/* Grafisch live-klassenoverzicht: klasraster, hulpsignalen, funnel,
   zevendaagse voortgang, sessietijdlijn en directe leerkrachtacties. */
"use strict";

function liveSessionTime(value){
  const seconds=Math.max(0,Math.round((Date.now()-new Date(value).getTime())/1000));
  if(seconds<60)return T("amLiveJustNow");
  const minutes=Math.floor(seconds/60);
  if(minutes<60)return T("amLiveMinutes").replace("{count}",minutes);
  const hours=Math.floor(minutes/60);
  return T("amLiveHours").replace("{count}",hours);
}

function liveDuration(start,end){
  const seconds=Math.max(1,Math.round((new Date(end).getTime()-new Date(start).getTime())/1000));
  if(seconds<60)return seconds+"s";
  const minutes=Math.round(seconds/60);
  return minutes<60?minutes+"m":Math.round(minutes/60)+"u";
}

function updateLiveConnectionState(host,state){
  const badge=host.querySelector(".live-connection");
  if(!badge)return;
  badge.className="live-connection "+state;
  badge.textContent=T(state==="connected"?"amLiveConnected":"amLiveReconnecting");
}

function liveSvg(tag,attrs={}){
  const element=document.createElementNS("http://www.w3.org/2000/svg",tag);
  Object.entries(attrs).forEach(([key,value])=>element.setAttribute(key,String(value)));
  return element;
}

function liveSparkline(points){
  const svg=liveSvg("svg",{class:"live-sparkline",viewBox:"0 0 100 28",
    role:"img","aria-label":T("amTrendAccuracy")});
  const usable=(points||[]).map((point,index)=>({index,value:point.accuracy}))
    .filter(point=>Number.isFinite(point.value));
  if(!usable.length){
    svg.appendChild(liveSvg("line",{x1:2,y1:25,x2:98,y2:25,class:"empty"}));
    return svg;
  }
  const d=usable.map((point,index)=>{
    const x=2+(point.index/Math.max(1,(points.length-1)))*96;
    const y=26-(point.value/100)*23;
    return(index?"L":"M")+x.toFixed(1)+" "+y.toFixed(1);
  }).join(" ");
  svg.appendChild(liveSvg("path",{d,class:"line"}));
  return svg;
}

function renderLiveFunnel(host,dashboard,live){
  const card=document.createElement("section");
  card.className="live-graphic-card live-funnel";
  const title=document.createElement("strong");
  title.textContent=T("amFunnelTitle");
  card.appendChild(title);
  const base=Math.max(1,dashboard.funnel?.total||dashboard.pupils?.length||0);
  const active=live.liveCount||0;
  const started=Math.max(dashboard.funnel?.started||0,active);
  const steps=[
    ["amFunnelAssigned",dashboard.funnel?.assigned||0],
    ["amFunnelStarted",started],
    ["amFunnelActive",active],
    ["amFunnelCompleted",dashboard.funnel?.completed||0],
  ];
  steps.forEach(([key,value],index)=>{
    const row=document.createElement("div");
    row.className="live-funnel-row";
    const label=document.createElement("span");
    label.textContent=T(key);
    const track=document.createElement("span");
    track.className="live-funnel-track";
    const fill=document.createElement("i");
    fill.style.width=Math.max(value?6:0,Math.round((value/base)*100))+"%";
    fill.style.setProperty("--funnel-step",String(index));
    track.appendChild(fill);
    const count=document.createElement("strong");
    count.textContent=String(value);
    row.append(label,track,count);
    card.appendChild(row);
  });
  host.appendChild(card);
}

