/*
 * The contents of this file are subject to the Interbase 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.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, 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 Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../common/common.h"
#include "../common/gdsassert.h"
#include "../jrd/flags.h"
#include "../jrd/ibase.h"
#include "../jrd/jrd.h"
#include "../jrd/val.h"
#include "../jrd/irq.h"
#include "../jrd/tra.h"
#include "../jrd/lck.h"
#include "../jrd/req.h"
#include "../jrd/exe.h"
#include "../jrd/blb.h"
#include "../jrd/met.h"
#include "../jrd/align.h"
#include "../dsql/ExprNodes.h"
#include "../dsql/StmtNodes.h"
#include "../jrd/blb_proto.h"
#include "../jrd/cmp_proto.h"
#include "../common/dsc_proto.h"
#include "../jrd/evl_proto.h"
#include "../jrd/exe_proto.h"
#include "../jrd/flu_proto.h"
#include "../jrd/fun_proto.h"
#include "../jrd/lck_proto.h"
#include "../jrd/met_proto.h"
#include "../jrd/mov_proto.h"
#include "../jrd/par_proto.h"
#include "../jrd/vio_proto.h"
#include "../jrd/thread_proto.h"
#include "../common/utils_proto.h"
#include "../jrd/DebugInterface.h"

#include "../jrd/Function.h"

using namespace Firebird;
using namespace Jrd;

DATABASE DB = FILENAME "ODS.RDB";

const char* const Function::EXCEPTION_MESSAGE = "The user defined function: \t%s\n\t   referencing"
	" entrypoint: \t%s\n\t                in module: \t%s\n\tcaused the fatal exception:";

Function* Function::lookup(thread_db* tdbb, USHORT id, bool return_deleted, bool noscan, USHORT flags)
{
	Jrd::Attachment* attachment = tdbb->getAttachment();
	Function* check_function = NULL;

	Function* function = (id < attachment->att_functions.getCount()) ? attachment->att_functions[id] : NULL;

	if (function && function->getId() == id &&
		!(function->fun_flags & FUN_being_scanned) &&
		((function->fun_flags & FUN_scanned) || noscan) &&
		!(function->fun_flags & FUN_being_altered) &&
		(!(function->fun_flags & FUN_obsolete) || return_deleted))
	{
		if (!(function->fun_flags & FUN_check_existence))
		{
			return function;
		}

		check_function = function;
		LCK_lock(tdbb, check_function->fun_existence_lock, LCK_SR, LCK_WAIT);
	}

	// We need to look up the function in RDB$FUNCTIONS

	function = NULL;

	AutoCacheRequest request(tdbb, irq_l_fun_id, IRQ_REQUESTS);

	FOR(REQUEST_HANDLE request)
		X IN RDB$FUNCTIONS WITH X.RDB$FUNCTION_ID EQ id
	{
		function = loadMetadata(tdbb, X.RDB$FUNCTION_ID, noscan, flags);
	}
	END_FOR

	if (check_function)
	{
		check_function->fun_flags &= ~FUN_check_existence;
		if (check_function != function)
		{
			LCK_release(tdbb, check_function->fun_existence_lock);
			check_function->fun_flags |= FUN_obsolete;
		}
	}

	return function;
}

Function* Function::lookup(thread_db* tdbb, const QualifiedName& name, bool noscan)
{
	Jrd::Attachment* attachment = tdbb->getAttachment();

	Function* check_function = NULL;

	// See if we already know the function by name

	for (Function** iter = attachment->att_functions.begin(); iter < attachment->att_functions.end(); ++iter)
	{
		Function* const function = *iter;

		if (function && !(function->fun_flags & FUN_obsolete) &&
			((function->fun_flags & FUN_scanned) || noscan) &&
			!(function->fun_flags & FUN_being_scanned) &&
			!(function->fun_flags & FUN_being_altered))
		{
			if (function->getName() == name)
			{
				if (function->fun_flags & FUN_check_existence)
				{
					check_function = function;
					LCK_lock(tdbb, check_function->fun_existence_lock, LCK_SR, LCK_WAIT);
					break;
				}

				return function;
			}
		}
	}

	// We need to look up the function in RDB$FUNCTIONS

	Function* function = NULL;

