Integrate version resolver

* You can now download multiple packages at once.
* Improved UX.

.gitignore

@@ -1,4 +1,6 @@
+.jscratesrc.json
+.jscrates-cache
 bin
 node_modules
 tars
-.jscratesrc.json
+jscrates

README.md

@@ -43,16 +43,23 @@ docker run -e HOME=/tmp -v $HOME/.jscrates/docker:/tmp/.jscrates -it --rm jscrat
 
 ## Commands
 
-1. `jscrates download`
+1. `unload`
 
 #### Description
 
-Downloads the specified package from the official repository of JSCrates.
+Downloads the specified package(s) from official repository of JSCrates.
 
 #### Usage
 
 ```bash
-$ jscrates download <package-name> [version]
+jscrates unload <packages>
+```
+
+### Example
+
+```bash
+jscrates unload physics bodmas@1.0.0
+jscrates unload @jscrates/cli @jscrates/unload@1.0.0
 ```
 
 2. `publish`
@@ -66,7 +73,7 @@ Have a package that you want to share with the world? This command will help you
 This command requires you to set or open the terminal in your project directory.
 
 ```bash
-$ jscrates publish
+jscrates publish
 ```
 
 ---

actions/packages/unload.js

@@ -0,0 +1,126 @@
+// @ts-check
+
+import https from 'https'
+import { createWriteStream, createReadStream } from 'fs'
+import Spinner from 'mico-spinner'
+import tempDirectory from 'temp-dir'
+import chalk from 'chalk'
+import tar from 'tar'
+import { getPackages } from '../../lib/api/actions.js'
+import { logError } from '../../utils/loggers.js'
+import upsertDir from '../../utils/upsert-dir.js'
+
+// This is the directory on the OS's temp location where
+// crates will be cached to enable offline operations.
+const cacheDir = tempDirectory + '/.jscrates-cache'
+// Directory in the current project where packages will
+// be installed (unzipped). Consider this as `node_modules`
+// for JSCrates
+const installDir = './jscrates'
+
+// Generates directory path suffixed with the package name.
+const suffixPackageName = (baseDir, packageName) => baseDir + '/' + packageName
+
+// Used for storing packages in cache.
+const generateCacheDirPath = (packageName = '') =>
+  suffixPackageName(cacheDir, packageName)
+
+// Used for unzipping packages in the CWD.
+const generateCratesInstallDir = (packageName = '') =>
+  suffixPackageName(installDir, packageName)
+
+// Extracts tarball name from the provided URL.
+const getTarballName = (tarballURL) => {
+  return tarballURL.substring(tarballURL.lastIndexOf('/') + 1)
+}
+
+/**
+ * Action to download packages from repository.
+ *
+ * TODO: Implement logic to check packages in cache before
+ * requesting the API.
+ *
+ * @param {string[]} packages
+ */
+async function unloadPackages(packages, ...args) {
+  // Since we are accepting variadic arguments, other arguments can only
+  // be accessing by spreading them.
+  const store = args[1].__store
+  const spinner = Spinner(`Downloading packages`)
+
+  try {
+    if (!store?.isOnline) {
+      return logError('Internet connection is required to download packages.')
+    }
+
+    spinner.start()
+
+    const response = await getPackages(packages)
+
+    // `data` contains all the resolved packages metadata.
+    // 1. Download the tarball to cache directory.
+    // 2. Read the cached tarball & install in CWD.
+    response?.data?.map((res) => {
+      const timerLabel = chalk.green(`Installed \`${res.name}\` in`)
+      console.time(timerLabel)
+
+      const tarballFileName = getTarballName(res?.dist?.tarball)
+      const cacheLocation = upsertDir(generateCacheDirPath(res?.name))
+      const installLocation = upsertDir(generateCratesInstallDir(res?.name))
+
+      // Create a write file stream to download the tar file
+      const file = createWriteStream(`${cacheLocation}/${tarballFileName}`)
+
+      // Initiate the HTTP request to download package archive
+      // (.tgz) files from the cloud repository
+      https.get(res?.dist?.tarball, function (response) {
+        response
+          .on('error', function () {
+            throw 'Something went wrong downloading the package.'
+          })
+          .on('data', function (data) {
+            file.write(data)
+          })
+          .on('end', function () {
+            file.end()
+            createReadStream(`${cacheLocation}/${tarballFileName}`).pipe(
+              tar.x({ cwd: installLocation })
+            )
+          })
+      })
+
+      console.timeEnd(timerLabel)
+    })
+
+    console.log('\n')
+
+    // When only a few packages are resolved, the errors array
+    // contains list of packages that were not resolved.
+    // We shall display these for better UX.
+    console.group(
+      chalk.yellow('The following errors occured during this operation:')
+    )
+
+    if (response?.errors?.length) {
+      logError(response?.errors?.join('\n'))
+    }
+
+    console.groupEnd()
+
+    console.log('\n')
+
+    spinner.succeed()
+  } catch (error) {
+    spinner.fail()
+
+    // When all the requested packages could not be resolved
+    // API responds with status 404 and list of errors.
+    if (Array.isArray(error)) {
+      return logError(error.join('\n'))
+    }
+
+    return logError(error)
+  }
+}
+
+export default unloadPackages

