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

/*  ptycon: a pty-console bridge                         */

/*  Copyright (C) 2016  Z. Gilboa                        */

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

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

#include <ntcon/ntcon.h>

#include <ntapi/ntapi.h>

#include <ntapi/nt_atomic.h>

#include <gdi/gdi.h>

#include <stdint.h>

#include <ptycon/ptycon.h>

#include "ptycon_init_impl.h"

#include "ptycon_nolibc_impl.h"

#define ARGV_DRIVER

#include "ptycon_version.h"

#include "ptycon_daemon_impl.h"

#include "ptycon_driver_impl.h"

#include "argv/argv.h"

/* ntapi accessor table */

const ntapi_vtbl * ptyc_ntapi;

/* ntcon accessor table */

static ntcon_vtbl ptyc_ntcon_vtbl;

const  ntcon_vtbl * const ptyc_ntcon = &ptyc_ntcon_vtbl;

/* gdi accessor table */

static gdi_vtbl ptyc_gdi_vtbl;

const  gdi_vtbl * const ptyc_gdi = &ptyc_gdi_vtbl;

/* daemon */

static struct ptyc_daemon_ctx ptyc_daemon_ctx;

/* package info */

static const struct ptyc_source_version ptyc_src_version = {

	PTYC_TAG_VER_MAJOR,

	PTYC_TAG_VER_MINOR,

	PTYC_TAG_VER_PATCH,

	PTYCON_GIT_VERSION

};

struct ptyc_driver_ctx_alloc {

	struct argv_meta *		meta;

	struct ptyc_driver_ctx_impl	ctx;

	uint64_t			guard;

	const char *			units[];

};

struct ptyc_split_vector {

	char **		targv;

	char **		eargv;

};

static int32_t ptyc_once = 0;

static int32_t ptyc_vtbl_init(void)

{

	int32_t		status;

	nt_timeout	timeout;

	switch (at_locked_cas_32(&ptyc_once,0,1)) {

		case 0:

			if ((status = ntcon_vtbl_init(&ptyc_ntcon_vtbl))) {

				at_locked_add_32(&ptyc_once,2);

				return status;

			}

			if ((status = gdi_vtbl_init(&ptyc_gdi_vtbl))) {

				at_locked_add_32(&ptyc_once,2);

				return status;

			}

			at_locked_inc_32(&ptyc_once);

			return 0;

		case 1:

			timeout.quad = -10;

			for (; (at_locked_cas_32(&ptyc_once,0,1) == 1); )

				ntapi->zw_delay_execution(

					NT_SYNC_ALERTABLE,

					&timeout);

			return (ptyc_once == 2)

				? 0 : -1;

		case 2:

			return 0;

		case 3:

		default:

			return -1;

	}

}

static uint32_t ptyc_argv_flags(uint32_t flags)

{

	uint32_t ret = 0;

	if (flags & PTYC_DRIVER_VERBOSITY_NONE)

		ret |= ARGV_VERBOSITY_NONE;

	if (flags & PTYC_DRIVER_VERBOSITY_ERRORS)

		ret |= ARGV_VERBOSITY_ERRORS;

	if (flags & PTYC_DRIVER_VERBOSITY_STATUS)

		ret |= ARGV_VERBOSITY_STATUS;

	return ret;

}

static int ptyc_driver_usage(

	const char *			program,

	const char *			arg,

	const struct argv_option *	options,

	struct argv_meta *		meta)

{

	char header[512];

	snprintf(header,sizeof(header),

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

		program);

	argv_usage(stdout,header,options,arg);

	argv_free(meta);

	return PTYC_USAGE;

}

static struct ptyc_driver_ctx_impl * ptyc_driver_ctx_alloc(

	struct argv_meta *		meta,

	const struct ptyc_common_ctx *	cctx,

	size_t				nunits)

{

	struct ptyc_driver_ctx_alloc *	ictx;

	size_t				size;

	struct argv_entry *		entry;

	const char **			units;

	nt_runtime_data *		rtdata;

	if (ntapi->tt_get_runtime_data(&rtdata,0))

		return 0;

	size =  sizeof(struct ptyc_driver_ctx_alloc);

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

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

		return 0;

	if (cctx)

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

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

		if (entry->tag == TAG_CAT)

			*units++ = entry->arg;

	ictx->meta = meta;

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

	ictx->ctx.rtdata = rtdata;

	return &ictx->ctx;

}

static int ptyc_get_driver_ctx_fail(struct argv_meta * meta)

{

	argv_free(meta);

	return -1;

}

#define PTYC_SARGV_ELEMENTS		1024

static int ptyc_split_argv(

	char **				argv,

	struct ptyc_split_vector *	sargv)

{

	ptrdiff_t	argc;

	char **		parg;

	/* argc */

	for (parg=argv; *parg; )

		parg++;

	if ((argc = parg - argv) >= PTYC_SARGV_ELEMENTS)

		return -1;

	/* clone argv into targv */

	ntapi->tt_aligned_block_memset(

		(uintptr_t *)sargv->targv,

		0,PTYC_SARGV_ELEMENTS*sizeof(char *));

	ntapi->tt_aligned_block_memcpy(

		(uintptr_t *)sargv->targv,

		(uintptr_t *)argv,

		argc*sizeof(char *));

