package day3

import (
	"bufio"
	"fmt"
	"os"
)

func in_set(target rune, set []rune) bool {
	for _, char := range set {
		if char == target {
			return true
		}
	}
	return false
}

func priority(value rune) int {
	var base_value int = 0

	if value >= 'A' && value <= 'Z' {
		base_value = int('A') - 27
	}

	if value >= 'a' && value <= 'z' {
		base_value = int('a') - 1
	}

	return int(value) - base_value
}

func part1_addition(runes []rune) int {
	var total int = 0

	midpoint := len(runes) / 2
	left_runes := runes[0:midpoint]
	right_runes := runes[midpoint:]

	for pos, char := range left_runes {
		if !in_set(char, left_runes[0:pos]) {
			if in_set(char, right_runes) {
				total += priority(char)
			}
		}
	}

	return total
}

func score_badge(set1 []rune, set2 []rune, set3 []rune) int {
	for pos, char := range set1 {
		if !in_set(char, set1[0:pos]) {
			if in_set(char, set2) && in_set(char, set3) {
				return priority(char)
			}
		}
	}
	fmt.Println("PANIC: Couldn't find overlapping badge item")
	return 0
}

func Run(filename string) {
	file, err := os.Open(filename)

	if err != nil {
		fmt.Println("Error opening file:", err)
		return
	}

	scanner := bufio.NewScanner(file)
	scanner.Split(bufio.ScanLines)
	var total_overlap int = 0
	var total_badge int = 0
	var grouping [][]rune = [][]rune{}

	for scanner.Scan() {
		line := scanner.Text()
		runes := []rune(line)
		total_overlap += part1_addition(runes)

		grouping = append(grouping, runes)
		if len(grouping) == 3 {
			total_badge += score_badge(grouping[0], grouping[1], grouping[2])
			grouping = [][]rune{}
		}
	}

	file.Close()

	fmt.Println("Total initial score is", total_overlap)
	fmt.Println("Total badge score is", total_badge)
}