/*
    // Example data:
    
    JSImageGalleryData['block1'] = {
        'index': 0,
        'infoSpanText': 'neupejpej se a kokni na nás!',
        'photoCount': 5,
        'images':
            [ {'src' : 'img/foto01.jpg', 'alt' : 'Foto 01', 'width': '550'},
              {'src' : 'img/foto02.jpg', 'alt' : 'Foto 02', 'width': '550'},
              {'src' : 'img/foto03.jpg', 'alt' : 'Foto 03', 'width': '550'},
              {'src' : 'img/foto04.jpg', 'alt' : 'Foto 04', 'width': '550'},
              {'src' : 'img/foto05.jpg', 'alt' : 'Foto 05', 'width': '550'}
            ]
    };
    
    JSImageGalleryData['block2'] = {
        'index': 0,
        'infoSpanText': 'neupejpej se a kokni na nás!',
        'photoCount': 2,
        'images':
            [ {'src' : 'img/1-one.png', 'alt' : '1', 'width': '550'},
              {'src' : 'img/2-two.png', 'alt' : '2', 'width': '550'}
            ]
        }
    };  
*/

var JSImageGalleryData = {}

var canMoveToNext = function(blockID) {
    return (JSImageGalleryData[blockID].index < JSImageGalleryData[blockID].photoCount - 1) ? true : false;
};

var canMoveToPrev = function(blockID) {
    return (JSImageGalleryData[blockID].index > 0) ? true : false;
};

var swapImageByCurrentIndex = function(blockID) {
    blockData = JSImageGalleryData[blockID];
    
    updateNodeAttributes(blockID + 'photo-element', blockData.images[blockData.index]);
};

var goToNextImg = function(blockID) {
    if (canMoveToNext(blockID)) {
        JSImageGalleryData[blockID].index++;
        swapImageByCurrentIndex(blockID);
        refreshPhotoInfoSpanInGalleryViewingMode(blockID);
    }
};

var goToPrevImg = function(blockID) {
    if (canMoveToPrev(blockID)) {
        JSImageGalleryData[blockID].index--;
        swapImageByCurrentIndex(blockID);
        refreshPhotoInfoSpanInGalleryViewingMode(blockID);
    }
};

var swapPhotoInfoSpanToNonGalleryViewingMode = function(blockID) {
    photoInfoSpanID = blockID + 'photo-info-span';
    photoInfoSpanViewingID = photoInfoSpanID + 'viewing';
    
    newSpan = SPAN({id: photoInfoSpanID}, '[' + JSImageGalleryData[blockID].infoSpanText + ']' );
    swapDOM($(photoInfoSpanViewingID), newSpan);
}

var swapPhotoInfoSpanToGalleryViewingMode = function(blockID) {
    photoInfoSpanID = blockID + 'photo-info-span';
        
    refreshPhotoInfoSpanInGalleryViewingMode(blockID, photoInfoSpanID);
}

var refreshPhotoInfoSpanInGalleryViewingMode = function(blockID, /* optional */ oldPhotoInfoSpanViewingID) {
    photoInfoSpanID = blockID + 'photo-info-span';
    photoInfoSpanViewingID = photoInfoSpanID + 'viewing';
    oldPhotoInfoSpanViewingID = (oldPhotoInfoSpanViewingID == null) ? photoInfoSpanViewingID : oldPhotoInfoSpanViewingID;
    myFormater = numberFormatter('000');
    
    newSpan = SPAN({id: photoInfoSpanViewingID},
        IMG({src: '/site-media/img/sipka_l.gif', alt: 'předchozí < ', height: '18', width: '14', onclick: "javascript:goToPrevImg('" + blockID + "')"}),
        SPAN(null, myFormater(JSImageGalleryData[blockID].index + 1) + '/' + myFormater(JSImageGalleryData[blockID].photoCount)),
        IMG({src: '/site-media/img/sipka_p.gif', alt: ' > následující', height: '18', width: '14', onclick: "javascript:goToNextImg('" + blockID + "')"})
    );
    swapDOM($(oldPhotoInfoSpanViewingID), newSpan);
}