package main

import (
	"fmt"
	"math"
	"strings"

	h "git.bullercodeworks.com/brian/adventofcode/helpers"
)

func main() {
	inp := h.StdinToStringSlice()
	part1(inp)
}

func part1(inp []string) {
	volcano := NewVolcano(inp)
	timeLeft := 30
	currRoom := volcano.FindRoom("AA")
	_, _ = timeLeft, currRoom
	fmt.Println("Steps from AA -> JJ:", volcano.CountSteps("AA", "JJ"))
}

type Volcano struct {
	rooms []*Room
}

func NewVolcano(inp []string) *Volcano {
	v := &Volcano{}
	for i := range inp {
		v.rooms = append(v.rooms, StringToRoom(inp[i]))
	}
	for i := range v.rooms {
		for _, valve := range v.rooms[i].RawTunnels {
			v.rooms[i].Tunnels = append(v.rooms[i].Tunnels, v.FindRoom(valve))
		}
	}
	return v
}

func (v *Volcano) CountSteps(from string, to string) int {
	start, end := v.FindRoom(from), v.FindRoom(to)
	if start == nil || end == nil {
		fmt.Println("Couldn't find requested rooms:", from, ":", start, " ; ", to, ":", end)
		return math.MaxInt
	}
	return v.TrackStepCount(start, end, []*Room{})
}

func (v *Volcano) TrackStepCount(from *Room, to *Room, visited []*Room) int {
	if from == to {
		return 0
	}
	minSteps := math.MaxInt
	for _, t := range from.Tunnels {
		fmt.Println("TrackStepCount:", from, "->", to, "::", t)
		if !IsRoomIn(t, visited) {
			fmt.Println("  Haven't Visited")
			wrk := v.TrackStepCount(t, to, append(visited, t)) + 1
			fmt.Println("  From", from, "to", to, "in", wrk)
			minSteps = h.Min(minSteps, wrk)
		}
	}
	return minSteps
}

func (v *Volcano) FindRoom(valve string) *Room {
	for _, r := range v.rooms {
		if r.Valve == valve {
			return r
		}
	}
	return nil
}

func IsRoomIn(room *Room, rooms []*Room) bool {
	for i := range rooms {
		if rooms[i] == room {
			return true
		}
	}
	return false
}

type Room struct {
	Valve      string
	FlowRate   int
	RawTunnels []string
	Tunnels    []*Room
}

func StringToRoom(s string) *Room {
	room := &Room{}
	r := strings.NewReader(s)
	fmt.Fscanf(r, "Valve %s has flow rate=%d; tunnels lead to valve", &room.Valve, &room.FlowRate)
	readTunnels := strings.Split(s, " valve")[1]
	if readTunnels[0] == ' ' {
		readTunnels = readTunnels[1:]
	} else {
		readTunnels = readTunnels[2:]
	}
	room.RawTunnels = strings.Split(readTunnels, ", ")
	return room
}

func (r Room) String() string {
	return r.Valve
}

func (r Room) FullString() string {
	return fmt.Sprintf("Valve %s has flow rate=%d; tunnels lead to valves %v", r.Valve, r.FlowRate, r.RawTunnels)
}