/**
 * Ajax upload plugin for jQuery
 * Project page - http://valums.com/ajax-upload/
 * Copyright (c) 2008 Andris Valums, http://valums.com
 * Licensed under the MIT license (http://valums.com/mit-license/)
 * Version 1.0 (24.01.2009)
 */

(function($) {
    // we need jQuery to run
    if (!$) return;

    /**
    * Function generates unique id
    */
    var get_uid = function() {
        var uid = 0;
        return function() {
            return uid++;
        }
    } ();

    /**
    * button - jQuery element
    * option - hash of options :
    *   action - URL which iframe will use to post data
    *   name - file input name
    *   data - extra data hash to post within the file
    *   onSubmit - callback to fire on file submit
    *   onComplete - callback to fire when iframe has finished loading
    */
    window.Ajax_upload = function(button, options) {
        // make sure it is jquery object
        button = $(button);

        if (button.size() != 1) {
            //You should pass only 1 element to ajax upload ot once
            return;
        }

        this.button = button;

        this.wrapper = null;
        this.form = null;
        this.input = null;
        this.iframe = null;

        this.disabled = false;
        this.submitting = false;

        this.settings = {
            // EDIT
            buttonSize: {
                height: 100,
                width: 100
            },
            // Location of the server-side upload script
            action: 'upload.php',
            // File upload name
            name: 'userfile',
            // Additional data to send
            data: {},
            // Callback to fire when user selects file
            // You can return false to cancel upload
            onSubmit: function(file, extension) { },
            // Fired when file upload is completed
            onComplete: function(file, response) { }
        };

        // Merge the users options with our defaults	
        $.extend(this.settings, options);

        this.create_wrapper();
        this.create_input();

        if (jQuery.browser.msie) {
            //fixes bug, which occur when you use div with transparent background as upload button
            this.make_parent_opaque();
        }

        this.create_iframe();
    }

    // assigning methods to our class
    Ajax_upload.prototype = {
        set_data: function(data) {
            this.settings.data = data;
        },
        disable: function() {
            this.disabled = true;
            if (!this.submitting) {
                this.input.attr('disabled', true);
                this.button.removeClass('hover');
            }
        },
        enable: function() {
            this.disabled = false;
            this.input.attr('disabled', false);
        },
        /**
        * Creates wrapper for button and invisible file input
        */
        create_wrapper: function() {
            // Shorten names
            var self = this;
            var button = this.button, wrapper;

            wrapper = this.wrapper = $('<div></div>')
				.insertAfter(button)
				.append(button);

            // wait a bit because of FF bug
            // it can't properly calculate the outerHeight
            setTimeout(function() {
                wrapper.css({
                    position: 'relative'
					, display: 'block'
					, overflow: 'hidden'

                    // we need dimensions because of ie bug that allows to move 
                    // input outside even if overflow set to hidden
					, height: self.button_size("height")
					, width: self.button_size("width")
                });
            }, 1);


            wrapper.mousemove(function(e) {
                // Move the input with the mouse, so the user can't misclick it
                if (!self.input) {
                    return;
                }

                self.input.css({
                    top: e.pageY - wrapper.offset().top - 5 + 'px'
					, left: e.pageX - wrapper.offset().left - 170 + 'px'
                });
            });
        },
        button_size: function(heightOrWidth) {
            var button = this.button;
            var settings = this.settings;

            switch (heightOrWidth) {
                case "height":
                    if (button.outerHeight(true) < settings.buttonSize.height) {
                        return settings.buttonSize.height;
                    }
                    else {
                        return button.outerHeight(true);
                    }
                    break;

                case "width":
                    if (button.outerWidth(true) < settings.buttonSize.width) {
                        return settings.buttonSize.width;
                    }
                    else {
                        return button.outerWidth(true);
                    }
                    break;
            }
        },
        /**
        * Creates invisible file input above the button 
        */
        create_input: function() {
            var self = this;

            this.input =
				$('<input type="file" />')
				.attr('name', this.settings.name)
				.css({
				    'position': 'absolute'
					, 'margin': 0
					, 'padding': 0
					, 'width': '220px'
					, 'height': '10px'
					, 'opacity': 0
					, cursor: 'pointer'
				})
				.change(function() {
				    if ($(this).val() == '') {
				        // there is no file
				        return;
				    }

				    // we need to lock "disable" method
				    self.submitting = true;

				    // Submit form when value is changed
				    self.submit();

				    if (self.disabled) {
				        self.disable();
				    }

				    // unlock "disable" method
				    self.submitting = false;

				    // clear input to allow user to select same file
				    // Thanks to boston for fix
				    $(this).val('');
				})
				.appendTo(this.wrapper)

            // Emulate button hover effect				
				.hover(
					function() { self.button.addClass('hover'); }
					, function() { self.button.removeClass('hover'); }
				);

            if (this.disabled) {
                this.input.attr('disabled', true);
            }

        },
        /**
        * Creates iframe with unique name
        */
        create_iframe: function() {
            // unique name
            // We cannot use getTime, because it sometimes return
            // same value in safari :(
            var id = 'valums97hhu' + get_uid();

            // create iframe, so we dont need to refresh page
            this.iframe =
				$('<iframe id="' + id + '" name="' + id + '"></iframe>')
				.css('display', 'none')
				.appendTo('body');
        },
        /**
        * Upload file without refreshing the page
        */
        submit: function() {
            var self = this, settings = this.settings;

            // get filename from input
            var file = this.file_from_path(this.input.val());

            // execute user event
            if (settings.onSubmit.call(this, file, this.get_ext(file)) === false) {
                // Do not continue if user function returns false						
                return;
            }

            this.create_form();
            this.input.appendTo(this.form);
            this.form.submit();

            this.input.remove(); this.input = null;
            this.form.remove(); this.form = null;

            this.submitting = false;

            // create new input
            this.create_input();

            var iframe = this.iframe;
            iframe.load(function() {
                if (iframe[0].src == "about:blank") {
                    return;
                }

                var response = iframe.contents().find('body').html();

                settings.onComplete.call(self, file, response);
                // Workaround for FF2 bug, which causes cursor to be in busy state after post.
                setTimeout(function() {
                    // Workaround for ie6 bug, which causes progress bar to be in busy state after post.
                    // Thanks to Lei for the fix
                    iframe[0].src = "about:blank";
                    iframe.remove();
                }, 1);
            });

            // Create new iframe, so we can have multiple uploads at once
            this.create_iframe();
        },
        /**
        * Creates form, that will be submitted to iframe
        */
        create_form: function() {
            // method, enctype must be specified here
            // because changing this attr on the fly is not allowed in IE 6/7
            this.form =
				$('<form method="post" enctype="multipart/form-data"></form>')
				.attr({
				    "action": this.settings.action
					, "target": this.iframe.attr('name')
				})
				.appendTo('body');

            // Create hidden input element for each data key
            for (var i in this.settings.data) {
                $('<input type="hidden" />')
					.appendTo(this.form)
					.attr({
					    'name': i
						, 'value': this.settings.data[i]
					});
            }
        },
        file_from_path: function(file) {
            return file.replace(/.*(\/|\\)/, "");
        },
        get_ext: function(file) {
            return (/[.]/.exec(file)) ? /[^.]+$/.exec(file.toLowerCase()) : '';
        },
        make_parent_opaque: function() {
            // ie transparent background bug
            this.button.add(this.button.parents()).each(function() {
                var color = $(this).css('backgroundColor');
                var image = $(this).css('backgroundImage');

                if (color != 'transparent' || image != 'none') {
                    $(this).css('opacity', 1);
                    return false;
                }
            });
        }

    };
})(jQuery);