"use strict";

// ─── Path Network (orthogonal) ─────────
function genNet(li){
  var cfg=LEVELS[li];
  var cols=6+li*2, rows=8+li*3;
  var gapX=100+rng(-10,10), gapY=80+rng(-10,10);
  var offX=80, offY=80;
  var mapW=offX*2+cols*gapX, mapH=offY*2+rows*gapY;

  var grid=[];
  var nodes=[];
  var nid=0;

  for(var r=0;r<=rows;r++){
    grid[r]=[];
    for(var c=0;c<=cols;c++){
      var keep = r===0||r===rows||c===0||c===cols||
        (r===rows&&c===Math.floor(cols/2))||
        (r===0&&c===Math.floor(cols/2))||
        (r===rows-1&&c<=1)||
        (r===Math.floor(rows*0.4)&&c>=cols-1);
      if(!keep && Math.random()<0.35){
        grid[r][c]=null; continue;
      }
      var jx=(r>0&&r<rows&&c>0&&c<cols)?rng(-12,12):0;
      var jy=(r>0&&r<rows&&c>0&&c<cols)?rng(-8,8):0;
      var nd={x:offX+c*gapX+jx, y:offY+r*gapY+jy, id:nid, r:r, c:c, role:"path"};
      nodes.push(nd);
      grid[r][c]=nd;
      nid++;
    }
  }

  var edges=[];
  var edgeSet={};
  function addEdge(a,b){
    if(!a||!b)return;
    var k=Math.min(a.id,b.id)+"-"+Math.max(a.id,b.id);
    if(edgeSet[k])return;
    edgeSet[k]=true;
    edges.push([a.id,b.id]);
  }

  for(var r=0;r<=rows;r++){
    for(var c=0;c<=cols;c++){
      if(!grid[r][c])continue;
      if(c<cols&&grid[r][c+1]) addEdge(grid[r][c],grid[r][c+1]);
      if(r<rows&&grid[r+1]&&grid[r+1][c]) addEdge(grid[r][c],grid[r+1][c]);
    }
  }

  for(var d=0;d<2+li;d++){
    var src=nodes[Math.floor(Math.random()*nodes.length)];
    var dir=Math.floor(Math.random()*4);
    var dx=[gapX,0,-gapX,0][dir], dy=[0,gapY,0,-gapY][dir];
    var nx=src.x+dx+rng(-8,8), ny=src.y+dy+rng(-8,8);
    if(nx>40&&nx<mapW-40&&ny>40&&ny<mapH-40){
      var dn={x:nx,y:ny,id:nid,role:"deadend"};
      nodes.push(dn); nid++;
      edges.push([src.id,dn.id]);
    }
  }

  var startC=Math.floor(cols/2);
  var startN=grid[rows][startC];
  if(!startN){
    for(var cc=0;cc<=cols;cc++){
      if(grid[rows][cc]){startN=grid[rows][cc];break;}
    }
  }
  var visited={};
  var queue=[startN.id];
  visited[startN.id]=true;
  var adj={};
  edges.forEach(function(e){
    if(!adj[e[0]])adj[e[0]]=[];
    if(!adj[e[1]])adj[e[1]]=[];
    adj[e[0]].push(e[1]);
    adj[e[1]].push(e[0]);
  });
  while(queue.length){
    var cur=queue.shift();
    (adj[cur]||[]).forEach(function(nb){
      if(!visited[nb]){visited[nb]=true;queue.push(nb);}
    });
  }
  nodes.forEach(function(n){
    if(visited[n.id])return;
    var best=null,bd=Infinity;
    nodes.forEach(function(m){
      if(!visited[m.id])return;
      var d=dist(n,m);
      if(d<bd){bd=d;best=m;}
    });
    if(best){
      edges.push([n.id,best.id]);
      if(!adj[n.id])adj[n.id]=[];
      if(!adj[best.id])adj[best.id]=[];
      adj[n.id].push(best.id);
      adj[best.id].push(n.id);
      visited[n.id]=true;
    }
  });

