Restore original Space files and editable Bot API URL

README.md

@@ -11,18 +11,24 @@ short_description: Play Baghchal in-browser vs a tablebase-checked engine
 
 # Baghchal — Tigers & Goats
 
-The default opponent is **hosted Venom**, served over HTTPS from the Oracle VM:
+Play the Nepali board game against a real engine. Everything runs **in your browser**: legal-move
+generation, the OBX board notation, and the engine ladder from `pebble` (random) up to `phantom`
+(PVS + LMR search).
 
-- Bot API: https://venom.129.159.173.183.sslip.io/
-- Health: https://venom.129.159.173.183.sslip.io/health
+**How strong is `phantom`?** Baghchal is a solved game — it is a draw with best play — so every
+move can be checked against the truth. Over 400 sampled positions `phantom` plays a value-optimal
+move **90.3%** of the time *on positions where the choice actually matters*: the ones where at
+most half the legal moves hold the game value. A uniformly random player scores **20.6%** there.
 
-Venom uses full-game WDL, distance to win, trap density and phase evaluation.
-The board requests Venom explicitly and checks that replies identify the selected bot.
-If the connection fails, the move stops with a visible error. It never silently plays a
-browser engine in place of Venom. The old HTTP VM URL is upgraded to HTTPS on this page
-because browsers block HTTP API requests from HTTPS pages.
+That qualifier is the whole point. The unrestricted "agreement with perfect play" figure is
+**96.0%** for `phantom` — but **64.1%** for a bot playing at random, because in a drawn game
+almost any move preserves the draw. Quoting the unrestricted number alone makes a listless engine
+look nearly perfect, so both are published here. (Reproduce with `python -m bagh_bench.agreement
+--states 400 --time-ms 300 --bots pebble,shepherd,hunter,stalker,phantom,venom`.)
 
-To use browser engines offline, clear the Bot API field and select a local engine.
-Python search bots run through Pyodide; they do not have the hosted solved database.
-The API response panel uses the configured hosted bot, or an explicitly local Python
-preview when no API URL is configured. This static Space itself is not a bot API endpoint.
+There is no server. This is a *static* Space; the Python engine is CPython compiled to WebAssembly
+via [Pyodide](https://pyodide.org), loaded on your first bot move. If Pyodide cannot start, the
+board falls back to a lighter JavaScript engine so the game always works.
+
+Set a **Bot API** URL in the side panel to use a hosted engine instead — that is the only way to
+reach the *perfect* tablebase bot, which needs an 8.7 GB solved database no browser can hold.

bagh_engine.zip

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:9c541fe2641f44236f14ce033b2064e688942deae2445b8da2bf646ac282cc87
-size 1022769
+oid sha256:04e2bf1382a2e42bf4aed0a7b299638890d1dffa392294e702b614aee8a4f10a
+size 1021420

index.html

@@ -277,9 +277,8 @@
         </div>
         <div class="ctl-line">
           <label for="serverUrl" title="Optional: point at a running bagh-server for named bots + exact tablebase / venom analysis">Bot&nbsp;API</label>
-          <input type="text" id="serverUrl" value="http://129.159.173.183:8080" placeholder="http://129.159.173.183:8080">
+          <input type="text" id="serverUrl" placeholder="http://127.0.0.1:8080 (optional)">
         </div>
-        <div id="apiStatus" class="src" role="status" aria-live="polite">Connecting to Bot API…</div>
       </div>
 
       <div class="card">
@@ -595,7 +594,7 @@ let analyzeTimer = null;
 function analyze() {
   refreshPlacementHints();
   render();
-  const url = serverBase();
+  const url = document.getElementById("serverUrl").value.trim();
   clearTimeout(analyzeTimer);
   analyzeTimer = setTimeout(() => (url ? analyzeServer(url) : analyzeLocal()), 60);
 }
@@ -644,8 +643,8 @@ async function analyzeServer(url) {
     setEvalBar(top ? (top.value === "WIN" ? 9999 : top.value === "LOSS" ? -9999 : 0) * (state.turn === "T" ? 1 : -1) : 0);
     document.getElementById("pv").textContent = "server analysis — see ranking";
   } catch (e) {
+    src.textContent = "· local eval (server unreachable)";
     analyzeLocal();
-    src.textContent = "· local analysis only (Bot API unreachable)";
   }
 }
 function renderMoves(view) {
@@ -668,7 +667,14 @@ function renderMoves(view) {
 
