/*-
 * Copyright (c) 2003-2007 Tim Kientzle
 * Copyright (c) 2008 Joerg Sonnenberger
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
 */

#include "archive_platform.h"

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif

#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
#include "archive_write_private.h"
#include "archive_write_set_format_private.h"

struct shar {
	int			 dump;
	int			 end_of_line;
	struct archive_entry	*entry;
	int			 has_data;
	char			*last_dir;

	/* Line buffer for uuencoded dump format */
	char			 outbuff[45];
	size_t			 outpos;

	int			 wrote_header;
	struct archive_string	 work;
	struct archive_string	 quoted_name;
};

static int	archive_write_shar_close(struct archive_write *);
static int	archive_write_shar_free(struct archive_write *);
static int	archive_write_shar_header(struct archive_write *,
		    struct archive_entry *);
static ssize_t	archive_write_shar_data_sed(struct archive_write *,
		    const void * buff, size_t);
static ssize_t	archive_write_shar_data_uuencode(struct archive_write *,
		    const void * buff, size_t);
static int	archive_write_shar_finish_entry(struct archive_write *);

/*
 * Copy the given string to the buffer, quoting all shell meta characters
 * found.
 */
static void
shar_quote(struct archive_string *buf, const char *str, int in_shell)
{
	static const char meta[] = "\n \t'`\";&<>()|*?{}[]\\$!#^~";
	size_t len;

	while (*str != '\0') {
		if ((len = strcspn(str, meta)) != 0) {
			archive_strncat(buf, str, len);
			str += len;
		} else if (*str == '\n') {
			if (in_shell)
				archive_strcat(buf, "\"\n\"");
			else
				archive_strcat(buf, "\\n");
			++str;
		} else {
			archive_strappend_char(buf, '\\');
			archive_strappend_char(buf, *str);
			++str;
		}
	}
}

/*
 * Set output format to 'shar' format.
 */
int
archive_write_set_format_shar(struct archive *_a)
{
	struct archive_write *a = (struct archive_write *)_a;
	struct shar *shar;

	archive_check_magic(_a, ARCHIVE_WRITE_MAGIC,
	    ARCHIVE_STATE_NEW, "archive_write_set_format_shar");

	/* If someone else was already registered, unregister them. */
	if (a->format_free != NULL)
		(a->format_free)(a);

	shar = (struct shar *)calloc(1, sizeof(*shar));
	if (shar == NULL) {
		archive_set_error(&a->archive, ENOMEM, "Can't allocate shar data");
		return (ARCHIVE_FATAL);
	}
	archive_string_init(&shar->work);
	archive_string_init(&shar->quoted_name);
	a->format_data = shar;
	a->format_name = "shar";
	a->format_write_header = archive_write_shar_header;
	a->format_close = archive_write_shar_close;
	a->format_free = archive_write_shar_free;
	a->format_write_data = archive_write_shar_data_sed;
	a->format_finish_entry = archive_write_shar_finish_entry;
	a->archive.archive_format = ARCHIVE_FORMAT_SHAR_BASE;
	a->archive.archive_format_name = "shar";
	return (ARCHIVE_OK);
}

/*
 * An alternate 'shar' that uses uudecode instead of 'sed' to encode
 * file contents and can therefore be used to archive binary files.
 * In addition, this variant also attempts to restore ownership, file modes,
 * and other extended file information.
 */
int
archive_write_set_format_shar_dump(struct archive *_a)
{
	struct archive_write *a = (struct archive_write *)_a;
	struct shar *shar;

	archive_write_set_format_shar(&a->archive);
	shar = (struct shar *)a->format_data;
	shar->dump = 1;
	a->format_write_data = archive_write_shar_data_uuencode;
	a->archive.archive_format = ARCHIVE_FORMAT_SHAR_DUMP;
	a->archive.archive_format_name = "shar dump";
	return (ARCHIVE_OK);
}

static int
archive_write_shar_header(struct archive_write *a, struct archive_entry *entry)
{
	const char *linkname;
	const char *name;
	char *p, *pp;
	struct shar *shar;

	shar = (struct shar *)a->format_data;
	if (!shar->wrote_header) {
		archive_strcat(&shar->work, "#!/bin/sh\n");
		archive_strcat(&shar->work, "# This is a shell archive\n");
		shar->wrote_header = 1;
	}

