Refactor: Update ShellContext.java

Author: SauravBhowmick

src/main/java/com/mycmd/ShellContext.java

@@ -1,41 +1,184 @@
 package com.mycmd;
 
 import java.io.File;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Scanner;
+import java.util.*;
 
+/**
+ * Context object that holds the shell's state including current directory,
+ * environment variables, command history, aliases, and shared Scanner.
+ */
 public class ShellContext {
+    private File currentDir;
+    private final Map<String, String> environment;
+    private final List<String> history;
+    private final Map<String, String> aliases;
+    private Scanner scanner;
+    private long startTime;
 
-  private File currentDir;
-  private final Map<String, String> aliases;
+    public ShellContext() {
+        this.currentDir = new File(System.getProperty("user.dir"));
+        this.environment = new HashMap<>();
+        this.history = new ArrayList<>();
+        this.aliases = new HashMap<>();
+        this.scanner = null;
+        this.startTime = System.currentTimeMillis();
+    }
+
+    // ==================== Scanner Management ====================
+    
+    /**
+     * Set the shared Scanner instance for all commands to use.
+     * Should only be called once by App.java during initialization.
+     */
+    public void setScanner(Scanner scanner) {
+        this.scanner = scanner;
+    }
+
+    /**
+     * Get the shared Scanner instance.
+     * All commands should use this instead of creating their own Scanner.
+     * @return the shared Scanner instance
+     * @throws IllegalStateException if Scanner hasn't been initialized
+     */
+    public Scanner getScanner() {
+        if (scanner == null) {
+            throw new IllegalStateException("Scanner not initialized in ShellContext");
+        }
+        return scanner;
+    }
+
+    // ==================== Directory Management ====================
+    
+    public File getCurrentDir() {
+        return currentDir;
+    }
+
+    public void setCurrentDir(File dir) {
+        if (dir != null && dir.exists() && dir.isDirectory()) {
+            this.currentDir = dir;
+        }
+    }
+
+    /**
+     * Resolve a path relative to the current directory.
+     * If the path is absolute, return it as-is.
+     * If relative, resolve it against the current directory.
+     */
+    public File resolvePath(String path) {
+        File file = new File(path);
+        if (file.isAbsolute()) {
+            return file;
+        }
+        return new File(currentDir, path);
+    }
+
+    // ==================== Environment Variables ====================
+    
+    public String getEnvVar(String key) {
+        return environment.get(key);
+    }
+
+    public void setEnvVar(String key, String value) {
+        environment.put(key, value);
+    }
 
-  private Scanner scanner;
+    public Map<String, String> getAllEnvVars() {
+        return new HashMap<>(environment);
+    }
 
-  public ShellContext() {
-    this.currentDir = new File(System.getProperty("user.dir"));
-    this.aliases = new HashMap<>();
-  }
+    /**
+     * Legacy method name support for compatibility.
+     */
+    public Map<String, String> getEnvVars() {
+        return getAllEnvVars();
+    }
 
-  public File getCurrentDir() {
-    return currentDir;
-  }
+    // ==================== Command History ====================
+    
+    public void addToHistory(String command) {
+        history.add(command);
+    }
 
-  public void setCurrentDir(File dir) {
-    if (dir != null && dir.exists() && dir.isDirectory()) {
-      this.currentDir = dir;
+    public List<String> getHistory() {
+        return new ArrayList<>(history);
     }
-  }
 
-  public Map<String, String> getAliases() {
-    return aliases;
-  }
+    /**
+     * Legacy method name support for compatibility.
+     */
+    public List<String> getCommandHistory() {
+        return getHistory();
+    }
 
-  public void addAlias(String name, String command) {
-    aliases.put(name, command);
-  }
+    public void clearHistory() {
+        history.clear();
+    }
 
-  public String resolveAlias(String cmd) {
-    return aliases.getOrDefault(cmd, cmd);
-  }
+    // ==================== Aliases ====================
+    
+    /**
+     * Get all aliases (for compatibility with existing code).
+     */
+    public Map<String, String> getAliases() {
+        return new HashMap<>(aliases);
+    }
+
+    /**
+     * Add an alias (for compatibility with existing code).
+     */
+    public void addAlias(String name, String command) {
+        aliases.put(name, command);
+    }
+
+    /**
+     * Resolve an alias (for compatibility with existing code).
+     */
+    public String resolveAlias(String cmd) {
+        return aliases.getOrDefault(cmd, cmd);
+    }
+
+    /**
+     * Set an alias.
+     */
+    public void setAlias(String alias, String command) {
+        aliases.put(alias, command);
+    }
+
+    /**
+     * Get alias command.
+     */
+    public String getAlias(String alias) {
+        return aliases.get(alias);
+    }
+
+    /**
+     * Check if alias exists.
+     */
+    public boolean hasAlias(String alias) {
+        return aliases.containsKey(alias);
+    }
+
+    /**
+     * Remove an alias.
+     */
+    public void removeAlias(String alias) {
+        aliases.remove(alias);
+    }
+
+    /**
+     * Get all aliases.
+     */
+    public Map<String, String> getAllAliases() {
+        return new HashMap<>(aliases);
+    }
+
+    // ==================== Start Time (for uptime command) ====================
+    
+    public long getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(long startTime) {
+        this.startTime = startTime;
+    }
 }