package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strings"
)

type cart struct {
	x, y  int
	state int // 0 = turn left, 1 = go straight, 2 = go right
	on    byte
	cart  byte
}

func main() {
	f, _ := os.Open("input")
	defer f.Close()
	scan := bufio.NewScanner(f)
	tracks := make([]string, 0)
	carts := make([]cart, 0)
	for scan.Scan() {
		track := scan.Text()
		for i := range track {
			if strings.ContainsAny(string(track[i]), "^v") {
				carts = append(carts, cart{i, len(tracks), 0, '|', track[i]})
			} else if strings.ContainsAny(string(track[i]), "<>") {
				carts = append(carts, cart{i, len(tracks), 0, '-', track[i]})
			}
		}
		tracks = append(tracks, track)
	}
	for /*a := 0; a < 3; a++*/ {
		/*for _, track := range tracks {
			fmt.Println(track)
		}*/
		sort.Slice(carts, func(i, j int) bool {
			return carts[i].y < carts[j].y || carts[i].y == carts[j].y && carts[i].x < carts[j].x
		})
		for c := range carts {
			tracks[carts[c].y] = tracks[carts[c].y][:carts[c].x] + string(carts[c].on) + tracks[carts[c].y][carts[c].x+1:]
			switch carts[c].cart {
			case 'v':
				carts[c].y++
			case '<':
				carts[c].x--
			case '>':
				carts[c].x++
			case '^':
				carts[c].y--
			}
			if strings.ContainsAny(string(tracks[carts[c].y][carts[c].x]), "^v<>") {
				fmt.Println("yeet:", carts[c].x, carts[c].y)
				return
			} else if strings.ContainsAny(string(tracks[carts[c].y][carts[c].x]), "-|") {
				carts[c].on = tracks[carts[c].y][carts[c].x]
				tracks[carts[c].y] = tracks[carts[c].y][:carts[c].x] + string(carts[c].cart) + tracks[carts[c].y][carts[c].x+1:]
				continue
			}
			carts[c].on = tracks[carts[c].y][carts[c].x]
			switch carts[c].cart {
			case 'v':
				if carts[c].on == '/' {
					carts[c].cart = '<'
				} else if carts[c].on == '\\' {
					carts[c].cart = '>'
				} else {
					//do stuff
					if carts[c].state == 0 {
						carts[c].cart = '>'
					} else if carts[c].state == 2 {
						carts[c].cart = '<'
					}
					carts[c].state = (carts[c].state + 1) % 3
				}
			case '<':
				if carts[c].on == '/' {
					carts[c].cart = 'v'
				} else if carts[c].on == '\\' {
					carts[c].cart = '^'
				} else {
					//do stuff
					if carts[c].state == 0 {
						carts[c].cart = 'v'
					} else if carts[c].state == 2 {
						carts[c].cart = '^'
					}
					carts[c].state = (carts[c].state + 1) % 3
				}
			case '>':
				if carts[c].on == '/' {
					carts[c].cart = '^'
				} else if carts[c].on == '\\' {
					carts[c].cart = 'v'
				} else {
					//do stuff
					if carts[c].state == 0 {
						carts[c].cart = '^'
					} else if carts[c].state == 2 {
						carts[c].cart = 'v'
					}
					carts[c].state = (carts[c].state + 1) % 3
				}
			case '^':
				if carts[c].on == '/' {
					carts[c].cart = '>'
				} else if carts[c].on == '\\' {
					carts[c].cart = '<'
				} else {
					//do stuff
					if carts[c].state == 0 {
						carts[c].cart = '<'
					} else if carts[c].state == 2 {
						carts[c].cart = '>'
					}
					carts[c].state = (carts[c].state + 1) % 3
				}
			}
			tracks[carts[c].y] = tracks[carts[c].y][:carts[c].x] + string(carts[c].cart) + tracks[carts[c].y][carts[c].x+1:]
		}
	}
}