package day24

import (
	"math"
	"tools"
)

func getInputGrid(inp []string) (tools.GridToggle, map[int]tools.Coordinate) {
	grid := tools.NewGridToggle()
	targets := make(map[int]tools.Coordinate)

	for y, line := range inp {
		for x, c := range line {
			if c == '#' {
				grid.Set(x, y, tools.On)
			} else if c != '.' {
				targets[int(c-48)] = tools.Coordinate{X: x, Y: y}
			}
		}
	}

	return grid, targets
}

func findShortestPathBetweenNodes(grid tools.GridToggle, targets map[int]tools.Coordinate, startNode int, alreadyVisited tools.Set, pathLen int, part2 bool) int {
	alreadyVisited.Add(startNode)
	minLen := math.MaxInt32
	for node, target := range targets {
		if alreadyVisited.Contains(node) {
			continue
		}
		thisLen := len(grid.GetPathAStar(targets[startNode], target, false)) - 1
		if alreadyVisited.Len() == len(targets)-1 {
			if part2 {
				return thisLen + pathLen + len(grid.GetPathAStar(target, targets[0], false)) - 1
			} else {
				return thisLen + pathLen
			}
		} else {
			thisLen = findShortestPathBetweenNodes(grid, targets, node, alreadyVisited.Copy(), thisLen, part2)
			if thisLen < minLen {
				minLen = thisLen
			}
		}
	}
	return minLen + pathLen
}

func Part1(puzzle tools.AoCPuzzle) interface{} {
	grid, targets := getInputGrid(puzzle.GetInputArray())

	return findShortestPathBetweenNodes(grid, targets, 0, tools.NewSet(), 0, false)
}

func Part2(puzzle tools.AoCPuzzle) interface{} {
	grid, targets := getInputGrid(puzzle.GetInputArray())

	return findShortestPathBetweenNodes(grid, targets, 0, tools.NewSet(), 0, true)
}