/*	$OpenBSD: parser.c,v 1.34 2013/05/24 17:03:14 eric Exp $	*/

/*
 * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
 * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/tree.h>

#include <event.h>
#include <imsg.h>

#include <openssl/ssl.h>

#include "smtpd.h"

#include "parser.h"

enum token_type {
	NOTOKEN,
	ENDTOKEN,
	KEYWORD,
	VARIABLE
};

struct token {
	enum token_type		 type;
	const char		*keyword;
	int			 value;
	const struct token	*next;
};

static const struct token t_log[];
static const struct token t_main[];
static const struct token t_pause[];
static const struct token t_remove[];
static const struct token t_resume[];
static const struct token t_schedule[];
static const struct token t_show[];
static const struct token t_show_envelope[];
static const struct token t_show_message[];
static const struct token t_update[];
static const struct token t_update_table[];
static const struct token t_trace[];
static const struct token t_untrace[];
static const struct token t_profile[];
static const struct token t_unprofile[];

static const struct token t_main[] = {
	{KEYWORD,	"schedule",	NONE,		t_schedule},
	{KEYWORD,	"show",		NONE,		t_show},
	{KEYWORD,	"monitor",	MONITOR,	NULL},
	{KEYWORD,	"pause",	NONE,		t_pause},
	{KEYWORD,	"remove",	NONE,		t_remove},
	{KEYWORD,	"resume",	NONE,		t_resume},
	{KEYWORD,	"stop",		SHUTDOWN,	NULL},
	{KEYWORD,	"log",		NONE,		t_log},
	{KEYWORD,	"profile",	NONE,		t_profile},
	{KEYWORD,	"trace",	NONE,		t_trace},
	{KEYWORD,	"unprofile",	NONE,		t_unprofile},
	{KEYWORD,	"untrace",	NONE,		t_untrace},
	{KEYWORD,	"update",	NONE,		t_update},
	{ENDTOKEN,	"",		NONE,		NULL}
};

static const struct token t_remove[] = {
	{VARIABLE,	"evpid",	REMOVE,		NULL},
	{ENDTOKEN,	"",		NONE,		NULL}
};

static const struct token t_schedule[] = {
	{VARIABLE,	"msgid/evpid/all",	SCHEDULE,	NULL},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_show[] = {
	{KEYWORD,	"queue",	SHOW_QUEUE,	NULL},
	{KEYWORD,	"stats",	SHOW_STATS,	NULL},
	{KEYWORD,	"envelope",	NONE,		t_show_envelope},
	{KEYWORD,	"message",	SHOW_MESSAGE,	t_show_message},
	{ENDTOKEN,	"",		NONE,		NULL}
};

static const struct token t_show_envelope[] = {
	{VARIABLE,	"evpid",	SHOW_ENVELOPE,	NULL},
	{ENDTOKEN,	"",		NONE,		NULL}
};

static const struct token t_show_message[] = {
	{VARIABLE,	"evpid",	SHOW_MESSAGE,	NULL},
	{ENDTOKEN,	"",		NONE,		NULL}
};

static const struct token t_pause[] = {
	{KEYWORD,	"mda",			PAUSE_MDA,	NULL},
	{KEYWORD,	"mta",		        PAUSE_MTA,	NULL},
	{KEYWORD,	"smtp",		        PAUSE_SMTP,	NULL},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_resume[] = {
	{KEYWORD,	"mda",			RESUME_MDA,	NULL},
	{KEYWORD,	"mta",		        RESUME_MTA,	NULL},
	{KEYWORD,	"smtp",		        RESUME_SMTP,	NULL},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_log[] = {
	{KEYWORD,	"verbose",		LOG_VERBOSE,	NULL},
	{KEYWORD,	"brief",		LOG_BRIEF,	NULL},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_update[] = {
	{KEYWORD,	"table",		NONE,		t_update_table},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_update_table[] = {
	{VARIABLE,	"name",			UPDATE_TABLE,	NULL},
	{ENDTOKEN,	"",			NONE,		NULL}
};

static const struct token t_trace[] = {
	{KEYWORD,	"imsg",			LOG_TRACE_IMSG,		NULL},
	{KEYWORD,	"io",			LOG_TRACE_IO,		NULL},
	{KEYWORD,	"smtp",			LOG_TRACE_SMTP,		NULL},
	{KEYWORD,	"filter",      		LOG_TRACE_MFA,		NULL},
	{KEYWORD,	"transfer",    		LOG_TRACE_MTA,		NULL},
	{KEYWORD,	"bounce",    		LOG_TRACE_BOUNCE,	NULL},
	{KEYWORD,	"scheduler",   		LOG_TRACE_SCHEDULER,  	NULL},
	{KEYWORD,	"lookup",   		LOG_TRACE_LOOKUP,  	NULL},
	{KEYWORD,	"stat",   		LOG_TRACE_STAT,	  	NULL},
	{KEYWORD,	"rules",   		LOG_TRACE_RULES,  	NULL},
	{KEYWORD,	"mproc",   		LOG_TRACE_MPROC,	NULL},
	{KEYWORD,	"expand",   		LOG_TRACE_EXPAND,	NULL},
	{KEYWORD,	"all",   		LOG_TRACE_ALL,		NULL},
	{ENDTOKEN,	"",			NONE,			NULL}
};

