From e24906fdeb4e6bd9ab844aae02da4aff81ce8b63 Mon Sep 17 00:00:00 2001
From: Toby Tso <7851076+tpnonthealps@users.noreply.github.com>
Date: Thu, 9 Sep 2021 16:37:41 +0800
Subject: [PATCH] feat(middleware): `brief` parameter (#8074)
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Co-authored-by: SettingDust <settingdust@gmail.com>
Co-authored-by: ギャラ <me@gyara.moe>
---
 docs/parameter.md           |  8 ++++++++
 lib/middleware/parameter.js | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/docs/parameter.md b/docs/parameter.md
index 2b08bd7d9..b5e302b55 100644
--- a/docs/parameter.md
+++ b/docs/parameter.md
@@ -93,3 +93,11 @@ RSSHub 同时支持 RSS 2.0 和 Atom 输出格式，在路由末尾添加 `.rss`
 -   RSS 2.0 - <https://rsshub.app/jianshu/home.rss>
 -   Atom - <https://rsshub.app/jianshu/home.atom>
 -   和 filter 或其他 URL query 一起使用 `https://rsshub.app/bilibili/user/coin/2267573.atom?filter=微小微|赤九玖|暴走大事件`
+
+## 输出简讯
+
+可以使用 `brief` 参数输出特定字数 ( ≥ `100` 字 ) 的纯文本内容
+
+举例：
+
+-   输出 100 字简讯: `?brief=100`
diff --git a/lib/middleware/parameter.js b/lib/middleware/parameter.js
index d78454827..aa7390f86 100644
--- a/lib/middleware/parameter.js
+++ b/lib/middleware/parameter.js
@@ -239,6 +239,29 @@ module.exports = async (ctx, next) => {
                     item.description = simplecc(item.description, ctx.query.opencc);
                 });
             }
+
+            // brief
+            if (ctx.query.brief) {
+                const num = /[1-9]\d{2,}/;
+                if (num.test(ctx.query.brief)) {
+                    ctx.query.brief = parseInt(ctx.query.brief);
+                    ctx.state.data.item.forEach((item) => {
+                        let text;
+                        if (item.description) {
+                            text = item.description.replace(/<\/?[^>]+(>|$)/g, '');
+                        }
+                        if (text && text.length) {
+                            if (text.length > ctx.query.brief) {
+                                item.description = `<p>${text.substring(0, ctx.query.brief)}…</p>`;
+                            } else {
+                                item.description = `<p>${text}</p>`;
+                            }
+                        }
+                    });
+                } else {
+                    throw Error(`Invalid parameter <code>brief=${ctx.query.brief}</code>. Please check the doc https://docs.rsshub.app/parameter.html#shu-chu-jian-xun`);
+                }
+            }
         }
     }
 };