/* Вариант 1 || Работа 6 || Антипенко, Дробышевский */


-- Task 1 -- 
/* a) Напишите запрос, используя конструкцию WITH, выбирающий
рекурсивно сотрудника с идентификатором 1 и все его подчинённых,
как прямых, так и подчинённых более низкого ранга*.
b) Напишите программу на языке PL/SQL, печатающую на экран фамилию
и имя сотрудника с идентификатором 1 и всех его подчинённых, как
прямых, так и подчинённых более низкого ранга. */

-- Пункт а)
WITH RECURSIVE tmp AS (

  SELECT id, first_name, last_name, manager_id, 1 AS level
  FROM bd6_employees
  WHERE id = 1
  UNION all
  SELECT e.id, e.first_name, e.last_name, e.manager_id, t.level + 1
  FROM bd6_employees e
  JOIN tmp t ON e.manager_id = t.id 
)
SELECT * 
FROM tmp
;

-- Пункт б)
CREATE OR REPLACE PROCEDURE depa(integer) AS $$
DECLARE 
	d_attrs RECORD;
	i integer;
	l integer;
BEGIN
FOR d_attrs IN 
	(
	SELECT id,last_name, first_name, manager_id
	FROM bd6_employees 
	ORDER BY manager_id
	)   
	LOOP
	IF d_attrs.manager_id=$1 THEN
	 	RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;   
		l:= d_attrs.id;
    	CALL depa(l); 
	END IF;
	END LOOP; 
END $$ LANGUAGE plpgsql; 

CREATE OR REPLACE PROCEDURE dep(integer) AS $$
DECLARE
	d_attrs RECORD;
	BEGIN
	FOR d_attrs IN 
	(
	SELECT 
		id,
		last_name, 
		first_name, 
		manager_id   
	FROM bd6_employees 
	ORDER BY manager_id
	)
      
	LOOP   
	IF d_attrs.id=$1 THEN   
	RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;
    END IF;
	END LOOP; 
CALL depa($1);
END $$ LANGUAGE plpgsql; 
CALL dep(1);   

-- Task 2 --
/* Напишите программу на языке PL/SQL, выбирающую строки из таблицы
employees в порядке возрастания заработной платы (salary) и печатающие на
экран следующие данные: фамилия, имя, модифицированная заработная
плата. Модифицированная заработная плата получается следующим
образом: у первого по порядку сотрудника она округляется до сотен в
меньшую сторону, а у всех последующих сотрудников она сначала
увеличивается на остаток от округления, полученный от предыдущего
сотрудника, а затем округляется до сотен в меньшую сторону. */ 

UPDATE bd6_employees SET salary_in_euro = 299 WHERE id = 3;

CREATE OR REPLACE PROCEDURE print_employees() AS $$
DECLARE
current_salary INTEGER;
m_salary INTEGER;
mod_salary INTEGER := 0;
employee_rec RECORD;
BEGIN
FOR employee_rec IN 
	(
   SELECT last_name, first_name, salary_in_euro 
   FROM bd6_employees 
   ORDER BY salary_in_euro
	) 

LOOP
	current_salary := employee_rec.salary_in_euro;
	
	m_salary := ((current_salary + mod_salary) / 100) * 100;

RAISE NOTICE 'Employee: % % || Modified Salary: %', employee_rec.last_name, employee_rec.first_name, m_salary;
mod_salary := mod(current_salary + mod_salary,100);
END LOOP;
END $$ LANGUAGE plpgsql;

CALL print_employees();
SELECT * 
FROM bd6_employees
ORDER BY salary_in_euro;


-- Task 3 -- 
/* Напишите программу на языке PL/SQL, удаляющую 10 сотрудников с
самой маленькой заработной платой. При этом их заработная плата должна
добавиться 10 сотрудникам с самой большой заработной платой. Причём
самая маленькая заработная плата должна добавиться к человеку с самой
большой заработной платой. 2-я с конца заработная плата должна добавиться
к человеку со второй по размеру заработной платой и т.д. */

CREATE OR REPLACE FUNCTION rearrange_salaries() RETURNS VOID AS $$
DECLARE
    salaries RECORD;
	small NUMERIC[];
	larg NUMERIC[];
	const CONSTANT INTEGER = 3;
BEGIN
    FOR salaries IN 
        SELECT id, salary_in_euro
        FROM bd6_employees 
        ORDER BY salary_in_euro 
        LIMIT const
	LOOP
		small = array_append(small, (SELECT salary_in_euro FROM bd6_employees WHERE id = salaries.id));
    	DELETE FROM bd6_employees
    	WHERE id = salaries.id;
	END LOOP;

    FOR salaries IN 
        SELECT id, salary_in_euro
        FROM bd6_employees 
        ORDER BY salary_in_euro DESC 
        LIMIT const
	LOOP
		larg = array_append(larg, (SELECT id FROM bd6_employees WHERE id = salaries.id));
	END LOOP;
	
