graphql schema file

todo.js

const { buildSchema } = require('graphql')

const DB = require('../core/my_db/DB')

const schema = buildSchema(`
  type Todo {
    id: ID!
    content: String!
    completed: Boolean!
  }

  type Query {
    allTodos: String
    allTodosPag(p: String): String
  }

  type Mutation {
    addTodo(content: String!): Todo
    toggleTodo(id: ID!): Boolean
    delTodo(id: ID!): Boolean
  }
`)

class Todo {
  constructor(id, content, completed) {
    this.id = id
    this.content = content
    this.completed = completed
  }
}

const root = {

  allTodos: () => {
    // 1 check the name an pass in the database
    return new Promise((resolve, reject) => {
      DB.pool.query(
        'SELECT * FROM `todos`',
        (err, res) => {
          if (err) reject(err)
          resolve(JSON.stringify(res))
        }
      )
    })
  },

  allTodosPag: ({ p }) => {
    return new Promise((resolve, reject) => {
      // number entries on the page
      const num = 3
      // current page
      console.log('p = ', p);
      p = Number(p)

      const cur_page = p || 1
      console.log('cur_page = ', cur_page);
      // get current number messages in the database
      DB.pool.query(
        'SELECT COUNT(*) FROM `todos`',
        (err, res) => {
          if (err) throw err
          // console.log('res = ', res[0]['COUNT(*)']);
          const posts = res[0]['COUNT(*)']
          console.log('posts = ', posts);
          const total = Math.floor(1 + (posts - 1) / num)
          console.log('total = ', total);
          // the beggining of messages for a current page
          let page = cur_page
          if (!page || page < 0) page = 1
          if(page > total) page = total

          // number of the starting output messages
          console.log('page = ', page);
          const start = page * num - num
          console.log('start = ', start, ' num = ', num);
          DB.pool.query(
            'SELECT * FROM `todos` LIMIT ?, ?',
            [start, num],
            (err, res) => {
              if (err) reject(err)

              let result = {}
              console.log('res = ', res);
              // make a navigation links
              result['items'] = res

              let pervpage = ''
              let nextpage = ''
              let page2left = ''
              let page1left = ''
              let page2right = ''
              let page1right = ''
              // check arrows back
              if (page != 1) pervpage = '<a href = "./page?page=1"><<</a><a href="./page?page=' + (page-1) + '"'
              // check arrows forward
              if (page != total) nextpage = ' <a href="./page/?page="' + (page + 1) + '>></a><a href=".page?page=' + total + '>>></a>'

              // find two the closest pages from both sides if they are
              if (page - 2 > 0) page2left = ' <a href=".page?page=' + (page - 2) + '">' + (page - 2) + '</a> |'
              if (page - 1 > 0) page1left = '<a href="./page?page=' + (page - 1) + '">' + (page -1) + '</a> |'
              if (page + 2 <= total) page2right = ' | <a href="./page?page=' + (page + 2) + '">' + (page + 2) + '</a>'
              if (page + 1 <= total) page1right = ' | <a href=".page?page=' + (page + 1) + '">' + (page + 1) + '</a>'

              // output the menu
              result['menu'] = pervpage + page2left + page1left + '<b>' + page + '</b>' + page1right + page2right + nextpage
              console.log('result[\'menu\'] = ', result['menu']);
              result['total'] = total
              result['page'] = page
              result = JSON.stringify(result)
              resolve(result)
            }
          )
        }
      )

      // return 'pagination'
    })
  },

  addTodo: ({ content }) => {
    return new Promise((resolve, reject) => {
      DB.pool.query(
        'INSERT INTO `todos` (content) VALUES (?)',
        [content],
        (err, res) => {
          if (err) reject(err)
          const obj = new Todo(res.insertId, content, false)
          resolve(obj)
        }
      )
    })
  },

  toggleTodo: ({ id }) => {
    return new Promise((resolve, reject) => {
      DB.pool.query(
        'SELECT completed FROM `todos` WHERE `id` = ?',
        [id],
        (err, res) => {
          if (err) reject(err)
          DB.pool.query(
            'UPDATE `todos` SET `completed` = ? WHERE `id` = ?',
            [!res[0].completed, id],
            (err, res) => {
              if (err) throw err
              resolve(true)
            }
          )

        }
      )

    })
  },

  delTodo: ({ id }) => {
    return new Promise((resolve, reject) => {
      DB.pool.query(
        'DELETE FROM `todos` WHERE `id` = ?',
        [id],
        (err, res) => {
          if (err) reject(err)
          resolve(true)
        }
      )
    })
  }
}

module.exports = { schema, root }