From dda730dfa2d37e7e530e77f76df373fe4b287d26 Mon Sep 17 00:00:00 2001
From: Luc Mcgrady <lucmcgrady@gmail.com>
Date: Thu, 4 Sep 2025 05:35:00 +0100
Subject: [PATCH] Fix/Invalid memory states in simulator after parameters
 changed (#4317)

* Fix/Invalid memory states after optimization for simulator

* Update ts/routes/deck-options/FsrsOptions.svelte

* typo

* ./check
---
 ftl/core/deck-config.ftl                  |  1 +
 ts/routes/deck-options/FsrsOptions.svelte | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ftl/core/deck-config.ftl b/ftl/core/deck-config.ftl
index 43d03c6bb..e365d9553 100644
--- a/ftl/core/deck-config.ftl
+++ b/ftl/core/deck-config.ftl
@@ -498,6 +498,7 @@ deck-config-desired-retention-below-optimal = Your desired retention is below op
 # cards that can be recalled or retrieved on a specific date.
 deck-config-fsrs-simulator-experimental = FSRS Simulator (Experimental)
 deck-config-fsrs-simulate-desired-retention-experimental = FSRS Desired Retention Simulator (Experimental)
+deck-config-fsrs-simulate-save-preset = After optimizing, please save your config before running the simulator.
 deck-config-fsrs-desired-retention-help-me-decide-experimental = Help Me Decide (Experimental)
 deck-config-additional-new-cards-to-simulate = Additional new cards to simulate
 deck-config-simulate = Simulate
diff --git a/ts/routes/deck-options/FsrsOptions.svelte b/ts/routes/deck-options/FsrsOptions.svelte
index a166f2081..48124771f 100644
--- a/ts/routes/deck-options/FsrsOptions.svelte
+++ b/ts/routes/deck-options/FsrsOptions.svelte
@@ -53,6 +53,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     let desiredRetentionFocused = false;
     let desiredRetentionEverFocused = false;
     let optimized = false;
+    const initialParams = [...fsrsParams($config)];
     $: if (desiredRetentionFocused) {
         desiredRetentionEverFocused = true;
     }
@@ -338,6 +339,14 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
         state.save(UpdateDeckConfigsMode.COMPUTE_ALL_PARAMS);
     }
 
+    function showSimulatorModal(modal: Modal) {
+        if (fsrsParams($config).toString() === initialParams.toString()) {
+            modal?.show();
+        } else {
+            alert(tr.deckConfigFsrsSimulateSavePreset());
+        }
+    }
+
     let simulatorModal: Modal;
     let workloadModal: Modal;
 </script>
@@ -368,7 +377,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     class="btn btn-primary"
     on:click={() => {
         simulateFsrsRequest.reviewLimit = 9999;
-        workloadModal?.show();
+        showSimulatorModal(workloadModal);
     }}
 >
     {tr.deckConfigFsrsDesiredRetentionHelpMeDecideExperimental()}
@@ -455,7 +464,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 <hr />
 
 <div class="m-1">
-    <button class="btn btn-primary" on:click={() => simulatorModal?.show()}>
+    <button class="btn btn-primary" on:click={() => showSimulatorModal(simulatorModal)}>
         {tr.deckConfigFsrsSimulatorExperimental()}
     </button>
 </div>