/*
 *  Copyright (C) 2010  Dennis Schafroth <dennis@schafroth.com>
 *  Copyright (C) 2010  Johannes Thoma <johannes.thoma@gmx.at>
 *  Copyright (C) 2010 - 2013 LINBIT Information Technologies GmbH
 *
 *  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.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "csync2.h"
#if defined(HAVE_SQLITE3)
#include <sqlite3.h>
#endif
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include "db_api.h"
#include "db_sqlite.h"
#include "dl.h"

#ifndef HAVE_SQLITE3
int db_sqlite_open(const char *file, db_conn_p * conn_p)
{
	return DB_ERROR;
}
#else

static struct db_sqlite3_fns {
	int (*sqlite3_open_fn) (const char *, sqlite3 **);
	int (*sqlite3_close_fn) (sqlite3 *);
	const char *(*sqlite3_errmsg_fn) (sqlite3 *);
	int (*sqlite3_exec_fn) (sqlite3 *, const char *, int (*)(void *, int, char **, char **), void *, char **);
	int (*sqlite3_prepare_v2_fn) (sqlite3 *, const char *, int, sqlite3_stmt **, const char **pzTail);
	const unsigned char *(*sqlite3_column_text_fn) (sqlite3_stmt *, int);
	const void *(*sqlite3_column_blob_fn) (sqlite3_stmt *, int);
	int (*sqlite3_column_int_fn) (sqlite3_stmt *, int);
	int (*sqlite3_step_fn) (sqlite3_stmt *);
	int (*sqlite3_finalize_fn) (sqlite3_stmt *);
} f;

static void *dl_handle;

static void db_sqlite3_dlopen(void)
{
	csync_debug(2, "Opening shared library libsqlite3.so.0\n");

	dl_handle = dlopen("libsqlite3.so.0", RTLD_LAZY);
	if (dl_handle == NULL) {
		csync_fatal
		    ("Could not open libsqlite3.so.0: %s\n"
		     "Please install sqlite3 client library (libsqlite3) or use other database (postgres, mysql)\n",
		     dlerror());
	}
	csync_debug(2, "Reading symbols from shared library libsqlite3.so.0\n");

	LOOKUP_SYMBOL(dl_handle, sqlite3_open);
	LOOKUP_SYMBOL(dl_handle, sqlite3_close);
	LOOKUP_SYMBOL(dl_handle, sqlite3_errmsg);
	LOOKUP_SYMBOL(dl_handle, sqlite3_exec);
	LOOKUP_SYMBOL(dl_handle, sqlite3_prepare_v2);
	LOOKUP_SYMBOL(dl_handle, sqlite3_column_text);
	LOOKUP_SYMBOL(dl_handle, sqlite3_column_blob);
	LOOKUP_SYMBOL(dl_handle, sqlite3_column_int);
	LOOKUP_SYMBOL(dl_handle, sqlite3_step);
	LOOKUP_SYMBOL(dl_handle, sqlite3_finalize);
}

static int sqlite_errors[] = { SQLITE_OK, SQLITE_ERROR, SQLITE_BUSY, SQLITE_ROW, SQLITE_DONE, -1 };
static int db_errors[] = { DB_OK, DB_ERROR, DB_BUSY, DB_ROW, DB_DONE, -1 };

int db_sqlite_error_map(int sqlite_err)
{
	int index;
	for (index = 0;; index++) {
		if (sqlite_errors[index] == -1)
			return DB_ERROR;
		if (sqlite_err == sqlite_errors[index])
			return db_errors[index];
	}
}

int db_sqlite_open(const char *file, db_conn_p * conn_p)
{
	sqlite3 *db;

	db_sqlite3_dlopen();

	int rc = f.sqlite3_open_fn(file, &db);
	if (rc != SQLITE_OK) {
		return db_sqlite_error_map(rc);
	};
	db_conn_p conn = calloc(1, sizeof(*conn));
	if (conn == NULL) {
		return DB_ERROR;
	}
	*conn_p = conn;
	conn->private = db;
	conn->close = db_sqlite_close;
	conn->exec = db_sqlite_exec;
	conn->prepare = db_sqlite_prepare;
	conn->errmsg = db_sqlite_errmsg;
	conn->upgrade_to_schema = db_sqlite_upgrade_to_schema;
	return db_sqlite_error_map(rc);
}

void db_sqlite_close(db_conn_p conn)
{
	if (!conn)
		return;
	if (!conn->private)
		return;
	f.sqlite3_close_fn(conn->private);
	conn->private = 0;
}

const char *db_sqlite_errmsg(db_conn_p conn)
{
	if (!conn)
		return "(no connection)";
	if (!conn->private)
		return "(no private data in conn)";
	return f.sqlite3_errmsg_fn(conn->private);
}

int db_sqlite_exec(db_conn_p conn, const char *sql)
{
	int rc;
	if (!conn)
		return DB_NO_CONNECTION;

	if (!conn->private) {
		/* added error element */
		return DB_NO_CONNECTION_REAL;
	}
	rc = f.sqlite3_exec_fn(conn->private, sql, 0, 0, 0);
	return db_sqlite_error_map(rc);
}

int db_sqlite_prepare(db_conn_p conn, const char *sql, db_stmt_p * stmt_p, char **pptail)
{
	int rc;

