-- Переводим все текущие шаблоны сообщений в последовательности (по одному сообщению).
-- Старые строки message_templates оставляем как фолбэк для кода.
INSERT INTO bot.message_sequences (key, title, description)
SELECT t.key,
       coalesce(nullif(t.description, ''), t.key),
       t.description
FROM bot.message_templates AS t
WHERE NOT EXISTS (SELECT 1 FROM bot.message_sequences AS s WHERE s.key = t.key)
ON CONFLICT (key) DO NOTHING;

INSERT INTO bot.message_sequence_items (sequence_key, position, text, enabled)
SELECT t.key, 0, t.text, t.enabled
FROM bot.message_templates AS t
WHERE NOT EXISTS (
    SELECT 1
    FROM bot.message_sequence_items AS i
    WHERE i.sequence_key = t.key AND i.position = 0
)
ON CONFLICT (sequence_key, position) DO NOTHING;