feat: add algocasts.io 视频更新 (#2210)

* feat: add algocasts.io 视频更新

* fix: 修复 AlgoCasts 缓存问题

* fix: AlgoCasts 默认输出全文

* feat: 补上 AlgoCasts 不抓取列表代码中忘记的返回

* fix: 删去 AlgoCasts 中多余的缓存代码

docs/programming.md

@@ -4,6 +4,14 @@ pageClass: routes
 
 # 编程
 
+## AlgoCasts
+
+### 视频更新
+
+<Route author="ImSingee" example="/algocasts" path="/algocasts"></Route>
+
+> AlgoCasts 需要付费订阅, RSS 仅做更新提醒, 不含付费内容.
+
 ## Dockone
 
 ### 周报

lib/router.js

@@ -1345,6 +1345,9 @@ router.get('/steamgifts/discussions/:category?', require('./routes/steamgifts/di
 // Steamgifts
 router.get('/zzz', require('./routes/zzz/index'));
 
+// AlgoCasts
+router.get('/algocasts', require('./routes/algocasts/all'));
+
 // aqicn
 router.get('/aqicn/:city', require('./routes/aqicn/index'));
 

lib/routes/algocasts/all.js

@@ -0,0 +1,98 @@
+const axios = require('@/utils/axios');
+const cheerio = require('cheerio');
+
+const getCacheParsed = async (ctx, key) => {
+    const value = await ctx.cache.get(key);
+    if (value) {
+        return JSON.parse(value);
+    }
+};
+
+const generateResponse = async (ctx, items) => ({
+    // 源标题
+    title: 'AlgoCasts',
+    // 源链接
+    link: `https://www.algocasts.com`,
+    // 源说明
+    description: `AlgoCasts 旨在用心做好每一个算法讲解视频。每个视频包含两个部分：题目的剖析讲解以及编码，力求在讲解清楚到位的基础上，尽可能地保持视频精简短小，让大家可以在碎片时间里进行学习，并收获这些算法题背后的思想与乐趣。`,
+    item: await Promise.all(
+        items.map(async (item) => ({
+            // 文章标题
+            title: `${item.title} | AlgoCasts 视频更新`,
+            // 文章正文
+            description: item.description || '',
+            // 文章链接
+            link: item.link,
+        }))
+    ),
+});
+
+const makeFull = async (ctx, infos) => {
+    const limit = 10; // 仅获取最近十条信息（避免无意义请求）
+    infos = infos.slice(0, limit);
+
+    return await Promise.all(
+        infos.map(async (item) => {
+            const cacheKey = `episode-${item.episode}`;
+
+            // 尝试从缓存查找相关数据
+            let info = await getCacheParsed(ctx, cacheKey);
+            // console.log(info);
+            if (info) {
+                // 找到 -> 直接返回
+                return info;
+            } else {
+                // 未找到 -> 返回
+                info = item;
+            }
+            // 抓取详细信息
+            const response = await axios({
+                method: 'get',
+                url: info.link,
+            });
+            const $ = cheerio.load(response.data);
+
+            const badges = [];
+            $('.badge').each((index, badge) => {
+                badges.push($(badge).text());
+            });
+
+            info.description = `<h1>${info.title}</h1><div>${badges.join(' | ')}</div><div>${$('#my-content p').html()}</div>`;
+            ctx.cache.set(cacheKey, info);
+
+            // console.log(info);
+
+            return info;
+        })
+    );
+};
+
+module.exports = async (ctx) => {
+    const response = await axios({
+        method: 'get',
+        url: 'http://algocasts.io/episodes',
+    });
+
+    const $ = cheerio.load(response.data);
+    const infos = [];
+
+    $('tr')
+        .slice(1)
+        .each((i, e) => {
+            const id = parseInt(
+                $(e)
+                    .find('th')
+                    .text()
+            );
+            const titleLabel = $(e).find('td a');
+            const title = `${id}. ${titleLabel.text()}`;
+            const episode = titleLabel
+                .attr('href')
+                .trim()
+                .split('/')[2];
+            const link = `http://algocasts.io/episodes/${episode}`;
+
+            infos.push({ id, title, episode, link });
+        });
+    ctx.state.data = await generateResponse(ctx, await makeFull(ctx, infos));
+};