From a4adf36837b43e693b288cc700fcd72bbba78cb3 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 27 Dec 2023 22:56:12 +0100
Subject: [PATCH] Clean up the refutation line choice logic a bit.

---
 www/js/remoteglot.js | 47 ++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 24 deletions(-)

diff --git a/www/js/remoteglot.js b/www/js/remoteglot.js
index 34b413f..cf5fba7 100644
--- a/www/js/remoteglot.js
+++ b/www/js/remoteglot.js
@@ -75,34 +75,29 @@ let occupied_by_arrows = [];
 
 /** Currently displayed refutation lines (on-screen).
  * Can either come from the current_analysis_data, displayed_analysis_data,
- * or hash_refutation_lines.
+ * or hash_refutation_lines (choose_displayed_refutation_lines() chooses which one).
  *
- * TODO: This is a mess, and we should probably just let update_refutation_lines()
- * decide anew every time instead of storing the state here in multiple global
- * variables.
- *
- * @type {Array.<{
+ * @typedef {{
  *     score: Array,
  *     depth: string,
  *     pv: Array.<string>,
  *     move: string
- * }>}
+ * }}
  * @private
  */
-let refutation_lines = [];
+var RefutationLine;
 
 /** Refutation lines from current hash probe.
- *
  * If non-null, will override refutation lines from the base position.
- * Note that these are relative to display_fen, not base_fen.
+ *
+ * @type {Array.<RefutationLine>}
  */
 let hash_refutation_lines = null;
 
 /**
- * What FEN refutation_lines is relative to. Will usually be base_fen,
- * but if another move gets loaded while we are looking, they can diverge.
+ * What FEN hash_refutation_lines is relative to.
  */
-let refutation_lines_base_fen = null;
+let hash_refutation_lines_base_fen = null;
 
 /** @type {number} @private */
 let ims = 0;
@@ -861,12 +856,23 @@ function collapse_history(truncate_history) {
 }
 window['collapse_history'] = collapse_history;
 
-/** Update the HTML display of multi-PV from the global "refutation_lines".
+function choose_displayed_refutation_lines() {
+	if (hash_refutation_lines) {
+		// If we're in hash exploration, that takes precedence.
+		return [hash_refutation_lines, hash_refutation_lines_base_fen];
+	} else {
+		let data = displayed_analysis_data || current_analysis_data;
+		return [data['refutation_lines'], data['position']['fen']];
+	}
+}
+
+/** Update the HTML display of multi-PV.
  *
  * Also recreates the global "display_lines".
  */
 function update_refutation_lines() {
-	if (refutation_lines_base_fen === null) {
+	const [refutation_lines, refutation_lines_base_fen] = choose_displayed_refutation_lines();
+	if (!refutation_lines) {
 		return;
 	}
 	if (display_lines.length > 2) {
@@ -1253,8 +1259,6 @@ function update_board() {
 		document.getElementById("refutationlines").replaceChildren();
 		document.getElementById("whiteclock").replaceChildren();
 		document.getElementById("blackclock").replaceChildren();
-		refutation_lines = [];
-		refutation_lines_base_fen = null;
 		update_refutation_lines();
 		clear_arrows();
 		update_displayed_line();
@@ -1391,12 +1395,7 @@ function update_board() {
 		}
 	}
 
-	// Update the refutation lines.
 	base_fen = data['position']['fen'];
-	if (hash_refutation_lines === null) {
-		refutation_lines = data['refutation_lines'];
-		refutation_lines_base_fen = base_fen;
-	}
 	update_refutation_lines();
 
 	// Update the sparkline last, since its size depends on how everything else reflowed.
@@ -1750,7 +1749,6 @@ function show_line(line_num, move_num) {
 		current_display_line = null;
 		current_display_move = null;
 		hash_refutation_lines = null;
-		refutation_lines_base_fen = base_fen;
 		if (displayed_analysis_data) {
 			// TODO: Support exiting to history position if we are in an
 			// analysis line of a history position.
@@ -2076,7 +2074,7 @@ function show_explore_hash_results(data, fen) {
 	}
 	current_hash_display_timer = null;
 	hash_refutation_lines = data['lines'];
-	refutation_lines_base_fen = fen;
+	hash_refutation_lines_base_fen = fen;
 	update_board();
 }
 
@@ -2188,6 +2186,7 @@ function get_best_move(game, source, target, invert) {
 	let best_move = null;
 	let best_move_score = null;
 
+	let refutation_lines = choose_displayed_refutation_lines()[0];
 	for (let move in refutation_lines) {
 		let line = refutation_lines[move];
 		if (!line['score']) {
-- 
2.39.2