From dd5d5e6ee86104c8e20ead33bdf58355113d6c75 Mon Sep 17 00:00:00 2001
From: Daniele Teti <d.teti@bittime.it>
Date: Wed, 18 Oct 2023 15:54:03 +0200
Subject: [PATCH] Added IMVCDotEnv.RequireKeys(const Keys: TArray<String>) --
 more info https://github.com/bkeepers/dotenv#required-keys

---
 samples/dotenv_showcase/MainFormU.dfm | 18 +++++++++++++++++
 samples/dotenv_showcase/MainFormU.pas | 17 ++++++++++++++++
 sources/MVCFramework.DotEnv.pas       | 29 +++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/samples/dotenv_showcase/MainFormU.dfm b/samples/dotenv_showcase/MainFormU.dfm
index a17ea817..09eff904 100644
--- a/samples/dotenv_showcase/MainFormU.dfm
+++ b/samples/dotenv_showcase/MainFormU.dfm
@@ -74,4 +74,22 @@ object MainForm: TMainForm
     WordWrap = True
     OnClick = btnSingleEnvClick
   end
+  object btnRequireKeys: TButton
+    Left = 8
+    Top = 264
+    Width = 169
+    Height = 49
+    Caption = 'Require Keys (OK)'
+    TabOrder = 5
+    OnClick = btnRequireKeysClick
+  end
+  object btnRequireKeys2: TButton
+    Left = 8
+    Top = 319
+    Width = 169
+    Height = 49
+    Caption = 'Require Keys (FAIL)'
+    TabOrder = 6
+    OnClick = btnRequireKeys2Click
+  end
 end
diff --git a/samples/dotenv_showcase/MainFormU.pas b/samples/dotenv_showcase/MainFormU.pas
index 59e2c43c..d9da3264 100644
--- a/samples/dotenv_showcase/MainFormU.pas
+++ b/samples/dotenv_showcase/MainFormU.pas
@@ -15,10 +15,14 @@   TMainForm = class(TForm)
     btnProdEnv: TButton;
     Shape1: TShape;
     btnSingleEnv: TButton;
+    btnRequireKeys: TButton;
+    btnRequireKeys2: TButton;
     procedure btnSimpleClick(Sender: TObject);
     procedure btnTestEnvClick(Sender: TObject);
     procedure btnProdEnvClick(Sender: TObject);
     procedure btnSingleEnvClick(Sender: TObject);
+    procedure btnRequireKeysClick(Sender: TObject);
+    procedure btnRequireKeys2Click(Sender: TObject);
   private
     procedure UpdateUI(dotEnv: IMVCDotEnv);
   public
@@ -43,6 +47,19 @@ procedure TMainForm.btnProdEnvClick(Sender: TObject);
   UpdateUI(dotEnv);
 end;
 
+procedure TMainForm.btnRequireKeys2Click(Sender: TObject);
+begin
+  var dotEnv := NewDotEnv.WithStrategy(TMVCDotEnvPriority.EnvThenFile).Build();
+  dotEnv.RequireKeys(['mode','dbuser','blablabla','dbhostname','unknown']);
+end;
+
+procedure TMainForm.btnRequireKeysClick(Sender: TObject);
+begin
+  var dotEnv := NewDotEnv.WithStrategy(TMVCDotEnvPriority.EnvThenFile).Build();
+  dotEnv.RequireKeys(['mode','dbuser','dbpassword','dbhostname']);
+  ShowMessage('Required Keys FOUND!');
+end;
+
 procedure TMainForm.btnSimpleClick(Sender: TObject);
 begin
   var dotEnv := NewDotEnv.WithStrategy(TMVCDotEnvPriority.EnvThenFile).Build();
diff --git a/sources/MVCFramework.DotEnv.pas b/sources/MVCFramework.DotEnv.pas
index fad19e63..83298183 100644
--- a/sources/MVCFramework.DotEnv.pas
+++ b/sources/MVCFramework.DotEnv.pas
@@ -45,6 +45,7 @@   EMVCDotEnv = class(Exception)
     function Env(const Name: string; const DefaultValue: String): string; overload;
     function Env(const Name: string; const DefaultValue: Integer): Integer; overload;
     function Env(const Name: string; const DefaultValue: Boolean): Boolean; overload;
+    procedure RequireKeys(const Keys: TArray<String>);
     function SaveToFile(const FileName: String): IMVCDotEnv;
     function ToArray(): TArray<String>;
   end;
@@ -104,6 +105,7 @@   TMVCDotEnv = class(TInterfacedObject, IMVCDotEnv, IMVCDotEnvBuilder)
     function Env(const Name: string; const DefaultValue: String): string; overload;
     function Env(const Name: string; const DefaultValue: Integer): Integer; overload;
     function Env(const Name: string; const DefaultValue: Boolean): Boolean; overload;
+    procedure RequireKeys(const Keys: TArray<String>);
     function SaveToFile(const FileName: String): IMVCDotEnv;
     function ToArray(): TArray<String>;
   public
@@ -455,6 +457,33 @@ procedure TMVCDotEnv.ReadEnvFile;
   end;
 end;
 
+procedure TMVCDotEnv.RequireKeys(const Keys: TArray<String>);
+var
+  lKey: String;
+  lNotFoundKeys: TArray<String>;
+  lMsg: string;
+begin
+  if Length(Keys) = 0 then
+  begin
+    Exit;
+  end;
+  DoLog('Checking required keys: ' + String.Join(', ', Keys));
+  lNotFoundKeys := [];
+  for lKey in Keys do
+  begin
+    if Env(lKey).IsEmpty then
+    begin
+      lNotFoundKeys := lNotFoundKeys + [lKey];
+    end;
+  end;
+  if Length(lNotFoundKeys) > 0 then
+  begin
+    lMsg := 'Required keys not found: ' + String.Join(', ', lNotFoundKeys);
+    DoLog(lMsg);
+    raise EMVCDotEnv.Create(lMsg);
+  end;
+end;
+
 function NewDotEnv: IMVCDotEnvBuilder;
 begin
   Result := TMVCDotEnv.Create;