 // ---------- controls ----------
 document.getElementById("btnEngine").addEventListener("click", () => {
-  doOneBotMove(document.getElementById("playBot").value || (serverBase() ? "venom" : LOCAL));
+  if (winner(state)) return;
+  const depth = +document.getElementById("depth").value;
+  const rows = rankMoves(state, depth);
+  if (rows.length) {
+    const best = rows[0].val;
+    const ties = rows.filter(r => r.val === best);
+    doMove(ties[Math.floor(Math.random() * ties.length)].m);
+  }
 });
 document.getElementById("btnUndo").addEventListener("click", () => {
   if (history.length) { state = history.pop(); lastMove = null; selected = null; destMap.clear(); analyze(); }
@@ -710,46 +716,25 @@ let botThinking = false;
 let watchRunning = false;
 
 const $ = id => document.getElementById(id);
-const SECURE_BOT_API = "https://venom.129.159.173.183.sslip.io";
-const serverBase = () => {
-  let val = $("serverUrl").value.trim().replace(/\/$/, "");
-  if (window.location.protocol === "https:" && /^http:\/\/129\.159\.173\.183:8080$/i.test(val)) {
-    val = SECURE_BOT_API;
-    $("serverUrl").value = val;
-  }
-  return val;
-};
-function resolveMoveStr(s, text) {
-  if (typeof text !== "string") return null;
-  const token = text.trim().replace(/^m/i, "");
-  for (const m of legalMoves(s)) {
-    const wire = m.kind === "place" ? coord(m.dst)
-      : coord(m.src) + coord(m.dst) + (m.kind === "capture" ? "(" + coord(m.over) + ")" : "");
-    if (moveStr(m) === token || wire === token) return m;
-  }
-  return null;
-}
+const serverBase = () => $("serverUrl").value.trim().replace(/\/$/, "");
+function resolveMoveStr(s, text) { for (const m of legalMoves(s)) if (moveStr(m) === text) return m; return null; }
 
-// Hosted selections must answer as the requested bot. Connection failures never play locally.
+// Ask a bot for a move: the named server bot if a Bot API is set, else the local JS engine.
 async function botChooseMove(botName) {
   const base = serverBase();
   if (base && botName && botName !== LOCAL) {
+    try {
       const res = await fetch(base + "/move", {
         method: "POST", headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ obx: serialize(state), bot: botName, time_ms: 1000 }),
-        signal: AbortSignal.timeout(15000)
+        body: JSON.stringify({ obx: serialize(state), bot: botName, time_ms: 1000 })
       });
-      if (!res.ok) throw new Error("Bot API returned HTTP " + res.status);
-      const data = await res.json();
-      if (data.bot !== botName || (["venom", "oracle"].includes(botName) && data.source !== "tablebase")) {
-        throw new Error("Bot API did not return the selected " + botName + " policy");
+      if (res.ok) {
+        const data = await res.json();
+        if (data.move) { const m = resolveMoveStr(state, data.move); if (m) return m; }
       }
-      const m = resolveMoveStr(state, data.algebraic) || resolveMoveStr(state, data.move);
-      if (!m) throw new Error("Bot API returned no legal move");
-      return m;
+    } catch (e) { /* fall through to local engine */ }
   }
-  if (botName && botName !== LOCAL) throw new Error("Set a Bot API URL to use " + botName);
-  // Only an explicit Local selection runs the JavaScript engine.
+  // Local fallback: depth-limited negamax, random among ties.
   const depth = +$("depth").value;
   const rows = rankMoves(state, depth);
   if (!rows.length) return null;
@@ -760,21 +745,11 @@ async function botChooseMove(botName) {
 async function doOneBotMove(botName) {
   if (winner(state) || botThinking) return false;
   botThinking = true; render();
-  const position = serialize(state);
-  try {
-    const m = await botChooseMove(botName);
-    if (!m || serialize(state) !== position) return false;
-    botThinking = false;
-    doMove(m);
-    return true;
-  } catch (e) {
-    setPlayStatus("Bot move stopped: " + e.message + ". No substitute engine was played.");
-    const status = $("apiStatus");
-    if (status) status.textContent = "Bot connection failed: " + e.message;
-    return false;
-  } finally {
-    botThinking = false;
-  }
+  const m = await botChooseMove(botName);
+  botThinking = false;
+  if (!m) return false;
+  doMove(m);   // doMove -> render + analyze + scheduleAuto
+  return true;
 }
 
