USING: accessors eval grouping io.encodings.utf8 io.files kernel
math math.functions math.parser math.statistics multiline
namespaces peg.ebnf prettyprint sequences sequences.extras
splitting ;
IN: aoc.11

: input ( -- lines ) "~/factor/aoc/11/11.in" utf8 file-lines ;

SYMBOL: monkeys
TUPLE: monkey items op test inspections ;
: parse-op ( str -- quot ) split-words reverse join-words "old" "dup" replace "[ " " ]" surround
    "USING: math kernel ; " prepend ( -- x ) eval ;
EBNF: parse-monkey [=[
    line-rest = (!("  ") .)+
    num       = [0-9]+ => [[ dec> ]]
    items     = "  Starting items: "~ (num ", "*~)+
    op        = "  Operation: new = old "~ line-rest => [[ parse-op ]]
    test      = "  Test: divisible by "~ num
                "    If true: throw to monkey "~ num
                "    If false: throw to monkey "~ num
    monkey = line-rest~ items op test => [[ first3 0 monkey boa ]]
]=]
: I ( -- ) input { "" } split [ concat parse-monkey ] map monkeys set ;

SYMBOL: manage
: inspect ( item monkey -- item' ) dup inspections>> 1 + >>inspections op>> call( x -- x ) manage get call( x -- x ) ;
: throw ( item monkey -- ) [ inspect dup ] keep test>> first3 [ divisor? ] 2dip ? monkeys get nth items>> push ;
: turn ( monkey -- ) [ items>> ] [ V{ } clone >>items ] bi '[ _ throw ] each ;    
: round ( -- ) monkeys get [ turn ] each ;
: (part) ( n quot -- n ) manage set [ round ] times monkeys get [ inspections>> ] map { 0 1 } kth-largests product ;

: part1 ( -- n ) I 20                                          [ 3 / floor ] (part) ;
: part2 ( -- n ) I 10000 monkeys get [ test>> first ] map-product '[ _ mod ] (part) ;
: solve ( -- ) part1 . part2 . ;