	FOR i IN 1..const
	LOOP
        UPDATE bd6_employees
        SET salary_in_euro = salary_in_euro + small[i]
        WHERE id = larg[i];
    END LOOP;
END;
$$ LANGUAGE plpgsql;
SELECT rearrange_salaries();

-- Task 4 --
/* Создайте таблицу spiral с 5 полями f1, f2, f3, f4, f5 – целые числа.
Напишите программу на языке PL/SQL, заполняющую данную таблицу 1000
строк по следующему принципу:
1 2 3 4 5
10 9 8 7 6
11 12 13 14 15
20 19 18 17 16
21 22 23 24 25 */

CREATE OR REPLACE PROCEDURE f() AS $$ 
DECLARE d_attrs RECORD; 
BEGIN

FOR d_attrs IN WITH RECURSIVE tmp AS ( 
    SELECT 1+i*5 AS f1, 2+i*5 AS f2, 3+i*5 AS f3, 4+i*5 AS f4,5+i*5 AS f5 
    FROM generate_series(0,199) i)

SELECT * FROM tmp 
LOOP 
case 
when ( mod(d_attrs.f1,2)!=0) 
then RAISE INFO ' % % % % %', d_attrs.f1, d_attrs.f2, d_attrs.f3, d_attrs.f4, d_attrs.f5; 
when ( mod(d_attrs.f1,2)=0) 
then RAISE INFO ' % % % % %', d_attrs.f5, d_attrs.f4, d_attrs.f3, d_attrs.f2, d_attrs.f1; 
end case; 
END LOOP; 
END $$ LANGUAGE plpgsql; 
call f();

-- Task 7 from lab4 -- 


CREATE table staff(
	id integer primary key,
	name varchar(64) NOT NULL,
	department varchar(64) NOT NULL
);

CREATE SEQUENCE staff_id_seq
	START WITH 12
	CYCLE
	INCREMENT BY 8
	CACHE 100;
	

INSERT INTO staff VALUES
	(nextval('staff_id_seq'), 'Ivan Makarenko', 'Director');
	
INSERT INTO staff
	(SELECT nextval('staff_id_seq'), last_name, department_name
	 FROM employees e JOIN departments d ON e.department_id = d.department_id);
	 
UPDATE staff SET department = 'Innovations department'
	WHERE id < 40;
	
DELETE FROM staff 
	WHERE name ILIKE('%K%');

CREATE VIEW dep_staff_counts AS
SELECT department, COUNT(*) AS ecount
FROM staff
GROUP BY department;

SELECT * FROM dep_staff_counts;





-- CREATE OR REPLACE PROCEDURE department_names(integer) AS $$
-- DECLARE 
-- 	d_attrs RECORD;
-- 	i INTEGER;
-- 	l INTEGER;
-- BEGIN
-- FOR d_attrs IN 
-- 	(
-- 	SELECT id,last_name, first_name, manager_id
-- 	FROM bd6_employees order by manager_id 
-- 	)   
-- 	LOOP
-- 		IF d_attrs.manager_id=$1 THEN
--     		RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;    
-- 			l:= d_attrs.id;
--     	CALL department_names(l);    
-- 	END IF;
-- END LOOP; 
-- END $$ LANGUAGE plpgsql; 


-- CREATE OR REPLACE PROCEDURE department_names2(integer) AS $$
-- DECLARE d_attrs RECORD;
-- BEGIN
-- 	FOR d_attrs IN 
-- 	(
-- 	SELECT id,last_name, first_name, manager_id   
-- 	FROM bd6_employees 
-- 	order by manager_id 
-- 	)
      
-- LOOP   
-- 	if d_attrs.id=$1 then    
-- 	RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;
-- 	end if;
-- 	END LOOP; 
-- CALL department_names($1);
-- END $$ LANGUAGE plpgsql; 
-- CALL department_names2(4);


/* Вариант 1 || Работа 6 || Антипенко, Дробышевский */


-- Task 1 -- 
-- Пункт а)
WITH RECURSIVE tmp AS (

  SELECT id, first_name, last_name, manager_id, 1 AS level
  FROM bd6_employees
  WHERE id = 1
  UNION all
  SELECT e.id, e.first_name, e.last_name, e.manager_id, t.level + 1
  FROM bd6_employees e
  JOIN tmp t ON e.manager_id = t.id 
)
SELECT * 
FROM tmp
;

-- Пункт б)
CREATE OR REPLACE PROCEDURE depa(integer) AS $$
DECLARE 
	d_attrs RECORD;
	i integer;
	l integer;
BEGIN
FOR d_attrs IN 
	(
	SELECT id,last_name, first_name, manager_id
	FROM bd6_employees 
	ORDER BY manager_id
	)   
	LOOP
	IF d_attrs.manager_id=$1 THEN
	 	RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;   
		l:= d_attrs.id;
    	CALL depa(l); 
	END IF;
	END LOOP; 
END $$ LANGUAGE plpgsql; 

