feat(middleware): brief parameter (#8074)

Co-authored-by: SettingDust <settingdust@gmail.com>
Co-authored-by: ギャラ <me@gyara.moe>

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`);
+                }
+            }
         }
     }
 };