package day18

import (
	"tools"
)

type coord struct {
	x int
	y int
}

func play(grid tools.ToggleGrid, stuckCorners bool) {
	neighbours := make(map[coord]int)
	for thisCoord := range grid.GetOnCoordinates() {
		for cx := thisCoord.X - 1; cx <= thisCoord.X+1; cx++ {
			for cy := thisCoord.Y - 1; cy <= thisCoord.Y+1; cy++ {
				if cy == thisCoord.Y && cx == thisCoord.X {
					continue
				}
				neighbours[coord{cx, cy}]++
			}
		}
	}

	for x := 0; x <= grid.MaxX; x++ {
		for y := 0; y <= grid.MaxY; y++ {
			if grid.State(x, y) {
				if neighbours[coord{x, y}] != 2 && neighbours[coord{x, y}] != 3 {
					if !stuckCorners || !grid.IsCorner(x, y) {
						grid.Set(x, y, tools.Off)
					}
				}
			} else if neighbours[coord{x, y}] == 3 {
				grid.Set(x, y, tools.On)
			}
		}
	}
}

func makeGridFromInput(input []string) tools.ToggleGrid {
	grid := tools.NewToogleGrid()
	for y, line := range input {
		for x, c := range line {
			if c == '#' {
				grid.Set(x, y, tools.On)
			}
		}
	}

	return grid
}

func Part1(puzzle tools.AoCPuzzle) interface{} {
	grid := makeGridFromInput(puzzle.GetInputArray())

	for i := 0; i < 100; i++ {
		play(grid, false)
	}

	return grid.GetOnCount()
}

func Part2(puzzle tools.AoCPuzzle) interface{} {
	grid := makeGridFromInput(puzzle.GetInputArray())
	grid.Set(0, 0, tools.On)
	grid.Set(0, grid.MaxY, tools.On)
	grid.Set(grid.MaxX, 0, tools.On)
	grid.Set(grid.MaxX, grid.MaxY, tools.On)

	for i := 0; i < 100; i++ {
		play(grid, true)
	}

	return grid.GetOnCount()
}