/* postgres headers */

#include "postgres.h"
#include "funcapi.h"
#include "access/reloptions.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_foreign_table.h"
#include "catalog/pg_user_mapping.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
#include "miscadmin.h"
#include "mb/pg_wchar.h"
#include "optimizer/cost.h"
#include "storage/fd.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#include "utils/memutils.h"

#if (PG_VERSION_NUM >= 90200)
#include "optimizer/pathnode.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/planmain.h"
#endif

/* DB-Library headers (e.g. FreeTDS */
#include <sybfront.h>
#include <sybdb.h>

#include "tds_fdw.h"
#include "options.h"

void tdsGetForeignServerOptions(List *options_list, TdsFdwOptionSet *option_set);
void tdsGetForeignServerTableOptions(List *options_list, TdsFdwOptionSet *option_set);
void tdsGetForeignTableOptions(List *options_list, TdsFdwOptionSet *option_set);
void tdsGetUserMappingOptions(List *options_list, TdsFdwOptionSet *option_set);

void tdsValidateForeignTableOptionSet(TdsFdwOptionSet *option_set);

void tdsSetDefaultOptions(TdsFdwOptionSet *option_set);

bool tdsIsValidOption(const char *option, Oid context);
void tdsOptionSetInit(TdsFdwOptionSet* option_set);

/* these are valid options */

static struct TdsFdwOption valid_options[] =
{
	{ "servername",				ForeignServerRelationId },
	{ "language",				ForeignServerRelationId },
	{ "character_set",			ForeignServerRelationId },
	{ "port",					ForeignServerRelationId },
	{ "database",				ForeignServerRelationId },
	{ "dbuse",					ForeignServerRelationId },
	{ "tds_version",			ForeignServerRelationId },
	{ "msg_handler",			ForeignServerRelationId },
	{ "row_estimate_method",	ForeignServerRelationId },
	{ "username",				UserMappingRelationId },
	{ "password",				UserMappingRelationId },
	{ "query", 					ForeignTableRelationId },
	{ "table",					ForeignTableRelationId },
	{ "row_estimate_method",	ForeignTableRelationId },
	{ NULL,						InvalidOid }
};

/* default IP address */

static const char *DEFAULT_SERVERNAME = "127.0.0.1";

/* default method to use to estimate rows in results */

static const char *DEFAULT_ROW_ESTIMATE_METHOD = "execute";

/* default function used to handle TDS messages */

static const char *DEFAULT_MSG_HANDLER = "blackhole";

void tdsValidateOptions(List *options_list, Oid context, TdsFdwOptionSet* option_set)
{
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsValidateOptions")
			));
	#endif
	
	tdsOptionSetInit(option_set);
	
	if (context == ForeignServerRelationId)
	{
		tdsGetForeignServerOptions(options_list, option_set);
		tdsGetForeignServerTableOptions(options_list, option_set);
	}
	
	else if (context == ForeignTableRelationId)
	{
		tdsGetForeignTableOptions(options_list, option_set);
		tdsValidateForeignTableOptionSet(option_set);
	}
	
	else if (context == UserMappingRelationId)
	{
		tdsGetUserMappingOptions(options_list, option_set);
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsValidateOptions")
			));
	#endif
}

/* get options for FOREIGN TABLE and FOREIGN SERVER objects using this module */

void tdsGetForeignTableOptionsFromCatalog(Oid foreigntableid, TdsFdwOptionSet* option_set)
{
	ForeignTable *f_table;
	ForeignServer *f_server;
	UserMapping *f_mapping;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsGetForeignTableOptionsFromCatalog")
			));
	#endif
	
	tdsOptionSetInit(option_set);
	
	f_table = GetForeignTable(foreigntableid);
	f_server = GetForeignServer(f_table->serverid);
	f_mapping = GetUserMapping(GetUserId(), f_table->serverid);
	
	tdsGetForeignServerOptions(f_server->options, option_set);
	tdsGetForeignServerTableOptions(f_server->options, option_set);
	
	tdsGetForeignTableOptions(f_table->options, option_set);
	
	tdsGetUserMappingOptions(f_mapping->options, option_set);

	tdsSetDefaultOptions(option_set);
	tdsValidateOptionSet(option_set);
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsGetForeignTableOptionsFromCatalog")
			));
	#endif
}

