From afe72b9ee18df06a433cafcaf043e74a9beec078 Mon Sep 17 00:00:00 2001
From: Codex Agent <agent@example.com>
Date: Sun, 8 Mar 2026 19:49:08 +0000
Subject: [PATCH] Use minimal share params and source-aware hydration

---
 .../src/lib/components/Calculator.svelte      | 39 ++++++++++++++++---
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/hdyc-svelte/src/lib/components/Calculator.svelte b/hdyc-svelte/src/lib/components/Calculator.svelte
index 07c60e8..e2f4bf6 100644
--- a/hdyc-svelte/src/lib/components/Calculator.svelte
+++ b/hdyc-svelte/src/lib/components/Calculator.svelte
@@ -80,10 +80,21 @@
     const v1 = toQueryValue(val1);
     const v2 = toQueryValue(val2);
     const v3 = toQueryValue(val3);
+    const source: 1 | 2 | 3 = has3 ? activeField : (activeField === 2 ? 2 : 1);
+    params.set('src', String(source));
 
-    if (v1 !== null) params.set('v1', v1);
-    if (v2 !== null) params.set('v2', v2);
-    if (has3 && v3 !== null) params.set('v3', v3);
+    if (!has3) {
+      const sourceValue = source === 1 ? v1 : v2;
+      if (sourceValue !== null) {
+        params.set(source === 1 ? 'v1' : 'v2', sourceValue);
+      }
+    } else if (source === 3) {
+      if (v2 !== null) params.set('v2', v2);
+      if (v3 !== null) params.set('v3', v3);
+    } else {
+      if (v1 !== null) params.set('v1', v1);
+      if (v2 !== null) params.set('v2', v2);
+    }
 
     const shareUrl = new URL($page.url);
     shareUrl.search = params.toString();
@@ -178,9 +189,25 @@
 
   onMount(() => {
     const params = new URLSearchParams($page.url.search);
-    if (params.has('v1')) { val1 = params.get('v1')!; handleInput(1); }
-    else if (params.has('v2')) { val2 = params.get('v2')!; handleInput(2); }
-    else if (params.has('v3') && has3) { val3 = params.get('v3')!; handleInput(3); }
+    const srcParam = Number(params.get('src'));
+    const shareSource = srcParam === 1 || srcParam === 2 || srcParam === 3 ? srcParam : null;
+
+    if (shareSource !== null) {
+      if (params.has('v1')) val1 = params.get('v1') ?? '';
+      if (params.has('v2')) val2 = params.get('v2') ?? '';
+      if (params.has('v3') && has3) val3 = params.get('v3') ?? '';
+      const sourceToApply: 1 | 2 | 3 = has3 ? shareSource : (shareSource === 2 ? 2 : 1);
+      handleInput(sourceToApply);
+    } else if (params.has('v1')) {
+      val1 = params.get('v1') ?? '';
+      handleInput(1);
+    } else if (params.has('v2')) {
+      val2 = params.get('v2') ?? '';
+      handleInput(2);
+    } else if (params.has('v3') && has3) {
+      val3 = params.get('v3') ?? '';
+      handleInput(3);
+    }
     setTimeout(() => { paramsInitializing = false; }, 0);
   });