USE dating_app;

-- Add the unified login field without deleting legacy data.
SET @column_exists = (
    SELECT COUNT(*)
    FROM information_schema.columns
    WHERE table_schema = DATABASE()
      AND table_name = 'users'
      AND column_name = 'email_or_phone'
);
SET @statement = IF(
    @column_exists = 0,
    'ALTER TABLE users ADD COLUMN email_or_phone VARCHAR(320) NULL AFTER id',
    'SELECT 1'
);
PREPARE migration_statement FROM @statement;
EXECUTE migration_statement;
DEALLOCATE PREPARE migration_statement;

-- Copy existing accounts into the unified field. Email is normalized to lowercase.
UPDATE users
SET email_or_phone = CASE
    WHEN email IS NOT NULL THEN LOWER(TRIM(email))
    ELSE TRIM(phone)
END
WHERE email_or_phone IS NULL;

SET @index_exists = (
    SELECT COUNT(*)
    FROM information_schema.statistics
    WHERE table_schema = DATABASE()
      AND table_name = 'users'
      AND column_name = 'email_or_phone'
      AND non_unique = 0
);
SET @statement = IF(
    @index_exists = 0,
    'CREATE UNIQUE INDEX uq_users_email_or_phone ON users (email_or_phone)',
    'SELECT 1'
);
PREPARE migration_statement FROM @statement;
EXECUTE migration_statement;
DEALLOCATE PREPARE migration_statement;

-- MVP has no OTP step, so previously pending accounts become usable immediately.
UPDATE users SET status = 'active' WHERE status = 'pending';
ALTER TABLE users MODIFY COLUMN status VARCHAR(20) NOT NULL DEFAULT 'active';

-- Older schemas may require these legacy columns on INSERT. Keep them compatible
-- while the application stops using them.
SET @column_exists = (
    SELECT COUNT(*) FROM information_schema.columns
    WHERE table_schema = DATABASE() AND table_name = 'users' AND column_name = 'email_verified'
);
SET @statement = IF(
    @column_exists > 0,
    'ALTER TABLE users MODIFY COLUMN email_verified BOOLEAN NOT NULL DEFAULT FALSE',
    'SELECT 1'
);
PREPARE migration_statement FROM @statement;
EXECUTE migration_statement;
DEALLOCATE PREPARE migration_statement;

SET @column_exists = (
    SELECT COUNT(*) FROM information_schema.columns
    WHERE table_schema = DATABASE() AND table_name = 'users' AND column_name = 'phone_verified'
);
SET @statement = IF(
    @column_exists > 0,
    'ALTER TABLE users MODIFY COLUMN phone_verified BOOLEAN NOT NULL DEFAULT FALSE',
    'SELECT 1'
);
PREPARE migration_statement FROM @statement;
EXECUTE migration_statement;
DEALLOCATE PREPARE migration_statement;

-- Legacy email, phone, verification columns and verification_codes are intentionally
-- retained so this migration does not destroy historical data. New code no longer uses them.