2 files changed, 40 insertions, 0 deletions
diff --git a/src-vue/src/utils/thunderstore/ThunderstoreModStatus.ts b/src-vue/src/utils/thunderstore/ThunderstoreModStatus.ts
new file mode 100644
index 00000000..f2351226
--- /dev/null
+++ b/src-vue/src/utils/thunderstore/ThunderstoreModStatus.ts
@@ -0,0 +1,7 @@
+export enum ThunderstoreModStatus {
+    INSTALLED,
+    BEING_INSTALLED,
+    BEING_UPDATED,
+    NOT_INSTALLED,
+    OUTDATED
+}
diff --git a/src-vue/src/utils/thunderstore/version.ts b/src-vue/src/utils/thunderstore/version.ts
new file mode 100644
index 00000000..a111e08c
--- /dev/null
+++ b/src-vue/src/utils/thunderstore/version.ts
@@ -0,0 +1,33 @@
+import {ThunderstoreMod} from "../../../../src-tauri/bindings/ThunderstoreMod";
+import {NorthstarMod} from "../../../../src-tauri/bindings/NorthstarMod";
+import {store} from "../../plugins/store";
+
+/**
+ * Strips off a Thunderstore dependency string from its version
+ * (e.g. "taskinoz-WallrunningTitans-1.0.0" to
+ * "taskinoz-WallrunningTitans").
+ **/
+function getThunderstoreDependencyStringPrefix(dependency: string): string {
+    const dependencyStringMembers = dependency.split('-');
+    return `${dependencyStringMembers[0]}-${dependencyStringMembers[1]}`;
+}
+
+function isThunderstoreModOutdated(mod: ThunderstoreMod): boolean {
+    // Ensure mod is up-to-date.
+    const tsModPrefix = getThunderstoreDependencyStringPrefix(mod.versions[0].full_name);
+    const matchingMods: NorthstarMod[] = store.state.installed_mods.filter((mod: NorthstarMod) => {
+        if (!mod.thunderstore_mod_string) return false;
+        return getThunderstoreDependencyStringPrefix(mod.thunderstore_mod_string!) === tsModPrefix;
+    });
+    if (matchingMods.length !== 0) {
+        // There shouldn't be several mods with same dependency string, but we never know...
+        const matchingMod = matchingMods[0];
+        // A mod is outdated if its dependency strings differs from Thunderstore dependency string
+        // (no need for semver check here).
+        // This assumes mod versions list is sorted from newest to oldest version.
+        return matchingMod.thunderstore_mod_string !== mod.versions[0].full_name;
+    }
+    return false;
+}
+
+export { isThunderstoreModOutdated };