#!/usr/bin/python

from gimpfu import *
import tempfile, subprocess, os

def plugin_main(timg, tdrawable, amount):
    sfx = '.png'
    pfx = 'gimp_convert_to_paletted_plugin'
    tmpifn = tempfile.mktemp(sfx, pfx)
    tmpofn = tempfile.mktemp(sfx, pfx)
    tmppfn = tempfile.mktemp(sfx, pfx)

    pal = pdb.gimp_context_get_palette()
    num_colors, colors = pdb.gimp_palette_get_colors(pal)

    tempimage = pdb.gimp_image_duplicate(timg)
    tempdrawable = pdb.gimp_layer_new_from_visible(tempimage, tempimage, "visible")
    pdb.gimp_file_save(tempimage, tempdrawable, tmpifn, "")
    pdb.gimp_image_delete(tempimage)

    tempimage = pdb.gimp_image_new(num_colors, 1, 0)
    tempdrawable = pdb.gimp_layer_new(tempimage, num_colors, 1, 1, "pal", 100, 0)
    for x,c in zip(xrange(num_colors), colors):
        pdb.gimp_drawable_set_pixel(tempdrawable, x, 0, 4, c)
    pdb.gimp_file_save(tempimage, tempdrawable, tmppfn, "")
    pdb.gimp_image_delete(tempimage)

    cmd = 'convert %s -dither floyd-steinberg -define dither:diffusion-amount=%i%% -remap %s %s' % \
          (tmpifn, amount, tmppfn, tmpofn)

    p = subprocess.Popen(cmd.split(), shell=False)
    p.communicate()

    layer = pdb.gimp_file_load_layer(timg, tmpofn)
    pdb.gimp_image_insert_layer(timg, layer, None, -1)

    for fn in [tmpifn, tmpofn, tmppfn]:
        os.remove(fn)

register(
        "python_fu_convert_to_paletted",
        "Convert to paletted",
        "Convert to paletted",
        "Anonymous",
        "Anonymous",
        "2019",
        "<Image>/Image/Convert to paletted...",
        "RGB*",
        [(PF_SLIDER, "diffusion_amount",  "Diffusion Amount, %:", 50, [0, 100, 1])],
        [],
        plugin_main)

main()