From 578b7d1db256d9a582cef45ae5d13d858a977416 Mon Sep 17 00:00:00 2001
From: Yuuta Liang <yuutaw@student.cs.ubc.ca>
Date: Thu, 26 Oct 2023 05:00:12 +0800
Subject: Add persistence

Signed-off-by: Yuuta Liang <yuutaw@student.cs.ubc.ca>
---
 src/main/ui/JCA.java | 95 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 76 insertions(+), 19 deletions(-)

(limited to 'src/main/ui/JCA.java')

diff --git a/src/main/ui/JCA.java b/src/main/ui/JCA.java
index 882c546..420ec10 100644
--- a/src/main/ui/JCA.java
+++ b/src/main/ui/JCA.java
@@ -1,9 +1,14 @@
 package ui;
 
+import model.asn1.exceptions.InvalidDBException;
 import model.asn1.exceptions.ParseException;
 import model.ca.CertificationAuthority;
+import persistence.Decoder;
+import persistence.FS;
 
+import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
 import java.security.NoSuchAlgorithmException;
 import java.security.spec.InvalidKeySpecException;
 import java.util.Scanner;
@@ -12,6 +17,11 @@ import java.util.Scanner;
  * Main program
  */
 public class JCA {
+    /**
+     * Default db file (./data/ca.json)
+     */
+    private static final Path PATH_DEFAULT = Path.of("data", "ca.json");
+
     /**
      * Instances of the five screens;
      */
@@ -23,12 +33,17 @@ public class JCA {
     /**
      * The CA
      */
-    private final CertificationAuthority ca;
+    private CertificationAuthority ca;
     /**
      * The current screen.
      */
     private UIHandler screen;
 
+    /**
+     * There are unsaved changes.
+     */
+    private boolean unsaved = false;
+
     /**
      * EFFECTS: Init with main screen and empty CA. No private key and no CA cert.
      * Throws {@link NoSuchAlgorithmException} when crypto issue happens.
@@ -106,34 +121,72 @@ public class JCA {
         screen.enter(args);
     }
 
+    /**
+     * EFFECTS: Read the database file and replace all local states.
+     * MODIFIES: this
+     */
+    private void load() {
+        if (unsaved) {
+            System.out.println("Current database is not saved yet.");
+            return;
+        }
+        try {
+            this.ca = Decoder.decodeCA(FS.read(PATH_DEFAULT));
+        } catch (InvalidDBException | NoSuchAlgorithmException e) {
+            System.out.println(e.getMessage());
+            if (e.getCause() != null) {
+                System.out.println(e.getCause().getMessage());
+                e.getCause().printStackTrace();
+            }
+        }
+    }
+
     private void handleLine(String... args) {
         if (args[0].equals("log")) {
             ca.getLogs().forEach(System.out::println);
             return;
         }
-        switch (args[0]) {
-            case "help":
-                screen.help();
-                System.out.println("log\tView audit logs");
-                break;
-            case "show":
-                screen.show();
-                break;
-            case "commit":
-                screen.commit();
-                break;
-            case "exit":
-                setScreen(screen.exit());
-                break;
-            default:
-                screen.command(args);
-                break;
+        if ("help".equals(args[0])) {
+            screen.help();
+            System.out.println("log\tView audit logs");
+            System.out.println("load\tLoad database");
+            System.out.println("save\tSave database");
+        } else if ("commit".equals(args[0])) {
+            screen.commit();
+        } else if ("show".equals(args[0])) {
+            screen.show();
+        } else if ("exit".equals(args[0])) {
+            setScreen(screen.exit());
+        } else if ("save".equals(args[0])) {
+            save();
+        } else if ("load".equals(args[0])) {
+            load();
+        } else {
+            screen.command(args);
         }
         printPS1();
     }
 
+    /**
+     * EFFECTS: Print the '*user@JCA PS1' line
+     */
     private void printPS1() {
-        System.out.printf("%s@JCA %s ", ca.getUser(), screen.getPS1());
+        System.out.printf("%s%s@JCA %s ",
+                unsaved ? "*" : "",
+                ca.getUser(),
+                screen.getPS1());
+    }
+
+    /**
+     * EFFECTS: Save the DB
+     */
+    public void save() {
+        try {
+            FS.write(PATH_DEFAULT, Decoder.encodeCA(ca));
+            unsaved = false;
+        } catch (IOException e) {
+            System.out.println(e.getMessage());
+        }
     }
 
     /**
@@ -152,6 +205,10 @@ public class JCA {
         }
     }
 
+    public void setUnsaved(boolean unsaved) {
+        this.unsaved = unsaved;
+    }
+
     public CertificationAuthority getCa() {
         return ca;
     }
-- 
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