/*
 * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/**
 * Note: Lifted from uncrunch.c from jdk sources
 */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <stdint.h>

#include <stdlib.h>
#include <assert.h>

#ifndef _MSC_VER
#include <strings.h>
#endif

#include "defines.h"
#include "bytes.h"
#include "utils.h"

#include "constants.h"
#include "unpack.h"

#include "zip.h"

#include "zlib.h"

inline uint32_t jar::get_crc32(uint32_t c, uchar *ptr, uint32_t len)
{
	return crc32(c, ptr, len);
}

// FIXME: this is bullshit. Do real endianness detection.
#ifdef sparc
#define SWAP_BYTES(a) ((((a) << 8) & 0xff00) | 0x00ff) & (((a) >> 8) | 0xff00)
#else
#define SWAP_BYTES(a) (a)
#endif

#define GET_INT_LO(a) SWAP_BYTES(a & 0xFFFF)

#define GET_INT_HI(a) SWAP_BYTES((a >> 16) & 0xFFFF);

void jar::init(unpacker *u_)
{
	BYTES_OF(*this).clear();
	u = u_;
	u->jarout = this;
}

// Write data to the ZIP output stream.
void jar::write_data(void *buff, int len)
{
	while (len > 0)
	{
		int rc = (int)fwrite(buff, 1, len, jarfp);
		if (rc <= 0)
		{
			fprintf(stderr, "Error: write on output file failed err=%d\n", errno);
			exit(1); // Called only from the native standalone unpacker
		}
		output_file_offset += rc;
		buff = ((char *)buff) + rc;
		len -= rc;
	}
}

void jar::add_to_jar_directory(const char *fname, bool store, int modtime, int len, int clen,
							   uint32_t crc)
{
	uint32_t fname_length = (uint32_t)strlen(fname);
	ushort header[23];
	if (modtime == 0)
		modtime = default_modtime;
	uint32_t dostime = get_dostime(modtime);

	header[0] = (ushort)SWAP_BYTES(0x4B50);
	header[1] = (ushort)SWAP_BYTES(0x0201);
	header[2] = (ushort)SWAP_BYTES(0xA);

	// required version
	header[3] = (ushort)SWAP_BYTES(0xA);

	// flags 02 = maximum  sub-compression flag
	header[4] = (store) ? 0x0 : SWAP_BYTES(0x2);

	// Compression method 8=deflate.
	header[5] = (store) ? 0x0 : SWAP_BYTES(0x08);

	// Last modified date and time.
	header[6] = (ushort)GET_INT_LO(dostime);
	header[7] = (ushort)GET_INT_HI(dostime);

	// CRC
	header[8] = (ushort)GET_INT_LO(crc);
	header[9] = (ushort)GET_INT_HI(crc);

	// Compressed length:
	header[10] = (ushort)GET_INT_LO(clen);
	header[11] = (ushort)GET_INT_HI(clen);

	// Uncompressed length.
	header[12] = (ushort)GET_INT_LO(len);
	header[13] = (ushort)GET_INT_HI(len);

	// Filename length
	header[14] = (ushort)SWAP_BYTES(fname_length);
	// So called "extra field" length.
	header[15] = 0;
	// So called "comment" length.
	header[16] = 0;
	// Disk number start
	header[17] = 0;
	// File flags => binary
	header[18] = 0;
	// More file flags
	header[19] = 0;
	header[20] = 0;
	// Offset within ZIP file.
	header[21] = (ushort)GET_INT_LO(output_file_offset);
	header[22] = (ushort)GET_INT_HI(output_file_offset);

	// Copy the whole thing into the central directory.
	central_directory.append(header, sizeof(header));

	// Copy the fname to the header.
	central_directory.append(fname, fname_length);

	central_directory_count++;
}

void jar::write_jar_header(const char *fname, bool store, int modtime, int len, int clen,
						   uint32_t crc)
{
	uint32_t fname_length = (uint32_t)strlen(fname);
	ushort header[15];
	if (modtime == 0)
		modtime = default_modtime;
	uint32_t dostime = get_dostime(modtime);

	// ZIP LOC magic.
	header[0] = (ushort)SWAP_BYTES(0x4B50);
	header[1] = (ushort)SWAP_BYTES(0x0403);

	// Version
	header[2] = (ushort)SWAP_BYTES(0xA);

	// flags 02 = maximum  sub-compression flag
	header[3] = (store) ? 0x0 : SWAP_BYTES(0x2);

