#include "plugin-img.h"

/*
 * Parse strings for format and color key
 **/
GimpPDBStatusType
img_read_options(ImageParasite * p, const gchar * fmt, const gchar * ckey,
                 GError ** error)
{
    gdouble r, g, b;
    guint32 R, G, B;

    if ((strcmp(fmt, FMT[0]) == 0) || (strcmp(fmt, "0") == 0))
        p->format = FMT_RGB565;
    else if ((strcmp(fmt, FMT[1]) == 0) || (strcmp(fmt, "1") == 0))
        p->format = FMT_RGB;
    else if ((strcmp(fmt, FMT[2]) == 0) || (strcmp(fmt, "2") == 0))
        p->format = FMT_RGBA;
    else
    {
        g_set_error(error, 0, 0, "Invalid file format: %s", fmt);
        return GIMP_PDB_CALLING_ERROR;
    }

    if (NULL == ckey)
    {
        p->ckey.is = 0;
        p->ckey.R = 0;
        p->ckey.G = 0;
        p->ckey.B = 0;
    }
    else
    {
        if ((strcmp(ckey, "") == 0) || (strcmp(ckey, "0") == 0) ||
            (strcmp(ckey, "no") == 0))
        {
            p->ckey.is = 0;
        }
        else if (3 == sscanf(ckey, "(%u, %u, %u)", &R, &G, &B))
        {
            if ((R < 256) && (G < 256) && (B < 256))
            {
                p->ckey.is = 1;
                p->ckey.R = R;
                p->ckey.G = G;
                p->ckey.B = B;
            }
            else
            {
                g_set_error(error, 0, 0,
                            "Invalid color key: %s; all values must be < 256",
                            ckey);
                return GIMP_PDB_CALLING_ERROR;
            }
        }
        else if (3 == sscanf(ckey, "(%lf; %lf; %lf)", &r, &g, &b))
        {
            if ((r <= 1.0) && (g <= 1.0) && (b <= 1.0) && (r >= 0.0) &&
                (g >= 0.0) && (b >= 0.0))
            {
                p->ckey.is = 1;
                p->ckey.R = (guint8) (r * 255);
                p->ckey.G = (guint8) (g * 255);
                p->ckey.B = (guint8) (b * 255);
            }
            else
            {
                g_set_error(error, 0, 0,
                            "Invalid color key: %s; example: (0.1; 0.7; 0.3), all values must be in [0; 1]",
                            ckey);
                return GIMP_PDB_CALLING_ERROR;
            }
        }
        else if (1 == sscanf(ckey, "0x%x", &R))
        {
            size_t l;

            l = strlen(ckey);
            if (5 == l) /* e. g. 0xAF9, but not 0xAAA6 */
            {
                p->ckey.is = 1;
                G = R & 0x000F00;
                p->ckey.R = (guint8) ((G >> 4) | (G >> 8));     /* Red */
                G = R & 0x0000F0;
                p->ckey.G = (guint8) (G | (G >> 4));    /* Green */
                G = R & 0x00000F;
                p->ckey.B = (guint8) ((G << 4) | G);    /* Blue */
            }
            else if (8 == l)    /* e. g. 0xFFAA99 */
            {
                p->ckey.is = 1;
                p->ckey.R = (guint8) ((R & 0xFF0000) >> 16);    /* Red */
                p->ckey.G = (guint8) ((R & 0x00FF00) >> 8);     /* Green */
                p->ckey.B = (guint8) (R & 0x0000FF);    /* Blue */
            }
            else
            {
                g_set_error(error, 0, 0,
                            "Hex color key %s is invalid; examples are 0xFFF or 0xFF44GG",
                            ckey);
                return GIMP_PDB_CALLING_ERROR;
            }
        }
        else
        {
            g_set_error(error, 0, 0, "Invalid color key: %s", ckey);
            return GIMP_PDB_CALLING_ERROR;
        }

    }
    D(("Parsed format: %s (%1u)\n", FMT[p->format], p->format));
    D(("Parsed color key: %s (%1u, %1u, %1u)\n", (p->ckey.is) ? "yes" : "no",
       p->ckey.R, p->ckey.G, p->ckey.B));
    return GIMP_PDB_SUCCESS;
}

static inline void
rgb_to_rgb565(const guint8 * c, guint16 * res)
{
    /*
     * How to:
     * |        24 bits       |
     * |   B  ||   G  ||  R   |
     * 11111xxx000000xx11111xxx
     * | B |   |  G |  | R |
     * 11111   000000  11111
     * |   high  ||  low   |
     * |       16 bits     |
     *
     */
    (*res) = 0;
    (*res) |= ((guint16) (c[0]) >> 3);  /* Red */
    (*res) |= ((guint16) (c[1]) >> 2) << 5;     /* Green */
    (*res) |= ((guint16) (c[2]) >> 3) << 11;    /* Blue */
}

