module advent_of_code.tasks.day_5.Star1

open System
open System.IO

let stream = new StreamReader("tasks/day-5/input.txt")

let rec buildFresh() =
    let line = stream.ReadLine()
    if line.Length = 0 then
        List.empty
    else
        let splitLine = line.Split("-")
        let low, high = splitLine[0] |> int64, splitLine[1] |> int64
        List.append [ (low, high) ] (buildFresh())

let isFresh (fruit: int64) (range: int64 * int64) =
    let low, high = range.Deconstruct()
    if (fruit >= low && fruit <= high) then 1 else 0

let rec checkFresh (freshList: (int64 * int64) list) =
    if stream.EndOfStream then
        0
    else
        let fruit = stream.ReadLine() |> int64
        let freshness = List.sum (freshList |> List.map (isFresh fruit))
        (if freshness = 0 then 0 else 1) + checkFresh freshList

let main =
    let freshSet = List.sort (buildFresh())
    checkFresh freshSet