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

/*  treebnf: a tree oriented bnf library                      */

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

/*  Released under GPLv2 and GPLv3; see COPYING.TREEBNF.      */

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

#include <stdint.h>

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#include <sys/mman.h>

#include <treebnf/treebnf.h>

#include "treebnf_driver_impl.h"

#include "treebnf_errinfo_impl.h"

#include "treebnf_tmpfile_impl.h"

static int tbnf_free_unit_ctx_impl(struct tbnf_unit_ctx_impl * ctx, int ret)

{

	if (ctx) {

		tbnf_lib_unmap_raw_input(&ctx->map);

		free(ctx);

	}

	return ret;

}

static int tbnf_stdin_to_tmp(const struct tbnf_driver_ctx * dctx)

{

	struct tbnf_driver_ctx_impl *	ictx;

	int				fdtmp;

	ssize_t ret;

	ssize_t cnt;

	char *	ch;

	char	buf[4096];

	ictx = tbnf_get_driver_ictx(dctx);

	if (ictx->fdtmpin >= 0)

		return dup(ictx->fdtmpin);

	if ((fdtmp = tbnf_tmpfile()) < 0)

		return -1;

	if ((ictx->fdtmpin = dup(fdtmp)) < 0) {

		close(fdtmp);

		return -1;

	}

	for (;;) {

		ret = read(0,buf,sizeof(buf)-1);

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

			ret = read(0,buf,sizeof(buf)-1);

		if (ret < 0) {

			close(fdtmp);

			return -1;

		} else if (ret == 0) {

			return fdtmp;

		} else {

			ch  = buf;

			cnt = ret;

			for (; cnt; ) {

				ret = write(fdtmp,ch,cnt);

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

					ret = write(fdtmp,ch,cnt);

				if (ret < 0) {

					close(fdtmp);

					return -1;

				}

				ch  += ret;

				cnt -= ret;

			}

		}

	}

}

int tbnf_lib_get_unit_ctx(

	const struct tbnf_driver_ctx *	dctx,

	const char *			path,

	struct tbnf_unit_ctx **		pctx)

{

	struct tbnf_unit_ctx_impl *	ctx;

	int				prot;

	int                             fd;

	if (!dctx)

		return TBNF_CUSTOM_ERROR(

			dctx,TBNF_ERR_NULL_CONTEXT);

	else if (!(ctx = calloc(1,sizeof(*ctx))))

		return TBNF_BUFFER_ERROR(dctx);

	tbnf_driver_set_ectx(

		dctx,0,path);

	prot = PROT_READ;

	if (strcmp(path,"-"))

		fd = -1;

	else if ((fd = tbnf_stdin_to_tmp(dctx)) < 0)

		return tbnf_free_unit_ctx_impl(

			ctx,TBNF_FILE_ERROR(dctx));

	if (tbnf_lib_map_raw_input(dctx,fd,path,prot,&ctx->map))

		return tbnf_free_unit_ctx_impl(

			ctx,TBNF_NESTED_ERROR(dctx));

	if (fd >= 0)

		close(fd);

	ctx->path	= path;

	ctx->uctx.path	= &ctx->path;

	ctx->uctx.map	= &ctx->map;

	*pctx = &ctx->uctx;

	return 0;

}

void tbnf_lib_free_unit_ctx(struct tbnf_unit_ctx * ctx)

{

	struct tbnf_unit_ctx_impl *	ictx;

	uintptr_t			addr;

	if (ctx) {

		addr = (uintptr_t)ctx - offsetof(struct tbnf_unit_ctx_impl,uctx);

		ictx = (struct tbnf_unit_ctx_impl *)addr;

		tbnf_free_unit_ctx_impl(ictx,0);

	}

}