	AutoCacheRequest request(tdbb, irq_l_fun_name, IRQ_REQUESTS);

	FOR(REQUEST_HANDLE request)
		X IN RDB$FUNCTIONS
		WITH X.RDB$FUNCTION_NAME EQ name.identifier.c_str() AND
			 X.RDB$PACKAGE_NAME EQUIV NULLIF(name.package.c_str(), '')
	{
		function = loadMetadata(tdbb, X.RDB$FUNCTION_ID, noscan, 0);
	}
	END_FOR

	if (check_function)
	{
		check_function->fun_flags &= ~FUN_check_existence;
		if (check_function != function)
		{
			LCK_release(tdbb, check_function->fun_existence_lock);
			check_function->fun_flags |= FUN_obsolete;
		}
	}

	return function;
}

Function* Function::loadMetadata(thread_db* tdbb, USHORT id, bool noscan, USHORT flags)
{
	Jrd::Attachment* attachment = tdbb->getAttachment();
	jrd_tra* sysTransaction = attachment->getSysTransaction();
	Database* const dbb = tdbb->getDatabase();

	if (id >= attachment->att_functions.getCount())
		attachment->att_functions.grow(id + 1);

	Function* function = attachment->att_functions[id];

	if (function && !(function->fun_flags & FUN_obsolete))
	{
		// Make sure FUN_being_scanned and FUN_scanned are not set at the same time
		fb_assert(!(function->fun_flags & FUN_being_scanned) || !(function->fun_flags & FUN_scanned));

		if ((function->fun_flags & FUN_being_scanned) || (function->fun_flags & FUN_scanned))
		{
			return function;
		}
	}

	if (!function)
		function = FB_NEW(*attachment->att_pool) Function(*attachment->att_pool);

	try
	{
	function->fun_flags |= (FUN_being_scanned | flags);
	function->fun_flags &= ~FUN_obsolete;

	function->setId(id);
	attachment->att_functions[id] = function;

	if (!function->fun_existence_lock)
	{
		Lock* const lock = FB_NEW_RPT(*attachment->att_pool, 0) Lock;
		function->fun_existence_lock = lock;
		lock->lck_parent = dbb->dbb_lock;
		lock->lck_dbb = dbb;
		lock->lck_key.lck_long = function->getId();
		lock->lck_length = sizeof(lock->lck_key.lck_long);
		lock->lck_type = LCK_fun_exist;
		lock->lck_owner_handle = LCK_get_owner_handle(tdbb, lock->lck_type);
		lock->lck_object = function;
		lock->lck_ast = blockingAst;
	}

	LCK_lock(tdbb, function->fun_existence_lock, LCK_SR, LCK_WAIT);

	if (!noscan)
	{
		bool valid_blr = true;

		AutoCacheRequest request_fun(tdbb, irq_l_functions, IRQ_REQUESTS);

		FOR(REQUEST_HANDLE request_fun)
			X IN RDB$FUNCTIONS
			WITH X.RDB$FUNCTION_ID EQ id
		{
			function->setName(QualifiedName(X.RDB$FUNCTION_NAME,
				(X.RDB$PACKAGE_NAME.NULL ? NULL : X.RDB$PACKAGE_NAME)));

			if (!X.RDB$SECURITY_CLASS.NULL)
			{
				function->setSecurityName(X.RDB$SECURITY_CLASS);
			}
			else if (!X.RDB$PACKAGE_NAME.NULL)
			{
				AutoCacheRequest requestHandle(tdbb, irq_l_procedure_pkg_class, IRQ_REQUESTS);

				FOR (REQUEST_HANDLE requestHandle)
					PKG IN RDB$PACKAGES
					WITH PKG.RDB$PACKAGE_NAME EQ X.RDB$PACKAGE_NAME

					if (!PKG.RDB$SECURITY_CLASS.NULL)
					{
						function->setSecurityName(PKG.RDB$SECURITY_CLASS);
					}

				END_FOR
			}

			size_t count = 0;
			ULONG length = 0;

			function->fun_inputs = 0;
			function->setDefaultCount(0);

			function->getInputFields().clear();
			function->getOutputFields().clear();

