'use strict';

module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('user_bans', {
      ban_id:      { type: Sequelize.BIGINT, primaryKey: true, autoIncrement: true },
      user_id:     { type: Sequelize.BIGINT, allowNull: false, references: { model: 'users', key: 'user_id' }, onDelete: 'CASCADE' },
      banned_by:   { type: Sequelize.BIGINT, allowNull: false, references: { model: 'users', key: 'user_id' } },
      reason:      { type: Sequelize.TEXT, allowNull: false },
      ban_type:    { type: Sequelize.STRING(20), allowNull: false },
      banned_at:   { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.NOW },
      expires_at:  { type: Sequelize.DATE, allowNull: true },
      is_lifted:   { type: Sequelize.BOOLEAN, allowNull: false, defaultValue: false },
      lifted_at:   { type: Sequelize.DATE, allowNull: true },
      lifted_by:   { type: Sequelize.BIGINT, allowNull: true, references: { model: 'users', key: 'user_id' } },
      lift_reason: { type: Sequelize.TEXT, allowNull: true },
      createdAt:   { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.NOW },
      updatedAt:   { type: Sequelize.DATE, allowNull: false, defaultValue: Sequelize.NOW },
    });

    await queryInterface.addConstraint('user_bans', {
      fields: ['ban_type'],
      type: 'check',
      name: 'check_ban_type',
      where: { ban_type: { [Sequelize.Op.in]: ['temporary', 'permanent'] } },
    });

    await queryInterface.addIndex('user_bans', ['user_id'], { name: 'idx_user_bans_user_id' });

    // Partial index — only rows relevant to the ban-expiry cron sweep.
    await queryInterface.sequelize.query(`
      CREATE INDEX idx_user_bans_expires_at
      ON user_bans (expires_at)
      WHERE is_lifted = false AND ban_type = 'temporary';
    `);
  },

  async down(queryInterface) {
    await queryInterface.dropTable('user_bans');
  },
};