 // Called at the end of every move. Drives the opponent in 'play' mode.
@@ -802,8 +777,7 @@ function updateWatchBtn() {
 }
 function setPlayStatus(msg, thinking) {
   const el = $("playStatus");
-  if (thinking) el.innerHTML = `<span class="think"><span class="spin"></span>${msg}</span>`;
-  else el.textContent = msg;
+  el.innerHTML = thinking ? `<span class="think"><span class="spin"></span>${msg}</span>` : msg;
 }
 
 function setMode(m) {
@@ -818,25 +792,12 @@ function setMode(m) {
 async function fetchBots() {
   const selects = [$("playBot"), $("tigerBot"), $("goatBot")];
   let opts = [{ name: LOCAL, title: "Local engine (in-browser)" }];
-  let serverDefault = "venom";
   const base = serverBase();
   if (base) {
-    opts = opts.concat(["venom", "oracle", "phantom"].map(name => ({name, title: name + " (hosted)"})));
     try {
-      const r = await fetch(base + "/bots", {signal: AbortSignal.timeout(15000)});
-      if (!r.ok) throw new Error("HTTP " + r.status);
-      if (r.ok) {
-        const d = await r.json();
-        if (d.default) serverDefault = d.default;
-        opts = opts.slice(0, 1).concat(d.bots.map(b => ({
-          name: b.name,
-          title: (b.title || b.name) + (b.algorithm ? ` — ${b.algorithm}` : (b.desc ? ` — ${b.desc}` : ""))
-        })));
-      }
-      if ($("apiStatus")) $("apiStatus").textContent = "Connected to Bot API · default " + serverDefault;
-    } catch (e) {
-      if ($("apiStatus")) $("apiStatus").textContent = "Bot API unreachable. Hosted moves are paused; check the connection.";
-    }
+      const r = await fetch(base + "/bots");
+      if (r.ok) { const d = await r.json(); opts = opts.concat(d.bots.map(b => ({ name: b.name, title: `${b.title} — ${b.algorithm}` }))); }
+    } catch (e) { /* server offline: keep Local only */ }
   }
   for (const sel of selects) {
     const cur = sel.value;
@@ -844,8 +805,8 @@ async function fetchBots() {
     for (const o of opts) { const el = document.createElement("option"); el.value = o.name; el.textContent = o.title; sel.appendChild(el); }
     if (cur && opts.some(o => o.name === cur)) sel.value = cur;
   }
-  // Default to the server's default bot (Venom) or strongest available.
-  const strongest = (serverDefault && opts.some(o => o.name === serverDefault)) ? serverDefault : opts[opts.length - 1].name;
+  // Default to the strongest available bot (last in the roster) for opponents.
+  const strongest = opts[opts.length - 1].name;
   if (!$("playBot").value || $("playBot").value === LOCAL) $("playBot").value = strongest;
   if (!$("tigerBot").value || $("tigerBot").value === LOCAL) $("tigerBot").value = strongest;
   if (!$("goatBot").value || $("goatBot").value === LOCAL) $("goatBot").value = strongest;

pyodide_boot.js

@@ -33,7 +33,7 @@
     { name: "shepherd", title: "Shepherd - greedy",    hint: "One-ply greedy heuristic (70.2%)" },
     { name: "hunter",   title: "Hunter - negamax",     hint: "Negamax, depth 3 (80.9%)" },
     { name: "stalker",  title: "Stalker - TT search",  hint: "Alpha-beta + transposition table (89.4%)" },
-    { name: "phantom",  title: "Phantom - local PVS",  hint: "Browser search; does not use the hosted Venom tablebase" },
+    { name: "phantom",  title: "Phantom - PVS (96%)",  hint: "PVS + LMR; 95.7% optimal on critical positions" },
   ];
   var PY_NAMES = PY_BOTS.map(function (b) { return b.name; });
 