function renderLiveTrend(host,live){
  const card=document.createElement("section");
  card.className="live-graphic-card live-trend";
  const title=document.createElement("strong");
  title.textContent=T("amTrendTitle");
  card.appendChild(title);
  const points=live.classTrend||[];
  const svg=liveSvg("svg",{viewBox:"0 0 600 190",role:"img",
    "aria-label":T("amTrendDescription")});
  [0,25,50,75,100].forEach(value=>{
    const y=155-(value/100)*125;
    svg.appendChild(liveSvg("line",{x1:42,y1:y,x2:580,y2:y,class:"grid"}));
    const label=liveSvg("text",{x:35,y:y+4,class:"axis","text-anchor":"end"});
    label.textContent=value+"%";svg.appendChild(label);
  });
  const maxCompleted=Math.max(1,...points.map(point=>Number(point.completed||0)));
  points.forEach((point,index)=>{
    const x=52+index*(520/Math.max(1,points.length-1));
    const height=(Number(point.completed||0)/maxCompleted)*48;
    svg.appendChild(liveSvg("rect",{x:x-10,y:155-height,width:20,height,
      rx:4,class:"completion"}));
    const day=liveSvg("text",{x,y:177,class:"axis","text-anchor":"middle"});
    day.textContent=new Date(point.date+"T12:00:00").toLocaleDateString(
      LANG==="nl"?"nl-NL":"en-GB",{weekday:"short"});
    svg.appendChild(day);
  });
  const usable=points.map((point,index)=>({index,value:point.accuracy}))
    .filter(point=>Number.isFinite(point.value));
  if(usable.length){
    const d=usable.map((point,index)=>{
      const x=52+point.index*(520/Math.max(1,points.length-1));
      const y=155-(point.value/100)*125;
      return(index?"L":"M")+x.toFixed(1)+" "+y.toFixed(1);
    }).join(" ");
    svg.appendChild(liveSvg("path",{d,class:"accuracy"}));
    usable.forEach(point=>{
      const x=52+point.index*(520/Math.max(1,points.length-1));
      const y=155-(point.value/100)*125;
      svg.appendChild(liveSvg("circle",{cx:x,cy:y,r:4,class:"accuracy-dot"}));
    });
  }
  card.appendChild(svg);
  const legend=document.createElement("div");
  legend.className="live-chart-legend";
  const accuracy=document.createElement("span");accuracy.className="accuracy";
  accuracy.textContent=T("amTrendAccuracy");
  const completed=document.createElement("span");completed.className="completed";
  completed.textContent=T("amTrendCompleted");
  legend.append(accuracy,completed);card.appendChild(legend);
  host.appendChild(card);
}

function renderLiveTimeline(host,sessions,serverTime,onPupil){
  const card=document.createElement("section");
  card.className="live-graphic-card live-timeline";
  const title=document.createElement("strong");
  title.textContent=T("amTimelineTitle");
  card.appendChild(title);
  const items=(sessions||[]).slice(0,12);
  if(!items.length){
    const empty=document.createElement("p");empty.className="guestnote";
    empty.textContent=T("amLiveRecentNone");card.appendChild(empty);
    host.appendChild(card);return;
  }
  const durations=items.map(session=>Math.max(1000,
    new Date(session.endedAt||session.lastSeenAt||serverTime).getTime()-new Date(session.startedAt).getTime()));
  const max=Math.max(...durations);
  items.forEach((session,index)=>{
    const row=document.createElement("button");
    row.type="button";row.className="live-timeline-row "+session.status;
    const name=document.createElement("strong");name.textContent=session.pupilName;
    const meta=document.createElement("span");
    meta.textContent=(T("wg_"+session.widgetType)||session.widgetType)+" · "+
      liveSessionTime(session.startedAt);
    const track=document.createElement("span");track.className="live-timeline-track";
    const fill=document.createElement("i");
    fill.style.width=Math.max(8,Math.round((durations[index]/max)*100))+"%";
    track.appendChild(fill);
    const duration=document.createElement("span");duration.className="live-timeline-duration";
    duration.textContent=session.paused?T("amStatePaused"):
      liveDuration(session.startedAt,session.endedAt||session.lastSeenAt||serverTime);
    row.append(name,meta,track,duration);
    row.addEventListener("click",()=>onPupil(session.pupilId));
    card.appendChild(row);
  });
  host.appendChild(card);
}

function renderLiveClassOverview(host,dashboard,live,onPupil,onAction){
  const section=document.createElement("section");
  section.className="live-class-overview";
  const head=document.createElement("div");
  head.className="live-session-head";
  const title=document.createElement("strong");title.textContent=T("amLiveSessions");
  const connection=document.createElement("span");
  connection.className="live-connection connecting";
  connection.textContent=T("amLiveReconnecting");
  head.append(title,connection);section.appendChild(head);

  const activeByPupil=new Map();
  const recentByPupil=new Map();
  (live.sessions||[]).forEach(session=>{
    const map=session.status==="live"?activeByPupil:recentByPupil;
    if(!map.has(session.pupilId))map.set(session.pupilId,session);
  });
  const pupils=(dashboard.pupils||[]).map(pupil=>{
    const session=activeByPupil.get(pupil.pupilId)||null;
    const recent=recentByPupil.get(pupil.pupilId)||null;
    const signal=session?.helpSignal||(pupil.status==="support"?"errors":null);
    const justStarted=!!session&&new Date(live.serverTime||Date.now()).getTime()
      -new Date(session.startedAt).getTime()<60000;
    const state=session?.paused?"paused":signal?"support":justStarted?"new":
      session?"active":pupil.status;
    return{...pupil,session,recent,signal,state,
      trend:live.pupilTrends?.[String(pupil.pupilId)]||[]};
  });