	*stmt_p = NULL;

	if (!conn)
		return DB_NO_CONNECTION;

	if (!conn->private) {
		/* added error element */
		return DB_NO_CONNECTION_REAL;
	}
	db_stmt_p stmt = malloc(sizeof(*stmt));
	sqlite3_stmt *sqlite_stmt = 0;
	/* TODO avoid strlen, use configurable limit? */
	rc = f.sqlite3_prepare_v2_fn(conn->private, sql, strlen(sql), &sqlite_stmt, (const char **)pptail);
	if (rc != SQLITE_OK)
		return db_sqlite_error_map(rc);
	stmt->private = sqlite_stmt;
	*stmt_p = stmt;
	stmt->get_column_text = db_sqlite_stmt_get_column_text;
	stmt->get_column_blob = db_sqlite_stmt_get_column_blob;
	stmt->get_column_int = db_sqlite_stmt_get_column_int;
	stmt->next = db_sqlite_stmt_next;
	stmt->close = db_sqlite_stmt_close;
	stmt->db = conn;
	return db_sqlite_error_map(rc);
}

const char *db_sqlite_stmt_get_column_text(db_stmt_p stmt, int column)
{
	if (!stmt || !stmt->private) {
		return 0;
	}
	sqlite3_stmt *sqlite_stmt = stmt->private;
	const unsigned char *result = f.sqlite3_column_text_fn(sqlite_stmt, column);
	/* error handling */
	return (const char *)result;
}

#if defined(HAVE_SQLITE3)
const void *db_sqlite_stmt_get_column_blob(db_stmt_p stmtx, int col)
{
	sqlite3_stmt *stmt = stmtx->private;
	return f.sqlite3_column_blob_fn(stmt, col);
}
#endif

int db_sqlite_stmt_get_column_int(db_stmt_p stmt, int column)
{
	sqlite3_stmt *sqlite_stmt = stmt->private;
	int rc = f.sqlite3_column_int_fn(sqlite_stmt, column);
	return db_sqlite_error_map(rc);
}

int db_sqlite_stmt_next(db_stmt_p stmt)
{
	sqlite3_stmt *sqlite_stmt = stmt->private;
	int rc = f.sqlite3_step_fn(sqlite_stmt);
	return db_sqlite_error_map(rc);
}

int db_sqlite_stmt_close(db_stmt_p stmt)
{
	sqlite3_stmt *sqlite_stmt = stmt->private;
	int rc = f.sqlite3_finalize_fn(sqlite_stmt);
	free(stmt);
	return db_sqlite_error_map(rc);
}

int db_sqlite_upgrade_to_schema(int version)
{
	if (version < 0)
		return DB_OK;

	if (version > 0)
		return DB_ERROR;

	csync_debug(2, "Upgrading database schema to version %d.\n", version);

	/* *INDENT-OFF* */
	csync_db_sql("Creating file table",
		"CREATE TABLE file ("
		"	filename, checktxt,"
		"	UNIQUE ( filename ) ON CONFLICT REPLACE"
		")");

	csync_db_sql("Creating dirty table",
		"CREATE TABLE dirty ("
		"	filename, forced, myname, peername,"
		"	UNIQUE ( filename, peername ) ON CONFLICT IGNORE"
		")");

	csync_db_sql("Creating hint table",
		"CREATE TABLE hint ("
		"	filename, recursive,"
		"	UNIQUE ( filename, recursive ) ON CONFLICT IGNORE"
		")");

	csync_db_sql("Creating action table",
		"CREATE TABLE action ("
		"	filename, command, logfile,"
		"	UNIQUE ( filename, command ) ON CONFLICT IGNORE"
		")");

	csync_db_sql("Creating x509_cert table",
		"CREATE TABLE x509_cert ("
		"	peername, certdata,"
		"	UNIQUE ( peername ) ON CONFLICT IGNORE"
		")");
	/* *INDENT-ON* */

	return DB_OK;
}

#endif