void tdsGetForeignServerOptions(List *options_list, TdsFdwOptionSet *option_set)
{
	ListCell *cell;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsGetForeignServerOptions")
			));
	#endif

	foreach (cell, options_list)
	{
		DefElem *def = (DefElem *) lfirst(cell);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Working on option %s", def->defname)
			));
		#endif
		
		if (!tdsIsValidOption(def->defname, ForeignServerRelationId))
		{
			TdsFdwOption *opt;
			StringInfoData buf;
			
			initStringInfo(&buf);
			for (opt = valid_options; opt->optname; opt++)
			{
				if (ForeignServerRelationId == opt->optcontext)
					appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", opt->optname);
			}
			
			ereport(ERROR,
				(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
					errmsg("Invalid option \"%s\"", def->defname),
					errhint("Valid options in this context are: %s", buf.len ? buf.data : "<none>")
				));
		}

		if (strcmp(def->defname, "servername") == 0)
		{
			if (option_set->servername)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: servername (%s)", defGetString(def))
					));
					
			option_set->servername = defGetString(def);	
		}
		
		else if (strcmp(def->defname, "language") == 0)
		{
			if (option_set->language)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: language (%s)", defGetString(def))
					));
					
			option_set->language = defGetString(def);	
		}
		
		else if (strcmp(def->defname, "character_set") == 0)
		{
			if (option_set->character_set)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: character_set (%s)", defGetString(def))
					));
					
			option_set->character_set = defGetString(def);	
		}
		
		else if (strcmp(def->defname, "port") == 0)
		{
			if (option_set->port)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: port (%s)", defGetString(def))
					));
					
			option_set->port = atoi(defGetString(def));	
		}
		
		else if (strcmp(def->defname, "database") == 0)
		{
			if (option_set->database)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: database (%s)", defGetString(def))
					));
					
			option_set->database = defGetString(def);	
		}	

		else if (strcmp(def->defname, "dbuse") == 0)
		{
			if (option_set->dbuse)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: dbuse (%s)", defGetString(def))
					));
					
			option_set->dbuse = atoi(defGetString(def));	
		}	

		else if (strcmp(def->defname, "tds_version") == 0)
		{
			int tds_version_test = 0;
			
			if (option_set->tds_version)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: database (%s)", defGetString(def))
					));
					
			option_set->tds_version = defGetString(def);	
			
			if (strcmp(option_set->tds_version, "4.2") == 0)
			{
				tds_version_test = 1;
			}
			
			else if (strcmp(option_set->tds_version, "5.0") == 0)
			{
				tds_version_test = 1;
			}
			
			else if (strcmp(option_set->tds_version, "7.0") == 0)
			{
				tds_version_test = 1;
			}
			
			#ifdef DBVERSION_71
			else if (strcmp(option_set->tds_version, "7.1") == 0)
			{
				tds_version_test = 1;
			}
			#endif
			
			#ifdef DBVERSION_72
			else if (strcmp(option_set->tds_version, "7.2") == 0)
			{
				tds_version_test = 1;
			}
			#endif

			#ifdef DBVERSION_73
			else if (strcmp(option_set->tds_version, "7.3") == 0)
			{
				tds_version_test = 1;
			}
			#endif
			
			if (!tds_version_test)
			{
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Unknown tds version: %s.", option_set->tds_version)
					));
			}
		}

		else if (strcmp(def->defname, "msg_handler") == 0)
		{
			int msg_handler_test;
			
			if (option_set->msg_handler)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: msg_handler (%s)", defGetString(def))
					));
					
			option_set->msg_handler = defGetString(def);

			if (strcmp(option_set->msg_handler, "notice") == 0)
			{
				msg_handler_test = 1;
			}
			
			else if (strcmp(option_set->msg_handler, "blackhole") == 0)
			{
				msg_handler_test = 1;
			}	

			if (!msg_handler_test)
			{
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Unknown msg handler: %s.", option_set->msg_handler)
					));
			}			
		}
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsGetForeignServerOptions")
			));
	#endif
}

void tdsGetForeignServerTableOptions(List *options_list, TdsFdwOptionSet *option_set)
{
	ListCell *cell;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsGetForeignServerTableOptions")
			));
	#endif
	
	foreach (cell, options_list)
	{
		DefElem *def = (DefElem *) lfirst(cell);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Working on option %s", def->defname)
			));
		#endif
		
