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

/*  treebnf: a tree oriented bnf library                      */

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

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

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

#include <stdint.h>

#include <unistd.h>

#include <fcntl.h>

#define ARGV_DRIVER

#include <treebnf/treebnf.h>

#include "treebnf_version.h"

#include "treebnf_driver_impl.h"

#include "argv/argv.h"

/* package info */

static const struct tbnf_source_version tbnf_src_version = {

	TBNF_TAG_VER_MAJOR,

	TBNF_TAG_VER_MINOR,

	TBNF_TAG_VER_PATCH,

	TREEBNF_GIT_VERSION

};

/* default fd context */

static const struct tbnf_fd_ctx tbnf_default_fdctx = {

	.fdin  = STDIN_FILENO,

	.fdout = STDOUT_FILENO,

	.fderr = STDERR_FILENO,

	.fdcwd = AT_FDCWD,

	.fddst = AT_FDCWD,

	.fdlog = (-1),

};

struct tbnf_driver_ctx_alloc {

	struct argv_meta *		meta;

	struct tbnf_driver_ctx_impl	ctx;

	uint64_t			guard;

	const char *			units[];

};

static uint32_t tbnf_argv_flags(uint32_t flags)

{

	uint32_t ret = ARGV_CLONE_VECTOR;

	if (flags & TBNF_DRIVER_VERBOSITY_NONE)

		ret |= ARGV_VERBOSITY_NONE;

	if (flags & TBNF_DRIVER_VERBOSITY_ERRORS)

		ret |= ARGV_VERBOSITY_ERRORS;

	if (flags & TBNF_DRIVER_VERBOSITY_STATUS)

		ret |= ARGV_VERBOSITY_STATUS;

	return ret;

}

static int tbnf_driver_usage(

	int				fdout,

	const char *			program,

	const char *			arg,

	const struct argv_option **	optv,

	struct argv_meta *		meta)

{

	char header[512];

	snprintf(header,sizeof(header),

		"Usage: %s [options] <file>...\n" "Options:\n",

		program);

	argv_usage(fdout,header,optv,arg);

	argv_free(meta);

	return TBNF_USAGE;

}

static struct tbnf_driver_ctx_impl * tbnf_driver_ctx_alloc(

	struct argv_meta *		meta,

	const struct tbnf_fd_ctx *	fdctx,

	const struct tbnf_common_ctx *	cctx,

	size_t				nunits)

{

	struct tbnf_driver_ctx_alloc *	ictx;

	size_t				size;

	struct argv_entry *		entry;

	const char **			units;

	int				elements;

	size =  sizeof(struct tbnf_driver_ctx_alloc);

	size += (nunits+1)*sizeof(const char *);

	if (!(ictx = calloc(1,size)))

		return 0;

	memcpy(&ictx->ctx.fdctx,fdctx,sizeof(*fdctx));

	memcpy(&ictx->ctx.cctx,cctx,sizeof(*cctx));

	elements = sizeof(ictx->ctx.erribuf) / sizeof(*ictx->ctx.erribuf);

	ictx->ctx.errinfp  = &ictx->ctx.erriptr[0];

	ictx->ctx.erricap  = &ictx->ctx.erriptr[--elements];

	ictx->meta = meta;

	for (entry=meta->entries,units=ictx->units; entry->fopt || entry->arg; entry++)

		if (!entry->fopt)

			*units++ = entry->arg;

	ictx->ctx.fdtmpin   = (-1);

	ictx->ctx.ctx.units = ictx->units;

	ictx->ctx.ctx.errv  = ictx->ctx.errinfp;

	return &ictx->ctx;

}

static int tbnf_get_driver_ctx_fail(struct argv_meta * meta)

{

	argv_free(meta);

	return -1;

}

int tbnf_lib_get_driver_ctx(

	char **				argv,

	char **				envp,

	uint64_t			flags,

	const struct tbnf_fd_ctx *	fdctx,

	struct tbnf_driver_ctx ** 	pctx)

