/*
   Copyright (C) 1999-2007 id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   GtkRadiant is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <stdio.h>
#include <string.h>
#include <glib.h>
#include "bmp.h"

#include "image.h"

static void BMPLineNone( FILE *f, char *sline, int pixbytes, int width ){
	int nbytes, i, k, j;

	switch ( pixbytes )
	{
	case 1:
		nbytes = ( width + 3 ) / 4;
		nbytes *= 4;

		fread( sline, width, 1, f );
		nbytes -= width;

		while ( nbytes-- > 0 ) fgetc( f );
		return;

	case 3:
		nbytes = ( ( width * 3 ) + 3 ) / 4;
		nbytes *= 4;

		fread( sline, width, 3, f );
		nbytes -= width * 3;

		while ( nbytes-- > 0 ) fgetc( f );

		// reorder bgr to rgb
		for ( i = 0, j = 0; i < width; i++, j += 3 )
		{
			k = sline[j];
			sline[j] = sline[j + 2];
			sline[j + 2] = k;
		}

		return;
	}

	Error( "BMPLineNone failed." );
}


static void BMPLineRLE8( FILE *f, char *sline, int pixbytes, int width ){
	Error( "RLE8 not yet supported." );
}


static void BMPLineRLE4( FILE *f, char *sline, int pixbytes, int width ){
	Error( "RLE4 not yet supported." );
}


static void BMPLine( FILE *f, char *scanline, int pixbytes, int width, int rle ){
	switch ( rle )
	{
	case xBI_NONE: BMPLineNone( f, scanline, pixbytes, width ); return;
	case xBI_RLE8: BMPLineRLE8( f, scanline, pixbytes, width ); return;
	case xBI_RLE4: BMPLineRLE4( f, scanline, pixbytes, width ); return;
	}

	Error( "Unknown compression type." );
}


/*
   static void PrintHeader(binfo_t *b)
   {
    printf("biSize         : %ld\n", b->biSize);
    printf("biWidth        : %ld\n", b->biWidth);
    printf("biHeight       : %ld\n", b->biHeight);
    printf("biPlanes       : %d\n", b->biPlanes);
    printf("biBitCount     : %d\n", b->biBitCount);
    printf("biCompression  : %ld\n", b->biCompression);
    printf("biSizeImage    : %ld\n", b->biSizeImage);
    printf("biXPelsPerMeter: %ld\n", b->biXPelsPerMeter);
    printf("biYPelsPerMeter: %ld\n", b->biYPelsPerMeter);
    printf("biClrUsed      : %ld\n", b->biClrUsed);
    printf("biClrImportant : %ld\n", b->biClrImportant);
   }
 */

// FIXME: calls to Error(const char *, ... ) are dependant on qe3.cpp
void LoadBMP( char *filename, bitmap_t *bit ){
	FILE    *f;
	bmphd_t bhd;
	binfo_t info;
	//    int      pxlsize = 1;
	int rowbytes, i, pixbytes;
	char    *scanline;

	// open file
	if ( ( f = fopen( filename, "rb" ) ) == NULL ) {
		Error( "Unable to open file" ); // %s.", filename);
	}

	// read in bitmap header
	if ( fread( &bhd, sizeof( bhd ), 1, f ) != 1 ) {
		fclose( f );
		Error( "Unable to read in bitmap header." );
	}

	// make sure we have a valid bitmap file
	if ( bhd.bfType != BMP_SIGNATURE_WORD ) {
		fclose( f );
		Error( "Invalid BMP file" ); //: %s", filename);
	}

	// load in info header
	if ( fread( &info, sizeof( info ), 1, f ) != 1 ) {
		fclose( f );
		Error( "Unable to read bitmap info header." );
	}

	// make sure this is an info type of bitmap
	if ( info.biSize != sizeof( binfo_t ) ) {
		fclose( f );
		Error( "We only support the info bitmap type." );
	}

	// PrintHeader(&info);

	bit->bpp      = info.biBitCount;
	bit->width    = info.biWidth;
	bit->height   = info.biHeight;
	bit->data     = NULL;
	bit->palette  = NULL;

	//currently we only read in 8 and 24 bit bmp files
	if      ( info.biBitCount == 8 ) {
		pixbytes = 1;
	}
	else if ( info.biBitCount == 24 ) {
		pixbytes = 3;
	}
	else
	{
		Error( "Only 8BPP and 24BPP supported" );
		//Error("BPP %d not supported.", info.biBitCount);
	}

	// if this is an eight bit image load palette
	if ( pixbytes == 1 ) {
		drgb_t q;

		bit->palette = reinterpret_cast<rgb_t*>( g_malloc( sizeof( rgb_t ) * 256 ) );

		for ( i = 0; i < 256; i++ )
		{
			if ( fread( &q, sizeof( drgb_t ), 1, f ) != 1 ) {
				fclose( f ); g_free( bit->palette );
				Error( "Unable to read palette." );
			}

			bit->palette[i].r   = q.red;
			bit->palette[i].g   = q.green;
			bit->palette[i].b   = q.blue;
		}
	}

	// position to start of bitmap
	fseek( f, bhd.bfOffBits, SEEK_SET );

