Cache manifest json files (#104)

* Add cache code

* Fix typo and add cache option to documentation

* Match logging style

* Add return

* Follow ESLint style guide

* Support older Node Versions

README.md

@@ -59,10 +59,11 @@ launcher.on('data', (e) => console.log(e));
 
 | Parameter                | Type     | Description                                                                               | Required |
 |--------------------------|----------|-------------------------------------------------------------------------------------------|----------|
-| `options.clientPackage`  | String   | Path or URL to a zip file, which will be extracted to the root directory. (Not recommended for produnction use)| False    |
+| `options.clientPackage`  | String   | Path or URL to a zip file, which will be extracted to the root directory. (Not recommended for production use)| False    |
 | `options.removePackage`  | Boolean  | Option to remove the client package zip file after its finished extracting.               | False    |
 | `options.installer`      | String   | Path to installer being executed.                                                         | False    |
 | `options.root`           | String   | Path where you want the launcher to work in.  like `C:/Users/user/AppData/Roaming/.mc`,   | True     |
+| `options.cache`           | String   | Path where launcher files will be cached in.  like `C:/Users/user/AppData/Roaming/.mc/cache`,   | False     |
 | `options.os`             | String   | windows, osx or linux. MCLC will auto determine the OS if this field isn't provided.      | False    |
 | `options.customLaunchArgs`| Array   | Array of custom Minecraft arguments you want to add.                                      | False    |
 | `options.customArgs`     | Array    | Array of custom Java arguments you want to add.                                           | False    |

components/handler.js

@@ -112,18 +112,44 @@ class Handler {
       }
 
       const manifest = `${this.options.overrides.url.meta}/mc/game/version_manifest.json`
+      const cache = this.options.cache ? `${this.options.cache}/json` : `${this.options.root}/cache/json`
       request.get(manifest, (error, response, body) => {
-        if (error) return resolve(error)
+        if (error && error.code !== 'ENOTFOUND') return resolve(error)
+        if (!error) {
+          if (!fs.existsSync(cache)) {
+            fs.mkdirSync(cache, { recursive: true })
+            this.client.emit('debug', '[MCLC]: Cache directory created.')
+          }
+          fs.writeFile(path.join(`${cache}/version_manifest.json`), body, (err) => {
+            if (err) return resolve(err)
+            this.client.emit('debug', '[MCLC]: Cached version_manifest.json')
+          })
+        }
 
-        const parsed = JSON.parse(body)
+        let parsed
+        if (error && (error.code === 'ENOTFOUND')) {
+          parsed = JSON.parse(fs.readFileSync(`${cache}/version_manifest.json`))
+        } else {
+          parsed = JSON.parse(body)
+        }
 
         for (const desiredVersion in parsed.versions) {
           if (parsed.versions[desiredVersion].id === this.options.version.number) {
             request.get(parsed.versions[desiredVersion].url, (error, response, body) => {
-              if (error) return resolve(error)
+              if (error && error.code !== 'ENOTFOUND') return resolve(error)
+              if (!error) {
+                fs.writeFile(path.join(`${cache}/${this.options.version.number}.json`), body, (err) => {
+                  if (err) return resolve(err)
+                  this.client.emit('debug', `[MCLC]: Cached ${this.options.version.number}.json`)
+                })
+              }
 
               this.client.emit('debug', '[MCLC]: Parsed version from version manifest')
-              this.version = JSON.parse(body)
+              if (error && (error.code === 'ENOTFOUND')) {
+                this.version = JSON.parse(fs.readFileSync(`${cache}/${this.options.version.number}.json`))
+              } else {
+                this.version = JSON.parse(body)
+              }
               return resolve(this.version)
             })
           }

index.d.ts

@@ -152,6 +152,10 @@ declare module "minecraft-launcher-core" {
     };
     overrides?: IOverrides;
     authorization: Promise<IUser>;
+    /**
+     * Path of json cache.
+     */
+    cache?: string;
   }