! Copyright (C) 2023 CapitalEx.
! See https://factorcode.org/license.txt for BSD license.

USING: assocs hashtables io.encodings.utf8 io.files kernel math
math.parser multiline pair-rocket peg.ebnf sequences ;
IN: aoc.2023.2
: input ( -- string )
    "vocab:aoc/2023/2/input.txt" utf8 file-contents ;

CONSTANT: bag H{
    "red"   => 12
    "green" => 13
    "blue"  => 14
}

EBNF: parse-game [=[ 
    Digit     = "0"|"1"|"2"|"3"|"4"|"5"|"6"|"7"|"8"|"9"
    Number    = Digit+ => [[ concat dec> ]]
    GameId    = "Game "~ Number ": "~
    CubeCount = Number " "~ ("red"|"green"|"blue") => [[ reverse ]]
    SubSet    = CubeCount (", "~ CubeCount)*       => [[ first2 swap prefix >hashtable ]]
    SubSets   = SubSet ("; "~ SubSet)*             => [[ first2 swap prefix ]]
    Set = GameId SubSets                           => [[ { "id" "sets" } swap H{ } zip-as ]]
]=]

: parse-games ( string -- games )
    split-lines [ parse-game ] map ;

: valid-game? ( sets -- ? )
    "sets" of [ [ swap bag at <= ] assoc-all? ] all? ;

: valid-games ( games -- valid ) 
    [ valid-game? ] filter ; inline

: game-ids ( games -- ids )
    [ "id" of ] map ; inline

: solve-part-one ( -- )
    input parse-games valid-games game-ids sum . ;

: minimum-bag ( game -- minimum-bag )
    "sets" of H{ } [ [ max ] assoc-merge ] reduce ;

: find-minimum-bags ( games -- bags )
    [ minimum-bag ] map ;

: sum-of-powers ( games -- power-sum )
    [ values product ] map-sum ;

: solve-part-two ( -- )
    input parse-games find-minimum-bags sum-of-powers  . ;