static void
img_map_gimp_to_file(GimpImageType image_type, guint8 fmt,
                     const ColorKey * ckey, guint8 * src, guint8 * dest,
                     size_t npixels)
{
    size_t s, d;
    guint8 r, g, b;

    switch (image_type)
    {
      case GIMP_RGB_IMAGE:
          npixels *= 3;
          switch (fmt)
          {
            case FMT_RGB565:   /* RGB -> RGB565 */
                for (s = 0, d = 0; s < npixels;)
                {
                    rgb_to_rgb565(&(src[s]), (guint16 *) & (dest[d]));
                    d += 2;
                    s += 3;
                }
                break;

            case FMT_RGB:      /* RGB -> RGB */
                memcpy(dest, src, npixels);
                break;

            case FMT_RGBA:     /* RGB -> RGBA */
                if (ckey->is == 0)
                    for (s = 0, d = 0; s < npixels;)
                    {
                        dest[d++] = src[s++];   /* Red */
                        dest[d++] = src[s++];   /* Green */
                        dest[d++] = src[s++];   /* Blue */
                        dest[d++] = 255;        /* Opaque */
                    }
                else    /* Color key to Alpha */
                    for (s = 0, d = 0; s < npixels;)
                    {
                        r = dest[d++] = src[s++];       /* Red */
                        g = dest[d++] = src[s++];       /* Green */
                        b = dest[d++] = src[s++];       /* Blue */
                        if ((r == ckey->R) && (g == ckey->G) && (b == ckey->B))
                            dest[d++] = 0;      /* Transparent */
                        else
                            dest[d++] = 255;    /* Opaque */
                    }
                break;

            default:
                break;
          }
          break;

      case GIMP_RGBA_IMAGE:
          npixels *= 4;
          switch (fmt)
          {
            case FMT_RGB565:   /* RGBA -> RGB565 */
                for (s = 0, d = 0; s < npixels;)
                {
                    rgb_to_rgb565(&(src[s]), (guint16 *) & (dest[d]));
                    d += 2;
                    s += 4;     /* Skip Alpha */
                }
                break;

            case FMT_RGB:      /* RGBA -> RGB */
                for (s = 0, d = 0; s < npixels;)
                {
                    dest[d++] = src[s++];       /* Red */
                    dest[d++] = src[s++];       /* Green */
                    dest[d++] = src[s++];       /* Blue */
                    s++;        /* Skip Alpha */
                }
                break;

            case FMT_RGBA:     /* RGBA -> RGBA */
                memcpy(dest, src, npixels);
                break;

            default:
                break;
          }
          break;

      default:
          break;
    }
}

GimpPDBStatusType
img_sanity_check(gint32 image_ID, GError ** error)
{
    gint32 *layers;
    gint nlayers;
    gint image_width;
    gint image_height;
    gint i;
    GimpPDBStatusType status = GIMP_PDB_SUCCESS;

    if (gimp_image_base_type(image_ID) != GIMP_RGB)
    {
        g_set_error(error, 0, 0, "Can save only RGB images.");
        return GIMP_PDB_EXECUTION_ERROR;
    }

    layers = gimp_image_get_layers(image_ID, &nlayers);
    if (nlayers == 0)
    {
        g_set_error(error, 0, 0, "Can't save empty images ;-)");
        return GIMP_PDB_EXECUTION_ERROR;
    }

    image_width = gimp_image_width(image_ID);
    image_height = gimp_image_height(image_ID);

    for (i = 0; i < nlayers; i++)
    {
        if ((gimp_drawable_width(layers[i]) != image_width) ||
            (gimp_drawable_height(layers[i]) != image_height))
        {
            g_set_error(error, 0, 0,
                        "All layers must exactly match width and height of image.");
            status = GIMP_PDB_EXECUTION_ERROR;
            break;
        }
    }

    g_free(layers);
    return status;
}

GimpPDBStatusType
img_save_image(gint32 image, const ImageParasite * plugin,
               const gchar * filename, GError ** error)
{
    FILE *fp;
    GimpPixelRgn pixel_rgn;
    GimpDrawable *drawable = NULL;
    gint *layers = NULL, nlayers;
    size_t nwritten;
    guint8 *data = NULL, *pixels = NULL;
    size_t data_size, npixels;
    gint i, width, height;
    FileHeader hdr;

#if 0
    ImageParasite test;
    GError *terr = NULL;

    img_read_options(&test, "RGB", "(23,45,6)", &terr);
    if (NULL != terr)
    {
        printf("%s\n", terr->message);
        g_error_free(terr);
    }
    img_read_options(&test, "RGBA", "0x999", &terr);
    if (NULL != terr)
    {
        printf("%s\n", terr->message);
        g_error_free(terr);
    }
    img_read_options(&test, "0", "0x321", &terr);
    if (NULL != terr)
    {
        printf("%s\n", terr->message);
        g_error_free(terr);
    }
    img_read_options(&test, "2", "0xFFFFFF", &terr);
    if (NULL != terr)
    {
        printf("%s\n", terr->message);
        g_error_free(terr);
    }
    img_read_options(&test, "RGB", "(0,1;0,7;0,346)", &terr);
    if (NULL != terr)
    {
        printf("%s\n", terr->message);
        g_error_free(terr);
    }
#endif
    /*
     * Should call sanity_check() for all secure checks
     */

    layers = gimp_image_get_layers(image, &nlayers);
    width = gimp_image_width(image);
    height = gimp_image_height(image);
    npixels = width * height;

