From 6fddfd26f0d8725586b215c44d05365c237fba3b Mon Sep 17 00:00:00 2001
From: Aleksandr Bukhalo <aleksandr@bukhalo.com>
Date: Thu, 19 Mar 2020 16:34:44 +0300
Subject: [PATCH] feat: TelegrafUse decorator added

---
 lib/decorators/index.ts                  |  1 +
 lib/decorators/telegraf-use.decorator.ts | 11 +++++++++++
 lib/telegraf-metadata.accessor.ts        |  7 +++++++
 lib/telegraf.constants.ts                |  1 +
 lib/telegraf.explorer.ts                 | 12 +++++++++++-
 5 files changed, 31 insertions(+), 1 deletion(-)
 create mode 100644 lib/decorators/telegraf-use.decorator.ts

diff --git a/lib/decorators/index.ts b/lib/decorators/index.ts
index d001649..42c00a1 100644
--- a/lib/decorators/index.ts
+++ b/lib/decorators/index.ts
@@ -1,3 +1,4 @@
+export * from './telegraf-use.decorator';
 export * from './telegraf-on.decorator';
 export * from './telegraf-hears.decorator';
 export * from './telegraf-start.decorator';
diff --git a/lib/decorators/telegraf-use.decorator.ts b/lib/decorators/telegraf-use.decorator.ts
new file mode 100644
index 0000000..2ff0dd7
--- /dev/null
+++ b/lib/decorators/telegraf-use.decorator.ts
@@ -0,0 +1,11 @@
+import { SetMetadata } from '@nestjs/common';
+import { DECORATORS } from '../telegraf.constants';
+
+/**
+ * Registers a middleware.
+ *
+ * https://telegraf.js.org/#/?id=use
+ */
+export function TelegrafUse(): MethodDecorator {
+  return SetMetadata(DECORATORS.USE, {});
+}
diff --git a/lib/telegraf-metadata.accessor.ts b/lib/telegraf-metadata.accessor.ts
index d4bc776..cad0d9b 100644
--- a/lib/telegraf-metadata.accessor.ts
+++ b/lib/telegraf-metadata.accessor.ts
@@ -7,6 +7,13 @@ import { DECORATORS } from './telegraf.constants';
 export class TelegrafMetadataAccessor {
   constructor(private readonly reflector: Reflector) {}
 
+  isTelegrafUse(target: Type<any> | Function): boolean {
+    if (!target) {
+      return false;
+    }
+    return !!this.reflector.get(DECORATORS.USE, target);
+  }
+
   isTelegrafStart(target: Type<any> | Function): boolean {
     if (!target) {
       return false;
diff --git a/lib/telegraf.constants.ts b/lib/telegraf.constants.ts
index edfedfd..d68f1aa 100644
--- a/lib/telegraf.constants.ts
+++ b/lib/telegraf.constants.ts
@@ -3,6 +3,7 @@ export const TELEGRAF_PROVIDER = 'TELEGRAF_PROVIDER';
 
 export const DECORATORS_PREFIX = 'TELEGRAF';
 export const DECORATORS = {
+  USE: `${DECORATORS_PREFIX}/USE`,
   ON: `${DECORATORS_PREFIX}/ON`,
   HEARS: `${DECORATORS_PREFIX}/HEARS`,
   START: `${DECORATORS_PREFIX}/START`,
diff --git a/lib/telegraf.explorer.ts b/lib/telegraf.explorer.ts
index ebe0405..feda0f0 100644
--- a/lib/telegraf.explorer.ts
+++ b/lib/telegraf.explorer.ts
@@ -39,7 +39,9 @@ export class TelegrafExplorer implements OnModuleInit {
         instance,
         Object.getPrototypeOf(instance),
         (key: string) => {
-          if (this.metadataAccessor.isTelegrafStart(instance[key])) {
+          if (this.metadataAccessor.isTelegrafUse(instance[key])) {
+            this.handleTelegrafUse(instance, key, telegraf);
+          } else if (this.metadataAccessor.isTelegrafStart(instance[key])) {
             this.handleTelegrafStart(instance, key, telegraf);
           } else if (this.metadataAccessor.isTelegrafOn(instance[key])) {
             const metadata = this.metadataAccessor.getTelegrafOnMetadata(
@@ -57,6 +59,14 @@ export class TelegrafExplorer implements OnModuleInit {
     });
   }
 
+  handleTelegrafUse(
+    instance: object,
+    key: string,
+    telegraf: Telegraf<ContextMessageUpdate>,
+  ) {
+    telegraf.use(instance[key].bind(instance));
+  }
+
   handleTelegrafOn(
     instance: object,
     key: string,