-- LegacyWorlds Beta 6
-- PostgreSQL database scripts
--
-- Research mananagement functions and views
--
-- Copyright(C) 2004-2011, DeepClone Development
-- --------------------------------------------------------




--
-- Implement a technology
--
-- Parameters:
--	e_id	Empire identifier
--	t_name	Technology name
--
-- Returns:
--	0		on success
--	1		if the empire does not posses the necessary resources
--	2		if the technology or empire were not found
--

CREATE OR REPLACE FUNCTION emp.implement_tech( e_id INT , t_name TEXT )
		RETURNS INT
		STRICT VOLATILE
		SECURITY DEFINER
	AS $$
DECLARE
	e_cash	DOUBLE PRECISION;
	t_id	INT;
	t_cost	DOUBLE PRECISION;
BEGIN
	SELECT INTO e_cash , t_id , t_cost e.cash , ns.id , td.cost
		FROM defs.strings ns
			INNER JOIN tech.technologies td
				ON td.name_id = ns.id
			INNER JOIN emp.researched_technologies rt
				ON rt.technology_id = td.name_id
			INNER JOIN emp.empires e
				ON rt.empire_id = e.name_id
		WHERE e.name_id = e_id AND ns.name = t_name
		FOR UPDATE OF e , rt;
	IF NOT FOUND THEN
		RETURN 2;
	END IF;
	
	IF e_cash < t_cost THEN
		RETURN 1;
	END IF;
	
	UPDATE emp.empires
		SET cash = e_cash - t_cost
		WHERE name_id = e_id;
	UPDATE emp.researched_technologies
		SET implemented = TRUE
		WHERE empire_id = e_id AND technology_id = t_id;

	RETURN 0;
END;
$$ LANGUAGE plpgsql;

GRANT EXECUTE ON FUNCTION emp.implement_tech( INT , TEXT ) TO :dbuser;



--
-- Prepare for research priorities updates
--

CREATE OR REPLACE FUNCTION emp.prepare_research_priorities_update( )
		RETURNS VOID
		STRICT VOLATILE
		SECURITY DEFINER
	AS $$
BEGIN
	CREATE TEMPORARY TABLE research_priorities_updates(
		technology		TEXT ,
		priority		INT
	);
	CREATE INDEX rpu_technology ON research_priorities_updates ( technology );
	IF session_user <> current_user THEN
		EXECUTE 'GRANT INSERT ON research_priorities_updates TO ' || session_user;
	END IF;
END;
$$ LANGUAGE plpgsql;

GRANT EXECUTE ON FUNCTION emp.prepare_research_priorities_update( ) TO :dbuser;


--
-- Applies research priorities updates
--
-- Parameters:
--	e_id		identifier of the empire the updates should be applied to
--
-- Returns:
--	an error code:
--		0		success
--		1		list of updates does not match current research topics
--		2		invalid priorities
--

CREATE OR REPLACE FUNCTION emp.apply_research_priorities( IN e_id INT )
		RETURNS INT
		STRICT VOLATILE
		SECURITY DEFINER
	AS $$
DECLARE
	rec		RECORD;
	t		INT;
	rval	INT;
BEGIN
	-- Lock empire and research info
	PERFORM er.technology_id
		FROM emp.empires e
			INNER JOIN emp.research er ON er.empire_id = e.name_id
		WHERE e.name_id = e_id
		FOR UPDATE OF e , er;

	-- Check values
	t := 0;
	rval := 0;
	FOR rec IN SELECT rpu.priority , r.technology_id FROM research_priorities_updates rpu
					LEFT OUTER JOIN emp.research_view r
						ON ( r.detailed AND r.technology = rpu.technology )
							OR ( NOT r.detailed AND ( 'unknown-' || ( r.technology_id * e_id )::TEXT ) = rpu.technology )
					WHERE r.empire = e_id OR r.empire IS NULL
				UNION SELECT rpu.priority , r.technology_id FROM research_priorities_updates rpu
					RIGHT OUTER JOIN emp.research_view r
						ON ( r.detailed AND r.technology = rpu.technology )
							OR ( NOT r.detailed AND ( 'unknown-' || ( r.technology_id * e_id )::TEXT ) = rpu.technology )
					WHERE r.empire = e_id
	LOOP
		IF rec.priority IS NULL OR rec.technology_id IS NULL THEN
			rval := 1;
			EXIT;
		ELSIF rec.priority NOT BETWEEN 0 AND 100 THEN
			rval := 2;
			EXIT;
		END IF;
		t := t + rec.priority;
	END LOOP;
	IF rval = 0 AND t <> 100 THEN
		rval := 2;
	END IF;

	-- Update research info
	IF rval = 0 THEN
		UPDATE emp.research er SET priority = rpu.priority
			FROM research_priorities_updates rpu , emp.research_view rv
			WHERE ( rpu.technology = CASE
							WHEN rv.detailed THEN
								rv.technology
							ELSE
								( 'unknown-' || ( rv.technology_id * e_id )::TEXT )
						END )
				AND rv.empire = e_id
				AND er.empire_id = e_id
				AND er.technology_id = rv.technology_id;
	END IF;
	DROP TABLE research_priorities_updates;
	RETURN rval;
END;
$$ LANGUAGE plpgsql;

GRANT EXECUTE ON FUNCTION emp.apply_research_priorities( INT ) TO :dbuser;




--
-- Base research view
--

CREATE VIEW emp.base_research_view
	AS SELECT er.empire_id AS empire , er.technology_id , ns.name AS technology ,
				td.points AS required , ( CASE
					WHEN er.accumulated > td.points THEN
						td.points - 1
					ELSE
						er.accumulated
				END ) AS accumulated , er.priority
			FROM emp.research er
				INNER JOIN tech.technologies td ON td.name_id = er.technology_id
				INNER JOIN defs.strings ns ON ns.id = er.technology_id;


--
-- Research view
--

CREATE VIEW emp.research_view
	AS SELECT empire , technology , technology_id ,
				FLOOR( 100 * accumulated / required )::INT AS completion ,
				( accumulated >= sys.get_constant( 'game.research.minPoints' )
					OR accumulated / required >= sys.get_constant( 'game.research.minRatio' ) ) AS detailed ,
				priority
			FROM emp.base_research_view;


--
-- Researched and implemented technologies view

CREATE VIEW emp.known_techs_view
	AS SELECT et.empire_id AS empire , et.technology_id , ns.name AS technology ,
				( CASE WHEN et.implemented THEN NULL::INT ELSE td.cost END ) AS cost
			FROM emp.researched_technologies et
				INNER JOIN tech.technologies td ON td.name_id = et.technology_id
				INNER JOIN defs.strings ns ON ns.id = et.technology_id;


--
-- Combined research and technologies view
--

CREATE VIEW emp.technologies_view
	AS SELECT empire , technology_id , technology ,
				detailed , completion , priority , NULL::INT AS cost
			FROM emp.research_view
	UNION ALL SELECT empire , technology_id , technology ,
				TRUE AS detailed , NULL::INT AS completion , NULL::INT AS priority , cost
			FROM emp.known_techs_view;

GRANT SELECT ON emp.technologies_view TO :dbuser;