@NotNull
private static MultiMap<String, GoImportSpec> collectImportsWithSameString(
@NotNull Collection<GoImportSpec> importsWithSameName) {
MultiMap<String, GoImportSpec> importsWithSameString = MultiMap.create();
for (PsiElement duplicateCandidate : importsWithSameName) {
GoImportSpec importSpec = getImportSpec(duplicateCandidate);
if (importSpec != null) {
importsWithSameString.putValue(importSpec.getPath(), importSpec);
}
}
return importsWithSameString;
}
@NotNull
public static Set<PsiElement> findRedundantImportIdentifiers(
@NotNull MultiMap<String, GoImportSpec> importMap) {
Set<PsiElement> importIdentifiersToDelete = ContainerUtil.newLinkedHashSet();
for (PsiElement importEntry : importMap.values()) {
GoImportSpec importSpec = getImportSpec(importEntry);
if (importSpec != null) {
String localPackageName = importSpec.getLocalPackageName();
if (!StringUtil.isEmpty(localPackageName)) {
if (Comparing.equal(importSpec.getAlias(), localPackageName)) {
importIdentifiersToDelete.add(importSpec.getIdentifier());
}
}
}
}
return importIdentifiersToDelete;
}
private static boolean hasImportUsers(@NotNull GoImportSpec spec) {
//noinspection SynchronizationOnLocalVariableOrMethodParameter
synchronized (spec) {
List<PsiElement> list = spec.getUserData(GoReferenceBase.IMPORT_USERS);
if (list != null) {
for (PsiElement e : list) {
if (e.isValid()) {
return true;
}
ProgressManager.checkCanceled();
}
}
}
return false;
}
public static MultiMap<String, GoImportSpec> filterUnusedImports(
@NotNull PsiFile file, @NotNull MultiMap<String, GoImportSpec> importMap) {
MultiMap<String, GoImportSpec> result = MultiMap.create();
result.putAllValues(importMap);
result.remove("_"); // imports for side effects are always used
Collection<GoImportSpec> implicitImports = ContainerUtil.newArrayList(result.get("."));
for (GoImportSpec importEntry : implicitImports) {
GoImportSpec spec = getImportSpec(importEntry);
if (spec != null && spec.isDot() && hasImportUsers(spec)) {
result.remove(".", importEntry);
}
}
file.accept(
new GoRecursiveVisitor() {
@Override
public void visitTypeReferenceExpression(@NotNull GoTypeReferenceExpression o) {
GoTypeReferenceExpression lastQualifier = o.getQualifier();
if (lastQualifier != null) {
GoTypeReferenceExpression previousQualifier;
while ((previousQualifier = lastQualifier.getQualifier()) != null) {
lastQualifier = previousQualifier;
}
markAsUsed(lastQualifier.getIdentifier(), lastQualifier.getReference());
}
}
@Override
public void visitReferenceExpression(@NotNull GoReferenceExpression o) {
GoReferenceExpression lastQualifier = o.getQualifier();
if (lastQualifier != null) {
GoReferenceExpression previousQualifier;
while ((previousQualifier = lastQualifier.getQualifier()) != null) {
lastQualifier = previousQualifier;
}
markAsUsed(lastQualifier.getIdentifier(), lastQualifier.getReference());
}
}
private void markAsUsed(@NotNull PsiElement qualifier, @NotNull PsiReference reference) {
String qualifierText = qualifier.getText();
if (!result.containsKey(qualifierText)) {
// already marked
return;
}
PsiElement resolve = reference.resolve();
if (!(resolve instanceof PsiDirectory
|| resolve instanceof GoImportSpec
|| resolve instanceof PsiDirectoryContainer)) {
return;
}
Collection<String> qualifiersToDelete = ContainerUtil.newHashSet();
for (GoImportSpec spec : result.get(qualifierText)) {
for (Map.Entry<String, Collection<GoImportSpec>> entry : result.entrySet()) {
for (GoImportSpec importSpec : entry.getValue()) {
if (importSpec == spec) {
qualifiersToDelete.add(entry.getKey());
}
}
}
}
for (String qualifierToDelete : qualifiersToDelete) {
result.remove(qualifierToDelete);
}
}
});
return result;
}