			AutoCacheRequest request_arg(tdbb, irq_l_args, IRQ_REQUESTS);

			FOR(REQUEST_HANDLE request_arg)
				Y IN RDB$FUNCTION_ARGUMENTS
				WITH Y.RDB$FUNCTION_NAME EQ function->getName().identifier.c_str() AND
					 Y.RDB$PACKAGE_NAME EQUIV NULLIF(function->getName().package.c_str(), '')
				SORTED BY Y.RDB$ARGUMENT_POSITION
			{
				Parameter* parameter = FB_NEW(function->getPool()) Parameter(function->getPool());

				if (Y.RDB$ARGUMENT_POSITION != X.RDB$RETURN_ARGUMENT)
				{
					function->fun_inputs++;
					int newCount = Y.RDB$ARGUMENT_POSITION - function->getOutputFields().getCount();
					fb_assert(newCount >= 0);

					function->getInputFields().resize(newCount + 1);
					function->getInputFields()[newCount] = parameter;
				}
				else
				{
					fb_assert(function->getOutputFields().isEmpty());
					function->getOutputFields().add(parameter);
				}

				parameter->prm_fun_mechanism = (FUN_T) Y.RDB$MECHANISM;
				parameter->prm_number = Y.RDB$ARGUMENT_POSITION;
				parameter->prm_name = Y.RDB$ARGUMENT_NAME.NULL ? "" : Y.RDB$ARGUMENT_NAME;
				parameter->prm_nullable = Y.RDB$NULL_FLAG.NULL || Y.RDB$NULL_FLAG == 0;
				parameter->prm_mechanism = Y.RDB$ARGUMENT_MECHANISM.NULL ?
					prm_mech_normal : (prm_mech_t) Y.RDB$ARGUMENT_MECHANISM;

				const SSHORT collation_id_null = Y.RDB$COLLATION_ID.NULL;
				const SSHORT collation_id = Y.RDB$COLLATION_ID;

				SSHORT default_value_null = Y.RDB$DEFAULT_VALUE.NULL;
				bid default_value = Y.RDB$DEFAULT_VALUE;

				if (!Y.RDB$FIELD_SOURCE.NULL)
				{
					parameter->prm_field_source = Y.RDB$FIELD_SOURCE;

					AutoCacheRequest request_arg_fld(tdbb, irq_l_arg_fld, IRQ_REQUESTS);

					FOR(REQUEST_HANDLE request_arg_fld)
						F IN RDB$FIELDS
						WITH F.RDB$FIELD_NAME = Y.RDB$FIELD_SOURCE
					{
						DSC_make_descriptor(&parameter->prm_desc, F.RDB$FIELD_TYPE,
											F.RDB$FIELD_SCALE, F.RDB$FIELD_LENGTH,
											F.RDB$FIELD_SUB_TYPE, F.RDB$CHARACTER_SET_ID,
											(collation_id_null ? F.RDB$COLLATION_ID : collation_id));

						if (default_value_null && fb_utils::implicit_domain(F.RDB$FIELD_NAME))
						{
							default_value_null = F.RDB$DEFAULT_VALUE.NULL;
							default_value = F.RDB$DEFAULT_VALUE;
						}
					}
					END_FOR
				}
				else
				{
					DSC_make_descriptor(&parameter->prm_desc, Y.RDB$FIELD_TYPE,
										Y.RDB$FIELD_SCALE, Y.RDB$FIELD_LENGTH,
										Y.RDB$FIELD_SUB_TYPE, Y.RDB$CHARACTER_SET_ID,
										(collation_id_null ? 0 : collation_id));
				}

				if (Y.RDB$ARGUMENT_POSITION != X.RDB$RETURN_ARGUMENT && !default_value_null)
				{
					function->setDefaultCount(function->getDefaultCount() + 1);