  var peakC=Math.floor(cols/2);
  var peakN=grid[0][peakC]||nodes[0];
  var labN=grid[rows-1]?grid[rows-1][0]||grid[rows][0]||nodes[1]:nodes[1];
  if(labN.id===startN.id){
    for(var ci=0;ci<=cols;ci++){
      if(grid[rows]&&grid[rows][ci]&&grid[rows][ci].id!==startN.id){labN=grid[rows][ci];break;}
    }
  }
  var apoRow=Math.floor(rows*0.4);
  var apoN=grid[apoRow]?grid[apoRow][cols]||grid[apoRow][cols-1]||nodes[3]:nodes[3];

  peakN.role="peak"; startN.role="start"; labN.role="lab"; apoN.role="apo";

  return {nodes:nodes,edges:edges,mapW:mapW,mapH:mapH,
    peak:peakN,start:startN,lab:labN,apo:apoN};
}

// ─── Vegetation ─────────
function genVeg(net){
  var trees=[],bushes=[];
  var segs=net.edges.map(function(e){return{a:net.nodes[e[0]],b:net.nodes[e[1]]};});
  function nearPath(x,y,minD){
    for(var i=0;i<segs.length;i++){
      var s=segs[i],ax=s.a.x,ay=s.a.y,bx=s.b.x,by=s.b.y;
      var dx=bx-ax,dy=by-ay,l2=dx*dx+dy*dy;
      var t=l2===0?0:clamp(((x-ax)*dx+(y-ay)*dy)/l2,0,1);
      var d=Math.sqrt((x-(ax+t*dx))**2+(y-(ay+t*dy))**2);
      if(d<minD)return true;
    }
    return false;
  }
  for(var i=0;i<500;i++){
    var vx=rng(15,net.mapW-15), vy=rng(15,net.mapH-15);
    if(nearPath(vx,vy,45))continue;
    if(Math.random()<0.5){
      trees.push({x:vx,y:vy,sz:rng(14,30),shade:Math.floor(rng(0,4)),trunk:rng(10,18)});
    }else{
      bushes.push({x:vx,y:vy,sz:rng(6,16),shade:Math.floor(rng(0,3))});
    }
  }
  return{trees:trees,bushes:bushes};
}

// ─── Stones on paths ────
function genStones(net,count,li){
  var stones=[];
  var cIdx=Math.floor(Math.random()*count);
  var segs=net.edges.map(function(e){return{a:net.nodes[e[0]],b:net.nodes[e[1]]};});
  for(var i=0;i<count;i++){
    var pt,tries=0;
    do{
      var s=segs[Math.floor(Math.random()*segs.length)];
      var t=rng(0.2,0.8);
      pt={x:lerp(s.a.x,s.b.x,t),y:lerp(s.a.y,s.b.y,t)};
      tries++;
    }while(tries<100&&(
      dist(pt,net.lab)<70||dist(pt,net.start)<60||dist(pt,net.peak)<70||dist(pt,net.apo)<70||
      stones.some(function(s2){return dist(pt,s2)<55;})
    ));
    var isC=i===cIdx;
    stones.push({id:i,x:pt.x,y:pt.y,isCystine:isC,
      color:isC?CYSTINE_COL:STONE_COLS[i%STONE_COLS.length],
      scanned:false,rolling:false,shape:Math.floor(Math.random()*3),
      rollAngle:0});
  }
  var cs=stones[cIdx];
  var hints=[];
  for(var h=0;h<3+li;h++){
    hints.push({x:cs.x+rng(-65,65),y:cs.y+rng(-65,65),phase:rng(0,Math.PI*2)});
  }
  return{stones:stones,hints:hints};
}

// ─── Closest point on path network ────
function closestOnPaths(px,py,edges,nodes){
  var best=Infinity,bx=px,by=py;
  for(var i=0;i<edges.length;i++){
    var a=nodes[edges[i][0]],b=nodes[edges[i][1]];
    var dx=b.x-a.x,dy=b.y-a.y,l2=dx*dx+dy*dy;
    var t=l2===0?0:clamp(((px-a.x)*dx+(py-a.y)*dy)/l2,0,1);
    var cx=a.x+t*dx,cy=a.y+t*dy;
    var d=(px-cx)**2+(py-cy)**2;
    if(d<best){best=d;bx=cx;by=cy;}
  }
  return{x:bx,y:by,d:Math.sqrt(best)};
}