@@ -147,13 +147,11 @@
           if (m) return m;
         }
       } catch (err) {
-        console.warn("[bagh] Python engine unavailable:", err);
-        status("Python engine unavailable - move stopped", "bad");
+        console.warn("[bagh] Python engine unavailable, using the JS fallback:", err);
+        status("Python engine unavailable - using JS fallback", "bad");
         ready = Promise.reject(err);           // do not retry the boot on every move
         ready.catch(function () {});
-        throw err;
       }
-      throw new Error("Local Python bot returned no legal move");
     }
     return original(botName);
   };
@@ -171,8 +169,9 @@
     card.className = "card";
     card.innerHTML =
       '<h2>API response <span style="opacity:.6;font-weight:400">· preview</span></h2>' +
-      '<div class="src" style="margin-bottom:8px">Uses your configured Bot API and selected bot.' +
-      ' With no API URL, this is an explicitly local Python preview.</div>' +
+      '<div class="src" style="margin-bottom:8px">The exact JSON the Bot API returns, produced by' +
+      ' the server\'s own code running here in your browser. A static Space cannot be called by' +
+      ' another site — point baghchal.net at a hosted API.</div>' +
       '<textarea id="apiObx" rows="2" spellcheck="false" style="width:100%;min-width:0;' +
       'box-sizing:border-box;font-family:var(--mono);font-size:11.5px;padding:7px 9px;' +
       'border-radius:7px;border:1px solid var(--panel-2);background:var(--bg);color:var(--ink)">' +
@@ -188,36 +187,24 @@
       var out = document.getElementById("apiOut");
       var note = document.getElementById("apiNote");
       var bot = (document.getElementById("playBot") || {}).value;
+      if (PY_NAMES.indexOf(bot) === -1) bot = "phantom";
       out.textContent = "thinking...";
       note.textContent = "";
       try {
+        var py = await ready;
         var obx = document.getElementById("apiObx").value;
         var t0 = performance.now();
-        var base = serverBase();
-        if (base) {
-          var response = await fetch(base + "/move", {
-            method: "POST", headers: {"Content-Type": "application/json"},
-            body: JSON.stringify({obx: obx, bot: bot, time_ms: THINK_MS}),
-            signal: AbortSignal.timeout(15000)
-          });
-          if (!response.ok) throw new Error("Bot API HTTP " + response.status);
-          out.textContent = JSON.stringify(await response.json(), null, 2);
-        } else {
-          if (PY_NAMES.indexOf(bot) === -1) throw new Error("Select a local Python bot for an offline preview");
-          if (!ready) ready = boot();
-          var py = await ready;
-          out.textContent = py.globals.get("bagh_api")(obx, bot, THINK_MS);
-        }
-        note.textContent = bot + (base ? " · hosted · " : " · local · ") + Math.round(performance.now() - t0) + "ms";
+        out.textContent = py.globals.get("bagh_api")(obx, bot, THINK_MS);
+        note.textContent = bot + " · " + Math.round(performance.now() - t0) + "ms";
       } catch (err) {
-        out.textContent = "Request failed: " + err;
+        out.textContent = "Python engine unavailable: " + err;
       }
     });
   }
 
   // Start downloading Pyodide now rather than on the first move: it is ~10 MB, and paying that
   // mid-game would look like the engine hanging. Failures are handled in botChooseMove.
-  if (!serverBase() && !ready) {
+  if (!ready) {
     ready = boot();
     ready.catch(function () {});
   }