					MemoryPool* const csb_pool = attachment->createPool();
					Jrd::ContextPoolHolder context(tdbb, csb_pool);

					try
					{
						parameter->prm_default_value = static_cast<ValueExprNode*>(MET_parse_blob(
							tdbb, NULL, &default_value, NULL, NULL, false, false));
					}
					catch (const Exception&)
					{
						attachment->deletePool(csb_pool);
						throw; // an explicit error message would be better
					}
				}

				if (parameter->prm_desc.dsc_dtype == dtype_cstring)
					parameter->prm_desc.dsc_length++;

				length += (parameter->prm_desc.dsc_dtype == dtype_blob) ?
					sizeof(udf_blob) : FB_ALIGN(parameter->prm_desc.dsc_length, FB_DOUBLE_ALIGN);

				count = MAX(count, size_t(Y.RDB$ARGUMENT_POSITION));
			}
			END_FOR

			for (int i = (int) function->getInputFields().getCount() - 1; i >= 0; --i)
			{
				if (!function->getInputFields()[i])
					function->getInputFields().remove(i);
			}

			function->fun_return_arg = X.RDB$RETURN_ARGUMENT;
			function->fun_temp_length = length;

			// Prepare the exception message to be used in case this function ever
			// causes an exception.  This is done at this time to save us from preparing
			// (thus allocating) this message every time the function is called.
			function->fun_exception_message.printf(EXCEPTION_MESSAGE,
				function->getName().toString().c_str(), X.RDB$ENTRYPOINT, X.RDB$MODULE_NAME);

			if (!X.RDB$DETERMINISTIC_FLAG.NULL)
				function->fun_deterministic = (X.RDB$DETERMINISTIC_FLAG != 0);

			function->setImplemented(true);
			function->setDefined(true);

			function->fun_entrypoint = NULL;
			function->fun_external = NULL;
			function->setStatement(NULL);

			BlrMessage inBlr;
			inBlr.blr = NULL;
			inBlr.blrLength = 0;
			inBlr.bufferLength = 0;

			BlrMessage outBlr;
			outBlr.blr = NULL;
			outBlr.blrLength = 0;
			outBlr.bufferLength = 0;

			if (!X.RDB$ENGINE_NAME.NULL || !X.RDB$FUNCTION_BLR.NULL)
			{
				if (!X.RDB$ENGINE_NAME.NULL)
				{
					HalfStaticArray<UCHAR, 512> body;

					if (!X.RDB$FUNCTION_SOURCE.NULL)
					{
						blb* const blob = BLB_open(tdbb, sysTransaction, &X.RDB$FUNCTION_SOURCE);
						const ULONG len = blob->BLB_get_data(tdbb,
							body.getBuffer(blob->blb_length + 1), blob->blb_length + 1);
						body[MIN(blob->blb_length, len)] = 0;
					}
					else
						body.getBuffer(1)[0] = 0;

					function->fun_external =
						dbb->dbb_extManager.makeFunction(tdbb, function, X.RDB$ENGINE_NAME,
						(X.RDB$ENTRYPOINT.NULL ? "" : X.RDB$ENTRYPOINT), (char*) body.begin(),
						&inBlr, &outBlr);

					if (!function->fun_external)
						function->setDefined(false);
				}

				MemoryPool* const csb_pool = attachment->createPool();
				Jrd::ContextPoolHolder context(tdbb, csb_pool);

				try
				{
					AutoPtr<CompilerScratch> csb(CompilerScratch::newCsb(*csb_pool, 5));

					if (X.RDB$ENGINE_NAME.NULL && !X.RDB$DEBUG_INFO.NULL)
						DBG_parse_debug_info(tdbb, &X.RDB$DEBUG_INFO, *csb->csb_dbg_info);

					try
					{
						MET_parse_routine_blr(tdbb, function, &X.RDB$FUNCTION_BLR, csb,
							!X.RDB$ENGINE_NAME.NULL, inBlr, outBlr);
					}
					catch (const Exception&)
					{
						if (!X.RDB$ENGINE_NAME.NULL)
							throw;

						const string name = function->getName().toString();
						status_exception::raise(Arg::Gds(isc_bad_fun_BLR) << Arg::Str(name));
					}
				}
				catch (const Exception&)
				{
					attachment->deletePool(csb_pool);
					throw;
				}

				function->getStatement()->function = function;
			}
			else if (!X.RDB$MODULE_NAME.NULL && !X.RDB$ENTRYPOINT.NULL)
			{
				function->fun_entrypoint =
					Module::lookup(X.RDB$MODULE_NAME, X.RDB$ENTRYPOINT, dbb->dbb_modules);

