(function ($) {
    $(function () {

        var options = $.extend({
            lang: undefined,
            plugins_url: undefined,
            youtube_url_patterns: undefined,
            youtube_image_url_format: undefined,
            errors: {}
        }, anv_edit_form);

        var frame,
            $title = $('#title'),
            $video_url = $('#video-url'),
            $image_url = $('#image-url'),
            $image_preview_container = $('.image-preview'),
            $btn_upload = $('.button-upload'),
            $btn_generate = $('.button-generate'),
            $visibility = $('#visibility');

        $visibility.hide();

        // set required fields
        var required = [$title, $video_url, $image_url];
        for (var i in required) {
            if (!required.hasOwnProperty(i)) continue;
            required[i].prop('required', true);
        }

        $image_url.on('change', on_image_url_change);
        $btn_upload.on('click', on_btn_upload_click);
        $btn_generate.on('click', on_btn_generate_click);

        function on_btn_upload_click(event) {
            event.preventDefault();

            if ( frame ) {
                frame.open();
                return;
            }

            frame = wp.media({
                title: 'Select or Upload Media Of Your Chosen Persuasion',
                button: {
                    text: 'Use this media'
                },
                library: {
                    type: 'image'
                },
                multiple: false
            });

            frame.on( 'select', function() {
                var image = frame.state().get('selection').first().toJSON();
                $image_url.val(image.url);
                $image_url.trigger('change');
            });

            frame.open();
        }

        function on_btn_generate_click(event) {
            event.preventDefault();

            var video_url = $video_url.val();
            if (video_url) {
                for (var i in options.youtube_url_patterns) {
                    if (!options.youtube_url_patterns.hasOwnProperty(i)) continue;
                    var re = new RegExp(options.youtube_url_patterns[i]);
                    var result = re.exec(video_url);
                    if (result) {
                        $image_url.val(options.youtube_image_url_format.replace('%s', result[1]));
                        $image_url.trigger('change');
                        return;
                    }
                }
                alert(options.errors.unknown_video_url_format);
            } else {
                alert(options.errors.video_url_empty);
            }
        }
        
        function on_image_url_change() {
            var $img = $('<img>');
            $img.prop('width', '320');
            $img.prop('src', $image_url.val());
            $image_preview_container.html('');
            $image_preview_container.append($img);
        }
    });
})(jQuery);