'use strict';

/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('user_bookmarks', {
      id: {
        type: Sequelize.CHAR(36),
        primaryKey: true,
        allowNull: false,
        comment: 'UUID primary key'
      },
      user_id: {
        type: Sequelize.CHAR(36),
        allowNull: false,
        references: {
          model: 'users',
          key: 'id'
        },
        onUpdate: 'CASCADE',
        onDelete: 'CASCADE',
        comment: 'Foreign key to users table'
      },
      question_id: {
        type: Sequelize.CHAR(36),
        allowNull: false,
        references: {
          model: 'questions',
          key: 'id'
        },
        onUpdate: 'CASCADE',
        onDelete: 'CASCADE',
        comment: 'Foreign key to questions table'
      },
      notes: {
        type: Sequelize.TEXT,
        allowNull: true,
        comment: 'Optional user notes about the bookmarked question'
      },
      created_at: {
        type: Sequelize.DATE,
        allowNull: false,
        defaultValue: Sequelize.literal('CURRENT_TIMESTAMP'),
        comment: 'When the bookmark was created'
      },
      updated_at: {
        type: Sequelize.DATE,
        allowNull: false,
        defaultValue: Sequelize.literal('CURRENT_TIMESTAMP'),
        comment: 'Record last update timestamp'
      }
    }, {
      charset: 'utf8mb4',
      collate: 'utf8mb4_unicode_ci',
      comment: 'Junction table for users bookmarking questions'
    });

    // Add indexes
    await queryInterface.addIndex('user_bookmarks', ['user_id'], {
      name: 'idx_user_bookmarks_user_id'
    });

    await queryInterface.addIndex('user_bookmarks', ['question_id'], {
      name: 'idx_user_bookmarks_question_id'
    });

    await queryInterface.addIndex('user_bookmarks', ['created_at'], {
      name: 'idx_user_bookmarks_created_at'
    });

    // Unique composite index to prevent duplicate bookmarks
    await queryInterface.addIndex('user_bookmarks', ['user_id', 'question_id'], {
      name: 'idx_user_bookmarks_user_question',
      unique: true
    });

    console.log('✅ User bookmarks table created with 5 fields and 4 indexes');
  },

  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('user_bookmarks');
    console.log('✅ User bookmarks table dropped');
  }
};