/*
 *	PROGRAM:	JRD Access Method
 *	MODULE:		execute_statement.cpp
 *	DESCRIPTION:	Dynamic SQL statements execution
 *
 *  The contents of this file are subject to the Initial
 *  Developer's Public License Version 1.0 (the "License");
 *  you may not use this file except in compliance with the
 *  License. You may obtain a copy of the License at
 *  http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
 *
 *  Software distributed under the License is distributed AS IS,
 *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
 *  See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Original Code was created by Alexander Peshkoff
 *  for the Firebird Open Source RDBMS project.
 *
 *  Copyright (c) 2003 Alexander Peshkoff <peshkoff@mail.ru>
 *  and all contributors signed below.
 *
 *  All Rights Reserved.
 *  Contributor(s): ______________________________________.
 *  Adriano dos Santos Fernandes
 */

#include "firebird.h"
#include "fb_types.h"
#include "gen/iberror.h"

#include "../jrd/common.h"
#include <string.h>
#include <math.h>
#include "../jrd/jrd.h"
#include "../jrd/tra.h"
#include "../jrd/dsc.h"
#include "../jrd/err_proto.h"
#include "../jrd/mov_proto.h"
#include "../jrd/evl_proto.h"
#include "../jrd/exe_proto.h"
#include "../jrd/sch_proto.h"
#include "../jrd/thread_proto.h"
#define	WHY_NO_API
#include "../jrd/why_proto.h"
#include "../jrd/y_handle.h"
#include "../jrd/align.h"

#include "../jrd/execute_statement.h"
#include "../common/classes/GenericMap.h"
#include "../common/classes/init.h"

using namespace Jrd;
using namespace Firebird;

YValve::Attachment* GetWhyAttachment(ISC_STATUS*, Attachment*);

namespace {

const SSHORT sqlType[] =
{
/* dtype_unknown	*/ -1,
/* dtype_text		*/ SQL_TEXT,
/* dtype_cstring	*/ -1,
/* dtype_varying	*/ SQL_VARYING,
/* dtype_none1		*/ -1,
/* dtype_none2		*/ -1,
/* dtype_packed		*/ -1,
/* dtype_byte		*/ -1,
/* dtype_short		*/ SQL_SHORT,
/* dtype_long		*/ SQL_LONG,
/* dtype_quad		*/ SQL_QUAD,
/* dtype_real		*/ SQL_FLOAT,
/* dtype_double		*/ SQL_DOUBLE,
/* dtype_d_float	*/ -1,				// Fix to use in VMS
/* dtype_sql_date	*/ SQL_TYPE_DATE,
/* dtype_sql_time	*/ SQL_TYPE_TIME,
/* dtype_timestamp	*/ SQL_TIMESTAMP,
/* dtype_blob		*/ SQL_BLOB,
/* dtype_array		*/ SQL_ARRAY,		// Not supported for a while
/* dtype_int64		*/ SQL_INT64
};

static InitInstance<GenericMap<Pair<NonPooled<SSHORT, UCHAR> > > > sqlTypeToDscType;

class CallbackWrapper
{
public:
	explicit CallbackWrapper(thread_db* arg)
		: tdbb(arg)
	{
		tdbb->getTransaction()->tra_callback_count++;
		tdbb->getDatabase()->checkout();
	}

	~CallbackWrapper()
	{
		tdbb->getDatabase()->checkin();
		tdbb->getTransaction()->tra_callback_count--;
	}

private:
	// copying is prohibited
	CallbackWrapper(const CallbackWrapper&);
	CallbackWrapper& operator=(const CallbackWrapper&);

	thread_db* tdbb;
};

} // anonymous namespace

void ExecuteStatement::Open(thread_db* tdbb, jrd_nod* sql, SSHORT nVars, bool SingleTon)
{
	SET_TDBB(tdbb);

	// initialize sqlTypeToDscType in the first call to this function
	// non-thread safe, require mutex in Fb3
	if (sqlTypeToDscType().count() == 0)
	{
		for (int i = 0; i < FB_NELEM(sqlType); ++i)
			sqlTypeToDscType().put(sqlType[i], static_cast<UCHAR>(i));
	}

	if (tdbb->getTransaction()->tra_callback_count >= MAX_CALLBACKS)
		ERR_post(isc_exec_sql_max_call_exceeded, 0);

