KTIJ-26423 [AA] Return more info from KtFirImportOptimizer

Deprecate `unusedImports`, since they are supposed to be computed
on the IDE side from now on based on the information from
Analysis API

Currently the `unusedImports` property is not removed completely
so it can still be used by the Kotlin side import optimizer
tests; they should be moved/adapted to the intellij repository
also

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirImportOptimizer.kt

@@ -57,7 +57,7 @@ internal class KtFirImportOptimizer(
 
     override fun analyseImports(file: KtFile): KtImportOptimizerResult {
         val existingImports = file.importDirectives
-        if (existingImports.isEmpty()) return KtImportOptimizerResult(emptySet())
+        if (existingImports.isEmpty()) return KtImportOptimizerResult()
 
         val firFile = file.getOrBuildFirFile(firResolveSession).apply { lazyResolveToPhase(FirResolvePhase.BODY_RESOLVE) }
 
@@ -68,9 +68,10 @@ internal class KtFirImportOptimizer(
             .map { it.fqName }
             .toSet()
 
-        val (usedImports, unresolvedNames) = collectReferencedEntities(firFile)
+        val (usedDeclarations, unresolvedNames) = collectReferencedEntities(firFile)
 
-        val referencesEntities = usedImports
+        // TODO remove unused imports computing code completely
+        val referencesEntities = usedDeclarations
             .filterNot { (fqName, referencedByNames) ->
                 val fromCurrentPackage = fqName.parentOrNull() == file.packageFqName
                 val noAliasedImports = referencedByNames.singleOrNull() == fqName.shortName()
@@ -104,7 +105,7 @@ internal class KtFirImportOptimizer(
             }
         }
 
-        return KtImportOptimizerResult(unusedImports)
+        return KtImportOptimizerResult(unusedImports, usedDeclarations, unresolvedNames)
     }
 
     private data class ReferencedEntitiesResult(

analysis/analysis-api-impl-base/tests/org/jetbrains/kotlin/analysis/api/impl/base/test/cases/components/importOptimizer/AbstractAnalysisApiImportOptimizerTest.kt

@@ -16,6 +16,7 @@ abstract class AbstractAnalysisApiImportOptimizerTest : AbstractAnalysisApiBased
         val mainKtFile = ktFiles.singleOrNull() ?: ktFiles.first { it.name == "main.kt" }
         val unusedImports = analyseForTest(mainKtFile) {
             val results = analyseImports(mainKtFile)
+            @Suppress("DEPRECATION")
             results.unusedImports
         }
 

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/components/KtImportOptimizer.kt

@@ -7,6 +7,8 @@ package org.jetbrains.kotlin.analysis.api.components
 
 import org.jetbrains.kotlin.analysis.api.lifetime.KtLifetimeOwner
 import org.jetbrains.kotlin.analysis.api.lifetime.withValidityAssertion
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtImportDirective
 
@@ -28,5 +30,8 @@ public interface KtImportOptimizerMixIn : KtAnalysisSessionMixIn {
 }
 
 public class KtImportOptimizerResult(
-    public val unusedImports: Set<KtImportDirective>,
+    @Deprecated("Compute unused import on the IntelliJ side instead, see org.jetbrains.kotlin.idea.base.analysis.api.utils.computeUnusedImports")
+    public val unusedImports: Set<KtImportDirective> = emptySet(),
+    public val usedDeclarations: Map<FqName, Set<Name>> = emptyMap(),
+    public val unresolvedNames: Set<Name> = emptySet(),
 )