introduce PyPsiFacade; extract interface from QualifiedNameResolver

python/psi-api/python-psi-api.iml

@@ -8,6 +8,7 @@
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="module" module-name="core-api" />
+    <orderEntry type="module" module-name="projectModel-api" />
   </component>
 </module>
 

python/psi-api/src/com/jetbrains/python/psi/PyPsiFacade.java

@@ -0,0 +1,19 @@
+package com.jetbrains.python.psi;
+
+import com.intellij.openapi.components.ServiceManager;
+import com.intellij.openapi.project.Project;
+import com.jetbrains.python.psi.impl.PyQualifiedName;
+import com.jetbrains.python.psi.resolve.QualifiedNameResolver;
+
+/**
+ * @author yole
+ */
+public abstract class PyPsiFacade {
+  public static PyPsiFacade getInstance(Project project) {
+    return ServiceManager.getService(project, PyPsiFacade.class);
+  }
+
+  public abstract QualifiedNameResolver qualifiedNameResolver(String qNameString);
+  public abstract QualifiedNameResolver qualifiedNameResolver(PyQualifiedName qualifiedName);
+
+}

python/psi-api/src/com/jetbrains/python/psi/resolve/QualifiedNameResolver.java

@@ -0,0 +1,41 @@
+package com.jetbrains.python.psi.resolve;
+
+import com.intellij.openapi.module.Module;
+import com.intellij.openapi.projectRoots.Sdk;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFileSystemItem;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+/**
+ * @author yole
+ */
+public interface QualifiedNameResolver {
+  QualifiedNameResolver fromElement(@NotNull PsiElement foothold);
+
+  QualifiedNameResolver fromModule(@NotNull Module module);
+
+  QualifiedNameResolver withAllModules();
+
+  QualifiedNameResolver withSdk(Sdk sdk);
+
+  QualifiedNameResolver withRelative(int relativeLevel);
+
+  QualifiedNameResolver withoutRoots();
+
+  QualifiedNameResolver withPlainDirectories();
+
+  @NotNull
+  List<PsiFileSystemItem> resultsAsList();
+
+  @Nullable
+  PsiFileSystemItem firstResult();
+
+  @NotNull
+  <T extends PsiElement> List<T> resultsOfType(Class<T> clazz);
+
+  @Nullable
+  <T extends PsiElement> T firstResultOfType(Class<T> clazz);
+}