package seven

import (
	"bufio"
	"math"
	"os"
	"strconv"
	"strings"
)

type crabs struct {
	crabs map[int]int
	count int
	max   int
}

func (c *crabs) load(filename string) error {
	c.crabs = map[int]int{}

	file, err := os.Open(filename)
	if err != nil {
		return err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		initialPositions := strings.Split(scanner.Text(), ",")
		for _, n := range initialPositions {
			position, err := strconv.Atoi(n)
			if err != nil {
				return err
			}

			if position > c.max {
				c.max = position
			}

			c.crabs[position]++
		}

		for _, count := range c.crabs {
			c.count += count
		}
	}
	return nil
}

func (c *crabs) align(notConstant bool) (fuel int) {
	for i := 0; i < c.max; i++ {
		fuelUsed := 0
		for k, count := range c.crabs {
			fuelPerCrab := int(math.Abs(float64(i - k)))
			
			if notConstant {
				for i := fuelPerCrab - 1; i > 0; i-- {
					fuelPerCrab += i
				}
			}

			fuelUsed += fuelPerCrab * count
		}

		if i == 0 || fuelUsed < fuel {
			fuel = fuelUsed
		}
	}

	return fuel
}