package main

import (
	"fmt"
	"slices"
	"strconv"
	"strings"

	"tangled.org/evan.jarrett.net/aoc2025/internal/puzzle"
)

type IDRange struct {
	first int
	last  int
}

type DayFive struct {
	freshIds []IDRange
	tocheck  []int
}

func (d *DayFive) ParseInput(input string) error {
	for line := range strings.SplitSeq(strings.TrimSpace(input), "\n") {
		line = strings.TrimSpace(line)
		if strings.Contains(line, "-") {
			splits := strings.Split(line, "-")
			first, _ := strconv.Atoi(splits[0])
			last, _ := strconv.Atoi(splits[1])
			d.freshIds = append(d.freshIds, IDRange{first, last})
		} else if line == "" {
			continue
		} else {
			ingredient, _ := strconv.Atoi(line)
			d.tocheck = append(d.tocheck, ingredient)
		}
	}
	return nil
}

func (d *DayFive) Part1() (int, error) {
	count := 0
	for _, i := range d.tocheck {
		for _, idrange := range d.freshIds {
			if i >= idrange.first && i <= idrange.last {
				count++
				break
			}
		}
	}
	return count, nil
}

func (d *DayFive) Part2() (int, error) {
	count := 0

	slices.SortFunc(d.freshIds, func(a, b IDRange) int {
		return a.first - b.first
	})
	var combinedFreshIds []IDRange
	last := d.freshIds[0]
	for _, current := range d.freshIds {
		if current.first <= last.last {
			last.last = max(last.last, current.last)
		} else {
			combinedFreshIds = append(combinedFreshIds, last)
			last = current
		}
	}
	// combine one last time
	combinedFreshIds = append(combinedFreshIds, last)

	for _, idrange := range combinedFreshIds {
		numInRange := idrange.last - idrange.first + 1
		fmt.Println(numInRange)
		count += numInRange
	}
	return count, nil
}

func main() {
	puzzle.Run(5, &DayFive{})
}