index.js

import http from 'http'
import fs from 'fs'
import path from 'path'
// import { createFile } from './modules/filesystem.js'
import { getProducts } from './modules/products.js'
import { getUsers } from './modules/users.js'

const server = http.createServer((req, res) => {
  if(req.url == '/') {
    return res.end('Welcome to our server')
  } else if(req.url == '/products') {
    const products = getProducts()
    const result = products.map(product => product.title)
    res.setHeader('Content-Type', 'application/json')
    return res.end(JSON.stringify(result))
  } else if(req.url == '/users') {
    const users = getUsers()
    res.setHeader('Content-Type', 'application/json')
    return res.end(JSON.stringify(users))
  }
  res.end('This is our default route')
})

server.listen(3000, () => {
  console.log('Server is running :)')
})

/* --------------------- */
/*
  # File System
    - Built-in Node.js Module ('fs' module)
    - Used to work with files and folders

    - Common Operations:
      - Read Files
      - Create Files
      - Append Files
      - Delete Files
      - Create Folders
      - Delete Folders

    - Synchronous vs Asynchronous File updates:
      - Synchronous: Blocks code execution until operation completes
        - Eg.: readFileSync, writeFileSync, etc.
      - Asynchronous: Does not block execution, uses callback function (Preferred)
        - Eg.: readFile, writeFile, etc.

    - Async Read File
      - Method: readFile()
      - Syntax:
        fs.readFile(fileName, charEncoding, (error, data) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log(data)
        })
        
    - Async Write File
      - Method: writeFile()
      - Syntax:
        fs.writeFile(fileName, data, (error) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log('File created')
        })

    - Async Append File
      - Method: appendFile()
      - Syntax:
        fs.appendFile(fileName, additionalData, (error) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log('Content added')
        })
    
    - Async Delete File
      - Method: unlink()
      - Syntax:
        fs.unlink(fileName, (error) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log('File deleted')
        })
      
    - Create Folder
      - Method: mkdir()
      - Syntax:
        fs.mkdir(folderName, (error) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log('Folder created')
        })

    - Delete Folder
      - Method: rmdir()
      - Syntax:
        fs.rmdir(folderName, (error) => {
          if(error) {
            console.log(error)
            return 
          }
          
          console.log('Folder deleted')
        })

   # Path module
    - Built-in Node.js module (path)
    - Used to work with file and folder paths
    - Why path module?
      - File paths are different across Operating Systems
        - Windows: C:\Users\ankit\Documents
        - Mac/Linux: /home/ankit/Documents
       - path module handles these differences automatically

    - In CommonJS module system, there are 2 reserved keywords:
      - __dirname: Absolute path to current directory
      - __filename: Absolute path to current file

    - Methods:
      - .extname(): Returns file extension
      - .join(): Join path segments together
*/   

/* --------------------- */

// READ FILE
// fs.readFile('content.txt', 'utf-8', (error, data) => {
//   if(error) {
//     console.log('Error while reading the file', error)
//     return 
//   }
  
//   console.log(data)
// })

// WRITE FILE
// const data = `It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English. Many desktop publishing packages and web page editors now use Lorem Ipsum as their default model text, and a search for 'lorem ipsum' will uncover many web sites still in their infancy. Various versions have evolved over the years, sometimes by accident, sometimes on purpose (injected humour and the like).`
// fs.writeFile('content-2.txt', data, (error) => {
//   if(error) {
//     console.log('Error while creating the file', error)
//     return 
//   }
  
//   console.log('File created')
// })

// APPEND FILE
// let content = `There are many variations of passages of Lorem Ipsum available, but the majority have suffered alteration in some form, by injected humour, or randomised words which don't look even slightly believable. If you are going to use a passage of Lorem Ipsum, you need to be sure there isn't anything embarrassing hidden in the middle of text. All the Lorem Ipsum generators on the Internet tend to repeat predefined chunks as necessary, making this the first true generator on the Internet. It uses a dictionary of over 200 Latin words, combined with a handful of model sentence structures, to generate Lorem Ipsum which looks reasonable. The generated Lorem Ipsum is therefore always free from repetition, injected humour, or non-characteristic words etc.`
// fs.appendFile('content.txt', '\n' + content , (error) => {
//   if(error) {
//     console.log('Error while appending the file', error)
//     return 
//   }
  
//   console.log('Content added')
// })

// DELETE FILE
// fs.unlink('content.txt', (error) => {
//   if(error) {
//     console.log('Error while deleting the file', error)
//     return 
//   }
  
//   console.log('File deleted')
// })

// CREATE FOLDER
// fs.mkdir('assets', (error) => {
//   if(error) {
//     console.log('Error while creating the folder', error)
//     return 
//   }
  
//   console.log('Folder created')
// })

// DELETE FOLDER
// fs.rmdir('assets', (error) => {
//   if(error) {
//     console.log('Error while deleting the folder', error)
//     return 
//   }
  
//   console.log('Folder deleted')
// })

// PATH MODULE
// console.log(path.extname('index.js'))
// console.log(path.extname('index.html'))
// console.log(path.extname('resume.pdf'))

// console.log(path.join('assets', 'css', 'index.css'))
// console.log(path.join('modules', 'users', 'login.js'))

/* ---------------------------- */
// Example 1
// let count = 1

// const server = http.createServer((req, res) => {
//   if(req.url == '/create-new-file') {
//     createFile(`new-file-${count++}.txt`, 'Some content')
//     return res.end('New file created')
//   }
//   res.end('Hi everyone!')
// })

// server.listen(3000, () => {
//   console.log('Server is up :)')
// })

// Example 2
// let count = 1

// const server = http.createServer((req, res) => {
//   if(req.url == '/favicon.ico') {
//     return
//   }

//   if(req.url == '/') {
//     return res.end('Hi everyone!')
//   }

//   const filePath = path.join('random-files', `${req.url.slice(1)}.txt`)
//   createFile(filePath, 'Some content')
//   res.end('A new file created')
// })

// server.listen(3000, () => {
//   console.log('Server is up :)')
// })

// Example 3
// import { createServer } from 'http'

// const server = createServer((req, res) => {
//   if(req.url == '/students') {
//     fs.readFile('students.json', 'utf-8', (error, data) => {
//       if(error) {
//         return console.log('Error reading file', error)
//       }

//       res.setHeader('Content-Type', 'application/json')
//       res.end(data)
//     })
//     return
//   }
//   res.end('Welcome to our server')
// })

// server.listen(3000, () => {
//   console.log('Server is running :)')
// })