static const struct token t_untrace[] = {
	{KEYWORD,	"imsg",			LOG_UNTRACE_IMSG,	NULL},
	{KEYWORD,	"io",			LOG_UNTRACE_IO,		NULL},
	{KEYWORD,	"smtp",			LOG_UNTRACE_SMTP,	NULL},
	{KEYWORD,	"filter",      		LOG_UNTRACE_MFA,	NULL},
	{KEYWORD,	"transfer",    		LOG_UNTRACE_MTA,	NULL},
	{KEYWORD,	"bounce",    		LOG_UNTRACE_BOUNCE,	NULL},
	{KEYWORD,	"scheduler",   		LOG_UNTRACE_SCHEDULER, 	NULL},
	{KEYWORD,	"lookup",   		LOG_UNTRACE_LOOKUP, 	NULL},
	{KEYWORD,	"stat",   		LOG_UNTRACE_STAT,  	NULL},
	{KEYWORD,	"rules",   		LOG_UNTRACE_RULES,  	NULL},
	{KEYWORD,	"mproc",   		LOG_UNTRACE_MPROC,	NULL},
	{KEYWORD,	"expand",   		LOG_UNTRACE_EXPAND,	NULL},
	{KEYWORD,	"all",   		LOG_UNTRACE_ALL,	NULL},
	{ENDTOKEN,	"",			NONE,			NULL}
};

static const struct token t_profile[] = {
	{KEYWORD,	"imsg",			LOG_PROFILE_IMSG,	NULL},
	{KEYWORD,	"queue",       		LOG_PROFILE_QUEUE,     	NULL},
	{ENDTOKEN,	"",			NONE,			NULL}
};

static const struct token t_unprofile[] = {
	{KEYWORD,	"imsg",			LOG_UNPROFILE_IMSG,    	NULL},
	{KEYWORD,	"queue",       		LOG_UNPROFILE_QUEUE,	NULL},
	{ENDTOKEN,	"",			NONE,			NULL}
};


static const struct token *match_token(const char *, const struct token [],
    struct parse_result *);
static void show_valid_args(const struct token []);

struct parse_result *
parse(int argc, char *argv[])
{
	static struct parse_result	res;
	const struct token	*table = t_main;
	const struct token	*match;

	bzero(&res, sizeof(res));

	while (argc >= 0) {
		if ((match = match_token(argv[0], table, &res)) == NULL) {
			fprintf(stderr, "valid commands/args:\n");
			show_valid_args(table);
			return (NULL);
		}

		argc--;
		argv++;

		if (match->type == NOTOKEN || match->next == NULL)
			break;

		table = match->next;
	}

	if (argc > 0) {
		fprintf(stderr, "superfluous argument: %s\n", argv[0]);
		return (NULL);
	}

	return (&res);
}

const struct token *
match_token(const char *word, const struct token table[],
    struct parse_result *res)
{
	uint			 i, match;
	const struct token	*t = NULL;

	match = 0;

	for (i = 0; table[i].type != ENDTOKEN; i++) {
		switch (table[i].type) {
		case NOTOKEN:
			if (word == NULL || strlen(word) == 0) {
				match++;
				t = &table[i];
			}
			break;
		case KEYWORD:
			if (word != NULL && strncmp(word, table[i].keyword,
			    strlen(word)) == 0) {
				match++;
				t = &table[i];
				if (t->value)
					res->action = t->value;
			}
			break;
		case VARIABLE:
			if (word != NULL && strlen(word) != 0) {
				match++;
				t = &table[i];
				if (t->value) {
					res->action = t->value;
					res->data = word;
				}
			}
			break;
		case ENDTOKEN:
			break;
		}
	}

	if (match != 1) {
		if (word == NULL)
			fprintf(stderr, "missing argument:\n");
		else if (match > 1)
			fprintf(stderr, "ambiguous argument: %s\n", word);
		else if (match < 1)
			fprintf(stderr, "unknown argument: %s\n", word);
		return (NULL);
	}

	return (t);
}

static void
show_valid_args(const struct token table[])
{
	int	i;

	for (i = 0; table[i].type != ENDTOKEN; i++) {
		switch (table[i].type) {
		case NOTOKEN:
			fprintf(stderr, "  <cr>\n");
			break;
		case KEYWORD:
			fprintf(stderr, "  %s\n", table[i].keyword);
			break;
		case VARIABLE:
			fprintf(stderr, "  %s\n", table[i].keyword);
			break;
		case ENDTOKEN:
			break;
		}
	}
}