"""
Advent of Code 2021 - Day 03

Run with:
    python puzzles/day03.py inputs/day03.txt
"""

import pathlib
import sys
from typing import Dict, List, Tuple

from collections import defaultdict

class Diagnostics:
    _most_common = None
    report = None

    def __init__(self, report: List[int]) -> None:
        self.report = report
        self._most_common = self.commonality(report)


    def power_usage(self) -> None:
        half_count = len(self.report)/2
        gamma = epsilon = ""
        for common in self._most_common:
            if common == 1:
                gamma += "1"
                epsilon += "0"
            else:
                gamma += "0"
                epsilon += "1"

        gamma = int(gamma, 2)
        epsilon = int(epsilon, 2)
        return gamma * epsilon


    def calculate_oxygen_generator_rating(self, inputs) -> int:
        """
        Bit Criteria:
          Most common value in current bit position
              If 0 and 1 are equally common, keep values with a 1
          Keep only values with this bit in this position
        """
        report = inputs.copy()
        for column in range(len(report[0])):
            most_common = self.commonality(report)
            for binary in list(report):
                if (int(binary[column]) != most_common[column] and most_common[column] != 2) or (most_common[column] == 2 and binary[column] != "1"):
                    report.remove(binary)

                if len(report) == 1:
                    return int(report[0], 2)

        if len(report) > 1: # May not be necessary
            report = self.calculate_oxygen_generator_rating(report)

        return int(report[0], 2)


    def calculate_co2_scrubber_rating(self, inputs) -> int:
        """
        Bit Criteria:
          Least common value in current position
              If 0 and 1 are equally common, keep values with a 0
          Keep only values with this bit in this position
        """
        report = inputs.copy()
        for column in range(len(report[0])):
            most_common = self.commonality(report)
            for binary in list(report):
                if (int(binary[column]) == most_common[column]) or (most_common[column] == 2 and binary[column] != "0"):
                    report.remove(binary)

                if len(report) == 1:
                    return int(report[0], 2)

        if len(report) > 1: # May not be necessary
            report = self.calculate_oxygen_generator_rating(report)

        return int(report[0], 2)


    def calculate_life_support_rating(self) -> int:
        oxygen_generator_rating = self.calculate_oxygen_generator_rating(self.report)
        co2_scrubber_rating = self.calculate_co2_scrubber_rating(self.report)
        return oxygen_generator_rating * co2_scrubber_rating

    @staticmethod
    def commonality(report: List[int]) -> List[Dict[str, int]]:
        common_counts = []
        for binary in report:
            for column, bit in enumerate(binary):
                try:
                    common_counts[column][bit] += 1
                except IndexError:
                    common_counts.append(defaultdict(int))
                    common_counts[column][bit] = 1
        common = []
        half_total = len(report)/2
        for count in common_counts:
            if count["1"] == half_total:
                common.append(2) # Indicating equally common
            elif count["1"] > half_total:
                common.append(1)
            else:
                common.append(0)

        return common



def part1(inputs: List[int]) -> int:
    diag = Diagnostics(inputs)
    return diag.power_usage()

def part2(inputs: List[int]) -> int:
    diag = Diagnostics(inputs)
    return diag.calculate_life_support_rating()


def parse(inputs: str) -> List[int]:
    """Parse the input string"""
    return [line for line in inputs.split()]


def solve(path: str) -> Tuple[int, int]:
    """Solve the puzzle"""
    puzzle_input = parse(pathlib.Path(path).read_text().strip())
    part1_result = part1(puzzle_input)
    part2_result = part2(puzzle_input)

    return part1_result, part2_result


def main() -> None:
    for path in sys.argv[1:]:
        print(f"Input File: {path}")

        part1_result, part2_result = solve(path)

        print(f"Part 1 Result: {part1_result}")
        print(f"Part 2 Result: {part2_result}")


if __name__ == "__main__":
    main()