    /*
     * Making file header
     */
    hdr.fmt = plugin->format;
    hdr.ncols = 1;      /* Always one column */
    hdr.nrows = nlayers;
    hdr.width = width * hdr.ncols;
    hdr.height = height * hdr.nrows;

    hdr.nrows = GUINT32_TO_LE(hdr.nrows);
    hdr.ncols = GUINT32_TO_LE(hdr.ncols);
    hdr.width = GUINT32_TO_LE(hdr.width);
    hdr.height = GUINT32_TO_LE(hdr.height);

    D(("*** Saving \"%s\"\n", filename));

    gimp_progress_init_printf("Saving '%s'", gimp_filename_to_utf8(filename));

    if (!(fp = g_fopen(filename, "wb")))
    {
        g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                    "Could not open '%s' for writing: %s",
                    gimp_filename_to_utf8(filename), g_strerror(errno));
        g_free(layers);
        return GIMP_PDB_EXECUTION_ERROR;
    }

    /*
     * Write file
     */
    D(("Writing header: format: %s (%1u), frames: %ux%u, size: %ux%u\n",
       FMT[hdr.fmt], hdr.fmt, hdr.ncols, hdr.nrows, hdr.width, hdr.height));
    nwritten = fwrite((const void *)&hdr, sizeof(hdr), 1, fp);
    if (nwritten != 1)
    {
        D(("Error: %s\n", g_strerror(errno)));
        g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                    "Writing file header: %s\n", g_strerror(errno));
        fclose(fp);
        g_free(layers);
        return GIMP_PDB_EXECUTION_ERROR;
    }

    /*
     * File format specific preparations
     */
    data_size = width * height;
    switch (hdr.fmt)
    {
      case FMT_RGB565:
          data_size *= 2;
          break;

      case FMT_RGB:
          D(("Writing color key: %s (%1u, %1u, %1u)\n",
             (plugin->ckey.is) ? "yes" : "no", plugin->ckey.R, plugin->ckey.G,
             plugin->ckey.B));
          nwritten =
              fwrite((const void *)&(plugin->ckey), sizeof(plugin->ckey), 1,
                     fp);
          if (nwritten != 1)
          {
              D(("Error: %s\n", g_strerror(errno)));
              g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                          "Writing color key: %s\n", g_strerror(errno));
              fclose(fp);
              g_free(layers);
              return GIMP_PDB_EXECUTION_ERROR;
          }
          data_size *= 3;
          break;

      case FMT_RGBA:
          __DEBUG(if (plugin->ckey.is)
                  D(("Will convert color key "
                     "(%1u, %1u, %1u) to full transparent\n", plugin->ckey.R,
                     plugin->ckey.G, plugin->ckey.B)););
          data_size *= 4;
          break;
    }

    /*
     * Writing each layer (frame)
     */
    data = g_new(guint8, data_size);
    pixels = g_new(guint8, npixels * 4);        /* Enough for RGB or RGBA */
    for (i = 0; i < nlayers; i++)
    {
        gimp_progress_update((gdouble) i / (gdouble) nlayers);
        drawable = gimp_drawable_get(layers[i]);
        gimp_pixel_rgn_init(&pixel_rgn, drawable, 0, 0, width, height, FALSE,
                            FALSE);
        gimp_pixel_rgn_get_rect(&pixel_rgn, (guchar *) pixels, 0, 0, width,
                                height);
        D(("Writing frame #%u of %u (%u bytes)\n", i + 1, nlayers, data_size));
        /*
         * Allow different image type for different layers
         */
        img_map_gimp_to_file(gimp_drawable_type(layers[i]), hdr.fmt,
                             &(plugin->ckey), pixels, data, npixels);

        nwritten = fwrite((const void *)data, data_size, 1, fp);
        if (nwritten != 1)
        {
            D(("Error: %s\n", g_strerror(errno)));
            g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
                        "Writing layer #%u: %s\n", i, g_strerror(errno));
            fclose(fp);
            g_free(layers);
            g_free(data);
            g_free(pixels);
            return GIMP_PDB_EXECUTION_ERROR;
        }
    }

    fclose(fp);
    g_free(layers);
    g_free(data);
    g_free(pixels);
    gimp_progress_update(1.0);
    D(("*** Written \"%s\"\n", filename));

    return GIMP_PDB_SUCCESS;
}