USE lifanghe_education;

SET @schema_name = DATABASE();

SET @has_trial_booking_limit := (
  SELECT COUNT(1)
  FROM INFORMATION_SCHEMA.COLUMNS
  WHERE TABLE_SCHEMA = @schema_name
    AND TABLE_NAME = 'users'
    AND COLUMN_NAME = 'trial_booking_limit'
);
SET @add_trial_booking_limit_sql := IF(
  @has_trial_booking_limit = 0,
  'ALTER TABLE users ADD COLUMN trial_booking_limit INT NOT NULL DEFAULT 1 AFTER child_focus',
  'SELECT 1'
);
PREPARE add_trial_booking_limit_stmt FROM @add_trial_booking_limit_sql;
EXECUTE add_trial_booking_limit_stmt;
DEALLOCATE PREPARE add_trial_booking_limit_stmt;

SET @has_unique_user_index := (
  SELECT COUNT(1)
  FROM INFORMATION_SCHEMA.STATISTICS
  WHERE TABLE_SCHEMA = @schema_name
    AND TABLE_NAME = 'appointments'
    AND INDEX_NAME = 'uk_appointments_user'
);
SET @drop_unique_user_index_sql := IF(
  @has_unique_user_index > 0,
  'ALTER TABLE appointments DROP INDEX uk_appointments_user',
  'SELECT 1'
);
PREPARE drop_unique_user_index_stmt FROM @drop_unique_user_index_sql;
EXECUTE drop_unique_user_index_stmt;
DEALLOCATE PREPARE drop_unique_user_index_stmt;

SET @has_appointment_user_index := (
  SELECT COUNT(1)
  FROM INFORMATION_SCHEMA.STATISTICS
  WHERE TABLE_SCHEMA = @schema_name
    AND TABLE_NAME = 'appointments'
    AND INDEX_NAME = 'idx_appointments_user'
);
SET @add_appointment_user_index_sql := IF(
  @has_appointment_user_index = 0,
  'ALTER TABLE appointments ADD INDEX idx_appointments_user (user_id)',
  'SELECT 1'
);
PREPARE add_appointment_user_index_stmt FROM @add_appointment_user_index_sql;
EXECUTE add_appointment_user_index_stmt;
DEALLOCATE PREPARE add_appointment_user_index_stmt;