		if (!tdsIsValidOption(def->defname, ForeignServerRelationId))
		{
			TdsFdwOption *opt;
			StringInfoData buf;
			
			initStringInfo(&buf);
			for (opt = valid_options; opt->optname; opt++)
			{
				if (ForeignServerRelationId == opt->optcontext)
					appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", opt->optname);
			}
			
			ereport(ERROR,
				(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
					errmsg("Invalid option \"%s\"", def->defname),
					errhint("Valid options in this context are: %s", buf.len ? buf.data : "<none>")
				));
		}
	
		if (strcmp(def->defname, "row_estimate_method") == 0)
		{	
			if (option_set->row_estimate_method)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: row_estimate_method (%s)", defGetString(def))
					));
					
			option_set->row_estimate_method = defGetString(def);
			
			if ((strcmp(option_set->row_estimate_method, "execute") != 0)
				&& (strcmp(option_set->row_estimate_method, "showplan_all") != 0))
			{
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("row_estimate_method should be set to \"execute\" or \"showplan_all\". Currently set to %s", option_set->row_estimate_method)
					));
			}
		}
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsGetForeignServerTableOptions")
			));
	#endif
}

void tdsGetForeignTableOptions(List *options_list, TdsFdwOptionSet *option_set)
{
	ListCell *cell;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsGetForeignTableOptions")
			));
	#endif
	
	foreach (cell, options_list)
	{
		DefElem *def = (DefElem *) lfirst(cell);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Working on option %s", def->defname)
			));
		#endif
		
		if (!tdsIsValidOption(def->defname, ForeignTableRelationId))
		{
			TdsFdwOption *opt;
			StringInfoData buf;
			
			initStringInfo(&buf);
			for (opt = valid_options; opt->optname; opt++)
			{
				if (ForeignTableRelationId == opt->optcontext)
					appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", opt->optname);
			}
			
			ereport(ERROR,
				(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
					errmsg("Invalid option \"%s\"", def->defname),
					errhint("Valid options in this context are: %s", buf.len ? buf.data : "<none>")
				));
		}
		
		if (strcmp(def->defname, "query") == 0)
		{			
			if (option_set->query)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: query (%s)", defGetString(def))
					));
					
			option_set->query = defGetString(def);
		}
		
		else if (strcmp(def->defname, "table") == 0)
		{			
			if (option_set->table)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: table (%s)", defGetString(def))
					));
					
			option_set->table = defGetString(def);
		}
	
		else if (strcmp(def->defname, "row_estimate_method") == 0)
		{	
			if (option_set->row_estimate_method)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: row_estimate_method (%s)", defGetString(def))
					));
					
			option_set->row_estimate_method = defGetString(def);
			
			if ((strcmp(option_set->row_estimate_method, "execute") != 0)
				&& (strcmp(option_set->row_estimate_method, "showplan_all") != 0))
			{
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("row_estimate_method should be set to \"execute\" or \"showplan_all\". Currently set to %s", option_set->row_estimate_method)
					));
			}
		}
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsGetForeignTableOptions")
			));
	#endif
}

void tdsGetUserMappingOptions(List *options_list, TdsFdwOptionSet *option_set)
{
	ListCell *cell;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsGetUserMappingOptions")
			));
	#endif
	
	foreach (cell, options_list)
	{
		DefElem *def = (DefElem *) lfirst(cell);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Working on option %s", def->defname)
			));
		#endif
		
		if (!tdsIsValidOption(def->defname, UserMappingRelationId))
		{
			TdsFdwOption *opt;
			StringInfoData buf;
			
			initStringInfo(&buf);
			for (opt = valid_options; opt->optname; opt++)
			{
				if (UserMappingRelationId == opt->optcontext)
					appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", opt->optname);
			}
			
			ereport(ERROR,
				(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
					errmsg("Invalid option \"%s\"", def->defname),
					errhint("Valid options in this context are: %s", buf.len ? buf.data : "<none>")
				));
		}

		if (strcmp(def->defname, "username") == 0)
		{
			if (option_set->username)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: username (%s)", defGetString(def))
					));
					
			option_set->username = defGetString(def);	
		}
		
		else if (strcmp(def->defname, "password") == 0)
		{
			if (option_set->password)
				ereport(ERROR,
					(errcode(ERRCODE_SYNTAX_ERROR),
						errmsg("Redundant option: password (%s)", defGetString(def))
					));
					
