package day_08

import (
	"strings"
)

type Point struct {
	X, Y int
}

// task:https://adventofcode.com/2024/day/8
func SolveBasic(input string) int {
	antennas, width, height := loadAntennas(input)
	antinodes := map[Point]bool{}

	for _, v := range antennas {
		for i := 0; i < len(v); i++ {
			for j := i + 1; j < len(v); j++ {
				for _, antinode := range findAntinodes(v[i], v[j], width, height) {
					antinodes[antinode] = true
				}
			}
		}
	}
	return len(antinodes)
}

// task:https://adventofcode.com/2024/day/8#part2
func SolveComplex(input string) int {
	antennas, width, height := loadAntennas(input)
	antinodes := map[Point]bool{}

	for _, v := range antennas {
		for i := 0; i < len(v); i++ {
			for j := i + 1; j < len(v); j++ {
				for _, antinode := range findAllAntinodes(v[i], v[j], width, height) {
					antinodes[antinode] = true
				}
			}
		}
	}
	return len(antinodes)
}

func findAntinodes(A Point, B Point, width int, height int) []Point {
	dx := B.X - A.X
	dy := B.Y - A.Y

	points := []Point{}
	p := Point{
		X: A.X - dx,
		Y: A.Y - dy,
	}
	if inGrid(p, width, height) {
		points = append(points, p)
	}
	p = Point{
		X: B.X + dx,
		Y: B.Y + dy,
	}
	if inGrid(p, width, height) {
		points = append(points, p)
	}
	return points
}

func findAllAntinodes(A Point, B Point, width int, height int) []Point {
	dx := B.X - A.X
	dy := B.Y - A.Y

	points := []Point{}
	for inGrid(A, width, height) {
		points = append(points, Point{A.X, A.Y})
		A.X -= dx
		A.Y -= dy
	}
	for inGrid(B, width, height) {
		points = append(points, Point{B.X, B.Y})
		B.X += dx
		B.Y += dy
	}
	return points
}

func inGrid(p Point, width, height int) bool {
	return p.X >= 0 && p.X < width && p.Y >= 0 && p.Y < height
}

func loadAntennas(input string) (map[rune][]Point, int, int) {
	results := map[rune][]Point{}
	substrings := strings.Split(input, "\n")
	for y, line := range substrings {
		for x, char := range line {
			if char != '.' {
				results[char] = append(results[char], Point{x, y})
			}
		}
	}
	return results, len(substrings[0]), len(substrings)
}