				// Could not find a function with given MODULE, ENTRYPOINT.
				// Try the list of internally implemented functions.
				if (!function->fun_entrypoint)
				{
					function->fun_entrypoint =
						BUILTIN_entrypoint(X.RDB$MODULE_NAME, X.RDB$ENTRYPOINT);
				}

				if (!function->fun_entrypoint)
					function->setDefined(false);
			}
			else
				function->setImplemented(false);

			if (X.RDB$VALID_BLR.NULL || X.RDB$VALID_BLR == FALSE)
				valid_blr = false;

			function->fun_flags |= FUN_scanned;
		}
		END_FOR

		if (!(dbb->dbb_flags & DBB_read_only) && !valid_blr)
		{
			// if the BLR was marked as invalid but the function was compiled,
			// mark the BLR as valid

			AutoRequest request_set_valid;

			FOR(REQUEST_HANDLE request_set_valid)
				F IN RDB$FUNCTIONS WITH F.RDB$FUNCTION_ID EQ function->getId()
			{
				MODIFY F USING
					F.RDB$VALID_BLR = TRUE;
					F.RDB$VALID_BLR.NULL = FALSE;
				END_MODIFY
			}
			END_FOR
		}
	}

	// Make sure that it is really being scanned
	fb_assert(function->fun_flags & FUN_being_scanned);

	function->fun_flags &= ~FUN_being_scanned;

	}	// try
	catch (const Exception&)
	{
		function->fun_flags &= ~(FUN_being_scanned | FUN_scanned);

		if (function->fun_existence_lock)
		{
			LCK_release(tdbb, function->fun_existence_lock);
			function->fun_existence_lock = NULL;
		}

		throw;
	}

	return function;
}

int Function::blockingAst(void* ast_object)
{
	Function* const function = static_cast<Function*>(ast_object);

	try
	{
		Database* const dbb = function->fun_existence_lock->lck_dbb;
		Jrd::Attachment* const att = function->fun_existence_lock->lck_attachment;

		AsyncContextHolder tdbb(dbb, att);

		LCK_release(tdbb, function->fun_existence_lock);
		function->fun_flags |= FUN_obsolete;
	}
	catch (const Firebird::Exception&)
	{} // no-op

	return 0;
}

void Function::remove(thread_db* tdbb)
{
	if (fun_existence_lock)
	{
		LCK_release(tdbb, fun_existence_lock);
		delete fun_existence_lock;
		fun_existence_lock = NULL;
	}

	if (!(fun_flags & FUN_being_altered) && !fun_use_count)
	{
		delete this;
	}
	else
	{
		setName(QualifiedName());
		setSecurityName("");
		setId(0);
		setDefaultCount(0);
	}
}

void Function::addRef()
{
	fun_use_count++;
}

void Function::release(thread_db* tdbb)
{
	if (fun_use_count)
	{
		fun_use_count--;

		Jrd::Attachment* attachment = tdbb->getAttachment();
		if (fun_use_count == 0 && attachment->att_functions[getId()] != this)
		{
			if (getStatement())
			{
				getStatement()->release(tdbb);
				setStatement(NULL);
			}
			fun_flags &= ~FUN_being_altered;
			remove(tdbb);
		}
	}
}

void Function::releaseLocks(thread_db* tdbb)
{
	if (fun_existence_lock)
	{
		LCK_release(tdbb, fun_existence_lock);
		fun_flags |= FUN_check_existence;
		fun_use_count = 0;
	}
}

USHORT Function::incrementAlterCount()
{
	if (fun_alter_count == Function::MAX_ALTER_COUNT)
	{
		status_exception::raise(Arg::Gds(isc_no_meta_update) <<
				 Arg::Gds(isc_udf_name) << Arg::Str(getName().toString()) <<
				 Arg::Gds(isc_version_err));
	}

	return ++fun_alter_count;
}