	// Compression method = deflate
	header[4] = (store) ? 0x0 : SWAP_BYTES(0x08);

	// Last modified date and time.
	header[5] = (ushort)GET_INT_LO(dostime);
	header[6] = (ushort)GET_INT_HI(dostime);

	// CRC
	header[7] = (ushort)GET_INT_LO(crc);
	header[8] = (ushort)GET_INT_HI(crc);

	// Compressed length:
	header[9] = (ushort)GET_INT_LO(clen);
	header[10] = (ushort)GET_INT_HI(clen);

	// Uncompressed length.
	header[11] = (ushort)GET_INT_LO(len);
	header[12] = (ushort)GET_INT_HI(len);

	// Filename length
	header[13] = (ushort)SWAP_BYTES(fname_length);
	// So called "extra field" length.
	header[14] = 0;

	// Write the LOC header to the output file.
	write_data(header, (int)sizeof(header));

	// Copy the fname to the header.
	write_data((char *)fname, (int)fname_length);
}

void jar::write_central_directory()
{
	bytes mc;
	mc.set("PACK200");

	ushort header[11];

	// Create the End of Central Directory structure.
	header[0] = (ushort)SWAP_BYTES(0x4B50);
	header[1] = (ushort)SWAP_BYTES(0x0605);
	// disk numbers
	header[2] = 0;
	header[3] = 0;
	// Number of entries in central directory.
	header[4] = (ushort)SWAP_BYTES(central_directory_count);
	header[5] = (ushort)SWAP_BYTES(central_directory_count);
	// Size of the central directory}
	header[6] = (ushort)GET_INT_LO((int)central_directory.size());
	header[7] = (ushort)GET_INT_HI((int)central_directory.size());
	// Offset of central directory within disk.
	header[8] = (ushort)GET_INT_LO(output_file_offset);
	header[9] = (ushort)GET_INT_HI(output_file_offset);
	// zipfile comment length;
	header[10] = (ushort)SWAP_BYTES((int)mc.len);

	// Write the central directory.
	write_data(central_directory.b);

	// Write the End of Central Directory structure.
	write_data(header, (int)sizeof(header));

	// Write the comment.
	write_data(mc);
}

// Public API

// Open a Jar file and initialize.
void jar::openJarFile(const char *fname)
{
	if (!jarfp)
	{
		jarfp = fopen(fname, "wb");
		if (!jarfp)
		{
			fprintf(stderr, "Error: Could not open jar file: %s\n", fname);
			exit(3); // Called only from the native standalone unpacker
		}
	}
}

// Add a ZIP entry and copy the file data
void jar::addJarEntry(const char *fname, bool deflate_hint, int modtime, bytes &head,
					  bytes &tail)
{
	int len = (int)(head.len + tail.len);
	int clen = 0;

	uint32_t crc = get_crc32(0, Z_NULL, 0);
	if (head.len != 0)
		crc = get_crc32(crc, (uchar *)head.ptr, (uint32_t)head.len);
	if (tail.len != 0)
		crc = get_crc32(crc, (uchar *)tail.ptr, (uint32_t)tail.len);

	bool deflate = (deflate_hint && len > 0);

	if (deflate)
	{
		if (deflate_bytes(head, tail) == false)
		{
			deflate = false;
		}
	}
	clen = (int)((deflate) ? deflated.size() : len);
	add_to_jar_directory(fname, !deflate, modtime, len, clen, crc);
	write_jar_header(fname, !deflate, modtime, len, clen, crc);

	if (deflate)
	{
		write_data(deflated.b);
	}
	else
	{
		write_data(head);
		write_data(tail);
	}
}

// Add a ZIP entry for a directory name no data
void jar::addDirectoryToJarFile(const char *dir_name)
{
	bool store = true;
	add_to_jar_directory((const char *)dir_name, store, default_modtime, 0, 0, 0);
	write_jar_header((const char *)dir_name, store, default_modtime, 0, 0, 0);
}

// Write out the central directory and close the jar file.
void jar::closeJarFile(bool central)
{
	if (jarfp)
	{
		fflush(jarfp);
		if (central)
			write_central_directory();
		fflush(jarfp);
		fclose(jarfp);
	}
	reset();
}