	/* eargv */

	for (parg=sargv->targv; *parg; parg++) {

		if (!(strcmp(*parg,"-e")) || !(strcmp(*parg,"--exec"))) {

			sargv->eargv = parg;

			sargv->eargv++;

			*parg = 0;

			return 0;

		}

	}

	return 0;

}

int ptyc_get_driver_ctx(

	char **				argv,

	char **				envp,

	uint32_t			flags,

	struct ptyc_driver_ctx **	pctx)

{

	struct ptyc_driver_ctx_impl *	ctx;

	struct ptyc_common_ctx		cctx;

	struct ptyc_split_vector	sargv;

	const struct argv_option *	options;

	struct argv_meta *		meta;

	struct argv_entry *		entry;

	size_t				nunits;

	const char *			program;

	char *				targv[PTYC_SARGV_ELEMENTS];

	(void)envp;

	if (ptyc_init())

		return -1;

	if (ptyc_vtbl_init())

		return -1;

	options = ptyc_default_options;

	sargv.targv = targv;

	sargv.eargv = 0;

	if (ptyc_split_argv(argv,&sargv))

		return -1;

	if (!(meta = argv_get(sargv.targv,options,ptyc_argv_flags(flags))))

		return -1;

	nunits	= 0;

	program = argv_program_name(argv[0]);

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

	cctx.drvflags = flags;

	cctx.eargv = sargv.eargv;

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

		return ptyc_driver_usage(program,0,options,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 & PTYC_DRIVER_VERBOSITY_USAGE)

						return ptyc_driver_usage(program,entry->arg,options,meta);

				case TAG_VERSION:

					cctx.drvflags |= PTYC_DRIVER_VERSION;

					break;

				case TAG_DAEMON:

					if (!strcmp("always",entry->arg))

						cctx.drvflags |= PTYC_DRIVER_DAEMON_ALWAYS;

					else if (!strcmp("never",entry->arg))

						cctx.drvflags |= PTYC_DRIVER_DAEMON_NEVER;

					break;

				case TAG_DEBUG:

					if (!entry->arg) {

						cctx.drvflags |= PTYC_DRIVER_DBG_EVENT;

					} else if (!strcmp("event",entry->arg)) {

						cctx.drvflags |= PTYC_DRIVER_DBG_EVENT;

					} else if (!strcmp("oven",entry->arg)) {

						cctx.drvflags &= ~(uint64_t)PTYC_DRIVER_DBG_RAW;

						cctx.drvflags |= PTYC_DRIVER_DBG_OVEN;

					} else if (!strcmp("raw",entry->arg)) {

						cctx.drvflags &= ~(uint64_t)PTYC_DRIVER_DBG_OVEN;

						cctx.drvflags |= PTYC_DRIVER_DBG_RAW;

					}

					break;

				case TAG_CAT:

					nunits++;

					break;

				case TAG_SYSROOT:

					cctx.sysroot = entry->arg;

					break;

				case TAG_WAIT:

					cctx.drvflags |= PTYC_DRIVER_DBG_WAIT;

					break;

			}

		} else

			/* strict */

			return ptyc_driver_usage(program,0,options,meta);

	}

	if (cctx.sysroot && ptyc_open_dir(&cctx.hroot,0,cctx.sysroot,false)) {

		if (flags & PTYC_DRIVER_VERBOSITY_ERRORS)

			fprintf(stderr,

				"%s: error: could not open sysroot directory '%s'",

				program,cctx.sysroot);

		return ptyc_get_driver_ctx_fail(meta);

	}

	if (!(ctx = ptyc_driver_ctx_alloc(meta,&cctx,nunits)))

		return ptyc_get_driver_ctx_fail(meta);

	if (ptyc_daemon_init(&ptyc_daemon_ctx,cctx.drvflags))

		return ptyc_get_driver_ctx_fail(meta);

	ctx->ctx.program	= program;

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

	*pctx = &ctx->ctx;

	return PTYC_OK;

}

int ptyc_create_driver_ctx(

	const struct ptyc_common_ctx *	cctx,

	struct ptyc_driver_ctx **	pctx)

{

	struct argv_meta *		meta;

	struct ptyc_driver_ctx_impl *	ctx;

	char *				argv[] = {"ptycon_driver",0};

	if (ptyc_init())

		return -1;

	if (ptyc_vtbl_init())

		return -1;

	if (!(meta = argv_get(argv,ptyc_default_options,0)))

		return -1;

	if (!(ctx = ptyc_driver_ctx_alloc(meta,cctx,0)))

		return ptyc_get_driver_ctx_fail(0);

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

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

	*pctx = &ctx->ctx;

	return PTYC_OK;

}

static void ptyc_free_driver_ctx_impl(struct ptyc_driver_ctx_alloc * ictx)

{

	ptyc_free_pty(&ictx->ctx.ctx);

	argv_free(ictx->meta);

	free(ictx);

}

void ptyc_free_driver_ctx(struct ptyc_driver_ctx * ctx)

{

	struct ptyc_driver_ctx_alloc *	ictx;

	uintptr_t			addr;

	if (ctx) {

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

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

		ictx = (struct ptyc_driver_ctx_alloc *)addr;

		ptyc_free_driver_ctx_impl(ictx);

	}

}

const struct ptyc_source_version * ptyc_source_version(void)

{

	return &ptyc_src_version;

}