package main

import (
	"log"
	"os"
	"sort"
	"strings"

	"github.com/thoas/go-funk"
)

func main() {
	inputBytes, _ := os.ReadFile("input.txt")
	input := strings.Split(string(inputBytes), "\n")

	log.Println("Puzzle 1:", puzzle1(input))
	log.Println("Puzzle 2:", puzzle2(input))
}

func puzzle1(input []string) int {
	correctClosingChar := map[rune]rune{'(': ')', '[': ']', '{': '}', '<': '>'}
	points := map[rune]int{')': 3, ']': 57, '}': 1197, '>': 25137}
	count := 0
	for _, line := range input {
		stack := []rune{}
		// Check every character in the line
		for _, char := range line {
			// If the character is a opening bracket, push it to the stack
			if char == '(' || char == '[' || char == '{' || char == '<' {
				stack = append(stack, char)
				continue
			}
			// If the character is a closing bracket, pop the stack
			if char == ')' || char == ']' || char == '}' || char == '>' {
				// Check if the char is the correct one
				topOnStack := stack[len(stack)-1]
				if char != correctClosingChar[topOnStack] {
					// It isn't, so add the points of the closing char to the count
					count += points[char]
					break
				}
				// It is, so pop the stack
				stack = stack[:len(stack)-1]
			}
		}
	}
	return count
}

func puzzle2(input []string) int {
	correctClosingChar := map[rune]rune{'(': ')', '[': ']', '{': '}', '<': '>'}
	points := map[rune]int{')': 1, ']': 2, '}': 3, '>': 4}
	scores := []int{}
forlines:
	for _, line := range input {
		stack := []rune{}
		score := 0
		// Check every character in the line
		for _, char := range line {
			// If the character is a opening bracket, push it to the stack
			if char == '(' || char == '[' || char == '{' || char == '<' {
				stack = append(stack, char)
				continue
			}
			// If the character is a closing bracket, pop the stack
			if char == ')' || char == ']' || char == '}' || char == '>' {
				// Check if the char is the correct one
				topOnStack := stack[len(stack)-1]
				if char != correctClosingChar[topOnStack] {
					// It isn't, discard the line and continue with the next one
					continue forlines
				}
				// It is, so pop the stack
				stack = stack[:len(stack)-1]
			}
		}
		// Find correct closing brackets and add their points to the score
		reversedStack := funk.Reverse(stack).([]rune)
		for _, char := range reversedStack {
			score = score*5 + points[correctClosingChar[char]]
		}
		// Add the score of the line to the scores
		scores = append(scores, score)
	}
	// Return the middle one from the scores
	sort.Ints(scores)
	return scores[len(scores)/2]
}