/* Convert the date y/n/d and time h:m:s to a four byte DOS date and
 *  time (date in high two bytes, time in low two bytes allowing magnitude
 *  comparison).
 */
inline uint32_t jar::dostime(int y, int n, int d, int h, int m, int s)
{
	return y < 1980 ? dostime(1980, 1, 1, 0, 0, 0)
					: (((uint32_t)y - 1980) << 25) | ((uint32_t)n << 21) | ((uint32_t)d << 16) |
						  ((uint32_t)h << 11) | ((uint32_t)m << 5) | ((uint32_t)s >> 1);
}
/*
#ifdef _REENTRANT // solaris
extern "C" struct tm *gmtime_r(const time_t *, struct tm *);
#else
#define gmtime_r(t, s) gmtime(t)
#endif
*/
/*
 * Return the Unix time in DOS format
 */
uint32_t jar::get_dostime(int modtime)
{
	// see defines.h
	if (modtime != 0 && modtime == modtime_cache)
		return dostime_cache;
	if (modtime != 0 && default_modtime == 0)
		default_modtime = modtime; // catch a reasonable default
	time_t t = modtime;
	struct tm sbuf;
	(void)memset((void *)&sbuf, 0, sizeof(sbuf));
	struct tm *s = gmtime_r(&t, &sbuf);
	modtime_cache = modtime;
	dostime_cache =
		dostime(s->tm_year + 1900, s->tm_mon + 1, s->tm_mday, s->tm_hour, s->tm_min, s->tm_sec);
	// printf("modtime %d => %d\n", modtime_cache, dostime_cache);
	return dostime_cache;
}

/* Returns true on success, and will set the clen to the compressed
   length, the caller should verify if true and clen less than the
   input data
*/
bool jar::deflate_bytes(bytes &head, bytes &tail)
{
	int len = (int)(head.len + tail.len);

	z_stream zs;
	BYTES_OF(zs).clear();

	// NOTE: the window size should always be -MAX_WBITS normally -15.
	// unzip/zipup.c and java/Deflater.c

	int error =
		deflateInit2(&zs, Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS, 8, Z_DEFAULT_STRATEGY);
	if (error != Z_OK)
	{
		/*
		switch (error)
		{
		case Z_MEM_ERROR:
			PRINTCR((2, "Error: deflate error : Out of memory \n"));
			break;
		case Z_STREAM_ERROR:
			PRINTCR((2, "Error: deflate error : Invalid compression level \n"));
			break;
		case Z_VERSION_ERROR:
			PRINTCR((2, "Error: deflate error : Invalid version\n"));
			break;
		default:
			PRINTCR((2, "Error: Internal deflate error error = %d\n", error));
		}
		*/
		return false;
	}

	deflated.empty();
	zs.next_out = (uchar *)deflated.grow(len + (len / 2));
	zs.avail_out = (int)deflated.size();

	zs.next_in = (uchar *)head.ptr;
	zs.avail_in = (int)head.len;

	bytes *first = &head;
	bytes *last = &tail;
	if (last->len == 0)
	{
		first = nullptr;
		last = &head;
	}
	else if (first->len == 0)
	{
		first = nullptr;
	}

	if (first != nullptr && error == Z_OK)
	{
		zs.next_in = (uchar *)first->ptr;
		zs.avail_in = (int)first->len;
		error = deflate(&zs, Z_NO_FLUSH);
	}
	if (error == Z_OK)
	{
		zs.next_in = (uchar *)last->ptr;
		zs.avail_in = (int)last->len;
		error = deflate(&zs, Z_FINISH);
	}
	if (error == Z_STREAM_END)
	{
		if (len > (int)zs.total_out)
		{
			deflated.b.len = zs.total_out;
			deflateEnd(&zs);
			return true;
		}
		deflateEnd(&zs);
		return false;
	}