	// create scanline to read data into
	rowbytes = ( ( info.biWidth * pixbytes ) + 3 ) / 4;
	rowbytes *= 4;

	scanline = reinterpret_cast<char*>( g_malloc( rowbytes ) );

	// alloc space for new bitmap
	bit->data = reinterpret_cast<unsigned char*>( g_malloc( info.biWidth * pixbytes * info.biHeight ) );

	// read in image
	for ( i = 0; i < info.biHeight; i++ )
	{
		BMPLine( f, scanline, pixbytes, info.biWidth, info.biCompression );

		// store line
		memcpy( &bit->data[info.biWidth * pixbytes * ( info.biHeight - i - 1 )], scanline, info.biWidth * pixbytes );
	}

	g_free( scanline );
	fclose( f );
}



static void BMPEncodeLine( FILE *f, unsigned char *data, int npxls, int pixbytes ){
	int nbytes, i, j, k;

	switch ( pixbytes )
	{
	case 1:
		nbytes = ( npxls + 3 ) / 4;
		nbytes *= 4;

		fwrite( data, npxls, 1, f );
		nbytes -= npxls;

		while ( nbytes-- > 0 ) fputc( 0, f );
		return;

	case 3:
		// reorder rgb to bgr
		for ( i = 0, j = 0; i < npxls; i++, j += 3 )
		{
			k = data[j];
			data[j] = data[j + 2];
			data[j + 2] = k;
		}

		nbytes = ( ( npxls * 3 ) + 3 ) / 4;
		nbytes *= 4;

		fwrite( data, npxls, 3, f );
		nbytes -= npxls * 3;

		while ( nbytes-- > 0 ) fputc( 0, f );
		return;
	}

	Error( "BMPEncodeLine Failed." );
}



void WriteBMP( char *filename, bitmap_t *bit ){
	FILE    *f;
	bmphd_t header;
	binfo_t info;
	drgb_t q;          // palette that gets written
	long bmofs;
	int w, h, i;
	int pixbytes;

	if      ( bit->bpp == 8 ) {
		pixbytes = 1;
	}
	else if ( bit->bpp == 24 ) {
		pixbytes = 3;
	}

	else
	{
		Error( "Only 8BPP and 24BPP supported" );
		//Error("BPP %d not supported.", bit->bpp);
	}


	if ( ( f = fopen( filename, "wb" ) ) == NULL ) {
		Error( "Unable to open file" ); //%s.", filename);
	}

	// write out an empty header as a place holder
	if ( fwrite( &header, sizeof( header ), 1, f ) != 1 ) {
		Error( "Unable to fwrite." );
	}

	// init and write info header
	info.biSize          = sizeof( binfo_t );
	info.biWidth         = bit->width;
	info.biHeight        = bit->height;
	info.biPlanes        = 1;
	info.biBitCount      = bit->bpp;
	info.biCompression   = xBI_NONE;
	info.biSizeImage     = bit->width * bit->height;
	info.biXPelsPerMeter = 0;
	info.biYPelsPerMeter = 0;
	info.biClrUsed       = 256;
	info.biClrImportant  = 256;

	if ( fwrite( &info, sizeof( binfo_t ), 1, f ) != 1 ) {
		Error( "fwrite failed." );
	}

	// write out palette if we need to
	if ( bit->bpp == 8 ) {
		for ( i = 0; i < 256; i++ )
		{
			q.red   = bit->palette[i].r;
			q.green = bit->palette[i].g;
			q.blue  = bit->palette[i].b;

			fwrite( &q, sizeof( q ), 1, f );
		}
	}

	// save offset to start of bitmap
	bmofs = ftell( f );

	// output bitmap
	w = bit->width;
	h = bit->height;

	for ( i = h - 1; i >= 0; i-- )
	{
		BMPEncodeLine( f, &bit->data[w * pixbytes * i], w, pixbytes );
	}

	// update and rewrite file header
	header.bfType    = BMP_SIGNATURE_WORD;
	header.bfSize    = ftell( f );
	header.bfOffBits = bmofs;

	fseek( f, 0L, SEEK_SET );
	fwrite( &header, sizeof( header ), 1, f );

	fclose( f );
}


void NewBMP( int width, int height, int bpp, bitmap_t *bit ){
	int pixbytes;

	if      ( bpp == 8 ) {
		pixbytes = 1;
	}
	else if ( bpp == 24 ) {
		pixbytes = 3;
	}

	else
	{
		Error( "NewBMP: 8 or 24 bit only." );
	}

	bit->bpp    = bpp;
	bit->width  = width;
	bit->height = height;

	bit->data = reinterpret_cast<unsigned char*>( g_malloc( width * height * pixbytes ) );

	if ( bit->data == NULL ) {
		Error( "NewBMP: g_malloc failed." );
	}

	// see if we need to create a palette
	if ( pixbytes == 1 ) {
		bit->palette = (rgb_t *) g_malloc( 768 );

		if ( bit->palette == NULL ) {
			Error( "NewBMP: unable to g_malloc palette." );
		}
	}
	else
	{
		bit->palette = NULL;
	}
}



void FreeBMP( bitmap_t *bitmap ){
	if ( bitmap->palette ) {
		g_free( bitmap->palette );
		bitmap->palette = NULL;
	}

	if ( bitmap->data ) {
		g_free( bitmap->data );
		bitmap->data = NULL;
	}
}