First correct answer to the "No Wires" challenge

jcazevedo-start-2017.js

function f(a){a=a.split("\n");for(var g=a.length,e=a[0].length,l=[[-1,-1],[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1]],b="",d=0;d<g;d++){for(var h=0;h<e;h++){var c=a[d].length<e?" ":a[d][h];if(" "==c)b+=" ";else if("H"==c)b+="t";else if("t"==c)b+=".";else if("."==c){for(var k=c=0;8>k;k++){var m=(d+g+l[k][0])%g;"H"==(a[m].length<e?" ":a[m][(h+e+l[k][1])%e])&&c++}b=1<=c&&2>=c?b+"H":b+"."}}d+1<g&&(b+="\n")}return b};

This is jcazevedo's first accepted answer to the Pixels Camp Quizshow qualifiers' No Wires challenge, with just 419 bytes.