package dev.forstenlechner.aoc;

import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Day12 {

    public static void main(String[] args) throws Exception {
        new Day12().solve();
    }

    private enum Orientation {
        N(0), E(1), S(2), W(3);

        int value;
        Orientation(int value) {
            this.value = value;
        }

        int getValue() {
            return value;
        }

        static Orientation from(int value) {
            return switch (value) {
                case 1 -> E;
                case 2 -> S;
                case 3 -> W;
                default -> N;
            };
        }
    }

    private enum Instruction {
        N {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                return new LocationFacing(current.east, current.north + value, current.orientation);
            }
        },
        S {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                return new LocationFacing(current.east, current.north - value, current.orientation);
            }
        },
        E {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                return new LocationFacing(current.east + value, current.north, current.orientation);
            }
        },
        W {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                return new LocationFacing(current.east - value, current.north, current.orientation);
            }
        },
        L {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                value = (value % 360) / 90;
                int newValue = (current.orientation.getValue() - value + 4) % 4;
                return new LocationFacing(current.east, current.north, Orientation.from(newValue));
            }
        },
        R {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                value = (value % 360) / 90;
                int newValue = (current.orientation.getValue() + value + 4) % 4;
                return new LocationFacing(current.east, current.north, Orientation.from(newValue));
            }
        },
        F {
            @Override
            LocationFacing move(LocationFacing current, int value) {
                if (current.orientation == Orientation.N) {
                    return N.move(current, value);
                }
                if (current.orientation == Orientation.S) {
                    return S.move(current, value);
                }
                if (current.orientation == Orientation.E) {
                    return E.move(current, value);
                }
                if (current.orientation == Orientation.W) {
                    return W.move(current, value);
                }
                throw new IllegalArgumentException("not implemented");
            }
        };

        abstract LocationFacing move(LocationFacing current, int value);
    }

    private record NavigationInstruction(Instruction ins, int value) {};

    private record LocationFacing(int east, int north, Orientation orientation) {};

    private void solve() throws Exception {
        Stream<String> lines = Files.lines(Paths.get("day12/input"));

        List<NavigationInstruction> navigationInstructions = lines
                .map(l -> new NavigationInstruction(Instruction.valueOf(l.substring(0, 1)), Integer.parseInt(l.substring(1))))
                .collect(Collectors.toList());

        LocationFacing result = navigationInstructions.stream().reduce(new LocationFacing(0, 0, Orientation.E), (l, n) -> {
            System.out.println(l);
            return n.ins().move(l, n.value());
        }, (l1, l2) -> l1);

        System.out.println(Math.abs(result.east) + Math.abs(result.north));
        // 5641
    }
}