	Sqlda = 0;
	Transaction = 0;
	Buffer = 0;
	SingleMode = SingleTon;

	fb_assert(tdbb->getTransaction()->tra_pool);
	Firebird::string SqlText;
	getString(tdbb, SqlText, EVL_expr(tdbb, sql), tdbb->getRequest());
	memcpy(StartOfSqlOperator, SqlText.c_str(), sizeof(StartOfSqlOperator) - 1);
	StartOfSqlOperator[sizeof(StartOfSqlOperator) - 1] = 0;

	YValve::Attachment* temp_dbb = GetWhyAttachment(tdbb->tdbb_status_vector,
		tdbb->getAttachment());
	if (!temp_dbb)
		ERR_punt();

	Attachment = temp_dbb->public_handle;

	YValve::Transaction* temp_tra = new YValve::Transaction(tdbb->getTransaction(), &Transaction, temp_dbb);

	Statement = 0;
	Sqlda = MakeSqlda(tdbb, nVars ? nVars : 1);
	Sqlda->sqln = nVars;
	Sqlda->version = 1;

	ISC_STATUS_ARRAY local_status;
	memset(local_status, 0, sizeof(local_status));

	try
	{
		CallbackWrapper cwHolder(tdbb);

		ISC_STATUS* status = local_status;

		if (isc_dsql_allocate_statement(status, &Attachment, &Statement))
			throw status;

		if (isc_dsql_prepare(status, &Transaction, &Statement,
							 SqlText.length(), SqlText.c_str(),
							 SQL_DIALECT_CURRENT, Sqlda))
		{
			throw status;
		}

		if (!Sqlda->sqld) {  // Non-select statement - reject for a while
			/*if (isc_dsql_execute(status, &Transaction,
								   &Statement, SQLDA_VERSION1, 0))
			{
				throw status;
			}*/
			if (isc_dsql_free_statement(status, &Statement, DSQL_drop))
				throw status;

			Statement = 0;

			status[0] = isc_arg_gds;
			status[1] = isc_exec_sql_invalid_req;
			status[2] = isc_arg_string;
			status[3] = (ISC_STATUS)(U_IPTR) ERR_cstring(StartOfSqlOperator);
			status[4] = isc_arg_end;
			throw status;
		}
		else {
			if (ReMakeSqlda(status, tdbb))
				throw status;

			if (isc_dsql_describe(status, &Statement,
								  SQLDA_VERSION1, Sqlda))
			{
				throw status;
			}

			Buffer = FB_NEW(*tdbb->getTransaction()->tra_pool) 
				SCHAR[XSQLDA_LENGTH(ParseSqlda())];

			ParseSqlda();

			if (isc_dsql_execute(status, &Transaction,
								 &Statement, SQLDA_VERSION1, 0))
			{
				throw status;
			}
		}
	}
	catch (const ISC_STATUS* status)
	{
		memcpy(tdbb->tdbb_status_vector, status, ISC_STATUS_LENGTH);
		Firebird::status_exception::raise(tdbb->tdbb_status_vector);
	}
}

bool ExecuteStatement::Fetch(thread_db* tdbb, jrd_nod** jrdVar)
{
	// If already bugged - we should never get here
	fb_assert(! (tdbb->tdbb_status_vector[0] == 1 &&
			  tdbb->tdbb_status_vector[1] != 0));
	if (! Statement)
		return false;

	ISC_STATUS_ARRAY local;
	ISC_STATUS* status = local;
	memset(local, 0, sizeof(local));
	status = local;

	{ // scope
		CallbackWrapper cwHolder(tdbb);
		if (isc_dsql_fetch(status, &Statement,
				SQLDA_VERSION1, Sqlda) == 100)
		{
			isc_dsql_free_statement(status, &Statement, DSQL_drop);

			Statement = 0;
			return false;
		}

		if (status[0] == 1 && status[1]) {
			memcpy(tdbb->tdbb_status_vector, status, sizeof(local));
			Firebird::status_exception::raise(tdbb->tdbb_status_vector);
		}
	}

	const XSQLVAR *var = Sqlda->sqlvar;
	for (int i = 0; i < Sqlda->sqld; i++, var++) {
		dsc* d = EVL_assign_to(tdbb, jrdVar[i]);
		if (d->dsc_dtype >= FB_NELEM(sqlType) || sqlType[d->dsc_dtype] < 0)
		{
			ERR_post(isc_exec_sql_invalid_var,
					 isc_arg_number, i + 1,
					 isc_arg_string, ERR_cstring(StartOfSqlOperator),
					 0);
		}