	deflateEnd(&zs);
	return false;
}

// Callback for fetching data from a GZIP input stream
static int64_t read_input_via_gzip(unpacker *u, void *buf, int64_t minlen, int64_t maxlen)
{
	assert(minlen <= maxlen); // don't talk nonsense
	int64_t numread = 0;
	char *bufptr = (char *)buf;
	char *inbuf = u->gzin->inbuf;
	size_t inbuflen = sizeof(u->gzin->inbuf);
	unpacker::read_input_fn_t read_gzin_fn = (unpacker::read_input_fn_t)u->gzin->read_input_fn;
	z_stream &zs = *(z_stream *)u->gzin->zstream;
	while (numread < minlen)
	{
		int readlen = (1 << 16); // pretty arbitrary
		if (readlen > (maxlen - numread))
			readlen = (int)(maxlen - numread);
		zs.next_out = (uchar *)bufptr;
		zs.avail_out = readlen;
		if (zs.avail_in == 0)
		{
			zs.avail_in = (int)read_gzin_fn(u, inbuf, 1, inbuflen);
			zs.next_in = (uchar *)inbuf;
		}
		int error = inflate(&zs, Z_NO_FLUSH);
		if (error != Z_OK && error != Z_STREAM_END)
		{
			unpack_abort("error inflating input");
			break;
		}
		int nr = readlen - zs.avail_out;
		numread += nr;
		bufptr += nr;
		assert(numread <= maxlen);
		if (error == Z_STREAM_END)
		{
			enum
			{
				TRAILER_LEN = 8
			};
			// skip 8-byte trailer
			if (zs.avail_in >= TRAILER_LEN)
			{
				zs.avail_in -= TRAILER_LEN;
			}
			else
			{
				// Bug: 5023768,we read past the TRAILER_LEN to see if there is
				// any extraneous data, as we dont support concatenated .gz
				// files just yet.
				int extra = (int)read_gzin_fn(u, inbuf, 1, inbuflen);
				zs.avail_in += extra - TRAILER_LEN;
			}
			// %%% should check final CRC and length here
			// %%% should check for concatenated *.gz files here
			if (zs.avail_in > 0)
				unpack_abort("garbage after end of deflated input stream");
			// pop this filter off:
			u->gzin->free();
			break;
		}
	}

	// fprintf(u->errstrm, "readInputFn(%d,%d) => %d (gunzip)\n",
	//        (int)minlen, (int)maxlen, (int)numread);
	return numread;
}

void gunzip::init(unpacker *u_)
{
	BYTES_OF(*this).clear();
	u = u_;
	assert(u->gzin == nullptr); // once only, please
	read_input_fn = (void *)u->read_input_fn;
	zstream = NEW(z_stream, 1);
	u->gzin = this;
	u->read_input_fn = read_input_via_gzip;
}

void gunzip::start(int magic)
{
	assert((magic & GZIP_MAGIC_MASK) == GZIP_MAGIC);
	int gz_flg = (magic & 0xFF); // keep "flg", discard other 3 bytes
	enum
	{
		FHCRC = (1 << 1),
		FEXTRA = (1 << 2),
		FNAME = (1 << 3),
		FCOMMENT = (1 << 4)
	};
	char gz_mtime[4];
	char gz_xfl[1];
	char gz_os[1];
	char gz_extra_len[2];
	char gz_hcrc[2];
	char gz_ignore;
	// do not save extra, name, comment
	read_fixed_field(gz_mtime, sizeof(gz_mtime));
	read_fixed_field(gz_xfl, sizeof(gz_xfl));
	read_fixed_field(gz_os, sizeof(gz_os));
	if (gz_flg & FEXTRA)
	{
		read_fixed_field(gz_extra_len, sizeof(gz_extra_len));
		int extra_len = gz_extra_len[0] & 0xFF;
		extra_len += (gz_extra_len[1] & 0xFF) << 8;
		for (; extra_len > 0; extra_len--)
		{
			read_fixed_field(&gz_ignore, 1);
		}
	}
	int null_terms = 0;
	if (gz_flg & FNAME)
		null_terms++;
	if (gz_flg & FCOMMENT)
		null_terms++;
	for (; null_terms; null_terms--)
	{
		for (;;)
		{
			gz_ignore = 0;
			read_fixed_field(&gz_ignore, 1);
			if (gz_ignore == 0)
				break;
		}
	}
	if (gz_flg & FHCRC)
		read_fixed_field(gz_hcrc, sizeof(gz_hcrc));

	// now the input stream is ready to read into the inflater
	int error = inflateInit2((z_stream *)zstream, -MAX_WBITS);
	if (error != Z_OK)
	{
		unpack_abort("cannot create input");
	}
}

void gunzip::free()
{
	assert(u->gzin == this);
	u->gzin = nullptr;
	u->read_input_fn = (unpacker::read_input_fn_t) this->read_input_fn;
	inflateEnd((z_stream *)zstream);
	::free(zstream);
	zstream = nullptr;
	::free(this);
}

void gunzip::read_fixed_field(char *buf, size_t buflen)
{
	int64_t nr = ((unpacker::read_input_fn_t)read_input_fn)(u, buf, buflen, buflen);
	if ((size_t)nr != buflen)
		unpack_abort("short stream header");
}
