feat: add Kindle Unlimited会员限时免费读书单 (#6031)

Co-authored-by: Henry Wang <hi@henry.wang>

docs/reading.md

@@ -10,6 +10,18 @@ pageClass: routes
 
 <Route author="HenryQW" example="/allpoetry/newest" path="/allpoetry/:order?" :paramsDesc="['排序方式, `best` 或 `newest`, 缺省 `best`']"/>
 
+## Kindle Unlimited
+
+### 会员限时免费读书单
+
+<Route author="nczitzk" example="/amazon/ku/this" path="/amazon/ku/:type?" :paramsDesc="['书单类型，见下表']">
+
+| 本月书单 | 好评返场 | 次月预告 |
+| -------- | -------- | -------- |
+| this     | back     | next     |
+
+</Route>
+
 ## Mobilism
 
 ### eBook Releases

lib/router.js

@@ -3384,6 +3384,9 @@ router.get('/dev.to/top/:period', require('./routes/dev.to/top'));
 router.get('/gameres/hot', require('./routes/gameres/hot'));
 router.get('/gameres/list/:id', require('./routes/gameres/list'));
 
+// Amazon
+router.get('/amazon/ku/:type?', require('./routes/amazon/ku'));
+
 // Citavi 中文网站论坛
 router.get('/citavi/:caty?', require('./routes/citavi/index'));
 

lib/routes/amazon/ku.js

@@ -0,0 +1,58 @@
+const got = require('@/utils/got');
+const cheerio = require('cheerio');
+
+const config = {
+    this: '2037295071',
+    back: '2330861071',
+    next: '2037296071',
+};
+
+module.exports = async (ctx) => {
+    const type = ctx.params.type || 'this';
+
+    const node = config[type];
+    if (!node) {
+        throw Error('Bad type. See <a href="https://docs.rsshub.app/reading.html#kindle-unlimited-hui-yuan-xian-shi-mian-fei-du-shu-dan">docs</a>');
+    }
+
+    const rootUrl = `https://www.amazon.cn/b?node=${node}`;
+    const response = await got({
+        method: 'get',
+        url: rootUrl,
+    });
+
+    const $ = cheerio.load(response.data);
+    const list = $('.s-access-detail-page')
+        .map((_, item) => {
+            item = $(item);
+            return {
+                link: item.attr('href'),
+                title: item.attr('title'),
+            };
+        })
+        .get();
+
+    const items = await Promise.all(
+        list.map(
+            async (item) =>
+                await ctx.cache.tryGet(item.link, async () => {
+                    const detailResponse = await got({
+                        method: 'get',
+                        url: item.link,
+                    });
+                    const content = cheerio.load(detailResponse.data);
+
+                    item.author = content('span.author').text();
+                    item.description = content('#ebooks-img-canvas').html() + content('#detailBullets_feature_div').html();
+
+                    return item;
+                })
+        )
+    );
+
+    ctx.state.data = {
+        title: `KU会员限时免费读 - ${$('title').text().split('-')[1]}`,
+        link: rootUrl,
+        item: items,
+    };
+};