{

	struct tbnf_driver_ctx_impl *	ctx;

	struct tbnf_common_ctx		cctx;

	const struct argv_option *	optv[TBNF_OPTV_ELEMENTS];

	struct argv_meta *		meta;

	struct argv_entry *		entry;

	size_t				nunits;

	const char *			program;

	(void)envp;

	if (!fdctx)

		fdctx = &tbnf_default_fdctx;

	argv_optv_init(tbnf_default_options,optv);

	if (!(meta = argv_get(

			argv,optv,

			tbnf_argv_flags(flags),

			fdctx->fderr)))

		return -1;

	nunits	= 0;

	program = argv_program_name(argv[0]);

	memset(&cctx,0,sizeof(cctx));

	cctx.drvflags = flags;

	if (!argv[1] && (flags & TBNF_DRIVER_VERBOSITY_USAGE))

		return tbnf_driver_usage(

			fdctx->fderr,

			program,

			0,optv,meta);

	/* get options, count units */

	for (entry=meta->entries; entry->fopt || entry->arg; entry++) {

		if (entry->fopt) {

			switch (entry->tag) {

				case TAG_HELP:

					if (flags & TBNF_DRIVER_VERBOSITY_USAGE)

						return tbnf_driver_usage(

							fdctx->fdout,

							program,entry->arg,

							optv,meta);

					break;

				case TAG_VERSION:

					cctx.drvflags |= TBNF_DRIVER_VERSION;

					break;

			}

		} else {

			nunits++;

		}

	}

	if (!(ctx = tbnf_driver_ctx_alloc(meta,fdctx,&cctx,nunits)))

		return tbnf_get_driver_ctx_fail(meta);

	ctx->ctx.program = program;

	ctx->ctx.cctx    = &ctx->cctx;

	*pctx = &ctx->ctx;

	return TBNF_OK;

}

static void tbnf_free_driver_ctx_impl(struct tbnf_driver_ctx_alloc * ictx)

{

	if (ictx->ctx.fdtmpin)

		close(ictx->ctx.fdtmpin);

	argv_free(ictx->meta);

	free(ictx);

}

void tbnf_lib_free_driver_ctx(struct tbnf_driver_ctx * ctx)

{

	struct tbnf_driver_ctx_alloc *	ictx;

	uintptr_t			addr;

	if (ctx) {

		addr = (uintptr_t)ctx - offsetof(struct tbnf_driver_ctx_impl,ctx);

		addr = addr - offsetof(struct tbnf_driver_ctx_alloc,ctx);

		ictx = (struct tbnf_driver_ctx_alloc *)addr;

		tbnf_free_driver_ctx_impl(ictx);

	}

}

const struct tbnf_source_version * tbnf_api_source_version(void)

{

	return &tbnf_src_version;

}

int tbnf_lib_get_driver_fdctx(

	const struct tbnf_driver_ctx *	dctx,

	struct tbnf_fd_ctx *		fdctx)

{

	struct tbnf_driver_ctx_impl *	ictx;

	ictx = tbnf_get_driver_ictx(dctx);

	fdctx->fdin  = ictx->fdctx.fdin;

	fdctx->fdout = ictx->fdctx.fdout;

	fdctx->fderr = ictx->fdctx.fderr;

	fdctx->fdlog = ictx->fdctx.fdlog;

	fdctx->fdcwd = ictx->fdctx.fdcwd;

	fdctx->fddst = ictx->fdctx.fddst;

	return 0;

}

int tbnf_lib_set_driver_fdctx(

	struct tbnf_driver_ctx *	dctx,

	const struct tbnf_fd_ctx *	fdctx)

{

	struct tbnf_driver_ctx_impl *	ictx;

	ictx = tbnf_get_driver_ictx(dctx);

	ictx->fdctx.fdin  = fdctx->fdin;

	ictx->fdctx.fdout = fdctx->fdout;

	ictx->fdctx.fderr = fdctx->fderr;

	ictx->fdctx.fdlog = fdctx->fdlog;

	ictx->fdctx.fdcwd = fdctx->fdcwd;

	ictx->fdctx.fddst = fdctx->fddst;

	return 0;

}