/*
 * Copyright (C) 2011-2012 Sansar Choinyambuu, 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 "pts_database.h"

#include <utils/debug.h>
#include <crypto/hashers/hasher.h>


typedef struct private_pts_database_t private_pts_database_t;

/**
 * Private data of a pts_database_t object.
 *
 */
struct private_pts_database_t {

	/**
	 * Public pts_database_t interface.
	 */
	pts_database_t public;

	/**
	 * database instance
	 */
	database_t *db;

};

METHOD(pts_database_t, create_file_meas_enumerator, enumerator_t*,
	private_pts_database_t *this, char *product)
{
	enumerator_t *e;

	/* look for all entries belonging to a product in the files table */
	e = this->db->query(this->db,
				"SELECT f.id, f.type, f.path FROM files AS f "
				"JOIN product_file AS pf ON f.id = pf.file "
				"JOIN products AS p ON p.id = pf.product "
				"WHERE p.name = ? AND pf.measurement = 1",
				DB_TEXT, product, DB_INT, DB_INT, DB_TEXT);
	return e;
}

METHOD(pts_database_t, create_file_meta_enumerator, enumerator_t*,
	private_pts_database_t *this, char *product)
{
	enumerator_t *e;

	/* look for all entries belonging to a product in the files table */
	e = this->db->query(this->db,
				"SELECT f.type, f.path FROM files AS f "
				"JOIN product_file AS pf ON f.id = pf.file "
				"JOIN products AS p ON p.id = pf.product "
				"WHERE p.name = ? AND pf.metadata = 1",
				DB_TEXT, product, DB_INT, DB_TEXT);
	return e;
}

METHOD(pts_database_t, create_file_hash_enumerator, enumerator_t*,
	private_pts_database_t *this, char *product, pts_meas_algorithms_t algo,
	int id, bool is_dir)
{
	enumerator_t *e;

	if (is_dir)
	{
		e = this->db->query(this->db,
				"SELECT f.path, fh.hash FROM file_hashes AS fh "
				"JOIN files AS f ON fh.file = f.id "
				"JOIN products AS p ON fh.product = p.id "
				"WHERE p.name = ? AND fh.directory = ? AND fh.algo = ? "
				"ORDER BY f.path",
				DB_TEXT, product, DB_INT, id, DB_INT, algo, DB_TEXT, DB_BLOB);
	}
	else
	{
		e = this->db->query(this->db,
				"SELECT f.path, fh.hash FROM file_hashes AS fh "
				"JOIN files AS f ON fh.file = f.id "
				"JOIN products AS p ON fh.product = p.id "
				"WHERE p.name = ? AND fh.file = ? AND fh.algo = ?",
				DB_TEXT, product, DB_INT, id, DB_INT, algo, DB_TEXT, DB_BLOB);
	}
	return e;
}

METHOD(pts_database_t, check_aik_keyid, status_t,
	private_pts_database_t *this, chunk_t keyid, int *kid)
{
	enumerator_t *e;

	/* If the AIK is registered get the primary key */
	e = this->db->query(this->db,
				"SELECT id FROM keys WHERE keyid = ?", DB_BLOB, keyid, DB_INT);
	if (!e)
	{
		DBG1(DBG_PTS, "no database query enumerator returned");
		return FAILED;
	}
	if (!e->enumerate(e, kid))
	{
		DBG1(DBG_PTS, "AIK %#B is not registered in database", &keyid);
		e->destroy(e);
		return FAILED;
	}
	e->destroy(e);

	return SUCCESS;
}

METHOD(pts_database_t, check_file_measurement, status_t,
	private_pts_database_t *this, char *product, pts_meas_algorithms_t algo,
	chunk_t measurement, char *filename)
{
	enumerator_t *e;
	chunk_t hash;
	status_t status = NOT_FOUND;

	e = this->db->query(this->db,
		"SELECT fh.hash FROM file_hashes AS fh "
		"JOIN files AS f ON f.id = fh.file "
		"JOIN products AS p ON p.id = fh.product "
		"WHERE p.name = ? AND f.path = ? AND fh.algo = ?",
		DB_TEXT, product, DB_TEXT, filename, DB_INT, algo, DB_BLOB);
	if (!e)
	{
		return FAILED;
	}
	while (e->enumerate(e, &hash))
	{
		/* with relative filenames there might be multiple entries */
		if (chunk_equals(measurement, hash))
		{
			status = SUCCESS;
			break;
		}
		else
		{
			status = VERIFY_ERROR;
		}
	}
	e->destroy(e);

	return status;
}

METHOD(pts_database_t, create_comp_evid_enumerator, enumerator_t*,
	private_pts_database_t *this, int kid)
{
	enumerator_t *e;

	/* look for all entries belonging to an AIK in the components table */
	e = this->db->query(this->db,
				"SELECT c.vendor_id, c.name, c.qualifier, kc.depth "
 				"FROM components AS c "
				"JOIN key_component AS kc ON c.id = kc.component "
				"WHERE kc.key = ? ORDER BY kc.seq_no",
				DB_INT, kid, DB_INT, DB_INT, DB_INT, DB_INT);
	return e;
}

