fix: get supported languages before fetching codeTemplate (#618)

src/commands/list.ts

@@ -36,7 +36,7 @@ export async function listProblems(): Promise<IProblem[]> {
                 });
             }
         }
-        return problems.reverse();
+        return problems.sort((p1: IProblem, p2: IProblem) => +p1.id - +p2.id);
     } catch (error) {
         await promptForOpenOutputChannel("Failed to list problems. Please open the output channel for details.", DialogType.error);
         return [];

src/commands/show.ts

@@ -105,13 +105,24 @@ export async function showSolution(input: LeetCodeNode | vscode.Uri): Promise<vo
     }
 }
 
-async function fetchProblemLanguage(): Promise<string | undefined> {
+async function fetchProblemLanguage(node?: IProblem): Promise<string | undefined> {
+    let supportLangs: string[] | null = null;
+    if (node) {
+        const problemDescription: string = await leetCodeExecutor.getDescription(node.id);
+        const matchLang: RegExpMatchArray | null = problemDescription.match(/\n(Langs:[\w\s]+)\n/);
+        supportLangs = matchLang && matchLang[1]
+            ? matchLang[1].slice(6).split(/\s+/).filter(Boolean)
+            : null;
+    }
+    if (!supportLangs) {
+        supportLangs = languages.slice();
+    }
     const leetCodeConfig: vscode.WorkspaceConfiguration = vscode.workspace.getConfiguration("leetcode");
     let defaultLanguage: string | undefined = leetCodeConfig.get<string>("defaultLanguage");
-    if (defaultLanguage && languages.indexOf(defaultLanguage) < 0) {
+    if (defaultLanguage && supportLangs.indexOf(defaultLanguage) < 0) {
         defaultLanguage = undefined;
     }
-    const language: string | undefined = defaultLanguage || await vscode.window.showQuickPick(languages, { placeHolder: "Select the language you want to use", ignoreFocusOut: true });
+    const language: string | undefined = defaultLanguage || await vscode.window.showQuickPick(supportLangs, { placeHolder: "Select the language you want to use", ignoreFocusOut: true });
     // fire-and-forget default language query
     (async (): Promise<void> => {
         if (language && !defaultLanguage && leetCodeConfig.get<boolean>("hint.setDefaultLanguage")) {
@@ -133,7 +144,7 @@ async function fetchProblemLanguage(): Promise<string | undefined> {
 
 async function showProblemInternal(node: IProblem): Promise<void> {
     try {
-        const language: string | undefined = await fetchProblemLanguage();
+        const language: string | undefined = await fetchProblemLanguage(node);
         if (!language) {
             return;
         }

src/leetCodeExecutor.ts

@@ -99,8 +99,8 @@ class LeetCodeExecutor implements Disposable {
         const templateType: string = showDescriptionInComment ? "-cx" : "-c";
 
         if (!await fse.pathExists(filePath)) {
-            await fse.createFile(filePath);
             const codeTemplate: string = await this.executeCommandWithProgressEx("Fetching problem data...", this.nodeExecutable, [await this.getLeetCodeBinaryPath(), "show", problemNode.id, templateType, "-l", language]);
+            await fse.createFile(filePath);
             await fse.writeFile(filePath, codeTemplate);
         }
     }