import { QueryInterface, DataTypes } from 'sequelize';

export async function up(queryInterface: QueryInterface): Promise<void> {
  // Create priority enum type
  await queryInterface.sequelize.query(`
    DO $$ BEGIN
      CREATE TYPE notification_priority_enum AS ENUM ('LOW', 'MEDIUM', 'HIGH', 'URGENT');
    EXCEPTION
      WHEN duplicate_object THEN null;
    END $$;
  `);

  // Create notifications table
  await queryInterface.createTable('notifications', {
    notification_id: {
      type: DataTypes.UUID,
      defaultValue: DataTypes.UUIDV4,
      primaryKey: true
    },
    user_id: {
      type: DataTypes.UUID,
      allowNull: false,
      references: {
        model: 'users',
        key: 'user_id'
      },
      onUpdate: 'CASCADE',
      onDelete: 'CASCADE'
    },
    request_id: {
      type: DataTypes.UUID,
      allowNull: true,
      references: {
        model: 'workflow_requests',
        key: 'request_id'
      },
      onUpdate: 'CASCADE',
      onDelete: 'SET NULL'
    },
    notification_type: {
      type: DataTypes.STRING(50),
      allowNull: false
    },
    title: {
      type: DataTypes.STRING(255),
      allowNull: false
    },
    message: {
      type: DataTypes.TEXT,
      allowNull: false
    },
    is_read: {
      type: DataTypes.BOOLEAN,
      defaultValue: false,
      allowNull: false
    },
    priority: {
      type: 'notification_priority_enum',
      defaultValue: 'MEDIUM',
      allowNull: false
    },
    action_url: {
      type: DataTypes.STRING(500),
      allowNull: true
    },
    action_required: {
      type: DataTypes.BOOLEAN,
      defaultValue: false,
      allowNull: false
    },
    metadata: {
      type: DataTypes.JSONB,
      allowNull: true,
      defaultValue: {}
    },
    sent_via: {
      type: DataTypes.ARRAY(DataTypes.STRING),
      defaultValue: [],
      allowNull: false
    },
    email_sent: {
      type: DataTypes.BOOLEAN,
      defaultValue: false,
      allowNull: false
    },
    sms_sent: {
      type: DataTypes.BOOLEAN,
      defaultValue: false,
      allowNull: false
    },
    push_sent: {
      type: DataTypes.BOOLEAN,
      defaultValue: false,
      allowNull: false
    },
    read_at: {
      type: DataTypes.DATE,
      allowNull: true
    },
    expires_at: {
      type: DataTypes.DATE,
      allowNull: true
    },
    created_at: {
      type: DataTypes.DATE,
      allowNull: false,
      defaultValue: DataTypes.NOW
    }
  });

  // Create indexes for better query performance
  await queryInterface.addIndex('notifications', ['user_id'], {
    name: 'idx_notifications_user_id'
  });

  await queryInterface.addIndex('notifications', ['user_id', 'is_read'], {
    name: 'idx_notifications_user_unread'
  });

  await queryInterface.addIndex('notifications', ['request_id'], {
    name: 'idx_notifications_request_id'
  });

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

  await queryInterface.addIndex('notifications', ['notification_type'], {
    name: 'idx_notifications_type'
  });
}

export async function down(queryInterface: QueryInterface): Promise<void> {
  await queryInterface.dropTable('notifications');
  await queryInterface.sequelize.query('DROP TYPE IF EXISTS notification_priority_enum;');
}