METHOD(pts_database_t, check_comp_measurement, status_t,
	private_pts_database_t *this, chunk_t measurement, int cid, int kid,
	int seq_no, int pcr, pts_meas_algorithms_t algo)
{
	enumerator_t *e;
	chunk_t hash;
	status_t status = NOT_FOUND;

	e = this->db->query(this->db,
					"SELECT hash FROM component_hashes "
					"WHERE component = ?  AND key = ? "
					"AND seq_no = ? AND pcr = ? AND algo = ? ",
					DB_INT, cid, DB_INT, kid, DB_INT, seq_no,
					DB_INT, pcr, DB_INT, algo, DB_BLOB);
	if (!e)
	{
		DBG1(DBG_PTS, "no database query enumerator returned");
		return FAILED;
	}

	while (e->enumerate(e, &hash))
	{
		if (chunk_equals(hash, measurement))
		{
			status = SUCCESS;
			break;
		}
		else
		{
			DBG1(DBG_PTS, "PCR %2d no matching component measurement #%d "
						  "found in database", pcr, seq_no);
			DBG1(DBG_PTS, "  expected: %#B", &hash);
			DBG1(DBG_PTS, "  received: %#B", &measurement);
			status = VERIFY_ERROR;
			break;
		}
	}
	e->destroy(e);

	if (status == NOT_FOUND)
	{
		DBG1(DBG_PTS, "PCR %2d no measurement #%d "
					  "found in database", pcr, seq_no);
	}

	return status;
}

METHOD(pts_database_t, insert_comp_measurement, status_t,
	private_pts_database_t *this, chunk_t measurement, int cid, int kid,
	int seq_no, int pcr, pts_meas_algorithms_t algo)
{
	int id;

	if (this->db->execute(this->db, &id,
					"INSERT INTO component_hashes "
					"(component, key, seq_no, pcr, algo, hash) "
					"VALUES (?, ?, ?, ?, ?, ?)",
					DB_INT, cid, DB_INT, kid, DB_INT, seq_no, DB_INT, pcr,
					DB_INT, algo, DB_BLOB, measurement) == 1)
	{
		return SUCCESS;
	}

	DBG1(DBG_PTS, "could not insert component measurement into database");
	return FAILED;
}

METHOD(pts_database_t, delete_comp_measurements, int,
	private_pts_database_t *this, int cid, int kid)
{
	return this->db->execute(this->db, NULL,
					"DELETE FROM component_hashes "
					"WHERE component = ? AND key = ?",
					DB_INT, cid, DB_INT, kid);
}

METHOD(pts_database_t, get_comp_measurement_count, status_t,
	private_pts_database_t *this, pts_comp_func_name_t *comp_name,
	chunk_t keyid, pts_meas_algorithms_t algo, int *cid, int *kid, int *count)
{
	enumerator_t *e;
	status_t status = SUCCESS;

	/* Initialize count */
	*count = 0;

	if (_check_aik_keyid(this, keyid, kid) != SUCCESS)
	{
		return FAILED;
	}

	/* Get the primary key of the Component Functional Name */
	e = this->db->query(this->db,
				"SELECT id FROM components "
			"	WHERE vendor_id = ?  AND name = ? AND qualifier = ?",
				DB_INT, comp_name->get_vendor_id(comp_name),
				DB_INT, comp_name->get_name(comp_name),
				DB_INT, comp_name->get_qualifier(comp_name),
				DB_INT);
	if (!e)
	{
		DBG1(DBG_PTS, "no database query enumerator returned");
		return FAILED;
	}
	if (!e->enumerate(e, cid))
	{
		DBG1(DBG_PTS, "component functional name not found in database");
		e->destroy(e);
		return FAILED;
	}
	e->destroy(e);

	/* Get the number of stored measurements for a given AIK and component */
	e = this->db->query(this->db,
				"SELECT COUNT(*) FROM component_hashes AS ch "
				"WHERE component = ?  AND key = ? AND algo = ?",
				DB_INT, *cid, DB_INT, *kid, DB_INT, algo, DB_INT);
	if (!e)
	{
		DBG1(DBG_PTS, "no database query enumerator returned");
		return FAILED;
	}
	if (!e->enumerate(e, count))
	{
		DBG1(DBG_PTS, "no component measurement count returned from database");
		status = FAILED;
	}
	e->destroy(e);

	return status;
}

METHOD(pts_database_t, destroy, void,
	private_pts_database_t *this)
{
	this->db->destroy(this->db);
	free(this);
}

/**
 * See header
 */
pts_database_t *pts_database_create(char *uri)
{
	private_pts_database_t *this;

	INIT(this,
		.public = {
			.create_file_meas_enumerator = _create_file_meas_enumerator,
			.create_file_meta_enumerator = _create_file_meta_enumerator,
			.create_comp_evid_enumerator = _create_comp_evid_enumerator,
			.create_file_hash_enumerator = _create_file_hash_enumerator,
			.check_aik_keyid = _check_aik_keyid,
			.check_file_measurement = _check_file_measurement,
			.check_comp_measurement = _check_comp_measurement,
			.insert_comp_measurement = _insert_comp_measurement,
			.delete_comp_measurements = _delete_comp_measurements,
			.get_comp_measurement_count = _get_comp_measurement_count,
			.destroy = _destroy,
		},
		.db = lib->db->create(lib->db, uri),
	);

	if (!this->db)
	{
		DBG1(DBG_PTS,
			 "failed to connect to PTS file measurement database '%s'", uri);
		free(this);
		return NULL;
	}

	return &this->public;
}