Facade pattern

Author: fadeevab

Cargo.toml

@@ -13,4 +13,5 @@ members = [
   "structural/bridge",
   "structural/composite",
   "structural/decorator",
+  "structural/facade",
 ]

structural/facade/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "facade"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[[bin]]
+name = "facade"
+path = "main.rs"

structural/facade/account.rs

@@ -0,0 +1,26 @@
+pub struct Account {
+    name: String,
+}
+
+impl Account {
+    pub fn new(name: String) -> Self {
+        Self { name }
+    }
+
+    pub fn check(&self, name: &String) -> Result<(), String> {
+        if &self.name != name {
+            return Err("Account name is incorrect".into());
+        }
+
+        println!("Account verified");
+        Ok(())
+    }
+}
+
+// func (a *Account) checkAccount(accountName string) error {
+//     if a.name != accountName {
+//         return fmt.Errorf("Account Name is incorrect")
+//     }
+//     fmt.Println("Account Verified")
+//     return nil
+// }

structural/facade/ledger.rs

@@ -0,0 +1,10 @@
+pub struct Ledger;
+
+impl Ledger {
+    pub fn make_entry(&mut self, account_id: &String, txn_type: String, amount: u32) {
+        println!(
+            "Make ledger entry for accountId {} with transaction type {} for amount {}",
+            account_id, txn_type, amount
+        );
+    }
+}

structural/facade/main.rs

@@ -0,0 +1,18 @@
+mod account;
+mod ledger;
+mod notification;
+mod security_code;
+mod wallet;
+mod wallet_facade;
+
+use wallet_facade::WalletFacade;
+
+fn main() -> Result<(), String> {
+    let mut wallet = WalletFacade::new("abc".into(), 1234);
+    println!("");
+
+    wallet.add_money_to_wallet(&"abc".into(), 1234, 10)?;
+    println!("");
+
+    wallet.deduct_money_from_wallet(&"abc".into(), 1234, 5)
+}

structural/facade/notification.rs

@@ -0,0 +1,11 @@
+pub struct Notification;
+
+impl Notification {
+    pub fn send_wallet_credit_notification(&self) {
+        println!("Sending wallet credit notification");
+    }
+
+    pub fn send_wallet_debit_notification(&self) {
+        println!("Sending wallet debit notification");
+    }
+}

structural/facade/security_code.rs

@@ -0,0 +1,18 @@
+pub struct SecurityCode {
+    code: u32,
+}
+
+impl SecurityCode {
+    pub fn new(code: u32) -> Self {
+        Self { code }
+    }
+
+    pub fn check(&self, code: u32) -> Result<(), String> {
+        if self.code != code {
+            return Err("Security code is incorrect".into());
+        }
+
+        println!("Security code verified");
+        Ok(())
+    }
+}

structural/facade/wallet.rs

@@ -0,0 +1,19 @@
+pub struct Wallet {
+    balance: u32,
+}
+
+impl Wallet {
+    pub fn new() -> Self {
+        Self { balance: 0 }
+    }
+
+    pub fn credit_balance(&mut self, amount: u32) {
+        self.balance += amount;
+    }
+
+    pub fn debit_balance(&mut self, amount: u32) {
+        self.balance
+            .checked_sub(amount)
+            .expect("Balance is not sufficient");
+    }
+}

structural/facade/wallet_facade.rs

@@ -0,0 +1,59 @@
+use crate::{
+    account::Account, ledger::Ledger, notification::Notification, security_code::SecurityCode,
+    wallet::Wallet,
+};
+
+pub struct WalletFacade {
+    account: Account,
+    wallet: Wallet,
+    code: SecurityCode,
+    notification: Notification,
+    ledger: Ledger,
+}
+
+impl WalletFacade {
+    pub fn new(account_id: String, code: u32) -> Self {
+        println!("Starting create account");
+
+        let this = Self {
+            account: Account::new(account_id),
+            wallet: Wallet::new(),
+            code: SecurityCode::new(code),
+            notification: Notification,
+            ledger: Ledger,
+        };
+
+        println!("Account created");
+        this
+    }
+
+    pub fn add_money_to_wallet(
+        &mut self,
+        account_id: &String,
+        security_code: u32,
+        amount: u32,
+    ) -> Result<(), String> {
+        println!("Starting add money to wallet");
+        self.account.check(account_id)?;
+        self.code.check(security_code)?;
+        self.wallet.credit_balance(amount);
+        self.notification.send_wallet_credit_notification();
+        self.ledger.make_entry(account_id, "credit".into(), amount);
+        Ok(())
+    }
+
+    pub fn deduct_money_from_wallet(
+        &mut self,
+        account_id: &String,
+        security_code: u32,
+        amount: u32,
+    ) -> Result<(), String> {
+        println!("Starting debit money from wallet");
+        self.account.check(account_id)?;
+        self.code.check(security_code)?;
+        self.wallet.debit_balance(amount);
+        self.notification.send_wallet_debit_notification();
+        self.ledger.make_entry(account_id, "debit".into(), amount);
+        Ok(())
+    }
+}