• Comece gerando a migration para a tabela episodes através da sequelize-cli:

npx sequelize-cli migration:generate --name create-episodes-table

• Adicione o conteúdo da migration:

// src/database/migrations/XXXXXXXXXXXXXX-create-episodes-table.js

'use strict';

module.exports = {
  async up (queryInterface, Sequelize) {
    await queryInterface.createTable('episodes', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.DataTypes.INTEGER
      },
      name: {
        allowNull: false,
        type: Sequelize.DataTypes.STRING
      },
      synopsis: {
        allowNull: false,
        type: Sequelize.DataTypes.TEXT
      },
      order: {
        allowNull: false,
        type: Sequelize.DataTypes.INTEGER
      },
      video_url: {
        type: Sequelize.DataTypes.STRING
      },
      seconds_long: {
        type: Sequelize.DataTypes.INTEGER
      },
      course_id: {
        allowNull: false,
        type: Sequelize.DataTypes.INTEGER,
        references: { model: 'courses', key: 'id' },
        onUpdate: 'CASCADE',
        onDelete: 'RESTRICT'
      },
      created_at: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updated_at: {
        allowNull: false,
        type: Sequelize.DATE
      }
    })
  },

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

• Não se esqueça de executar a migration:

npx sequelize-cli db:migrate

• Crie o model Episode.ts e adicione o seu conteúdo:

// src/models/Episode.ts

import { sequelize } from '../database'
import { DataTypes, Model, Optional } from 'sequelize'

export interface Episode {
  id: number
  name: string
  synopsis: string
  order: number
  videoUrl: string
  secondsLong: number
  courseId: number
}

export interface EpisodeCreationAttributes
  extends Optional<Episode, 'id' | 'videoUrl' | 'secondsLong' > {}

export interface EpisodeInstance
  extends Model<Episode, EpisodeCreationAttributes>, Episode {}

export const Episode = sequelize.define<EpisodeInstance, Episode>('Episode', {
  id: {
    allowNull: false,
    autoIncrement: true,
    primaryKey: true,
    type: DataTypes.INTEGER
  },
  name: {
    allowNull: false,
    type: DataTypes.STRING
  },
  synopsis: {
    allowNull: false,
    type: DataTypes.TEXT
  },
  order: {
    allowNull: false,
    type: DataTypes.STRING
  },
  videoUrl: {
    type: DataTypes.STRING
  },
  secondsLong: {
    type: DataTypes.INTEGER
  },
  courseId: {
    allowNull: false,
    type: DataTypes.INTEGER,
    references: { model: 'courses', key: 'id' },
    onUpdate: 'CASCADE',
    onDelete: 'RESTRICT'
  }
})

• E agora no arquivo index.ts da pasta model inclua as associações de Episode e Course:

// src/models/index.ts

import { Category } from './Category'
import { Course } from './Course'
import { Episode } from './Episode'

Category.hasMany(Course)

Course.belongsTo(Category)
Course.hasMany(Episode)

Episode.belongsTo(Course)

export {
  Category,
  Course,
  Episode
}

• Na pasta resources crie o arquivo episode.ts para as opções do recurso episodes:

// src/adminjs/resources/episode.ts

import { ResourceOptions } from "adminjs";

export const episodeResourceOptions: ResourceOptions = {
  navigation: 'Catálogo',
  editProperties: ['name', 'synopsis', 'courseId', 'order', 'uploadVideo', 'secondsLong'  ],
  filterProperties: ['name', 'synopsis', 'courseId', 'secondsLong', 'createdAt', 'updatedAt'],
  listProperties: ['id', 'name', 'courseId', 'order', 'secondsLong'],
  showProperties: ['id', 'name', 'synopsis', 'courseId', 'order', 'videoUrl', 'secondsLong', 'createdAt', 'updatedAt']
}

• E no arquivo resources.ts inclua o recurso e suas opções:

// src/adminjs/resources.ts

import { ResourceWithOptions } from "adminjs";
import { Category, Course, Episode } from "../../models";
import { categoryResourceOptions } from "./category";
import { courseResourceOptions } from "./course";
import { episodeResourceOptions } from "./episode";

export const adminJsResources: ResourceWithOptions[] = [
  {
    resource: Course,
    options: courseResourceOptions
  },
  {
    resource: Episode,
    options: episodeResourceOptions
  },
  {
    resource: Category,
    options: categoryResourceOptions
  },
]

• Já é possível testar a aplicação cadastrando alguns episódios pelo painel administrativo. Não se preocupe com questões como o upload dos vídeos no momento, as implementares nas próximas aulas. Por enquanto tente cadastrar episódios com alguns valores fictícios.