	/* Save the entry for the closing. */
	archive_entry_free(shar->entry);
	shar->entry = archive_entry_clone(entry);
	name = archive_entry_pathname(entry);

	/* Handle some preparatory issues. */
	switch(archive_entry_filetype(entry)) {
	case AE_IFREG:
		/* Only regular files have non-zero size. */
		break;
	case AE_IFDIR:
		archive_entry_set_size(entry, 0);
		/* Don't bother trying to recreate '.' */
		if (strcmp(name, ".") == 0  ||  strcmp(name, "./") == 0)
			return (ARCHIVE_OK);
		break;
	case AE_IFIFO:
	case AE_IFCHR:
	case AE_IFBLK:
		/* All other file types have zero size in the archive. */
		archive_entry_set_size(entry, 0);
		break;
	default:
		archive_entry_set_size(entry, 0);
		if (archive_entry_hardlink(entry) == NULL &&
		    archive_entry_symlink(entry) == NULL) {
			__archive_write_entry_filetype_unsupported(
			    &a->archive, entry, "shar");
			return (ARCHIVE_WARN);
		}
	}

	archive_string_empty(&shar->quoted_name);
	shar_quote(&shar->quoted_name, name, 1);

	/* Stock preparation for all file types. */
	archive_string_sprintf(&shar->work, "echo x %s\n", shar->quoted_name.s);

	if (archive_entry_filetype(entry) != AE_IFDIR) {
		/* Try to create the dir. */
		p = strdup(name);
		pp = strrchr(p, '/');
		/* If there is a / character, try to create the dir. */
		if (pp != NULL) {
			*pp = '\0';

			/* Try to avoid a lot of redundant mkdir commands. */
			if (strcmp(p, ".") == 0) {
				/* Don't try to "mkdir ." */
				free(p);
			} else if (shar->last_dir == NULL) {
				archive_strcat(&shar->work, "mkdir -p ");
				shar_quote(&shar->work, p, 1);
				archive_strcat(&shar->work,
				    " > /dev/null 2>&1\n");
				shar->last_dir = p;
			} else if (strcmp(p, shar->last_dir) == 0) {
				/* We've already created this exact dir. */
				free(p);
			} else if (strlen(p) < strlen(shar->last_dir) &&
			    strncmp(p, shar->last_dir, strlen(p)) == 0) {
				/* We've already created a subdir. */
				free(p);
			} else {
				archive_strcat(&shar->work, "mkdir -p ");
				shar_quote(&shar->work, p, 1);
				archive_strcat(&shar->work,
				    " > /dev/null 2>&1\n");
				shar->last_dir = p;
			}
		} else {
			free(p);
		}
	}

