.

migrations/20250510184011_channel_message.sql

@@ -102,4 +102,62 @@ BEGIN
     RAISE NOTICE 'DM channel created with ID: %', new_channel_id;
     RETURN new_channel_id;
 END;
-$$;
+$$;
+
+CREATE OR REPLACE FUNCTION create_group_channel(
+    p_creator_id UUID, -- The user initiating the group creation (will be owner)
+    p_recipient_user_ids UUID[], -- Array of all user IDs for the group (must include creator)
+    p_group_channel_type INT2 -- The channel type identifier for groups (e.g., 1)
+)
+    RETURNS UUID
+    LANGUAGE plpgsql
+AS
+$$
+DECLARE
+    new_channel_id                         UUID;
+    existing_channel_id                    UUID;
+    final_channel_name                     VARCHAR;
+    unique_sorted_recipient_ids            UUID[];
+    num_recipients                         INT;
+    uid                                    UUID;
+    -- Threshold for detailed name vs. summary name
+    MAX_MEMBERS_FOR_DETAILED_NAME CONSTANT INT := 3;
+BEGIN
+    -- Validate and process recipient IDs
+    IF p_recipient_user_ids IS NULL OR array_length(p_recipient_user_ids, 1) IS NULL THEN
+        RAISE EXCEPTION 'Recipient user IDs array must be provided and not empty.';
+    END IF;
+
+    -- Get unique, sorted recipient IDs for consistent checking and to avoid duplicates.
+    SELECT array_agg(DISTINCT u ORDER BY u) INTO unique_sorted_recipient_ids FROM unnest(p_recipient_user_ids) u;
+    num_recipients := array_length(unique_sorted_recipient_ids, 1);
+
+    -- Validate minimum number of recipients for a group
+    IF num_recipients < 1 THEN -- Groups typically have at least 2 members
+        RAISE EXCEPTION 'Group channels (type %) must have at least 2 recipients. Found %.', p_group_channel_type, num_recipients;
+    END IF;
+
+    -- Create new group channel
+    INSERT INTO "channel" ("name", "type", "position", "owner_id", "server_id", "parent")
+    VALUES ('Group',
+            p_group_channel_type,
+            0, -- Default position
+            p_creator_id,
+            NULL, -- Not a server channel
+            NULL -- Not a nested server channel
+           )
+    RETURNING id INTO new_channel_id;
+
+    -- Add all recipients to the channel_recipient table
+    INSERT INTO "channel_recipient" ("channel_id", "user_id")
+    VALUES (new_channel_id, p_creator_id);
+
+    INSERT INTO "channel_recipient" ("channel_id", "user_id")
+    SELECT new_channel_id, r_id
+    FROM unnest(unique_sorted_recipient_ids) AS r_id;
+
+    RAISE NOTICE 'Group channel (type %) named "%" created with ID: % by owner % for recipients: %',
+        p_group_channel_type, final_channel_name, new_channel_id, p_creator_id, unique_sorted_recipient_ids;
+    RETURN new_channel_id;
+END;
+$$;