from degal.command import command
from degal import templates
from degal.task import threadable_task

def render_image_html (ctx, image) :
    """
        Render the thumbnails and .html for one image
    """

    # render output
    tpl = templates.master(ctx.gallery, image.title, image.html, 
        templates.image_page(image)
    )
    
    # write output
    tpl.render_file(image.html)

def render_image_task (image) :
    """
        Render the image output for the given image
    """
    
    # XXX: is this really threadsafe?
    image.update()
    
    # return value is the image itself
    return image

def render_folder_images (ctx, images) :
    """
        Render the given series of images
    """
    
    # render them in parallel as required
    for image in ctx.tasks.execute([
        threadable_task(render_image_task, image) for image in images
    ]) :
        # log image path
        ctx.log_info("%s", image)

        render_image_html(ctx, image)

def render_folder_page (ctx, folder) :
    """
        Render the .html output for one folder
    """

    # render each page separately
    for page in xrange(folder.page_count) :
        # output .html page
        html_file = folder.html_file(page)
        
        # render template
        tpl = templates.master(ctx.gallery, folder.title, html_file,
            templates.folder_page(folder, page)
        )

        # write output
        tpl.render_file(html_file)

def render_folder (ctx, folder) :
    """
        Render the HTML/images for this folder if needed, and recrurse into subfolders.
    """

    # index images that require updating
    image_count = len(folder.images)
    new_images = list(folder.index_images(for_update=(not ctx.config.force_update)))
    
    if new_images or ctx.config.force_update:
        # update folder index
        render_folder_page(ctx, folder)
        
        ctx.log_info("%s - render %d/%d images", folder, len(new_images), image_count)

        # update images
        render_folder_images(ctx, new_images)
    
    else :
        ctx.log_info("%s - up to date", folder)

    # index subfolders
    for subfolder in folder.subfolders :
        render_folder(ctx, subfolder)

@command
def main (ctx) :
    """
        Scan the gallery for new folders/images, and render updated ones
    """

    # render the gallery
    render_folder(ctx, ctx.gallery)