添加掘金标签支持 (#506)

兼容旧的分类获取方式，改用tags标签获取更多掘金主题内容。
ps. 首页分类数据与标签数据一致

README.md

@@ -71,6 +71,7 @@ RSSHub 是一个轻量、易于扩展的 RSS 生成器，可以给任何奇奇
     -   电台节目
 -   掘金
     -   分类
+    -   标签
 -   简书
     -   首页
     -   7 日热门

docs/README.md

@@ -665,6 +665,14 @@ rid: 排行榜分区 id，默认 0
 | -------- | ------- | --- | ------- | ------ | ------- | -------- | ------- | -------- |
 | frontend | android | ios | backend | design | product | freebie  | article | ai       |
 
+### 标签
+
+举例: [https://rsshub.app/juejin/tag/架构](https://juejin.im/tag/架构)
+
+路由: `/juejin/tag/:tag`
+
+参数: tag，标签名，可在标签 URL 中找到
+
 ## 简书
 
 ### 首页

router.js

@@ -126,6 +126,7 @@ router.get('/ncm/djradio/:id', require('./routes/ncm/djradio'));
 
 // 掘金
 router.get('/juejin/category/:category', require('./routes/juejin/category'));
+router.get('/juejin/tag/:tag', require('./routes/juejin/tag'));
 
 // 自如
 router.get('/ziroom/room/:city/:iswhole/:room/:keyword', require('./routes/ziroom/room'));

routes/juejin/tag.js

@@ -0,0 +1,74 @@
+const axios = require('../../utils/axios');
+const cheerio = require('cheerio');
+
+module.exports = async (ctx) => {
+    const tag = ctx.params.tag;
+
+    const idResponse = await axios({
+        method: 'get',
+        url: 'https://gold-tag-ms.juejin.im/v1/tags',
+        headers: {
+            Referer: `https://juejin.im/tag/${encodeURI(tag)}`,
+            'X-Juejin-Client': '',
+            'X-Juejin-Src': 'web',
+            'X-Juejin-Token': '',
+            'X-Juejin-Uid': '',
+        },
+    });
+
+    const cat = idResponse.data.d.tags.filter((item) => item.title === tag)[0];
+    const id = cat.id;
+
+    const response = await axios({
+        method: 'get',
+        url: `https://timeline-merger-ms.juejin.im/v1/get_tag_entry?src=web&tagId=${id}&page=0&pageSize=10&sort=rankIndex`,
+        headers: {
+            Referer: `https://juejin.im/tag/${encodeURI(tag)}`,
+        },
+    });
+
+    let originalData = [];
+    if (response.data.d && response.data.d.entrylist) {
+        originalData = response.data.d && response.data.d.entrylist.slice(0, 10);
+    }
+    const resultItems = await Promise.all(
+        originalData.map(async (item) => {
+            const resultItem = {
+                title: item.title,
+                description: `${(item.content || item.summaryInfo || '无描述').replace(/[\x00-\x08\x0b-\x0c\x0e-\x1f\x7f]/g, '')}`,
+                pubDate: new Date(item.createdAt).toUTCString(),
+                link: item.originalUrl,
+            };
+            if (item.type === 'post') {
+                const key = 'juejin' + resultItem.link;
+                const value = await ctx.cache.get(key);
+
+                if (value) {
+                    resultItem.description = value;
+                } else {
+                    const detail = await axios({
+                        method: 'get',
+                        url: item.originalUrl,
+                        headers: {
+                            Referer: item.originalUrl,
+                        },
+                    });
+                    const content = cheerio.load(detail.data);
+                    resultItem.description = content('.article-content')
+                        .html()
+                        .replace(/[\x00-\x08\x0b-\x0c\x0e-\x1f\x7f]/g, '')
+                        .replace(/(<img.*?)(data-src)(.*?>)/g, '$1src$3');
+                    ctx.cache.set(key, resultItem.description, 24 * 60 * 60);
+                }
+            }
+            return Promise.resolve(resultItem);
+        })
+    );
+
+    ctx.state.data = {
+        title: `掘金${cat.title}`,
+        link: `https://juejin.im/tag/${encodeURI(tag)}`,
+        description: `掘金${cat.title}`,
+        item: resultItems,
+    };
+};