Initial attempt (untested)

index.js

@@ -1,21 +1,62 @@
 const core = require('@actions/core');
-const wait = require('./wait');
+const fs = require('fs');
+const glob = require('glob');
 
+import {
+  PackageCache,
+  BuildTarget,
+  Package,
+  Snapshot,
+  submitSnapshot
+} from '@github/dependency-submission-toolkit'
 
-// most @actions toolkit packages have async methods
 async function run() {
-  try {
-    const ms = core.getInput('milliseconds');
-    core.info(`Waiting ${ms} milliseconds ...`);
+  let spdxFiles = await parseFiles(await searchFiles());
+  
+  let snapshot = new Snapshot({
+    detector: new Detector({
+      name: "spdx-to-dependency-graph-action",
+      version: "0.0.1",
+      url: "https://github.com/jhutchings1/spdx-to-dependency-graph-action",
+    })
+  });
 
-    core.debug((new Date()).toTimeString()); // debug is only output if you set the secret `ACTIONS_RUNNER_DEBUG` to true
-    await wait(parseInt(ms));
-    core.info((new Date()).toTimeString());
+  spdxFiles.forEach(spdxFile => {
+    let manifest = new Manifest(spdxFile.name);
+    spdxFile.packages.forEach(pkg => {
+      let packageName = pkg.packageName;
+      let packageVersion = pkg.packageVersion;
+      let purl = pkg.purl;
 
-    core.setOutput('time', new Date().toTimeString());
-  } catch (error) {
-    core.setFailed(error.message);
-  }
+      manifest.addPackage(new Package(packageName, packageVersion, purl));
+      snapshot.addManifest(manifest);
+    });
+  });
+
+  submitSnapshot(snapshot);
+}
+
+async function parseFiles(files) {
+  let spdxFiles = [];
+  files.forEach(file => {
+    fs.readFile(file, (err, content) => {
+      spdxFiles.push(parseSPDXFile(JSON.parse(content)));
+    });
+  });
+  return spdxFiles;
+}
+
+async function searchFiles() {
+  let filePath = core.getInput('filePath');
+  let filePattern = core.getInput('filePattern');
+
+  glob(`${filePath}/${filePattern}`, {}, (err, files) => {
+    if (err) {
+      core.error(err);
+    } else {
+      return files;
+    }
+  });
 }
 
 run();