Add a CSV export for the Texas Hold'em hand history log

A dedicated dealer needs a paper trail that outlives the browser tab, not
just a scrollable in-app panel — the Export CSV button downloads the full
resolved-pot log (hand #, time, pot, payouts) for recordkeeping or a
disputed chip count after the session ends.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb

JoshHeaps.Net/Pages/Casino/TexasHoldem.cshtml

@@ -91,8 +91,11 @@
                 <div class="panelBody">
                     <div id="handHistoryList"></div>
                     <p id="handHistoryEmptyHint" class="fieldHint">Resolved pots show up here as you play, in case a chip count is disputed later.</p>
+                    <div class="handHistoryActions">
+                        <button id="exportHistoryBtn" class="holdemBtn holdemBtnSmall">Export CSV</button>
                         <button id="clearHistoryBtn" class="holdemBtn holdemBtnSmall holdemBtnDanger">Clear history</button>
                     </div>
+                </div>
             </details>
         </aside>
     </div>
@@ -196,5 +199,6 @@
     <script src="~/js/casino/holdem/state.js?v=@ViewData["cssVersion"]"></script>
     <script src="~/js/casino/holdem/render.js?v=@ViewData["cssVersion"]"></script>
     <script src="~/js/casino/holdem/potWizard.js?v=@ViewData["cssVersion"]"></script>
+    <script src="~/js/casino/holdem/handHistoryExport.js?v=@ViewData["cssVersion"]"></script>
     <script src="~/js/casino/holdem/main.js?v=@ViewData["cssVersion"]"></script>
 }

JoshHeaps.Net/wwwroot/css/casino/holdem.css

@@ -120,6 +120,18 @@ body {
     font-size: 0.75rem;
 }
 
+.holdemBtn:disabled {
+    opacity: 0.4;
+    cursor: not-allowed;
+    transform: none;
+}
+
+.handHistoryActions {
+    display: flex;
+    gap: 0.5rem;
+    margin-top: 0.5rem;
+}
+
 /* ---------- Layout ---------- */
 
 #holdemLayout {

JoshHeaps.Net/wwwroot/js/casino/holdem/handHistoryExport.js

@@ -0,0 +1,58 @@
+// Turns the in-memory hand history into a CSV file the dealer can download for a
+// paper trail — a house manager or a disputed chip count needs something that
+// outlives the browser tab, not just a scrollable panel in the sidebar.
+const HandHistoryExport = {
+    csvField(value) {
+        const str = String(value ?? "");
+        return /[",\n]/.test(str) ? `"${str.replace(/"/g, '""')}"` : str;
+    },
+
+    formatTimestamp(timestamp) {
+        try {
+            return new Date(timestamp).toLocaleString();
+        } catch {
+            return "";
+        }
+    },
+
+    toCsv(handHistory) {
+        const rows = [["Hand #", "Time", "Pot", "Payouts"]];
+        // handHistory is stored newest-first; the export reads better oldest-first.
+        [...handHistory].reverse().forEach(entry => {
+            const payouts = (entry.payouts || [])
+                .map(p => `${p.label}: ${Money.format(p.amount)}`)
+                .join("; ");
+            rows.push([
+                entry.handNumber,
+                this.formatTimestamp(entry.timestamp),
+                Money.format(entry.pot),
+                payouts,
+            ]);
+        });
+        return rows.map(row => row.map(f => this.csvField(f)).join(",")).join("\r\n");
+    },
+
+    fileName() {
+        const now = new Date();
+        const pad = n => String(n).padStart(2, "0");
+        const stamp = `${now.getFullYear()}-${pad(now.getMonth() + 1)}-${pad(now.getDate())}-${pad(now.getHours())}${pad(now.getMinutes())}`;
+        return `holdem-hand-history-${stamp}.csv`;
+    },
+
+    download(handHistory) {
+        const csv = this.toCsv(handHistory);
+        const blob = new Blob([csv], { type: "text/csv;charset=utf-8;" });
+        const url = URL.createObjectURL(blob);
+        const link = document.createElement("a");
+        link.href = url;
+        link.download = this.fileName();
+        document.body.appendChild(link);
+        link.click();
+        document.body.removeChild(link);
+        URL.revokeObjectURL(url);
+    },
+};
+
+if (typeof module !== "undefined" && module.exports) {
+    module.exports = HandHistoryExport;
+}

JoshHeaps.Net/wwwroot/js/casino/holdem/main.js

@@ -82,4 +82,9 @@ document.addEventListener("DOMContentLoaded", () => {
         hooks.save(state);
         Render.renderAll();
     });
+
+    document.getElementById("exportHistoryBtn").addEventListener("click", () => {
+        if ((state.handHistory || []).length === 0) return;
+        HandHistoryExport.download(state.handHistory);
+    });
 });

JoshHeaps.Net/wwwroot/js/casino/holdem/render.js

@@ -369,6 +369,7 @@ const Render = {
         const history = this.state.handHistory || [];
         list.innerHTML = "";
         emptyHint.hidden = history.length > 0;
+        document.getElementById("exportHistoryBtn").disabled = history.length === 0;
 
         const template = document.getElementById("handHistoryRowTemplate");
         history.forEach(entry => {