	/* Handle file-type specific issues. */
	shar->has_data = 0;
	if ((linkname = archive_entry_hardlink(entry)) != NULL) {
		archive_strcat(&shar->work, "ln -f ");
		shar_quote(&shar->work, linkname, 1);
		archive_string_sprintf(&shar->work, " %s\n",
		    shar->quoted_name.s);
	} else if ((linkname = archive_entry_symlink(entry)) != NULL) {
		archive_strcat(&shar->work, "ln -fs ");
		shar_quote(&shar->work, linkname, 1);
		archive_string_sprintf(&shar->work, " %s\n",
		    shar->quoted_name.s);
	} else {
		switch(archive_entry_filetype(entry)) {
		case AE_IFREG:
			if (archive_entry_size(entry) == 0) {
				/* More portable than "touch." */
				archive_string_sprintf(&shar->work,
				    "test -e \"%s\" || :> \"%s\"\n",
				    shar->quoted_name.s, shar->quoted_name.s);
			} else {
				if (shar->dump) {
					unsigned int mode = archive_entry_mode(entry) & 0777;
					archive_string_sprintf(&shar->work,
					    "uudecode -p > %s << 'SHAR_END'\n",
					    shar->quoted_name.s);
					archive_string_sprintf(&shar->work,
					    "begin %o ", mode);
					shar_quote(&shar->work, name, 0);
					archive_strcat(&shar->work, "\n");
				} else {
					archive_string_sprintf(&shar->work,
					    "sed 's/^X//' > %s << 'SHAR_END'\n",
					    shar->quoted_name.s);
				}
				shar->has_data = 1;
				shar->end_of_line = 1;
				shar->outpos = 0;
			}
			break;
		case AE_IFDIR:
			archive_string_sprintf(&shar->work,
			    "mkdir -p %s > /dev/null 2>&1\n",
			    shar->quoted_name.s);
			/* Record that we just created this directory. */
			free(shar->last_dir);

			shar->last_dir = strdup(name);
			/* Trim a trailing '/'. */
			pp = strrchr(shar->last_dir, '/');
			if (pp != NULL && pp[1] == '\0')
				*pp = '\0';
			/*
			 * TODO: Put dir name/mode on a list to be fixed
			 * up at end of archive.
			 */
			break;
		case AE_IFIFO:
			archive_string_sprintf(&shar->work,
			    "mkfifo %s\n", shar->quoted_name.s);
			break;
		case AE_IFCHR:
			archive_string_sprintf(&shar->work,
			    "mknod %s c %ju %ju\n", shar->quoted_name.s,
			    (uintmax_t)archive_entry_rdevmajor(entry),
			    (uintmax_t)archive_entry_rdevminor(entry));
			break;
		case AE_IFBLK:
			archive_string_sprintf(&shar->work,
			    "mknod %s b %ju %ju\n", shar->quoted_name.s,
			    (uintmax_t)archive_entry_rdevmajor(entry),
			    (uintmax_t)archive_entry_rdevminor(entry));
			break;
		default:
			return (ARCHIVE_WARN);
		}
	}

	return (ARCHIVE_OK);
}

static ssize_t
archive_write_shar_data_sed(struct archive_write *a, const void *buff, size_t n)
{
	static const size_t ensured = 65533;
	struct shar *shar;
	const char *src;
	char *buf, *buf_end;
	int ret;
	size_t written = n;

	shar = (struct shar *)a->format_data;
	if (!shar->has_data || n == 0)
		return (0);

	src = (const char *)buff;

	/*
	 * ensure is the number of bytes in buffer before expanding the
	 * current character.  Each operation writes the current character
	 * and optionally the start-of-new-line marker.  This can happen
	 * twice before entering the loop, so make sure three additional
	 * bytes can be written.
	 */
	if (archive_string_ensure(&shar->work, ensured + 3) == NULL) {
		archive_set_error(&a->archive, ENOMEM, "Out of memory");
		return (ARCHIVE_FATAL);
	}

	if (shar->work.length > ensured) {
		ret = __archive_write_output(a, shar->work.s,
		    shar->work.length);
		if (ret != ARCHIVE_OK)
			return (ARCHIVE_FATAL);
		archive_string_empty(&shar->work);
	}
	buf = shar->work.s + shar->work.length;
	buf_end = shar->work.s + ensured;

	if (shar->end_of_line) {
		*buf++ = 'X';
		shar->end_of_line = 0;
	}

	while (n-- != 0) {
		if ((*buf++ = *src++) == '\n') {
			if (n == 0)
				shar->end_of_line = 1;
			else
				*buf++ = 'X';
		}