			option_set->password = defGetString(def);
		}
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsGetUserMappingOptions")
			));
	#endif
}

void tdsSetDefaultOptions(TdsFdwOptionSet *option_set)
{
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsSetDefaultOptions")
			));
	#endif
	
	if (!option_set->servername)
	{
		if ((option_set->servername = palloc((strlen(DEFAULT_SERVERNAME) + 1) * sizeof(char))) == NULL)
        	{
                	ereport(ERROR,
                        	(errcode(ERRCODE_FDW_OUT_OF_MEMORY),
                                	errmsg("Failed to allocate memory for server name")
                        	));
        	}

		sprintf(option_set->servername, "%s", DEFAULT_SERVERNAME);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Set servername to default: %s", option_set->servername)
				));
		#endif
	}
	
	if (!option_set->row_estimate_method)
	{
		if ((option_set->row_estimate_method = palloc((strlen(DEFAULT_ROW_ESTIMATE_METHOD) + 1) * sizeof(char))) == NULL)
        	{
                	ereport(ERROR,
                        	(errcode(ERRCODE_FDW_OUT_OF_MEMORY),
                                	errmsg("Failed to allocate memory for row estimate method")
                        	));
        	}

		sprintf(option_set->row_estimate_method, "%s", DEFAULT_ROW_ESTIMATE_METHOD);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Set row_estimate_method to default: %s", option_set->row_estimate_method)
				));
		#endif
	}
	
	if (!option_set->msg_handler)
	{
		if ((option_set->msg_handler= palloc((strlen(DEFAULT_MSG_HANDLER) + 1) * sizeof(char))) == NULL)
        	{
                	ereport(ERROR,
                        	(errcode(ERRCODE_FDW_OUT_OF_MEMORY),
                                	errmsg("Failed to allocate memory for msg handler")
                        	));
        	}

		sprintf(option_set->msg_handler, "%s", DEFAULT_MSG_HANDLER);
		
		#ifdef DEBUG
			ereport(NOTICE,
				(errmsg("Set msg_handler to default: %s", option_set->msg_handler)
				));
		#endif
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsSetDefaultOptions")
			));
	#endif	
}

void tdsValidateOptionSet(TdsFdwOptionSet *option_set)
{
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsValidateOptionSet")
			));
	#endif
	
	tdsValidateForeignTableOptionSet(option_set);
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsValidateOptionSet")
			));
	#endif
}

void tdsValidateForeignTableOptionSet(TdsFdwOptionSet *option_set)
{
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsValidateForeignTableOptionSet")
			));
	#endif
	
	/* Check conflicting options */
	
	if (option_set->table && option_set->query)
	{
		ereport(ERROR,
			(errcode(ERRCODE_SYNTAX_ERROR),
				errmsg("Conflicting options: table and query options can't be used together.")
			));
	}
	
	/* Check required options */
	
	if (!option_set->table && !option_set->query)
	{
		ereport(ERROR,
			(errcode(ERRCODE_SYNTAX_ERROR),
				errmsg("Required options: either a table or a query must be specified")
			));
	}

	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsValidateForeignTableOptionSet")
			));
	#endif
}

/* validate options for FOREIGN TABLE and FOREIGN SERVER objects using this module */

bool tdsIsValidOption(const char *option, Oid context)
{
	TdsFdwOption *opt;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsIdValidOption")
			));
	#endif
	
	for (opt = valid_options; opt->optname; opt++)
	{
		if (context == opt->optcontext && strcmp(opt->optname, option) == 0)
			return true;
	}
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsIdValidOption")
			));
	#endif
	
	return false;
}

/* initialize the option set */

void tdsOptionSetInit(TdsFdwOptionSet* option_set)
{
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> starting tdsOptionSetInit")
			));
	#endif

	option_set->servername = NULL;
	option_set->language = NULL;
	option_set->character_set = NULL;
	option_set->port = 0;
	option_set->database = NULL;
	option_set->dbuse = 0;
	option_set->tds_version = NULL;
	option_set->msg_handler = NULL;
	option_set->username = NULL;
	option_set->password = NULL;
	option_set->query = NULL;
	option_set->table = NULL;
	option_set->row_estimate_method = NULL;
	
	#ifdef DEBUG
		ereport(NOTICE,
			(errmsg("----> finishing tdsOptionSetInit")
			));
	#endif	
}