package org.chromium.debug.ui.actions;

import org.chromium.debug.core.model.Variable;

import org.chromium.debug.ui.JsDebugModelPresentation;

import org.chromium.debug.ui.editors.JsEditor;

import org.chromium.sdk.JsFunction;

import org.chromium.sdk.JsObject;

import org.chromium.sdk.JsValue;

import org.chromium.sdk.JsVariable;

import org.chromium.sdk.Script;

import org.eclipse.core.resources.IFile;

import org.eclipse.jface.action.IAction;

import org.eclipse.jface.viewers.ISelection;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.swt.widgets.Event;

import org.eclipse.ui.IActionDelegate2;

import org.eclipse.ui.IEditorInput;

import org.eclipse.ui.IEditorPart;

import org.eclipse.ui.IObjectActionDelegate;

import org.eclipse.ui.IWorkbench;

import org.eclipse.ui.IWorkbenchPart;

import org.eclipse.ui.IWorkbenchWindow;

import org.eclipse.ui.PartInitException;

import org.eclipse.ui.PlatformUI;

import org.eclipse.ui.texteditor.ITextEditor;

/**

 * The action for context view in Variable view that opens selected function source text in editor.

 */

public class OpenFunctionAction implements IObjectActionDelegate, IActionDelegate2 {

  private Runnable currentRunnable = null;

  public void setActivePart(IAction action, IWorkbenchPart targetPart) {

  }

  public void run(IAction action) {

    if (currentRunnable == null) {

      return;

    }

    currentRunnable.run();

  }

  public void selectionChanged(IAction action, ISelection selection) {

    final Variable variable = getVariableFromSelection(selection);

    final JsFunction jsFunction = getJsFunctionFromVariable(variable);

    currentRunnable = createRunnable(variable, jsFunction);

    action.setEnabled(currentRunnable != null);

  }

  private Runnable createRunnable(final Variable variable, final JsFunction jsFunction) {

    if (jsFunction == null) {

      return null;

    }

    return new Runnable() {

      public void run() {

        // This works in UI thread.

        IWorkbench workbench = PlatformUI.getWorkbench();

        final IWorkbenchWindow activeWorkbenchWindow = workbench.getActiveWorkbenchWindow();

        Script script = jsFunction.getScript();

        if (script == null) {

          return;

        }

        IFile resource = variable.getDebugTarget().getResourceManager().getResource(script);

        IEditorInput input = JsDebugModelPresentation.toEditorInput(resource);

        IEditorPart editor;

        try {

          editor = activeWorkbenchWindow.getActivePage().openEditor(input, JsEditor.EDITOR_ID);

        } catch (PartInitException e) {

          throw new RuntimeException(e);

        }

        if (editor instanceof ITextEditor == false) {

          return;

        }

        ITextEditor textEditor = (ITextEditor) editor;

        textEditor.selectAndReveal(jsFunction.getSourcePosition(), 0);

      }

    };

  }

  public void dispose() {

    currentRunnable = null;

  }

  public void init(IAction action) {

  }

  public void runWithEvent(IAction action, Event event) {

    if (currentRunnable == null) {

      return;

    }

    currentRunnable.run();

  }

  private JsFunction getJsFunctionFromVariable(Variable variable) {

    if (variable == null) {

      return null;

    }

    JsVariable jsVariable = variable.getJsVariable();

    JsValue jsValue = jsVariable.getValue();

    JsObject jsObject = jsValue.asObject();

    if (jsObject == null) {

      return null;

    }

    return jsObject.asFunction();

  }

  private Variable getVariableFromSelection(ISelection selection) {

    if (selection instanceof IStructuredSelection == false) {

      return null;

    }

    IStructuredSelection structuredSelection = (IStructuredSelection) selection;

    if (structuredSelection.size() != 1) {

      // We do not support multiple selection.

      return null;

    }

    Object element = structuredSelection.getFirstElement();

    if (element instanceof Variable == false) {

      return null;

    }

    return (Variable) element;

  }

}