From ca0c596423e67f2196b3640afd214cc6dd1f128c Mon Sep 17 00:00:00 2001
From: Kallum Jones <kallummj071001@gmail.com>
Date: Sun, 7 Aug 2022 20:19:52 +0100
Subject: [PATCH] Added a force flag to migrate-possible

---
 src/commands/migrate_possible.ts | 23 +++++++++++++++++------
 src/mods/mods.ts                 | 12 ++++++++++--
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/commands/migrate_possible.ts b/src/commands/migrate_possible.ts
index eec30b0..0858060 100644
--- a/src/commands/migrate_possible.ts
+++ b/src/commands/migrate_possible.ts
@@ -10,8 +10,11 @@ export default class MigratePossibleCommand implements Subcommand {
         program.command("migrate-possible")
             .description("Reports whether it is possible to upgrade to the provided Minecraft version")
             .argument("[version]", "The Minecraft version to try and migrate to")
-            .action((version) => {
+            .option("-f, --force", "Checks whether a force migration is possible, where only essential mods are included", false)
+            .action((version, options) => {
                 ModManager.execute(async () => {
+                        const force = options.force;
+
                         // If no version is provided, prompt user for one
                         if (version === "" || version == undefined) {
                             version = await MinecraftUtils.getMinecraftVersionFromInput("What Minecraft version would you like to migrate to?");
@@ -19,12 +22,20 @@ export default class MigratePossibleCommand implements Subcommand {
 
                         // If version is valid, check if migration is possible
                         if (await MinecraftUtils.isValidVersion(version)) {
-                            const possible = await Mods.isMigratePossible(version);
+                            try {
+                                const possible = await Mods.isMigratePossible(version, force);
 
-                            if (possible) {
-                                PrintUtils.success(`It is possible to migrate to version ${version}`)
-                            } else {
-                                PrintUtils.error(`It is not possible to migrate to version ${version}`)
+                                if (possible) {
+                                    PrintUtils.success(`It is possible to migrate to version ${version}`)
+                                } else {
+                                    PrintUtils.error(`It is not possible to migrate to version ${version}`)
+                                }
+                            } catch (e) {
+                                if (!force) {
+                                    PrintUtils.error("There are no mods installed, try `mod-manager install -h` to learn more!")
+                                } else {
+                                    PrintUtils.error("There are no mods installed that are marked essential. Try `mod-manager essential -h` to learn more!")
+                                }
                             }
                         } else {
                             PrintUtils.error(`${version} is not a valid Minecraft version`);
diff --git a/src/mods/mods.ts b/src/mods/mods.ts
index 4ad6a85..dbb97b4 100644
--- a/src/mods/mods.ts
+++ b/src/mods/mods.ts
@@ -208,8 +208,12 @@ export default class Mods {
         return source
     }
 
-    static async isMigratePossible(version: string): Promise<boolean> {
-        const mods = this.getTrackedMods();
+    static async isMigratePossible(version: string, force: boolean): Promise<boolean> {
+        const mods = !force ? this.getTrackedMods() : this.getEssentialMods();
+
+        if (Util.isArrayEmpty(mods)) {
+            throw new Error("Mods list is empty")
+        }
 
         let availableList = [];
 
@@ -238,4 +242,8 @@ export default class Mods {
         // If the array is empty, all the mods reported as available, and a migration is possible
         return Util.isArrayEmpty(availableList);
     }
+
+    private static getEssentialMods() {
+        return this.getTrackedMods().filter(mod => mod.essential);
+    }
 }
\ No newline at end of file