		if (buf >= buf_end) {
			shar->work.length = buf - shar->work.s;
			ret = __archive_write_output(a, shar->work.s,
			    shar->work.length);
			if (ret != ARCHIVE_OK)
				return (ARCHIVE_FATAL);
			archive_string_empty(&shar->work);
			buf = shar->work.s;
		}
	}

	shar->work.length = buf - shar->work.s;

	return (written);
}

#define	UUENC(c)	(((c)!=0) ? ((c) & 077) + ' ': '`')

static void
uuencode_group(const char _in[3], char out[4])
{
	const unsigned char *in = (const unsigned char *)_in;
	int t;

	t = (in[0] << 16) | (in[1] << 8) | in[2];
	out[0] = UUENC( 0x3f & (t >> 18) );
	out[1] = UUENC( 0x3f & (t >> 12) );
	out[2] = UUENC( 0x3f & (t >> 6) );
	out[3] = UUENC( 0x3f & t );
}

static int
_uuencode_line(struct archive_write *a, struct shar *shar, const char *inbuf, size_t len)
{
	char *buf;
	size_t alloc_len;

	/* len <= 45 -> expanded to 60 + len byte + new line */
	alloc_len = shar->work.length + 62;
	if (archive_string_ensure(&shar->work, alloc_len) == NULL) {
		archive_set_error(&a->archive, ENOMEM, "Out of memory");
		return (ARCHIVE_FATAL);
	}

	buf = shar->work.s + shar->work.length;
	*buf++ = UUENC(len);
	while (len >= 3) {
		uuencode_group(inbuf, buf);
		len -= 3;
		inbuf += 3;
		buf += 4;
	}
	if (len != 0) {
		char tmp_buf[3];
		tmp_buf[0] = inbuf[0];
		if (len == 1)
			tmp_buf[1] = '\0';
		else
			tmp_buf[1] = inbuf[1];
		tmp_buf[2] = '\0';
		uuencode_group(tmp_buf, buf);
		buf += 4;
	}
	*buf++ = '\n';
	if ((buf - shar->work.s) > (ptrdiff_t)(shar->work.length + 62)) {
		archive_set_error(&a->archive,
		    ARCHIVE_ERRNO_MISC, "Buffer overflow");
		return (ARCHIVE_FATAL);
	}
	shar->work.length = buf - shar->work.s;
	return (ARCHIVE_OK);
}

#define uuencode_line(__a, __shar, __inbuf, __len) \
	do { \
		int r = _uuencode_line(__a, __shar, __inbuf, __len); \
		if (r != ARCHIVE_OK) \
			return (ARCHIVE_FATAL); \
	} while (0)

static ssize_t
archive_write_shar_data_uuencode(struct archive_write *a, const void *buff,
    size_t length)
{
	struct shar *shar;
	const char *src;
	size_t n;
	int ret;

	shar = (struct shar *)a->format_data;
	if (!shar->has_data)
		return (ARCHIVE_OK);
	src = (const char *)buff;

	if (shar->outpos != 0) {
		n = 45 - shar->outpos;
		if (n > length)
			n = length;
		memcpy(shar->outbuff + shar->outpos, src, n);
		if (shar->outpos + n < 45) {
			shar->outpos += n;
			return length;
		}
		uuencode_line(a, shar, shar->outbuff, 45);
		src += n;
		n = length - n;
	} else {
		n = length;
	}

	while (n >= 45) {
		uuencode_line(a, shar, src, 45);
		src += 45;
		n -= 45;

		if (shar->work.length < 65536)
			continue;
		ret = __archive_write_output(a, shar->work.s,
		    shar->work.length);
		if (ret != ARCHIVE_OK)
			return (ARCHIVE_FATAL);
		archive_string_empty(&shar->work);
	}
	if (n != 0) {
		memcpy(shar->outbuff, src, n);
		shar->outpos = n;
	}
	return (length);
}

static int
archive_write_shar_finish_entry(struct archive_write *a)
{
	const char *g, *p, *u;
	struct shar *shar;
	int ret;

