Add Post Scan Plugin --package-summary option

Signed-off-by: swastik <swastkk@gmail.com>

Author: swastkk

setup.cfg

@@ -188,6 +188,7 @@ scancode_scan =
 # scan plugins and before the output plugins. See also plugincode.post_scan
 # module for details and doc.
 scancode_post_scan =
+    package_summary = summarycode.package_summary:PackageSummary
     summary = summarycode.summarizer:ScanSummary
     tallies = summarycode.tallies:Tallies
     tallies-with-details = summarycode.tallies:TalliesWithDetails

src/summarycode/package_summary.py

@@ -0,0 +1,36 @@
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# ScanCode is a trademark of nexB Inc.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/scancode-toolkit for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
+
+from plugincode.post_scan import PostScanPlugin
+from plugincode.post_scan import post_scan_impl
+from commoncode.cliutils import PluggableCommandLineOption
+from commoncode.cliutils import POST_SCAN_GROUP
+
+@post_scan_impl
+class PackageSummary(PostScanPlugin):
+    """
+    Summary at the Package Level.
+    """
+
+    options = [
+        PluggableCommandLineOption(('--package-summary',),
+        is_flag=True, default=False,
+        help='Generate Package Level summary',
+        help_group=POST_SCAN_GROUP)
+    ]
+
+    def is_enabled(self, package_summary, **kwargs):
+        return package_summary
+
+    def process_codebase(self, codebase, package_summary, **kwargs):
+        """
+        Process the codebase.
+        """
+        if not self.is_enabled(package_summary):
+            return