From 50338ec07b247857598862dbc25c51fb0e973be3 Mon Sep 17 00:00:00 2001
From: Artemy <artegoser@gmail.com>
Date: Fri, 18 Aug 2023 20:50:26 +0300
Subject: [PATCH] feat: stackoverflow parser for questions page

---
 src/handlers/main.ts                          |  3 ++
 src/handlers/stackoverflow/main.ts            | 31 +++++++++++++++++++
 src/handlers/stackoverflow/post-parser.ts     |  9 ++++++
 src/handlers/stackoverflow/questions-posts.ts | 26 ++++++++++++++++
 static/get.css                                | 10 ++++--
 templates/get.ejs                             |  1 +
 6 files changed, 77 insertions(+), 3 deletions(-)
 create mode 100644 src/handlers/stackoverflow/main.ts
 create mode 100644 src/handlers/stackoverflow/post-parser.ts
 create mode 100644 src/handlers/stackoverflow/questions-posts.ts

diff --git a/src/handlers/main.ts b/src/handlers/main.ts
index 6769283..0fbb172 100644
--- a/src/handlers/main.ts
+++ b/src/handlers/main.ts
@@ -15,6 +15,7 @@ import {
   LocalResourceError,
   NotHtmlMimetypeError,
 } from "../errors/main";
+import stackoverflow from "./stackoverflow/main";
 
 export default async function handlePage(
   url: string, // remote URL
@@ -60,11 +61,13 @@ type EngineFunction = (window: DOMWindow) => Promise<IHandlerOutput>;
 export const engines: Engines = {
   readability,
   google,
+  stackoverflow,
 };
 
 export const engineList: string[] = Object.keys(engines);
 
 const fallback: Engines = {
+  "stackoverflow.com": engines.stackoverflow,
   "www.google.com": engines.google,
   "*": engines.readability,
 };
diff --git a/src/handlers/stackoverflow/main.ts b/src/handlers/stackoverflow/main.ts
new file mode 100644
index 0000000..4ed4878
--- /dev/null
+++ b/src/handlers/stackoverflow/main.ts
@@ -0,0 +1,31 @@
+import { IHandlerOutput } from "../handler.interface";
+import { DOMWindow } from "jsdom";
+import { EngineParseError } from "../../errors/main";
+import qPostsHandler from "./questions-posts";
+
+export default async function stackoverflow(
+  window: DOMWindow
+): Promise<IHandlerOutput> {
+  const url = new URL(window.location.href);
+
+  const path = url.pathname.split("/").filter((p) => p !== "");
+
+  let result: IHandlerOutput = {
+    content: "",
+    textContent: "",
+    title: "",
+    lang: "",
+  };
+
+  if (path[0] === "questions") {
+    if (path.length === 3) {
+      result = await qPostsHandler(window);
+    } else if (path.length === 1) {
+      result.content = "questions";
+    } else {
+      throw new EngineParseError("Invalid URL [stackoverflow]");
+    }
+  }
+
+  return result;
+}
diff --git a/src/handlers/stackoverflow/post-parser.ts b/src/handlers/stackoverflow/post-parser.ts
new file mode 100644
index 0000000..e5e6999
--- /dev/null
+++ b/src/handlers/stackoverflow/post-parser.ts
@@ -0,0 +1,9 @@
+export default function postParser(el: Element | null): string {
+  if (!el) {
+    return "";
+  }
+  const body = el.querySelector(".js-post-body")?.innerHTML || "";
+  const voteCount = el.querySelector(".js-vote-count")?.textContent || "";
+
+  return `<h3>${voteCount} votes</h3>${body}`;
+}
diff --git a/src/handlers/stackoverflow/questions-posts.ts b/src/handlers/stackoverflow/questions-posts.ts
new file mode 100644
index 0000000..3d011f8
--- /dev/null
+++ b/src/handlers/stackoverflow/questions-posts.ts
@@ -0,0 +1,26 @@
+import { DOMWindow } from "jsdom";
+import { IHandlerOutput } from "../handler.interface";
+import postParser from "./post-parser";
+
+export default async function qPostsHandler(
+  window: DOMWindow
+): Promise<IHandlerOutput> {
+  const questionEl = window.document.getElementById("question");
+  const question = postParser(questionEl);
+
+  const title =
+    window.document.querySelector(".question-hyperlink")?.innerHTML || "";
+
+  const allAnswers = [...window.document.querySelectorAll(".answer")];
+
+  const answers = allAnswers.map((a) => postParser(a));
+
+  return {
+    content: `${question}<hr>${answers.length} answers <hr>${answers.join(
+      "<hr>"
+    )}`,
+    textContent: "question",
+    title,
+    lang: "en",
+  };
+}
diff --git a/static/get.css b/static/get.css
index 0a03379..8966534 100644
--- a/static/get.css
+++ b/static/get.css
@@ -6,7 +6,8 @@
   font-size: 0.9rem;
 }
 .title {
-  font-weight: 500;
+  font-weight: 1000;
+  margin: 1rem;
 }
 
 a {
@@ -28,11 +29,14 @@ table {
   overflow-x: auto;
 }
 
-img, picture, video {
+img,
+picture,
+video {
   max-width: 100%;
   height: auto;
 }
 
-frame, iframe {
+frame,
+iframe {
   max-width: 100%;
 }
diff --git a/templates/get.ejs b/templates/get.ejs
index 41490ef..20cbf27 100644
--- a/templates/get.ejs
+++ b/templates/get.ejs
@@ -18,6 +18,7 @@
       <div class="title">
         <%= parsed.title %>
       </div>
+      <hr>
       <%- parsed.content %>
     </main>
   </body>