From d8c39876e684f6441a27d080b7d145c75b6f3771 Mon Sep 17 00:00:00 2001
From: HarveyMac <harvey.chou@origtek-mail.com>
Date: Sun, 6 Nov 2022 15:41:02 +0800
Subject: [PATCH] =?UTF-8?q?FactoryService=E4=BD=BF=E7=94=A8=20=E5=8F=AF?=
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---
 src/app/app.module.ts                | 20 ++++++++++++++------
 src/app/order-anniversary.service.ts | 18 ++++++++++++++++++
 2 files changed, 32 insertions(+), 6 deletions(-)
 create mode 100644 src/app/order-anniversary.service.ts

diff --git a/src/app/app.module.ts b/src/app/app.module.ts
index 4370fb4..dfd34c1 100644
--- a/src/app/app.module.ts
+++ b/src/app/app.module.ts
@@ -4,16 +4,24 @@ import { FormsModule } from '@angular/forms';
 
 import { AppComponent } from './app.component';
 import { OrderService } from './order.service';
-import { OrderDiscountService } from './order-discount.service';
+import { OrderAnniversaryService } from './order-anniversary.service';
 
 @NgModule({
   imports: [BrowserModule, FormsModule],
   declarations: [AppComponent],
-  providers: [{
-    provide: OrderService,
-    useValue:{computeTotal:()=>100},
-  },],
-
+  providers: [
+    {
+      provide: OrderService,
+      useFactory: () => {
+        const today = new Date(2020, 9, 3);
+        if (today.getMonth() === 9) {
+          return new OrderAnniversaryService();
+        } else {
+          return new OrderService();
+        }
+      },
+    },
+  ],
   bootstrap: [AppComponent],
 })
 export class AppModule {}
diff --git a/src/app/order-anniversary.service.ts b/src/app/order-anniversary.service.ts
new file mode 100644
index 0000000..d6ed08b
--- /dev/null
+++ b/src/app/order-anniversary.service.ts
@@ -0,0 +1,18 @@
+import { Injectable } from '@angular/core';
+
+import { OrderDetail } from './order-detail';
+
+@Injectable({
+  providedIn: 'root',
+})
+export class OrderAnniversaryService {
+  details: OrderDetail[] = [];
+
+  constructor() {}
+
+  computeTotal(): number {
+    return this.details
+      .map((d) => d.PurchaseCount * d.UnitPrice * 0.8)
+      .reduce((act, curr) => act + curr, 0);
+  }
+}