-- Customer phone numbers are stored in one form, 62… without + (util.NormalizePhoneNumber),
-- and every number a customer types is rewritten to it before it is looked up. This
-- rewrites the numbers stored before, so 0812…, +62 812… and 812… become 62812….
--
-- Only one customer may have a number. When several stored numbers become the same one,
-- the customer that already has it keeps it, else a registered one (with a password),
-- else the oldest; the others are left as they are. A number that is not an Indonesian
-- mobile number is left as it is too. Neither can log in until it is fixed by hand:
--
--   SELECT id, name, phone_number FROM customers
--   WHERE phone_number IS NOT NULL AND phone_number !~ '^628[0-9]{7,11}$';

WITH stripped AS (
    SELECT id, phone_number, password_hash, created_at,
           regexp_replace(regexp_replace(phone_number, '[[:space:]().-]', '', 'g'), '^\+', '') AS p
    FROM customers
    WHERE phone_number IS NOT NULL
),
normalized AS (
    SELECT id, phone_number, password_hash, created_at,
           CASE
               WHEN p LIKE '620%' THEN '62' || substr(p, 4)
               WHEN p LIKE '0%' THEN '62' || substr(p, 2)
               WHEN p LIKE '8%' THEN '62' || p
               ELSE p
           END AS new_phone
    FROM stripped
),
ranked AS (
    SELECT id, new_phone,
           row_number() OVER (
               PARTITION BY new_phone
               ORDER BY phone_number = new_phone DESC, password_hash IS NOT NULL DESC, created_at, id
           ) AS rank
    FROM normalized
    WHERE new_phone ~ '^628[0-9]{7,11}$'
)
UPDATE customers c
SET phone_number = r.new_phone, updated_at = NOW()
FROM ranked r
WHERE c.id = r.id AND r.rank = 1 AND c.phone_number <> r.new_phone;

-- A registration started before this migration finishes with the number in its OTP
-- session, and a resent OTP is found by it.
UPDATE otp_sessions
SET phone_number = n.new_phone, updated_at = NOW()
FROM (
    SELECT id,
           CASE
               WHEN p LIKE '620%' THEN '62' || substr(p, 4)
               WHEN p LIKE '0%' THEN '62' || substr(p, 2)
               WHEN p LIKE '8%' THEN '62' || p
               ELSE p
           END AS new_phone
    FROM (
        SELECT id, regexp_replace(regexp_replace(phone_number, '[[:space:]().-]', '', 'g'), '^\+', '') AS p
        FROM otp_sessions
    ) stripped
) n
WHERE otp_sessions.id = n.id
  AND n.new_phone ~ '^628[0-9]{7,11}$'
  AND otp_sessions.phone_number <> n.new_phone;