feat(helper-cli): Add a command to show insights into scan issues

Assign scan issues to categories and output for each category the amount
of dependency affected by a scan issue of the respective category. Also
show a secondary count which disregards the version.

These statistics can be useful as a basis to make a rough estimate of
the effort needed to fix the scan issues.

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

helper-cli/src/main/kotlin/HelperMain.kt

@@ -84,6 +84,7 @@ internal class HelperMain : CliktCommand(
             ExtractRepositoryConfigurationCommand(),
             GenerateTimeoutErrorResolutionsCommand(),
             GetPackageLicensesCommand(),
+            GroupScanIssuesCommand(),
             DownloadResultsFromPostgresCommand(),
             ImportCopyrightGarbageCommand(),
             ImportScanResultsCommand(),

helper-cli/src/main/kotlin/commands/GroupScanIssuesCommand.kt

@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2024 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * License-Filename: LICENSE
+ */
+
+package org.ossreviewtoolkit.helper.commands
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.options.convert
+import com.github.ajalt.clikt.parameters.options.option
+import com.github.ajalt.clikt.parameters.options.required
+import com.github.ajalt.clikt.parameters.types.file
+
+import org.ossreviewtoolkit.model.Issue
+import org.ossreviewtoolkit.model.OrtResult
+import org.ossreviewtoolkit.model.Severity
+import org.ossreviewtoolkit.model.readValue
+import org.ossreviewtoolkit.utils.common.expandTilde
+
+class GroupScanIssuesCommand : CliktCommand(
+    help = "Shows the amount of affected dependencies for each scan issue category."
+) {
+    private val ortFile by option(
+        "--ort-file", "-i",
+        help = "The ORT result file to read as input."
+    ).convert { it.expandTilde() }
+        .file(mustExist = true, canBeFile = true, canBeDir = false, mustBeWritable = false, mustBeReadable = true)
+        .convert { it.absoluteFile.normalize() }
+        .required()
+
+    override fun run() {
+        val ortResult = ortFile.readValue<OrtResult>()
+
+        val issues = ortResult.getScannerIssues(
+            omitExcluded = true,
+            omitResolved = true,
+            minSeverity = Severity.ERROR
+        ).filter { (id, _) -> ortResult.isPackage(id) }
+
+        val issueCategoriesForId = issues.mapValues { issue ->
+            issue.value.mapTo(mutableSetOf()) { it.category }
+        }
+
+        val issueCategoriesForIdWithoutVersion = issueCategoriesForId.entries.groupBy(
+            { it.key.copy(version = "") },
+            { it.value }
+        ).mapValues { it.value.flatten().toSet() }
+
+        val pkgCountsForIssueCategory = ScanIssueCategory.entries.associateWith { category ->
+            val numPackages = issueCategoriesForId.count { (_, categories) ->
+                category in categories
+            }
+
+            val numPackagesWithoutVersion = issueCategoriesForIdWithoutVersion.count { (_, categories) ->
+                category in categories
+            }
+
+            numPackages to numPackagesWithoutVersion
+        }
+
+        val stats = buildString {
+            pkgCountsForIssueCategory.entries.sortedByDescending { it.value.first }.forEach { (category, counts) ->
+                appendLine("$category: ${counts.first} / ${counts.second}")
+            }
+        }
+
+        print(stats)
+    }
+}
+
+private enum class ScanIssueCategory(
+    val regex: Regex
+) {
+    PROVENANCE_INFO_MISSING(
+        "IOException: Could not resolve provenance for package '.*' for source code origins \\[.*\\]\\."
+    ),
+    SCAN_TIMED_OUT(
+        "ERROR: Timeout after .* seconds while scanning file '.*'\\."
+    ),
+    VCS_REVISION_NOT_FOUND(
+        ".*Could not resolve revision.*Could not find any revision candidates.*"
+    ),
+    VCS_PATH_NOT_EXISTENT(
+        ".*Could not resolve provenance.*because the requested VCS path.*does not exist."
+    ),
+    VCS_TYPE_UNKNOWN(
+        ".*Could not determine VCS for type.*"
+    ),
+    OTHER("");
+
+    constructor(pattern: String) : this(pattern.toRegex(setOf(RegexOption.DOT_MATCHES_ALL, RegexOption.MULTILINE)))
+
+    companion object {
+        fun forIssue(issue: Issue) = entries.find { it.regex.matches(issue.message) } ?: OTHER
+    }
+}
+
+private val Issue.category: ScanIssueCategory
+    get() = ScanIssueCategory.forIssue(this)