/*
 * Copyright (c) 2005 Rob Braun
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Rob Braun nor the names of his contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
/*
 * 03-Apr-2005
 * DRI: Rob Braun <bbraun@opendarwin.org>
 */
/*
 * Portions Copyright 2006, Apple Computer, Inc.
 * Christopher Ryan <ryanc@apple.com>
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <zlib.h>
#include "config.h"
#ifndef HAVE_ASPRINTF
#include "asprintf.h"
#endif
#include "xar.h"
#include "filetree.h"
#include "io.h"

typedef struct _gzip_context{
	uint8_t		gzipcompressed;
	uint64_t        count;
	z_stream	z;
} gzip_context;

#define GZIP_CONTEXT(x) ((struct _gzip_context *)(*x))

int xar_gzip_fromheap_done(xar_t x, xar_file_t f, xar_prop_t p, void **context);

int xar_gzip_fromheap_in(xar_t x, xar_file_t f, xar_prop_t p, void **in, size_t *inlen, void **context) {
	const char *opt;
	void *out = NULL;
	size_t outlen, offset = 0;
	int r;
	xar_prop_t tmpp;
	
	/* on first run, we init the context and check the compression type */
	if( !GZIP_CONTEXT(context) ) {
		*context = calloc(1,sizeof(struct _gzip_context));
	
		opt = NULL;
		tmpp = xar_prop_pget(p, "encoding");
		if( tmpp )
			opt = xar_attr_pget(f, tmpp, "style");
		if( !opt ) return 0;
		if( strcmp(opt, "application/x-gzip") != 0 ) return 0;
		
		GZIP_CONTEXT(context)->gzipcompressed = 1;
		inflateInit(&GZIP_CONTEXT(context)->z);
	}else if( !GZIP_CONTEXT(context)->gzipcompressed ){
		/* once the context has been initialized, then we have already
		   checked the compression type, so we need only check if we
		   actually are compressed */
		return 0;
	}
		

	outlen = *inlen;

	GZIP_CONTEXT(context)->z.next_in = *in;
	GZIP_CONTEXT(context)->z.avail_in = *inlen;
	GZIP_CONTEXT(context)->z.next_out = out;
	GZIP_CONTEXT(context)->z.avail_out = 0;

	while( GZIP_CONTEXT(context)->z.avail_in != 0 ) {
		outlen = outlen * 2;
		out = realloc(out, outlen);
		if( out == NULL ) abort();

		GZIP_CONTEXT(context)->z.next_out = out + offset;
		GZIP_CONTEXT(context)->z.avail_out = outlen - offset;

		r = inflate(&(GZIP_CONTEXT(context)->z), Z_SYNC_FLUSH);
		if( (r != Z_OK) && (r != Z_STREAM_END) ) {
			xar_err_new(x);
			xar_err_set_file(x, f);
			xar_err_set_string(x, "Error decompressing file");
			xar_err_callback(x, XAR_SEVERITY_FATAL, XAR_ERR_ARCHIVE_EXTRACTION);
			return -1;
		}
		offset += outlen - offset - GZIP_CONTEXT(context)->z.avail_out;
		if( (r == Z_STREAM_END) && (offset == 0) )
			break;
	}

	free(*in);
	*in = out;
	*inlen = offset;
	return 0;
}

int xar_gzip_fromheap_done(xar_t x, xar_file_t f, xar_prop_t p, void **context) {

	if( !context || !GZIP_CONTEXT(context) )
		return 0;

	if( GZIP_CONTEXT(context)->gzipcompressed){
		inflateEnd(&GZIP_CONTEXT(context)->z);		
	}

	/* free the context */
	free(GZIP_CONTEXT(context));
	*context = NULL;
	
	return 0;
}
int xar_gzip_toheap_done(xar_t x, xar_file_t f, xar_prop_t p, void **context) {
	xar_prop_t tmpp;
	
	if( GZIP_CONTEXT(context)->gzipcompressed){
		deflateEnd(&GZIP_CONTEXT(context)->z);		
		
		if( GZIP_CONTEXT(context)->count ) {
			tmpp = xar_prop_pset(f, p, "encoding", NULL);
			if( tmpp )
				xar_attr_pset(f, tmpp, "style", "application/x-gzip");
		}
	}

	/* free the context */
	free(GZIP_CONTEXT(context));
	*context = NULL;
	
	return 0;
}

int32_t xar_gzip_toheap_in(xar_t x, xar_file_t f, xar_prop_t p, void **in, size_t *inlen, void **context) {
	void *out = NULL;
	size_t outlen, offset = 0;
	int r;
	const char *opt;

	/* on first run, we init the context and check the compression type */
	if( !GZIP_CONTEXT(context) ) {
		*context = calloc(1,sizeof(struct _gzip_context));
		
		opt = xar_opt_get(x, XAR_OPT_COMPRESSION);
		if( !opt )
			return 0;
		
		if( strcmp(opt, XAR_OPT_VAL_GZIP) != 0 )
			return 0;
		
		GZIP_CONTEXT(context)->gzipcompressed = 1;
		deflateInit(&GZIP_CONTEXT(context)->z, Z_BEST_COMPRESSION);
		if( *inlen == 0 )
			return 0;
	}else if( !GZIP_CONTEXT(context)->gzipcompressed ){
		/* once the context has been initialized, then we have already
		checked the compression type, so we need only check if we
		actually are compressed */
		return 0;
	}
		
	outlen = *inlen/2;
	if(outlen == 0) outlen = 1024;
	GZIP_CONTEXT(context)->z.next_in = *in;
	GZIP_CONTEXT(context)->z.avail_in = *inlen;
	GZIP_CONTEXT(context)->z.next_out = out;
	GZIP_CONTEXT(context)->z.avail_out = 0;

	do {
		outlen *= 2;
		out = realloc(out, outlen);
		if( out == NULL ) abort();

		GZIP_CONTEXT(context)->z.next_out = out + offset;
		GZIP_CONTEXT(context)->z.avail_out = outlen - offset;

		if( *inlen == 0 )
			r = deflate(&GZIP_CONTEXT(context)->z, Z_FINISH);
		else
			r = deflate(&GZIP_CONTEXT(context)->z, Z_SYNC_FLUSH);
		offset = outlen - GZIP_CONTEXT(context)->z.avail_out;
	} while( GZIP_CONTEXT(context)->z.avail_in != 0 );

	free(*in);
	*in = out;
	GZIP_CONTEXT(context)->count += *inlen;
	*inlen = offset;
	return 0;
}