	shar = (struct shar *)a->format_data;
	if (shar->entry == NULL)
		return (0);

	if (shar->dump) {
		/* Finish uuencoded data. */
		if (shar->has_data) {
			if (shar->outpos > 0)
				uuencode_line(a, shar, shar->outbuff,
				    shar->outpos);
			archive_strcat(&shar->work, "`\nend\n");
			archive_strcat(&shar->work, "SHAR_END\n");
		}
		/* Restore file mode, owner, flags. */
		/*
		 * TODO: Don't immediately restore mode for
		 * directories; defer that to end of script.
		 */
		archive_string_sprintf(&shar->work, "chmod %o ",
		    (unsigned int)(archive_entry_mode(shar->entry) & 07777));
		shar_quote(&shar->work, archive_entry_pathname(shar->entry), 1);
		archive_strcat(&shar->work, "\n");

		u = archive_entry_uname(shar->entry);
		g = archive_entry_gname(shar->entry);
		if (u != NULL || g != NULL) {
			archive_strcat(&shar->work, "chown ");
			if (u != NULL)
				shar_quote(&shar->work, u, 1);
			if (g != NULL) {
				archive_strcat(&shar->work, ":");
				shar_quote(&shar->work, g, 1);
			}
			archive_strcat(&shar->work, " ");
			shar_quote(&shar->work,
			    archive_entry_pathname(shar->entry), 1);
			archive_strcat(&shar->work, "\n");
		}

		if ((p = archive_entry_fflags_text(shar->entry)) != NULL) {
			archive_string_sprintf(&shar->work, "chflags %s ", p);
			shar_quote(&shar->work,
			    archive_entry_pathname(shar->entry), 1);
			archive_strcat(&shar->work, "\n");
		}

		/* TODO: restore ACLs */

	} else {
		if (shar->has_data) {
			/* Finish sed-encoded data:  ensure last line ends. */
			if (!shar->end_of_line)
				archive_strappend_char(&shar->work, '\n');
			archive_strcat(&shar->work, "SHAR_END\n");
		}
	}

	archive_entry_free(shar->entry);
	shar->entry = NULL;

	if (shar->work.length < 65536)
		return (ARCHIVE_OK);

	ret = __archive_write_output(a, shar->work.s, shar->work.length);
	if (ret != ARCHIVE_OK)
		return (ARCHIVE_FATAL);
	archive_string_empty(&shar->work);

	return (ARCHIVE_OK);
}

static int
archive_write_shar_close(struct archive_write *a)
{
	struct shar *shar;
	int ret;

	/*
	 * TODO: Accumulate list of directory names/modes and
	 * fix them all up at end-of-archive.
	 */

	shar = (struct shar *)a->format_data;

	/*
	 * Only write the end-of-archive markers if the archive was
	 * actually started.  This avoids problems if someone sets
	 * shar format, then sets another format (which would invoke
	 * shar_finish to free the format-specific data).
	 */
	if (shar->wrote_header == 0)
		return (ARCHIVE_OK);

	archive_strcat(&shar->work, "exit\n");

	ret = __archive_write_output(a, shar->work.s, shar->work.length);
	if (ret != ARCHIVE_OK)
		return (ARCHIVE_FATAL);

	/* Shar output is never padded. */
	archive_write_set_bytes_in_last_block(&a->archive, 1);
	/*
	 * TODO: shar should also suppress padding of
	 * uncompressed data within gzip/bzip2 streams.
	 */

	return (ARCHIVE_OK);
}

static int
archive_write_shar_free(struct archive_write *a)
{
	struct shar *shar;

	shar = (struct shar *)a->format_data;
	if (shar == NULL)
		return (ARCHIVE_OK);

	archive_entry_free(shar->entry);
	free(shar->last_dir);
	archive_string_free(&(shar->work));
	archive_string_free(&(shar->quoted_name));
	free(shar);
	a->format_data = NULL;
	return (ARCHIVE_OK);
}
