/*******************************************************************/

/*  slibtool: a skinny libtool implementation, written in C        */

/*  Copyright (C) 2016--2024  SysDeer Technologies, LLC            */

/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */

/*******************************************************************/

#include <time.h>

#include <fcntl.h>

#include <stdio.h>

#include <stddef.h>

#include <limits.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <inttypes.h>

#include <sys/stat.h>

#include <slibtool/slibtool.h>

#include <slibtool/slibtool_arbits.h>

#include "slibtool_ar_impl.h"

#include "slibtool_driver_impl.h"

#include "slibtool_errinfo_impl.h"

/****************************************************/

/* As elsewhere in slibtool, file-system operations */

/* utilizie the _at variants of the relevant posix  */

/* interfaces. In the case of archives, that means  */

/* passing dctx->fdctx->fdcwd as the _fdat_ param,  */

/* where dctx is the driver context which was used  */

/* with slbt_get_archive_ctx().                     */

/************************************************** */

#define PPRIX64 "%"PRIx64

int slbt_store_archive(

	struct slbt_archive_ctx * arctx,

	const char *              path,

	mode_t                    mode)

{

	const struct slbt_driver_ctx *  dctx;

	struct stat                     st;

	int                             fdat;

	int                             fdtmp;

	char *                          mark;

	char *                          slash;

	size_t                          buflen;

	size_t                          nbytes;

	ssize_t                         written;

	char                            buf[PATH_MAX];

	/* init dctx */

	if (!(dctx = slbt_get_archive_ictx(arctx)->dctx))

		return -1;

	/* validation */

	if (strlen(path) >= PATH_MAX)

		return SLBT_CUSTOM_ERROR(

			dctx,

			SLBT_ERR_FLOW_ERROR);

	/**************************************************/

	/* create temporary file in the target directory  */

	/*                                                */

	/* the tmpfile name pattern involes the inode     */

	/* of the target directory, a local stack address */

	/* in the calling thread, the current time, and   */

	/* finally the pid of the current process.        */

	/**************************************************/

	memset(buf,0,sizeof(buf));

	strcpy(buf,path);

	fdat = slbt_driver_fdcwd(dctx);

	mark = (slash = strrchr(buf,'/'))

		? slash : buf;

	if (slash) {

		*++mark = '\0';

		if (fstatat(fdat,buf,&st,0) < 0)

			return SLBT_SYSTEM_ERROR(

				dctx,0);

	} else {

		if (fstatat(fdat,".",&st,0) < 0)

			return SLBT_SYSTEM_ERROR(

				dctx,0);

	}

	buflen = sizeof(buf) - (mark - buf);

	nbytes = snprintf(

		mark,

		buflen,

		".slibtool.tmpfile"

		".inode."PPRIX64

		".time."PPRIX64

		".salt.%p"

		".pid.%d"

		".tmp",

		st.st_ino,

		time(0),&buf,

		getpid());

	if (nbytes >= buflen)

		return SLBT_CUSTOM_ERROR(

			dctx,

			SLBT_ERR_FLOW_ERROR);

	if ((fdtmp = openat(fdat,buf,O_WRONLY|O_CREAT|O_EXCL,mode)) < 0)

		return SLBT_SYSTEM_ERROR(dctx,0);

	/* set archive size */

	if (ftruncate(fdtmp,arctx->map->map_size) < 0)

		return SLBT_SYSTEM_ERROR(dctx,0);

	/* write archive */

	mark   = arctx->map->map_addr;

	nbytes = arctx->map->map_size;

	for (; nbytes; ) {

		written = write(fdtmp,mark,nbytes);

		while ((written < 0) && (errno == EINTR))

			written = write(fdtmp,mark,nbytes);

		if (written < 0) {

			unlinkat(fdat,buf,0);

			return SLBT_SYSTEM_ERROR(dctx,0);

		};

		nbytes -= written;

		mark   += written;

	}

	/* finalize (atomically) */

	if (renameat(fdat,buf,fdat,path) < 0) {

		unlinkat(fdat,buf,0);

		return SLBT_SYSTEM_ERROR(dctx,0);

	}

	/* yay */

	return 0;

}