var state = this.state,
			value = this.value;

		if (this._disabled && this.fm.searchStatus === 0) {
			this.state = -1;
		} else {
			this.state = s !== void(0) ? s : this.getstate();
		}

		this.value = v;
		
		if (state != this.state || value != this.value) {
			this.change();
		}
	}
	
	/**
	 * Bind handler / fire 'change' event.
	 *
	 * @param  Function|undefined  event callback
	 * @return void
	 */
	this.change = function(c) {
		var cmd, i;
		
		if (typeof(c) === 'function') {
			this.listeners.push(c);			
		} else {
			for (i = 0; i < this.listeners.length; i++) {
				cmd = this.listeners[i];
				try {
					cmd(this.state, this.value);
				} catch (e) {
					this.fm.debug('error', e)
				}
			}
		}
		return this;
	}
	

	/**
	 * With argument check given files hashes and return list of existed files hashes.
	 * Without argument return selected files hashes.
	 *
	 * @param  Array|String|void  hashes
	 * @return Array
	 */
	this.hashes = function(hashes) {
		return hashes
			? $.map(Array.isArray(hashes) ? hashes : [hashes], function(hash) { return fm.file(hash) ? hash : null; })
			: fm.selected();
	}
	
	/**
	 * Return only existed files from given fils hashes | selected files
	 *
	 * @param  Array|String|void  hashes
	 * @return Array
	 */
	this.files = function(hashes) {
		var fm = this.fm;
		
		return hashes
			? $.map(Array.isArray(hashes) ? hashes : [hashes], function(hash) { return fm.file(hash) || null })
			: fm.selectedFiles();
	}
};
