Postgres 14

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CREATE TABLE words_users (
    uid SERIAL PRIMARY KEY,
    muted BOOLEAN NOT NULL DEFAULT false
);

CREATE TABLE words_social (
    sid     text     NOT NULL CHECK (sid ~ '\S'),
    social  integer  NOT NULL CHECK (0 < social AND social <= 256),
    given   text     NOT NULL CHECK (given ~ '\S'),
    uid     integer  NOT NULL REFERENCES words_users ON DELETE CASCADE,
    PRIMARY KEY(sid, social)
);

CREATE TABLE words_games (
    gid      SERIAL PRIMARY KEY,
    player1  integer REFERENCES words_users(uid) ON DELETE CASCADE NOT NULL CHECK (player1 <> player2),
    player2  integer REFERENCES words_users(uid) ON DELETE CASCADE
);

CREATE TABLE words_chat (
        cid     BIGSERIAL PRIMARY KEY,
        created timestamptz NOT NULL,
        gid     integer NOT NULL REFERENCES words_games ON DELETE CASCADE,
        uid     integer NOT NULL REFERENCES words_users ON DELETE CASCADE,
        msg     text    NOT NULL
);

-- create 2 users: one is ok, while the other is muted (punished)
INSERT INTO words_users (uid, muted) VALUES (1, false), (2, true);
INSERT INTO words_social (sid, social, given, uid) VALUES ('abc', 100, 'Nice user', 1), ('def', 200, 'Bad user', 2);

-- put these 2 users into a game number 10
INSERT INTO words_games (gid, player1, player2) VALUES (10, 1, 2);

-- start chatting
INSERT INTO words_chat (gid, uid, created, msg) VALUES
(10, 1, CURRENT_TIMESTAMP + INTERVAL '1 min', 'Hi how are you doing?'),
(10, 1, CURRENT_TIMESTAMP + INTERVAL '2 min', 'I am a nice user'),
(10, 2, CURRENT_TIMESTAMP + INTERVAL '3 min', 'F*** ***!!'),
(10, 2, CURRENT_TIMESTAMP + INTERVAL '4 min', 'I am a bad user'),
(10, 1, CURRENT_TIMESTAMP + INTERVAL '5 min','Are you there??');

SELECT * FROM words_chat;

CREATE OR REPLACE FUNCTION words_get_chat(
                in_gid    integer,
                in_social integer,
                in_sid    text
        ) RETURNS TABLE (
                out_mine  integer,
                out_msg   text
        ) AS
$func$
        -- TODO display messages by muted users only to themselves
        SELECT
                CASE WHEN c.uid = s.uid THEN 1 ELSE 0 END,
                c.msg
        FROM    words_chat c 
        JOIN    words_games g USING (gid) 
        JOIN    words_social s ON s.uid IN (g.player1, g.player2)
        WHERE   c.gid    = in_gid
        AND     s.social = in_social
        AND     s.sid    = in_sid
        ORDER BY c.CREATED ASC;

$func$ LANGUAGE sql;

SELECT words_get_chat(10, 100, 'abc') AS nice_user;

SELECT words_get_chat(10, 200, 'def') AS muted_user;

2 rows affected

2 rows affected

1 rows affected

5 rows affected

cid	created	gid	uid	msg
1	2022-05-04 08:45:47.453606+01	10	1	Hi how are you doing?
2	2022-05-04 08:46:47.453606+01	10	1	I am a nice user
3	2022-05-04 08:47:47.453606+01	10	2	F* *!!
4	2022-05-04 08:48:47.453606+01	10	2	I am a bad user
5	2022-05-04 08:49:47.453606+01	10	1	Are you there??

nice_user
(1,"Hi how are you doing?")
(1,"I am a nice user")
(0,"F* *!!")
(0,"I am a bad user")
(1,"Are you there??")

muted_user
(0,"Hi how are you doing?")
(0,"I am a nice user")
(1,"F* *!!")
(1,"I am a bad user")
(0,"Are you there??")