		// build the src descriptor
		dsc src;
		src.clear();
		sqlTypeToDscType().get((var->sqltype & ~1), src.dsc_dtype);
		src.dsc_length = var->sqllen;
		src.dsc_scale = var->sqlscale;
		src.dsc_sub_type = var->sqlsubtype;
		src.dsc_address = (UCHAR*) var->sqldata;

		if ((var->sqltype & ~1) == SQL_VARYING)
			src.dsc_length += sizeof(SSHORT);

		// and assign to the target
		EXE_assignment(tdbb, jrdVar[i], &src, (var->sqltype & 1) && (*var->sqlind < 0), NULL, NULL);
	}

	if (SingleMode) {
		CallbackWrapper cwHolder(tdbb);
		if (isc_dsql_fetch(status, &Statement, SQLDA_VERSION1, Sqlda) == 100)
		{
			isc_dsql_free_statement(status, &Statement, DSQL_drop);

			Statement = 0;
			return false;
		}

		if (! (status[0] == 1 && status[1])) {
			status[0] = isc_arg_gds;
			status[1] = isc_sing_select_err;
			status[2] = isc_arg_end;
		}
		memcpy(tdbb->tdbb_status_vector, status, sizeof(local));
		Firebird::status_exception::raise(tdbb->tdbb_status_vector);
	}
	return true;
}

void ExecuteStatement::Close(thread_db* tdbb)
{
	if (Statement) {
		// for a while don't check for errors while freeing statement
		CallbackWrapper cwHolder(tdbb);
		isc_dsql_free_statement(0, &Statement, DSQL_drop);

		Statement = 0;
	}
	char* p = reinterpret_cast<char*>(Sqlda);
	delete[] p;
	Sqlda = 0;
	if (Transaction) {
		delete YValve::translate<YValve::Transaction>(&Transaction);
		Transaction = 0;
	}
	delete[] Buffer;
	Buffer = 0;
}

XSQLDA* ExecuteStatement::MakeSqlda(thread_db* tdbb, short n)
{
	return (XSQLDA*)
		FB_NEW(*tdbb->getTransaction()->tra_pool) char[XSQLDA_LENGTH(n)];
}

ISC_STATUS ExecuteStatement::ReMakeSqlda(ISC_STATUS *vector, thread_db* tdbb)
{
	if (Sqlda->sqln != Sqlda->sqld) {
		vector[0] = isc_arg_gds;
		vector[1] = isc_wronumarg;
		vector[2] = isc_arg_end;
	}
	return vector[1];
}

ULONG ExecuteStatement::ParseSqlda(void)
{
	ULONG offset = 0;
	int i = 0;

	for (XSQLVAR* var = Sqlda->sqlvar; i < Sqlda->sqld; var++, i++)
	{
		USHORT length = var->sqllen;
		const int type = var->sqltype & (~1);
		UCHAR dscType;
		sqlTypeToDscType().get(type, dscType);
		if (type == SQL_VARYING)
			length += sizeof (SSHORT);

		const USHORT align = type_alignments[dscType];
		if (align) {
			offset = FB_ALIGN(offset, align);
		}
		var->sqldata = &Buffer[offset];
		offset += length;

		offset = FB_ALIGN(offset, sizeof(short));
		var->sqlind = (short*) (&Buffer[offset]);
		offset += sizeof (short);
	}

	return offset;
}

void ExecuteStatement::getString(thread_db* tdbb, Firebird::string& s, const dsc* d, const jrd_req* r)
{
	MoveBuffer buffer;

	UCHAR* p = 0;
	const SSHORT l = (d && !(r->req_flags & req_null)) ?
		MOV_make_string2(tdbb, d, d->getTextType(), &p, buffer) : 0; // !!! How call Msgs ?
	if (!p) {
		ERR_post(isc_exec_sql_invalid_arg, 0);
	}

	s.assign((const char*)p, l);
}