  const metrics=document.createElement("div");
  metrics.className="live-class-metrics";
  [
    ["active",T("amMetricWorking"),pupils.filter(p=>p.state==="active").length],
    ["new",T("amMetricNew"),pupils.filter(p=>p.state==="new").length],
    ["support",T("amMetricHelp"),pupils.filter(p=>p.signal).length],
    ["complete",T("amMetricComplete"),pupils.filter(p=>p.status==="complete").length],
  ].forEach(([state,label,value])=>{
    const metric=document.createElement("div");metric.className="live-class-metric "+state;
    const count=document.createElement("strong");count.textContent=String(value);
    const text=document.createElement("span");text.textContent=label;
    metric.append(count,text);metrics.appendChild(metric);
  });
  section.appendChild(metrics);

  const help=pupils.filter(pupil=>pupil.signal);
  if(help.length){
    const signals=document.createElement("section");signals.className="live-help-signals";
    const signalTitle=document.createElement("strong");signalTitle.textContent=T("amHelpSignals");
    signals.appendChild(signalTitle);
    const list=document.createElement("div");
    help.forEach(pupil=>{
      const button=document.createElement("button");button.type="button";
      button.className="live-help-chip "+pupil.signal;
      button.textContent="⚑ "+pupil.pupilName+" · "+T(
        pupil.signal==="idle"?"amHelpIdle":"amHelpErrors");
      button.addEventListener("click",()=>onPupil(pupil.pupilId));
      list.appendChild(button);
    });
    signals.appendChild(list);section.appendChild(signals);
  }

  const controls=document.createElement("div");controls.className="live-grid-controls";
  const gridTitle=document.createElement("strong");gridTitle.textContent=T("amClassGrid");
  const sort=document.createElement("select");sort.className="am-sel";
  [["priority","amSortPriority"],["active","amSortActive"],["name","amSortName"]]
    .forEach(([value,key])=>sort.appendChild(new Option(T(key),value)));
  controls.append(gridTitle,sort);section.appendChild(controls);
  const grid=document.createElement("div");grid.className="live-class-grid";
  section.appendChild(grid);
  const actionMessage=document.createElement("div");
  actionMessage.className="live-dashboard-message";actionMessage.setAttribute("role","status");
  section.appendChild(actionMessage);

  const stateRank={support:0,paused:1,new:2,active:3,notStarted:4,complete:5};
  const drawGrid=()=>{
    grid.innerHTML="";
    if(!pupils.length){
      const empty=document.createElement("p");empty.className="guestnote";
      empty.textContent=T("castNoPupils");grid.appendChild(empty);return;
    }
    const ordered=[...pupils].sort((a,b)=>{
      if(sort.value==="name")return a.pupilName.localeCompare(b.pupilName);
      if(sort.value==="active")return Number(!!b.session)-Number(!!a.session)
        ||a.pupilName.localeCompare(b.pupilName);
      return(stateRank[a.state]??9)-(stateRank[b.state]??9)
        ||a.pupilName.localeCompare(b.pupilName);
    });
    ordered.forEach(pupil=>{
      const tile=document.createElement("article");
      tile.className="live-pupil-tile "+pupil.state;
      const top=document.createElement("button");top.type="button";
      top.className="live-pupil-main";
      const badge=document.createElement("span");badge.className="live-pupil-state";
      const stateKey={
        support:pupil.signal==="idle"?"amHelpIdle":"amHelpErrors",
        paused:"amStatePaused",new:"amLiveNew",active:"amLiveWorking",
        complete:"amDashboardStatus_complete",notStarted:"amDashboardStatus_notStarted",
      }[pupil.state]||"amDashboardStatus_active";
      badge.textContent=T(stateKey);
      const name=document.createElement("strong");name.textContent=pupil.pupilName;
      const task=document.createElement("span");task.className="live-pupil-task";
      const session=pupil.session||pupil.recent;
      task.textContent=session?(T("wg_"+session.widgetType)||session.widgetType):
        pupil.sequence?.title||T("amDashboardNoActivity");
      const progress=document.createElement("span");progress.className="live-pupil-progress";
      const fill=document.createElement("i");
      const percent=pupil.sequence?Math.round((pupil.sequence.completed/pupil.sequence.total)*100):
        pupil.attempts?pupil.accuracy:0;
      fill.style.width=Math.max(0,Math.min(100,percent))+"%";
      progress.appendChild(fill);
      const score=document.createElement("small");
      score.textContent=pupil.sequence?
        T("amDashboardSteps").replace("{done}",pupil.sequence.completed).replace("{total}",pupil.sequence.total):
        pupil.attempts?T("amLiveScore").replace("{correct}",pupil.correct)
          .replace("{attempts}",pupil.attempts):T("amDashboardNoActivity");
      top.append(badge,name,task,progress,score,liveSparkline(pupil.trend));
      top.addEventListener("click",()=>onPupil(pupil.pupilId));
      tile.appendChild(top);

