From f5d9cf13b6ef67a1f0a3b63004b2e9a67b94f31c Mon Sep 17 00:00:00 2001
From: Aleksandr Bukhalo <aleksandr@bukhalo.com>
Date: Thu, 19 Mar 2020 16:58:27 +0300
Subject: [PATCH] feat(decorators): TelegrafMention added

---
 lib/decorators/telegraf-mention.decorator.ts | 12 ++++++++++++
 lib/telegraf-metadata.accessor.ts            | 11 +++++++++++
 lib/telegraf.constants.ts                    |  1 +
 lib/telegraf.explorer.ts                     | 15 +++++++++++++++
 4 files changed, 39 insertions(+)
 create mode 100644 lib/decorators/telegraf-mention.decorator.ts

diff --git a/lib/decorators/telegraf-mention.decorator.ts b/lib/decorators/telegraf-mention.decorator.ts
new file mode 100644
index 0000000..e7a643b
--- /dev/null
+++ b/lib/decorators/telegraf-mention.decorator.ts
@@ -0,0 +1,12 @@
+import { SetMetadata } from '@nestjs/common';
+import { DECORATORS } from '../telegraf.constants';
+
+/**
+ * Mention handling.
+ * @param username Username
+ *
+ * https://telegraf.js.org/#/?id=mention
+ */
+export function TelegrafMention(username: string | string[]): MethodDecorator {
+  return SetMetadata(DECORATORS.MENTION, { username });
+}
diff --git a/lib/telegraf-metadata.accessor.ts b/lib/telegraf-metadata.accessor.ts
index 34c5f06..03809fb 100644
--- a/lib/telegraf-metadata.accessor.ts
+++ b/lib/telegraf-metadata.accessor.ts
@@ -78,4 +78,15 @@ export class TelegrafMetadataAccessor {
   getTelegrafEntityMetadata(target: Type<any> | Function) {
     return this.reflector.get(DECORATORS.ENTITY, target);
   }
+
+  isTelegrafMention(target: Type<any> | Function): boolean {
+    if (!target) {
+      return false;
+    }
+    return !!this.reflector.get(DECORATORS.MENTION, target);
+  }
+
+  getTelegrafMentionMetadata(target: Type<any> | Function) {
+    return this.reflector.get(DECORATORS.MENTION, target);
+  }
 }
diff --git a/lib/telegraf.constants.ts b/lib/telegraf.constants.ts
index fa18e0a..66c3371 100644
--- a/lib/telegraf.constants.ts
+++ b/lib/telegraf.constants.ts
@@ -11,4 +11,5 @@ export const DECORATORS = {
   HELP: `${DECORATORS_PREFIX}/HELP`,
   SETTINGS: `${DECORATORS_PREFIX}/SETTINGS`,
   ENTITY: `${DECORATORS_PREFIX}/ENTITY`,
+  MENTION: `${DECORATORS_PREFIX}/MENTION`,
 };
diff --git a/lib/telegraf.explorer.ts b/lib/telegraf.explorer.ts
index 2665b28..f30fafd 100644
--- a/lib/telegraf.explorer.ts
+++ b/lib/telegraf.explorer.ts
@@ -67,6 +67,11 @@ export class TelegrafExplorer implements OnModuleInit {
               instance[key],
             );
             this.handleTelegrafEntity(instance, key, telegraf, metadata);
+          } else if (this.metadataAccessor.isTelegrafMention(instance[key])) {
+            const metadata = this.metadataAccessor.getTelegrafMentionMetadata(
+              instance[key],
+            );
+            this.handleTelegrafMention(instance, key, telegraf, metadata);
           }
         },
       );
@@ -142,4 +147,14 @@ export class TelegrafExplorer implements OnModuleInit {
     // @ts-ignore
     telegraf.entity(metadata.entity, instance[key].bind(instance));
   }
+
+  handleTelegrafMention(
+    instance: object,
+    key: string,
+    telegraf: Telegraf<ContextMessageUpdate>,
+    metadata: any,
+  ) {
+    // @ts-ignore
+    telegraf.mention(metadata.username, instance[key].bind(instance));
+  }
 }