const { DataTypes } = require('sequelize');

module.exports = (sequelize) => {
  const Friendship = sequelize.define('Friendship', {
    id: {
      type: DataTypes.INTEGER,
      autoIncrement: true,
      primaryKey: true
    }
    // Foreign keys 'user1Id' and 'user2Id' are added via associations
  }, {
    timestamps: false,
    tableName: 'friendships',
    hooks: {
        // Ensure user1Id is always less than user2Id to guarantee
        // a unique friendship pair regardless of creation order.
        beforeValidate: (friendship) => {
            if (friendship.user1Id > friendship.user2Id) {
                [friendship.user1Id, friendship.user2Id] = [friendship.user2Id, friendship.user1Id];
            }
        }
    }
  });
  return Friendship;
};