Path finder

using System;
using System.Collections.Generic;
using UnityEngine;

public class DirectionFinder : MonoBehaviour
    {
        public enum TransitionType // Do not change.
        {
            WALK,
            RAIL,
            METRO_RAIL,
            SUBWAY,
            TRAM,
            MONORAIL,
            HEAVY_RAIL,
            COMMUTER_TRAIN,
            HIGH_SPEED_TRAIN,
            BUS,
            INTERCITY_BUS,
            TROLLEYBUS,
            SHARE_TAXI,
            FERRY,
            CABLE_CAR,
            GONDOLA_LIFT,
            FUNICULAR,
            OTHER
        }

        public TransitionType GetTransitionType(OnlineMapsGoogleDirectionsResult.Step step)
        {
            if (step.transit_details == null)
                return TransitionType.WALK;

            try
            {
                return (TransitionType)Enum.Parse(typeof(TransitionType), step.transit_details.line.vehicle.type);
            }
            catch (System.Exception ex)
            {
                Debug.LogException(ex);
                return TransitionType.OTHER;
            }
        }

        private Color GetColorForTransitionType(TransitionType type)
        {
            Color color = Color.magenta;
            switch (type)
            {
                case TransitionType.BUS:
                    color = Color.green;
                    break;
                case TransitionType.SUBWAY:
                    color = Color.yellow;
                    break;
                case TransitionType.TRAM:
                    color = Color.white;
                    break;
            }

            return color;
        }

        private void Start()
        {
            List<OnlineMapsGoogleDirectionsResult.Step> steps = new List<OnlineMapsGoogleDirectionsResult.Step>();

            FindPath("Los Angeles", "Compton", step => steps.Add(step), null,
                () =>
                {

                    foreach (var step in steps)
                    {
                        TransitionType transitionType = GetTransitionType(step);

                        OnlineMapsDrawingLine outline = new OnlineMapsDrawingLine(step.polylineD, Color.yellow, 6.0f);
                        OnlineMaps.instance.AddDrawingElement(outline);
                    }

                    foreach (var current in steps)
                    {
                        var transitionType = GetTransitionType(current);

                        var line = new OnlineMapsDrawingLine(new OnlineMapsVector2d[] { current.polylineD[0], current.polylineD[0] + new OnlineMapsVector2d(0, 0.000001f) }, Color.yellow, 15.0f);
                        OnlineMaps.instance.AddDrawingElement(line);
                    }

                    foreach (var step in steps)
                    {
                        var transitionType = GetTransitionType(step);
                        OnlineMapsDrawingLine route = new OnlineMapsDrawingLine(step.polylineD, GetColorForTransitionType(transitionType), 3.0f);
                        OnlineMaps.instance.AddDrawingElement(route);
                    }

                    foreach (var current in steps)
                    {
                        var transitionType = GetTransitionType(current);
                        var color = GetColorForTransitionType(transitionType);

                        var darkenColor = color;
                        darkenColor *= 0.5f;
                        darkenColor.a = 1.0f;

                        var line = new OnlineMapsDrawingLine(new OnlineMapsVector2d[] { current.polylineD[0], current.polylineD[0] + new OnlineMapsVector2d(0, 0.000001) }, color, 12.0f);
                        OnlineMaps.instance.AddDrawingElement(line);

                        var innerLine = new OnlineMapsDrawingLine(new OnlineMapsVector2d[] { current.polylineD[0], current.polylineD[0] + new OnlineMapsVector2d(0, 0.000001) }, darkenColor, 8.0f);
                        innerLine.tooltip = current.string_instructions;

                        OnlineMaps.instance.AddDrawingElement(innerLine);
                    }
                });
        }

        private void FindPath(object origin, object destination, Action<OnlineMapsGoogleDirectionsResult.Step> makePathPart, Action<OnlineMapsGoogleDirectionsResult.Step, OnlineMapsGoogleDirectionsResult.Step> makeSign = null, Action onTheEnd = null)
        {
            OnlineMapsGoogleDirections.Params parameters = new OnlineMapsGoogleDirections.Params(origin, destination);
            parameters.mode = OnlineMapsGoogleDirections.Mode.transit;
            parameters.traffic_model = OnlineMapsGoogleDirections.TrafficModel.optimistic;

            OnlineMapsGoogleDirections query = OnlineMapsGoogleDirections.Find(parameters);

            query.OnComplete += resultString =>
                {
                    OnlineMapsGoogleDirectionsResult result = OnlineMapsGoogleDirections.GetResult(resultString);

                    // Check that the result is not null, and the number of routes is not zero.
                    if (result == null || result.routes.Length == 0)
                    {
                        Debug.Log("Find direction failed");
                        Debug.Log(resultString);
                        return;
                    }

                    if (makePathPart != null)
                    {
                        foreach (var leg in result.routes[0].legs)
                            foreach (var step in leg.steps)
                                makePathPart(step);
                    }

                    if (makeSign != null)
                    {
                        OnlineMapsGoogleDirectionsResult.Step previous = null;
                        foreach (var leg in result.routes[0].legs)
                        {
                            foreach (var step in leg.steps)
                            {
                                makeSign(previous, step);
                                previous = step;
                            }
                        }
                    }

                    if (onTheEnd != null)
                        onTheEnd();
                };
        }
    }