// #define Day8
#if Day8
using System.Collections.Immutable;

var allSignals = File.ReadLines("day8/input").Select(l => {
    var seg = l.Split(" ").Where(s => s != "|")
        .ToList();
    return new Segments(seg.SkipLast(4).ToList(), seg.TakeLast(4).ToList());
}).ToList();


var partOne = allSignals.Select(sig => sig.result.Count(s => s.Length == 2 || s.Length == 4 || s.Length == 3 || s.Length == 7)).Sum();
Console.WriteLine(partOne);

var solutions = new Dictionary<string, string>() {
    {"abcefg",  "0"},
    {"cf",      "1"},
    {"acdeg",   "2"},
    {"acdfg",   "3"},
    {"bcdf",    "4"},
    {"abdfg",   "5"},
    {"abdefg",  "6"},
    {"acf",     "7"},
    {"abcdefg", "8"},
    {"abcdfg",  "9"},
};

var partTwo = allSignals.Select(segments => {
    var translate = Solve(segments.unique);
    var numbers = segments.result.Select(s => s.Select(c => translate[c]))
        .Select(tc => String.Join("", tc.OrderBy(c => c)))
        .Select(joined => solutions[joined]).ToList();
    return long.Parse(String.Join("", numbers));
}).Sum();

Console.WriteLine(partTwo);

Dictionary<char, char> Solve(List<string> unique) {
    var original = new Dictionary<char, char>();
    var patterns = unique.Select(s => ImmutableHashSet.Create(s.ToCharArray())).ToList();
    var one = patterns.First(p => p.Count == 2);
    var seven = patterns.First(p => p.Count == 3);
    var four = patterns.First(p => p.Count == 4);
    var eight = patterns.First(p => p.Count == 7);
    var zeroSixOrNine = patterns.Where(p => p.Count == 6).ToList();
    var twoThreeOrFive = patterns.Where(p => p.Count == 5).ToList();

    original['a'] = seven.Except(one).First();

    var eAndG = zeroSixOrNine.SelectMany(num => num.Except(four).Remove(original['a']))
        .GroupBy(c => c).ToDictionary(g => g.Count(), g => g.Key);
    original['e'] = eAndG[2];
    original['g'] = eAndG[3];

    var two = twoThreeOrFive.First(num => num.Contains(original['e']));
    var three = twoThreeOrFive.Where(num => !num.Except(two).IsEmpty).First(num => num.Except(two).Except(one).IsEmpty);
    var five = twoThreeOrFive.First(num => !num.Except(two).IsEmpty && !num.Except(three).IsEmpty);

    original['b'] = five.Except(two).Except(three).First();
    original['c'] = two.Except(five).Remove(original['e']).First();

    original['f'] = one.Remove(original['c']).First();
    original['d'] = eight.Except(original.Values).First();

    return original.ToDictionary(e => e.Value, e => e.Key);
}

record Segments(List<string> unique, List<string> result);
#endif