jscrates.js

@@ -1,19 +1,17 @@
-// @ts-check
+#!/usr/bin/env node
 
-import { readFile } from 'fs/promises'
 import { Command } from 'commander'
 import Configstore from 'configstore'
 import checkOnlineStatus from 'is-online'
 
 import { CONFIG_FILE } from './lib/constants.js'
-import downloadPackage from './actions/download.js'
+import unloadPackages from './actions/packages/unload.js'
 import publishPackage from './actions/publish.js'
 import login from './actions/auth/login.js'
 import register from './actions/auth/register.js'
 import logout from './actions/auth/logout.js'
 
 async function jscratesApp() {
-  const packageJSON = JSON.parse(await readFile('./package.json', 'utf-8'))
   const isOnline = await checkOnlineStatus()
   const program = new Command()
   const configStore = new Configstore(CONFIG_FILE, {
@@ -27,7 +25,8 @@ async function jscratesApp() {
   program
     .name('jscrates')
     .description(`Welcome to JSCrates 📦, yet another package manager for Node`)
-    .version(packageJSON.version, '-v, --version', 'display current version')
+    // TODO: Find a way to read version build time.
+    .version('0.0.0-alpha', '-v, --version', 'display current version')
     .hook('preAction', (_, actionCommand) => {
       actionCommand['__store'] = appState
     })
@@ -48,11 +47,17 @@ async function jscratesApp() {
     .action(logout(configStore))
 
   program
-    .command('download')
-    .description(`Download a package from official JSCrates registry`)
-    .argument('<package name>', 'package to download')
-    .argument('[version]', 'version of the package to download')
-    .action(downloadPackage)
+    .command('unload')
+    .description('🔽 Download package(s) from the JSCrates registry')
+    .argument('<packages...>', 'List of packages delimited by a space')
+    .action(unloadPackages)
+    .addHelpText(
+      'after',
+      '\nExamples:\n jscrates unload bodmas' +
+        '\n jscrates unload physics-formulae@1.0.0' +
+        '\n jscrates unload binary-search merge-sort bodmas@1.0.0'
+    )
+    .aliases(['u'])
 
   program
     .command('publish')

lib/api/actions.js

@@ -7,6 +7,14 @@ const apiErrorHandler = (error) => {
   }
 }
 
+const apiAction = async (bodyFn, errorHandlerFn = undefined) => {
+  try {
+    return await bodyFn()
+  } catch (error) {
+    return errorHandlerFn ? errorHandlerFn(error) : apiErrorHandler(error)
+  }
+}
+
 export const registerUser = async ({ email, password }) => {
   try {
     const { data: apiResponse } = await api.post('/auth/register', {
@@ -31,3 +39,14 @@ export const loginUser = async ({ email, password }) => {
     return apiErrorHandler(error)
   }
 }
+
+export const getPackages = async (packages) => {
+  return await apiAction(
+    async () => {
+      return (await api.put('/pkg', { packages })).data
+    },
+    (error) => {
+      throw error?.response?.data?.errors
+    }
+  )
+}