package two

import (
	"bytes"
	"math"

	"github.com/onyx-and-iris/aoc2024/day-20/internal/one"
	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
	log "github.com/sirupsen/logrus"
)

func Solve(buf []byte) (int, error) {
	r := bytes.NewReader(buf)
	graph, err := parseLines(r)
	if err != nil {
		return 0, err
	}

	log.Debugf("\n%s\n", graph.debug(one.Path))

	var count int
	for pair1 := one.Path.Front(); pair1 != nil; pair1 = pair1.Next() {
		for pair2 := one.Path.Front(); pair2 != nil; pair2 = pair2.Next() {
			if manhatten(pair1.Key, pair2.Key) > 20 ||
				pair1.Value-pair2.Value-manhatten(pair1.Key, pair2.Key) < 100 {
				continue
			}

			count++
		}
	}

	return count, nil
}

func manhatten(a, b point.Point) int {
	return int(math.Abs(float64(a.X)-float64(b.X)) + math.Abs(float64(a.Y)-float64(b.Y)))
}