UNO JavaScript: Keep the Card Effect and Turn Together

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<body class="game"><main><header><div class="eyebrow">Original interactive state lab</div><h1>UNO JavaScript: Keep the Card Effect and Turn Together</h1><p>A Skip advances only one seat, or a Wild leaves the hand before its color is chosen. <mark>Card movement and next-player selection form one transaction</mark>, so an unfinished effect cannot become a completed play.</p></header>
<p>Three-player card-effect component only. No ordinary draw turns, stacking, Wild Draw Four, full dealing, scoring, or manufacturer art.</p><nav><button type="button" id="play">Play selected card</button><button type="button" id="cancel">Cancel Wild</button><button type="button" id="blue">Choose Blue</button><button type="button" id="red">Choose Red</button><button type="button" id="green">Choose Green</button><button type="button" id="yellow">Choose Yellow</button><button type="button" id="reverse">Reverse preset</button><button type="button" id="last">Last Draw Two preset</button><button type="button" id="short">Short supply preset</button><button type="button" id="reset">Reset</button></nav><div id="hands" class="hands"></div><p id="result" class="result" role="status"></p><div id="ledger" class="ledger"></div>
<footer>A final Draw Two applies its penalty before the round ends; no player takes another turn.</footer></main><script>
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(function(){const cards={a:['Red','Skip'],b:['Blue','5'],c:['Wild','Wild'],d:['Red','2'],e:['Green','Reverse'],f:['Blue','7'],g:['Red','Draw Two'],h:['Green','4'],i:['Blue','Reverse'],C1:['Red','5'],j:['Green','9'],k:['Blue','2'],l:['Red','8'],m:['Yellow','3']};let hands={},supply=[],discard=[],actor='A',direction=1,color='Red',selected=null,pending=null,terminal='',moveHistory=[];const seats=['A','B','C'];const next=(labelName,steps=1)=>seats[(seats.indexOf(labelName)+direction*steps+6)%3];function invariant(){const all=[...Object.values(hands).flat(),...supply,...discard];return all.length===14&&new Set(all).size===14&&Object.keys(cards).every(id=>all.includes(id));}function render(message='',focusCard=null){q('hands').innerHTML=seats.map(labelName=>`<section><h2>${labelName}${!terminal&&actor===labelName?' · active':''}</h2>${hands[labelName].map(id=>`<button type="button" id="card${id}" ${terminal||labelName!==actor?'disabled':''}>${id}: ${cards[id].join(' ')}</button>`).join('')}</section>`).join('');for(const id of hands[actor]||[])on('card'+id,()=>{if(!terminal&&!pending){selected=id;render('Selected '+id+'.',id);}});set('result',`${terminal||'Active '+actor}; direction ${direction}; active color ${color}; top ${discard.at(-1)}. ${pending?'Wild pending: choose color or Cancel. ':''}${message}`);set('ledger',`14 unique card IDs conserved: ${invariant()?'yes':'ERROR'}. Hands ${seats.map(s=>s+':'+hands[s].join(',')).join(' | ')}; supply ${supply.join(',')}; discard ${discard.join(',')}. ${moveHistory.join(' / ')}`);if(focusCard)q('card'+focusCard).focus();}function commit(id,chosenColor){if(!hands[actor].includes(id)||terminal)return;const[c,v]=cards[id],discardTop=cards[discard.at(-1)],oldActor=actor;if(c!=='Wild'&&c!==color&&v!==discardTop[1])return render('Rejected: wrong color and value/action; transaction unchanged.');if(v==='Draw Two'&&supply.length<2)return render('BlockedSupply: fewer than two cards; no transfer or win committed.');hands[actor]=hands[actor].filter(x=>x!==id);discard.push(id);color=c==='Wild'?chosenColor:c;if(v==='Reverse')direction=-direction;const target=next(actor);if(v==='Draw Two'){const draw=supply.splice(0,2);hands[target].push(...draw);moveHistory.push(target+' received '+draw.join(',')+' and skipped.');}if(!hands[oldActor].length){terminal='RoundWon '+oldActor+' after effects settled';actor=null;moveHistory.push(oldActor+' played '+id+'; RoundWon '+oldActor+'.');}else{actor=next(oldActor,v==='Skip'||v==='Draw Two'?2:1);moveHistory.push(oldActor+' played '+id+'; next '+actor);}selected=null;pending=null;if(!invariant())throw Error('Card partition violated');render();}function setup(kind){hands={A:['a','b','c'],B:['d','e','f'],C:['g','h','i']};supply=['j','k','l','m'];discard=['C1'];actor='A';direction=1;color='Red';selected=pending=null;terminal='';moveHistory=[];if(kind==='reverse'){actor='C';color='Blue';hands.B=hands.B.filter(x=>x!=='f');discard.push('f');}if(kind==='last'||kind==='short'){actor='C';hands.B.push('h','i');hands.C=['g'];if(kind==='short')hands.B.push(...supply.splice(1));}render();}on('play',()=>{if(terminal)return;if(!selected||pending)return render('Select a card from the active hand.');if(cards[selected][0]==='Wild'){pending={id:selected,actor};render();}else commit(selected);});for(const chosen of['blue','red','green','yellow'])on(chosen,()=>{if(pending&&pending.actor===actor)commit(pending.id,chosen[0].toUpperCase()+chosen.slice(1));});on('cancel',()=>{if(terminal)return;pending=null;selected=null;render('Wild cancelled; card partition unchanged.');});for(const id of['reverse','last','short'])on(id,()=>setup(id));on('reset',()=>setup('start'));setup('start');})();})();
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