One line window pagination in Ruby

def getPages(current_page, minimum=1, maximum=20, window=2)
return((minimum+window<current_page ? minimum.upto(window).collect : minimum.upto(current_page+window).collect) + (current_page-window > minimum+window ? [".."] : []) + (current_page>minimum+window ? (current_page-window > minimum+window ? current_page-window : minimum+window).upto(current_page+window > maximum ? maximum : current_page+window).collect : [])+(current_page+window+1<maximum-window ? [".."] : [])+(current_page<maximum-2*window ? maximum-window : current_page+window+1).upto(maximum).collect)
end

Output:
>> 1.upto(20){|x| print x; print " : "; p getPages(x,1,20,1)}

1 : [1, 2, "..", 19, 20]
2 : [1, 2, 3, "..", 19, 20]
3 : [1, 2, 3, 4, "..", 19, 20]
4 : [1, "..", 3, 4, 5, "..", 19, 20]
5 : [1, "..", 4, 5, 6, "..", 19, 20]
6 : [1, "..", 5, 6, 7, "..", 19, 20]
7 : [1, "..", 6, 7, 8, "..", 19, 20]
8 : [1, "..", 7, 8, 9, "..", 19, 20]
9 : [1, "..", 8, 9, 10, "..", 19, 20]
10 : [1, "..", 9, 10, 11, "..", 19, 20]
11 : [1, "..", 10, 11, 12, "..", 19, 20]
12 : [1, "..", 11, 12, 13, "..", 19, 20]
13 : [1, "..", 12, 13, 14, "..", 19, 20]
14 : [1, "..", 13, 14, 15, "..", 19, 20]
15 : [1, "..", 14, 15, 16, "..", 19, 20]
16 : [1, "..", 15, 16, 17, "..", 19, 20]
17 : [1, "..", 16, 17, 18, 19, 20]
18 : [1, "..", 17, 18, 19, 20]
19 : [1, "..", 18, 19, 20]
20 : [1, "..", 19, 20]

Dunno if I should be proud of this or worried!