      const toggle=document.createElement("button");toggle.type="button";
      toggle.className="live-action-toggle";toggle.textContent="⚡ "+T("amActions");
      const actions=document.createElement("div");actions.className="live-action-row";
      actions.hidden=true;
      toggle.addEventListener("click",()=>{actions.hidden=!actions.hidden;});
      let sending=false;
      const trigger=async(kind,payload={})=>{
        if(sending)return;
        sending=true;tile.classList.add("sending");
        actionMessage.textContent=T("amActionSending");
        try{
          await onAction(pupil.pupilId,kind,payload);
          actionMessage.textContent=T("amActionSent");
        }catch(error){actionMessage.textContent=error.message;}
        finally{sending=false;tile.classList.remove("sending");}
      };
      const actionButton=(label,kind,handler,disabled=false)=>{
        const button=document.createElement("button");button.type="button";
        button.textContent=label;button.disabled=disabled;
        button.addEventListener("click",handler||(()=>trigger(kind)));
        actions.appendChild(button);
      };
      actionButton("💡 "+T("amActionHint"),"hint",()=>{
        const message=window.prompt(T("amActionHintPrompt"),T("amActionHintDefault"));
        if(message&&message.trim())trigger("hint",{message:message.trim()});
      });
      actionButton("👏 "+T("amActionEncourage"),"encourage",()=>{
        const message=window.prompt(T("amActionEncouragePrompt"),T("amActionEncourageDefault"));
        if(message&&message.trim())trigger("encourage",{message:message.trim()});
      });
      const subject=typeof REGISTRY!=="undefined"
        ?REGISTRY.find(def=>def.id===pupil.session?.widgetType)?.cat:null;
      actionButton("↘ "+T("amActionEasier"),"easier",
        ()=>{if(window.confirm(T("amActionEasierConfirm")))trigger("easier",{subject});},
        !pupil.session||!["taal","rekenen","world","creatief"].includes(subject));
      const pauseKind=pupil.session?.paused?"resume":"pause";
      actionButton((pauseKind==="pause"?"⏸ ":"▶ ")+
        T(pauseKind==="pause"?"amActionPause":"amActionResume"),pauseKind,
        ()=>trigger(pauseKind),!pupil.session);
      tile.append(toggle,actions);grid.appendChild(tile);
    });
  };
  sort.addEventListener("change",drawGrid);drawGrid();

  const graphics=document.createElement("div");graphics.className="live-graphics-grid";
  renderLiveFunnel(graphics,dashboard,live);
  renderLiveTrend(graphics,live);
  section.appendChild(graphics);
  renderLiveTimeline(section,live.sessions,live.serverTime,onPupil);
  host.appendChild(section);
}

function connectLiveClassDashboard(classId,onChange,isActive,onState){
  let source=null;
  let stopped=false;
  let reloadTimer=null;
  const queueReload=()=>{
    clearTimeout(reloadTimer);
    reloadTimer=setTimeout(()=>{if(!stopped&&isActive())onChange();},180);
  };
  if(typeof EventSource!=="undefined"){
    source=new EventSource("/api/progress/live/class/"+encodeURIComponent(classId)+"/stream");
    source.onopen=()=>onState("connected");
    source.onerror=()=>onState("reconnecting");
    source.addEventListener("sessions",queueReload);
  }
  const fallback=setInterval(()=>{
    if(!isActive()){stop();return;}
    onChange();
  },30000);
  function stop(){
    if(stopped)return;
    stopped=true;
    clearInterval(fallback);
    clearTimeout(reloadTimer);
    if(source)source.close();
  }
  return stop;
}