/*
 * Copyright (C) 2011 Andreas Steffen
 * HSR Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#include "tnc.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#include <utils/lexparser.h>
#include <debug.h>

typedef struct private_tnc_t private_tnc_t;

typedef tnccs_manager_t *(*tnc_create_tnccs_manager_t)(void);
typedef imc_manager_t *(*tnc_create_imc_manager_t)(void);
typedef imv_manager_t *(*tnc_create_imv_manager_t)(void);

/**
 * Private additions to tnc_t.
 */
struct private_tnc_t {

	/**
	 * Public members of tnc_t.
	 */
	tnc_t public;
};

/**
 * Single instance of tnc_t.
 */
tnc_t *tnc;

/**
 * Described in header.
 */
void libtnccs_init(void)
{
	private_tnc_t *this;

	INIT(this,
		.public = {
		},
	);	

	tnc = &this->public;
}

/**
 * Described in header.
 */
void libtnccs_deinit(void)
{
	private_tnc_t *this = (private_tnc_t*)tnc;

	free(this);
	tnc = NULL;
}

static bool load_imcvs_from_config(char *filename, bool is_imc)
{
	int fd, line_nr = 0;
	chunk_t src, line;
	struct stat sb;
	void *addr;
	char *label;

	label = is_imc ? "IMC" : "IMV";

	DBG1(DBG_TNC, "loading %ss from '%s'", label, filename);
	fd = open(filename, O_RDONLY);
	if (fd == -1)
	{
		DBG1(DBG_TNC, "opening configuration file '%s' failed: %s", filename,
			 strerror(errno));
		return FALSE;
	}
	if (fstat(fd, &sb) == -1)
	{
		DBG1(DBG_LIB, "getting file size of '%s' failed: %s", filename,
			 strerror(errno));
		close(fd);
		return FALSE;
	}
	addr = mmap(NULL, sb.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
	if (addr == MAP_FAILED)
	{
		DBG1(DBG_LIB, "mapping '%s' failed: %s", filename, strerror(errno));
		close(fd);
		return FALSE;
	}
	src = chunk_create(addr, sb.st_size);

	while (fetchline(&src, &line))
	{
		char *name, *path;
		bool success;
		chunk_t token;

		line_nr++;

		/* skip comments or empty lines */
		if (*line.ptr == '#' || !eat_whitespace(&line))
		{
			continue;
		}

		/* determine keyword */
		if (!extract_token(&token, ' ', &line))
		{
			DBG1(DBG_TNC, "line %d: keyword must be followed by a space",
						   line_nr);
			return FALSE;
		}

		/* only interested in IMCs or IMVs depending on label */
		if (!match(label, &token))
		{
			continue;
		}

		/* advance to the IMC/IMV name and extract it */
		if (!extract_token(&token, '"', &line) ||
			!extract_token(&token, '"', &line))
		{
			DBG1(DBG_TNC, "line %d: %s name must be set in double quotes",
						   line_nr, label);
			return FALSE;
		}

		/* copy the IMC/IMV name */
		name = malloc(token.len + 1);
		memcpy(name, token.ptr, token.len);
		name[token.len] = '\0';

		/* advance to the IMC/IMV path and extract it */
		if (!eat_whitespace(&line))
		{
			DBG1(DBG_TNC, "line %d: %s path is missing", line_nr, label);
			free(name);
			return FALSE;
		}
		if (!extract_token(&token, ' ', &line))
		{
			token = line;
		}

		/* copy the IMC/IMV path */
		path = malloc(token.len + 1);
		memcpy(path, token.ptr, token.len);
		path[token.len] = '\0';

		/* load and register an IMC/IMV instance */
		if (is_imc)
		{
			success = tnc->imcs->load(tnc->imcs, name, path);
		}
		else
		{
			success = tnc->imvs->load(tnc->imvs, name, path);
		}
		if (!success)
		{
			return FALSE;
		}
	}
	munmap(addr, sb.st_size);
	close(fd);
	return TRUE;
}

/**
 * Described in header.
 */
bool tnc_manager_register(plugin_t *plugin, plugin_feature_t *feature,
						  bool reg, void *data)
{
	bool load_imcvs = FALSE;
	bool is_imc = FALSE;

	if (feature->type == FEATURE_CUSTOM)
	{
		if (streq(feature->arg.custom, "tnccs-manager"))
		{
			if (reg)
			{
				tnc->tnccs = ((tnc_create_tnccs_manager_t)data)();
			}
			else
			{
				tnc->tnccs->destroy(tnc->tnccs);
				tnc->tnccs = NULL;
			}
		}
		else if (streq(feature->arg.custom, "imc-manager"))
		{
			if (reg)
			{
				tnc->imcs = ((tnc_create_imc_manager_t)data)();
				is_imc = TRUE;
				load_imcvs = TRUE;
			}
			else
			{
				tnc->imcs->destroy(tnc->imcs);
				tnc->imcs = NULL;
			}
		}
		else if (streq(feature->arg.custom, "imv-manager"))
		{
			if (reg)
			{
				tnc->imvs = ((tnc_create_imv_manager_t)data)();
				is_imc = FALSE;
				load_imcvs = TRUE;
			}
			else
			{
				tnc->imvs->destroy(tnc->imvs);
				tnc->imvs = NULL;
			}
		}
		else
		{
			return FALSE;
		}

		if (load_imcvs)
		{
			char *tnc_config;

			tnc_config = lib->settings->get_str(lib->settings,
								"libtnccs.tnc_config", "/etc/tnc_config");
			if (!load_imcvs_from_config(tnc_config, is_imc))
			{
				if (is_imc)
				{
					tnc->imcs->destroy(tnc->imcs);
					tnc->imcs = NULL;
				}
				else
				{
					tnc->imvs->destroy(tnc->imvs);
					tnc->imvs = NULL;
				}
				return FALSE;
			}
		}
	}
	return TRUE;
}