CREATE OR REPLACE PROCEDURE dep(integer) AS $$
DECLARE
	d_attrs RECORD;
	BEGIN
	FOR d_attrs IN 
	(
	SELECT 
		id,
		last_name, 
		first_name, 
		manager_id   
	FROM bd6_employees 
	ORDER BY manager_id
	)
      
	LOOP   
	IF d_attrs.id=$1 THEN   
	RAISE INFO ' % % % % ', d_attrs.first_name, d_attrs.last_name, d_attrs.id, d_attrs.manager_id;
    END IF;
	END LOOP; 
CALL depa($1);
END $$ LANGUAGE plpgsql; 
CALL dep(1);   

-- Task 2 --

UPDATE bd6_employees SET salary_in_euro = 299 WHERE id = 3;

CREATE OR REPLACE PROCEDURE print_employees() AS $$
DECLARE
current_salary INTEGER;
m_salary INTEGER;
mod_salary INTEGER := 0;
employee_rec RECORD;
i INTEGER = 0;
cnt INTEGER;
BEGIN
SELECT COUNT(*) INTO cnt FROM bd6_employees;
FOR employee_rec IN 
	(
   SELECT last_name, first_name, salary_in_euro 
   FROM bd6_employees 
   ORDER BY salary_in_euro
	) 
LOOP

	current_salary := employee_rec.salary_in_euro;
	
	IF cnt - 1 = i THEN 
	m_salary := ((current_salary) / 100) * 100 + mod_salary;
	ELSE 
	m_salary := ((current_salary) / 100) * 100;
	END IF;

RAISE NOTICE 'Employee: % % || Modified Salary: %', employee_rec.last_name, employee_rec.first_name, m_salary;

mod_salary := mod_salary + mod(current_salary, 100);
i := i+1;

END LOOP;

END $$ LANGUAGE plpgsql;

CALL print_employees();
SELECT * 
FROM bd6_employees
ORDER BY salary_in_euro;


-- Task 3 -- 
CREATE OR REPLACE FUNCTION rearrange_salaries() RETURNS VOID AS $$
DECLARE
    salaries RECORD;
	small NUMERIC[];
	larg NUMERIC[];
	const CONSTANT INTEGER = 10;
BEGIN
    FOR salaries IN 
        SELECT id, salary_in_euro
        FROM bd6_employees 
        ORDER BY salary_in_euro 
        LIMIT const
	LOOP
		small = array_append(small, (SELECT salary_in_euro FROM bd6_employees WHERE id = salaries.id));
		UPDATE bd6_employees SET manager_id = NULL WHERE manager_id = salaries.id;
    	DELETE FROM bd6_employees
    	WHERE id = salaries.id;
	END LOOP;

    FOR salaries IN 
        SELECT id, salary_in_euro
        FROM bd6_employees 
        ORDER BY salary_in_euro DESC 
        LIMIT const
	LOOP
		larg = array_append(larg, (SELECT id FROM bd6_employees WHERE id = salaries.id));
	END LOOP;
	
	FOR i IN 1..const
	LOOP
        UPDATE bd6_employees
        SET salary_in_euro = salary_in_euro + small[i]
        WHERE id = larg[i];
    END LOOP;
END;
$$ LANGUAGE plpgsql;
SELECT rearrange_salaries();

-- Task 4 --

CREATE OR REPLACE PROCEDURE f() AS $$ 
DECLARE d_attrs RECORD; 
BEGIN

FOR d_attrs IN WITH RECURSIVE tmp AS ( 
    SELECT 1+i*5 AS f1, 2+i*5 AS f2, 3+i*5 AS f3, 4+i*5 AS f4,5+i*5 AS f5 
    FROM generate_series(0,199) i)

SELECT * FROM tmp 
LOOP 
case 
when ( mod(d_attrs.f1,2)!=0) 
then RAISE INFO ' % % % % %', d_attrs.f1, d_attrs.f2, d_attrs.f3, d_attrs.f4, d_attrs.f5; 
when ( mod(d_attrs.f1,2)=0) 
then RAISE INFO ' % % % % %', d_attrs.f5, d_attrs.f4, d_attrs.f3, d_attrs.f2, d_attrs.f1; 
end case; 
END LOOP; 
END $$ LANGUAGE plpgsql; 
call f();

-- Task 7 from lab4 -- 
DROP VIEW IF EXISTS dep_staff_counts;

CREATE VIEW dep_staff_counts AS
SELECT department, COUNT(*) AS ecount
FROM staff
GROUP BY department;

SELECT * FROM dep_staff_counts;