Code golf ABC's: The ASCII Box Challenge

Pyth, 65 51 bytes

juXGhHX@GhHeH@jkQ~hZ{s[+L]0UhQ+R]thQUeQ+L]teQ_UhQ+R]0_UeQ)m*;hQeQ
AQjuXGhHX@GhHeH@jkQ~hZ{s[,L0G,RtGH_,LtHG_,R0H)m*;GH

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C#, 301 bytes

I'm sure there is a lot more golfing that can be done here but I'm just happy I got a solution that worked.

I found a bug where the bottom line was in the wrong order, damnit!

a=>b=>{var s=new string[b];int i=4,c=b-2,k=a;var t="";for(;i++<2*(a+b);)t+=t.EndsWith(a+"")?b:a;s[0]=t.Substring(0,a);if(b>2){for(i=0;++i<b-1;)s[i]=(a<2?t.Substring(1,c):t.Substring(2*a+c))[c-i]+(a>1?new string(' ',a-2)+t.Substring(a,c)[i-1]:"");for(;--k>=0;)s[b-1]+=t.Substring(a+c,a)[k];}return s;};

Old version: 280 bytes

a=>b=>{var s=new string[b];int i=4,c=b-2;var t="";for(;i++<2*(a+b);)t+=t.EndsWith(a+"")?b:a;s[0]=t.Substring(0,a);if(b>2){for(i=0;++i<b-1;)s[i]=(a<2?t.Substring(1,c):t.Substring(2*a+c))[c-i]+(a>1?new string(' ',a-2)+t.Substring(a,c)[i-1]:"");s[b-1]=t.Substring(a+c,a);}return s;};

Python 2, 199 bytes

w,h=input()
s=(`w`+`h`)*w*h
r=[s[:w]]+[[" "for i in[0]*w]for j in[0]*(h-2)]+[s[w+h-2:2*w+h-2][::-1]]*(h>1)
for y in range(1,h-1):r[y][w-1],r[y][0]=s[w+y-1],s[w+h+w-2-y]
print"\n".join(map("".join,r))