fix(reporter): Fix the creation of first level dependency relationships

As of [1] the SPDX reporter intends to associate any first level
dependency with all root projects it corresponds to. The implementation
introduced by [1] has the following issues:

1. Relationships to excluded packages are added, even though excluded
   packages are not contained in the report. For proof see [2] which
   adds such relationship.
2. Dependencies which are direct depdendencies of a sub-project, but not
   of any root project are not considered a first level dependency. Such
   dependencies may not be linked into the dependency tree of resulting
   SPDX document at all.

Rewrite the algorithm in order to fix both of the above mentioned
issues.

Fixes #7487.

[1] b471544
[2] b471544#diff-6de35dd2aff1f92b7f5ea558d3f77e02d0d596dd4ce2a8199056cfb31b47fcabR181-R184

Signed-off-by: Frank Viernau <frank_viernau@epam.com>

plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.json

@@ -240,10 +240,6 @@
     "spdxElementId" : "SPDXRef-Package-Maven-seventh-package-group-seventh-package-0.0.1",
     "relationshipType" : "GENERATED_FROM",
     "relatedSpdxElement" : "SPDXRef-Package-Maven-seventh-package-group-seventh-package-0.0.1-source-artifact"
-  }, {
-    "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
-    "relationshipType" : "DEPENDS_ON",
-    "relatedSpdxElement" : "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
   }, {
     "spdxElementId" : "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1",
     "relationshipType" : "DEPENDS_ON",

plugins/reporters/spdx/src/funTest/assets/spdx-document-reporter-expected-output.spdx.yml

@@ -241,9 +241,6 @@ relationships:
 - spdxElementId: "SPDXRef-Package-Maven-seventh-package-group-seventh-package-0.0.1"
   relationshipType: "GENERATED_FROM"
   relatedSpdxElement: "SPDXRef-Package-Maven-seventh-package-group-seventh-package-0.0.1-source-artifact"
-- spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
-  relationshipType: "DEPENDS_ON"
-  relatedSpdxElement: "SPDXRef-Package-Maven-fifth-package-group-fifth-package-0.0.1"
 - spdxElementId: "SPDXRef-Project-Maven-first-project-group-first-project-name-0.0.1"
   relationshipType: "DEPENDS_ON"
   relatedSpdxElement: "SPDXRef-Package-Maven-first-package-group-first-package-0.0.1"

plugins/reporters/spdx/src/main/kotlin/SpdxDocumentModelMapper.kt

@@ -26,6 +26,7 @@ import java.util.concurrent.atomic.AtomicInteger
 
 import org.apache.logging.log4j.kotlin.Logging
 
+import org.ossreviewtoolkit.model.Identifier
 import org.ossreviewtoolkit.model.OrtResult
 import org.ossreviewtoolkit.model.SourceCodeOrigin.ARTIFACT
 import org.ossreviewtoolkit.model.SourceCodeOrigin.VCS
@@ -64,21 +65,21 @@ internal object SpdxDocumentModelMapper : Logging {
 
         val projects = ortResult.getProjects(omitExcluded = true, includeSubProjects = false).sortedBy { it.id }
         val projectPackages = projects.map { project ->
-            val spdxProjectPackage = project.toPackage().toSpdxPackage(
+            project.toPackage().toSpdxPackage(
                 SpdxPackageType.PROJECT,
                 licenseInfoResolver,
                 ortResult
             )
+        }
 
-            ortResult.getDependencies(project.id, 1).mapTo(relationships) { dependency ->
-                SpdxRelationship(
-                    spdxElementId = spdxProjectPackage.spdxId,
+        ortResult.getRootProjectsForFirstLevelDependencies().forEach { (pkgId, rootProjectIds) ->
+            rootProjectIds.forEach { rootProjectId ->
+                relationships += SpdxRelationship(
+                    spdxElementId = rootProjectId.toSpdxId(SpdxPackageType.PROJECT),
                     relationshipType = SpdxRelationship.Type.DEPENDS_ON,
-                    relatedSpdxElement = dependency.toSpdxId()
+                    relatedSpdxElement = pkgId.toSpdxId(SpdxPackageType.BINARY_PACKAGE)
                 )
             }
-
-            spdxProjectPackage
         }
 
         val files = mutableListOf<SpdxFile>()
@@ -169,3 +170,25 @@ internal object SpdxDocumentModelMapper : Logging {
         ).addExtractedLicenseInfo(licenseTextProvider)
     }
 }
+
+/**
+ * Return a mapping from the identifiers of all non-excluded first level dependencies to the identifiers of the
+ * non-excluded root projects they correspond to.
+ */
+private fun OrtResult.getRootProjectsForFirstLevelDependencies(): Map<Identifier, Set<Identifier>> {
+    val result = mutableMapOf<Identifier, MutableSet<Identifier>>()
+
+    getProjects(omitExcluded = true).map { it.id }.forEach { rootProjectId ->
+        val subProjectIds = getDependencies(rootProjectId).filter { isProject(it) && !isExcluded(it) }
+
+        val firstLevelDependencies = (subProjectIds + rootProjectId).flatMapTo(mutableSetOf()) { projectId ->
+            getDependencies(projectId, maxLevel = 1).filter { isPackage(it) && !isExcluded(it) }
+        }
+
+        firstLevelDependencies.forEach { pkgId ->
+            result.getOrPut(pkgId) { mutableSetOf() } += rootProjectId
+        }
+    }
+
+    return result
+}