window.thrown_backend_exceptions = {};

function SK_ComponentHandler(cmp_prototype) {
	var prop;
	for (prop in cmp_prototype) {
		this[prop] = cmp_prototype[prop];
	}
	
	this.children = [];
	this.forms = [];
}

SK_ComponentHandler.prototype =
{
	DOMConstruct: function(cmp_class, auto_id)
	{
		this.cmp_class = cmp_class;
		this.auto_id = auto_id;
		
		this.container_node = jQuery('#'+auto_id).get(0);
	},

    /**
     * @return jQuery
     */
	$: function(selector, context) {
		selector = selector.replace('#', '#'+this.auto_id+'-');
		context = context || this.container_node;
		return jQuery(selector, context);
	},

	/**
	 * @return SK_BlockHandler
	 */
	$block: function(selector)
	{
		var $block = this.$(selector);

		if (!$block.length) {
			throw 'block element not found';
		}
		if (!$block.get(0).sk_block_handler) {
			throw 'element has no block handler';
		}

		return $block.get(0).sk_block_handler;
	},
	
	/**
	 * @return XMLHttpRequest
	 */
	ajax: function(options)
	{
        var handler = this;
		
		var _opt = {
			url: URL_RESPONDER,
			type: 'POST',
			data: {
				apply_func: options.apply_func,
				params: encodeURIComponent( JSON.stringify(options.params) ),
				COM_node: encodeURIComponent(
					JSON.stringify( this.getAjaxCOMNode(options.full_COM) )
				)
			},
			dataType: 'json',
			success: function(response)
			{
				if (response.errors) {
					$(response.errors).each(function() {
						handler.error(this);
					});
				}
				
				if (response.exec) {
					response.exec.call(handler);
				}
				
				if (options.success) {
					options.success(response.data);
				}
			},
			error: function(xhr) {
				if (options.error) {
					options.error(xhr);
				} else {
					// handling backend exception
					var json_e = xhr.getResponseHeader('SK-Exception');
					if (json_e) {
						if (window.thrown_backend_exceptions[json_e]) {
							return;
						}
						
						eval("var e = "+json_e);
						
						e.toString = function() {
							return e.message+"\ntrace: "+e.trace_str+"\nfile: "+e.file+" in line: "+e.line;
						}
						
						window.thrown_backend_exceptions[json_e] = e;
						
						if (e.class_name == 'SK_HttpRequestException' && e.code == 1) {
							// handling "Authentication required" exception
							SK_SignIn().bind('close', function() {
								window.location.reload();
							});
						}
						else {
							alert('An uncaught exception thrown:\n'+e.toString());
						}
					}
					else if (typeof console != 'undefined' && console !== null ) {
						console.error('http request error');
					}
				}
			}
		};
		
		if (options.complete) {
			_opt.complete = options.complete;
		}
		
		return $.ajax(_opt);
	},
	
	/**
	 * @return XMLHttpRequest
	 */
	ajaxCall: function(apply_func, params, options)
	{
		options = options || {};
		
		options.apply_func = apply_func;
		options.params = params;
		
		return this.ajax(options);
	},
	
	/**
	 * @return XMLHttpRequest
	 */
	reload: function(params, options) {
		params = params || {};
		options = options || {};
		options.full_COM = true;
		return this.ajaxCall('reload', params, options);
	},

	/**
	 * @return object
	 */
	getAjaxCOMNode: function(full_COM)
	{
		var COM_node = {
			cmp_class: this.cmp_class,
			auto_id: this.auto_id,
			forms: []
		};

		if (this.parent) {
			COM_node.parent = {
				cmp_class: this.parent.cmp_class,
				auto_id: this.parent.auto_id
			}
		}

		var i, child, form;

		if (full_COM) {
			COM_node.children = [];
			for (i = 0, child; child = this.children[i]; i++)
			{
				// filtering httpdoc canvas components
				if (this.auto_id === 'httpdoc' &&
					!$('#'+child.auto_id, this.container_node).length) {
					continue;
				}

				COM_node.children.push(child.getAjaxCOMNode(true, false));
			}
		}

		for (i = 0, form; form = this.forms[i]; i++)
		{
			COM_node.forms[i] = {
				form_class: form.form_class,
				auto_id: form.auto_id
			}
		}

		return COM_node;
	},
	
	error: function(err_msg) {
		SK_drawError(err_msg);
	},
	
	
	message: function(msg_text) {
		SK_drawMessage(msg_text);
	},
	
	debug: function(a) {
		if (console) {
			console.debug(a);
		}
		else {
			alert(JSON.stringify(a));
		}
	}
}