PY-2821: Support "reverse" and Co reference injection

* Drop Django 1.5 style {% url %} tag support
* Provide view name references for reverse etc
* Improve  DjangoFQNamesProvider API to support "package/name only" check

python/psi-api/src/com/jetbrains/python/nameResolver/FQNamesProvider.java

@@ -15,10 +15,20 @@
  */
 package com.jetbrains.python.nameResolver;
 
+import com.intellij.navigation.NavigationItem;
+import com.intellij.psi.util.QualifiedName;
+import com.intellij.util.ArrayUtil;
+import com.jetbrains.python.psi.PyQualifiedNameOwner;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
 /**
  * Some enum value that represents one or more fully qualified names for some function
+ *
  * @author Ilya.Kazakevich
  */
 public interface FQNamesProvider {
@@ -28,8 +38,73 @@ public interface FQNamesProvider {
   @NotNull
   String[] getNames();
 
+  @NotNull
+  default QualifiedName[] getQualifiedNames() {
+    return Arrays.stream(getNames()).map(QualifiedName::fromDottedString).toArray(QualifiedName[]::new);
+  }
+
+
+  @NotNull
+  default String getFirstName() {
+    return getNames()[0];
+  }
+
+  default boolean isShortNameMatches(@NotNull final NavigationItem item) {
+    final String name = item.getName();
+    if (name == null) {
+      return false;
+    }
+    return getShortNames().contains(name);
+  }
+
+  /**
+   * @return all names in unqualified ("after last dot") format
+   */
+  @NotNull
+  default List<String> getShortNames() {
+    return Arrays.stream(getQualifiedNames()).map(QualifiedName::getLastComponent).filter(o -> o != null).collect(Collectors.toList());
+  }
+
   /**
    * @return is name of class (true) or function (false)
    */
   boolean isClass();
+
+  /**
+   * @return if element should be checked by full name conformity by {@link #isNameMatches(PyQualifiedNameOwner)}
+   * or only name and package should be checked
+   * @see #isNameMatches(PyQualifiedNameOwner)
+   */
+  default boolean alwaysCheckQualifiedName() {
+    return true;
+  }
+
+  /**
+   * Checks if element name matches. {@link #alwaysCheckQualifiedName()} controls if full name should be checked, or only last and first
+   * parts (name and package) are enough. It may be used for cases when physical FQN is not documented.
+   */
+  default boolean isNameMatches(@NotNull final PyQualifiedNameOwner qualifiedNameOwner) {
+    final String qualifiedName = qualifiedNameOwner.getQualifiedName();
+    if (qualifiedName == null) {
+      return false;
+    }
+
+    // Only check qualified name
+    if (alwaysCheckQualifiedName()) {
+      return ArrayUtil.contains(qualifiedName, getNames());
+    }
+
+    // Relaxed check: package and name
+    final QualifiedName elementQualifiedName = QualifiedName.fromDottedString(qualifiedName);
+    final Stream<QualifiedName> nameStream = Arrays.stream(getQualifiedNames());
+    return nameStream.anyMatch((name) -> {
+                                 final String first = name.getFirstComponent();
+                                 final String last = name.getLastComponent();
+                                 return first != null
+                                        && last != null
+                                        && first.equals(elementQualifiedName.getFirstComponent())
+                                        && last.equals(elementQualifiedName.getLastComponent());
+                               }
+    );
+  }
 }

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

@@ -50,7 +50,7 @@ public abstract class PyElementGenerator {
 
   public abstract PyStringLiteralExpression createStringLiteralFromString(@NotNull String unescaped);
 
-  public abstract PyStringLiteralExpression createStringLiteral(@NotNull PyStringLiteralExpression oldElement, @NotNull String unescaped);
+  public abstract PyStringLiteralExpression createStringLiteral(@NotNull StringLiteralExpression oldElement, @NotNull String unescaped);
 
   public abstract PyListLiteralExpression createListLiteral();
 

python/src/com/jetbrains/python/PyStringLiteralReference.java

@@ -18,7 +18,6 @@ package com.jetbrains.python;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.psi.PsiElement;
 import com.jetbrains.python.psi.PyElementGenerator;
-import com.jetbrains.python.psi.PyStringLiteralUtil;
 import com.jetbrains.python.psi.StringLiteralExpression;
 import org.jetbrains.annotations.NotNull;
 
@@ -39,12 +38,12 @@ public abstract class PyStringLiteralReference extends BaseReference {
   @SuppressWarnings("RefusedBequest") // 1 instead of 1 in range and "-1" at the end because we do not need quotes
   @Override
   public final TextRange getRangeInElement() {
-    return PyStringLiteralUtil.getTextRange(myElement);
+    return myStringLiteral.getStringValueTextRange();
   }
 
   @Override
   public PsiElement handleElementRename(@NotNull final String newElementName) {
-    final PsiElement newString = PyElementGenerator.getInstance(myElement.getProject()).createStringLiteralFromString(newElementName);
+    final PsiElement newString = PyElementGenerator.getInstance(myElement.getProject()).createStringLiteral(myStringLiteral, newElementName);
     myStringLiteral.replace(newString);
     return newString;
   }

python/src/com/jetbrains/python/psi/PyUtil.java

@@ -1708,7 +1708,10 @@ public class PyUtil {
    * @param expectedPackage package like "django"
    * @param expectedName expected name (i.e. AppConfig)
    * @return true if element in package
+   * @deprecated  use {@link com.jetbrains.python.nameResolver.FQNamesProvider#isNameMatches(PyQualifiedNameOwner)}
+   * Remove in 2018
    */
+  @Deprecated
   public static boolean isSymbolInPackage(@NotNull final PyQualifiedNameOwner symbol,
                                           @NotNull final String expectedPackage,
                                           @NotNull final String expectedName) {

python/src/com/jetbrains/python/psi/impl/PyElementGeneratorImpl.java

@@ -108,7 +108,8 @@ public class PyElementGeneratorImpl extends PyElementGenerator {
     return createStringLiteralFromString(null, unescaped, true);
   }
 
-  public PyStringLiteralExpression createStringLiteral(@NotNull PyStringLiteralExpression oldElement, @NotNull String unescaped) {
+  @Override
+  public PyStringLiteralExpression createStringLiteral(@NotNull StringLiteralExpression oldElement, @NotNull String unescaped) {
     Pair<String, String> quotes = PyStringLiteralUtil.getQuotes(oldElement.getText());
     if (quotes != null) {
       return createStringLiteralAlreadyEscaped(quotes.first + unescaped + quotes.second);