feat(cli): updated bal graph to human readable tree output

cli/ballerina-cli/src/main/java/io/ballerina/cli/cmd/GraphCommand.java

@@ -22,6 +22,7 @@
 import io.ballerina.cli.TaskExecutor;
 import io.ballerina.cli.task.CleanTargetDirTask;
 import io.ballerina.cli.task.CreateDependencyGraphTask;
+import io.ballerina.cli.task.CreateDependencyTreeTask;
 import io.ballerina.cli.task.ResolveMavenDependenciesTask;
 import io.ballerina.cli.task.RunBuildToolsTask;
 import io.ballerina.cli.utils.FileUtils;
@@ -113,6 +114,7 @@ public void execute() {
                 .addTask(new CleanTargetDirTask(), isSingleFileProject())
                 .addTask(new RunBuildToolsTask(outStream, false, buildToolDiagnostics), isSingleFileProject())
                 .addTask(new ResolveMavenDependenciesTask(outStream))
+                .addTask(new CreateDependencyTreeTask(outStream))
                 .addTask(new CreateDependencyGraphTask(outStream, errStream, buildToolDiagnostics))
                 .build();
         taskExecutor.executeTasks(this.project);

cli/ballerina-cli/src/main/java/io/ballerina/cli/task/CreateDependencyTreeTask.java

@@ -0,0 +1,84 @@
+package io.ballerina.cli.task;
+
+import io.ballerina.projects.DependencyGraph;
+import io.ballerina.projects.PackageDescriptor;
+import io.ballerina.projects.Project;
+import io.ballerina.projects.util.ProjectUtils;
+import io.ballerina.tools.diagnostics.Diagnostic;
+
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Set;
+
+import static io.ballerina.cli.launcher.LauncherUtils.createLauncherException;
+
+/**
+ * Task for creating and printing the dependency graph as a human-readable tree.
+ */
+public class CreateDependencyTreeTask implements Task {
+    private final transient PrintStream out;
+
+    public CreateDependencyTreeTask(PrintStream out) {
+        this.out = out;
+    }
+
+    @Override
+    public void execute(Project project) {
+        if (ProjectUtils.isProjectEmpty(project)) {
+            throw createLauncherException("package is empty. Please add at least one .bal file.");
+        }
+
+
+        if (project.currentPackage().getResolution().diagnosticResult().hasErrors()) {            
+            throw createLauncherException("package resolution contains errors. Cannot display dependency tree.");
+        }
+
+
+        DependencyGraph<PackageDescriptor> graph = project.currentPackage().getResolution().dependencyGraph();
+
+
+        PackageDescriptor root = project.currentPackage().descriptor();
+
+
+        out.println(root.org() + "/" + root.name() + ":" + root.version());
+
+
+        printDependencies(graph, root, "", out);
+    }
+
+    /**
+     * Recursively traverses the dependency graph and prints the tree structure.
+     */
+    private void printDependencies(DependencyGraph<PackageDescriptor> graph, PackageDescriptor parent, 
+                                   String indent, PrintStream out) {
+
+
+        Set<PackageDescriptor> rawDependencies = graph.getDependencies(parent);
+
+
+        List<PackageDescriptor> dependencies = new ArrayList<>(rawDependencies);
+
+        dependencies.sort(Comparator
+                .comparing(PackageDescriptor::org)
+                .thenComparing(PackageDescriptor::name)
+                .thenComparing(PackageDescriptor::version));
+
+        for (int i = 0; i < dependencies.size(); i++) {
+            PackageDescriptor dep = dependencies.get(i);
+            boolean isLast = (i == dependencies.size() - 1);
+
+
+            String prefix = isLast ? "\\--- " : "+--- ";
+            String childIndent = isLast ? "    " : "|   ";
+
+
+            out.println(indent + prefix + dep.org() + "/" + dep.name() + ":" + dep.version());
+
+
+            printDependencies(graph, dep, indent + childIndent, out);
+        }
+    }
+}