package Advent2019;

import util.AdventOfCode;
import util.BitUtils;

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class Day24 extends AdventOfCode {

    int bugs;
    int moreBugs[];

    public Day24(List<String> input) {
        super(input);
    }

    int countAdj(int i) {
        int row = i / 5;
        int col = i % 5;
        int count = 0;
        if (row > 0) if (BitUtils.getBit(bugs, i - 5)) count++;
        if (row < 4) if (BitUtils.getBit(bugs, i + 5)) count++;
        if (col > 0) if (BitUtils.getBit(bugs, i - 1)) count++;
        if (col < 4) if (BitUtils.getBit(bugs, i + 1)) count++;
        return count;
    }

    int countAdjPart2(int i, int lvl) {
        int row = i / 5;
        int col = i % 5;
        int count = 0;
        if (row > 0)  {
            if (BitUtils.getBit(moreBugs[lvl], i - 5)) count++;
        } else {
            if (BitUtils.getBit(moreBugs[lvl - 1], 7)) count++;
        }
        if (row < 4) {
            if (BitUtils.getBit(moreBugs[lvl], i + 5)) count++;
        } else {
            if (BitUtils.getBit(moreBugs[lvl - 1], 17)) count++;
        }
        if (col > 0)  {
            if (BitUtils.getBit(moreBugs[lvl], i - 1)) count++;
        } else {
            if (BitUtils.getBit(moreBugs[lvl - 1], 11)) count++;
        }
        if (col < 4) {
            if (BitUtils.getBit(moreBugs[lvl], i + 1)) count++;
        } else {
            if (BitUtils.getBit(moreBugs[lvl - 1], 13)) count++;
        }
        if (i == 7) {
            for (int j = 0; j < 5; j++) {
                if (BitUtils.getBit(moreBugs[lvl + 1], j)) count++;
            }
        }
        if (i == 11) {
            for (int j = 0; j < 25; j+= 5) {
                if (BitUtils.getBit(moreBugs[lvl + 1], j)) count++;
            }
        }
        if (i == 13) {
            for (int j = 4; j < 25; j+= 5) {
                if (BitUtils.getBit(moreBugs[lvl + 1], j)) count++;
            }
        }
        if (i == 17) {
            for (int j = 20; j < 25; j++) {
                if (BitUtils.getBit(moreBugs[lvl + 1], j)) count++;
            }
        }
        return count;
    }
    @Override
    public Object part1() {
        Set<Integer> seen = new HashSet<>();
        while (true) {
            int nextgen = 0;
            for (int i = 0; i < 25; i++) {
                int count = countAdj(i);
                if (BitUtils.getBit(bugs, i)) {
                    if (count == 1) nextgen = BitUtils.setBit(nextgen, i);
                } else {
                    if (count > 0 && count < 3) nextgen = BitUtils.setBit(nextgen, i);
                }
            }
            bugs = nextgen;
            if (!seen.add(bugs)) return bugs;
        }
    }

    @Override
    public Object part2() {
        parse();
        moreBugs = new int[205];
        int iterations = 200;
        moreBugs[102] = bugs;
        for (int i = 0; i < iterations; i++) {
            int[] nextgen = new int[205];
            for (int j = 1; j < 204; j++) {
                for (int k = 0; k < 25; k++) {
                    if (k != 12) {
                        int count = countAdjPart2(k, j);
                        if (BitUtils.getBit(moreBugs[j], k)) {
                            if (count == 1) nextgen[j] = BitUtils.setBit(nextgen[j], k);
                        } else {
                            if (count > 0 && count < 3) nextgen[j] = BitUtils.setBit(nextgen[j], k);
                        }
                    }
                }
            }
            moreBugs = nextgen;
        }

        return Arrays.stream(moreBugs)
                .map(BitUtils::countBits)
                .sum();
    }


    @Override
    public void parse() {
        bugs = 0;
        for (int i = 0; i < input.size(); i++) {
            for (int j = 0; j < input.get(i).length(); j++) {
                if  (input.get(i).charAt(j) == '#') {
                    bugs |= 1 << (i * 5) + j;
                }
            }
        }

    }

}