SimUL/Assets/Scripts/DateTimeController.cs

using System;
using TMPro;
using UnityEngine;

public class DateTimeController : MonoBehaviour
{
    [SerializeField]
    private float _timeMultiplier;

    [SerializeField]
    private float _startHour;

    [SerializeField]
    private TextMeshProUGUI _timeText;

    [SerializeField]
    private Light _sunLight;

    [SerializeField]
    private float _sunriseHour;
    [SerializeField]
    private float _sunsetHour;

    [SerializeField]
    private Color _dayAmbientLight;

    [SerializeField]
    private Color _nightAmbientLight;

    [SerializeField]
    private AnimationCurve _lightChangeCurve;

    [SerializeField]
    private float _maxSunLightIntensity;

    [SerializeField]
    private Light _moonLight;

    [SerializeField]
    private float _maxMoonLightIntensity;

    private TimeSpan _sunriseTime;
    private TimeSpan _sunsetTime;

    private DateTime _currentTime;
    // Start is called before the first frame update
    void Start()
    {
        _currentTime = DateTime.Now.Date + TimeSpan.FromHours(_startHour);
        _sunriseTime = TimeSpan.FromHours(_sunriseHour);
        _sunsetTime = TimeSpan.FromHours(_sunsetHour);
    }

    // Update is called once per frame
    void Update()
    {
        UpdateTime();
        RotateSun();
    }

    private void UpdateTime()
    {
        _currentTime = _currentTime.AddSeconds(Time.deltaTime * _timeMultiplier);

        if (_timeText != null)
        {
            _timeText.text = _currentTime.ToString("HH:mm");
        }
    }

    private void RotateSun()
    {
        float sunLightRotation;
        if (_currentTime.TimeOfDay > _sunriseTime && _currentTime.TimeOfDay < _sunsetTime)
        {
            TimeSpan sunriseToSunsetDuration = CalculateTimeDifference(_sunriseTime, _sunsetTime);
            TimeSpan timeSinceSunrise = CalculateTimeDifference(_sunriseTime, _currentTime.TimeOfDay);

            double percentage = timeSinceSunrise.TotalMinutes / sunriseToSunsetDuration.TotalMinutes;

            sunLightRotation = Mathf.Lerp(0, 180, (float)percentage);
        }
        else
        {
            TimeSpan nightDuration = CalculateTimeDifference(_sunsetTime, _sunriseTime);
            TimeSpan timeSinceSunset = CalculateTimeDifference(_sunsetTime, _currentTime.TimeOfDay);

            double percentage = timeSinceSunset.TotalMinutes / nightDuration.TotalMinutes;

            sunLightRotation = Mathf.Lerp(180, 360, (float)percentage);
        }
        _sunLight.transform.rotation = Quaternion.AngleAxis(sunLightRotation, Vector3.right);
    }

    private void UpdateLightSettings()
    {
        float dotProduct = Vector3.Dot(_sunLight.transform.forward, Vector3.down);
        _sunLight.intensity = Mathf.Lerp(0, _maxSunLightIntensity, _lightChangeCurve.Evaluate(dotProduct));
        _moonLight.intensity = Mathf.Lerp(_maxMoonLightIntensity, 0, _lightChangeCurve.Evaluate(dotProduct));
        RenderSettings.ambientLight = Color.Lerp(_nightAmbientLight, _dayAmbientLight, _lightChangeCurve.Evaluate(dotProduct));
    }
    private TimeSpan CalculateTimeDifference(TimeSpan from, TimeSpan to)
    {
        TimeSpan diff = to - from;
        if (diff.TotalSeconds < 0)
        {
            diff += TimeSpan.FromHours(24);
        }

        return diff;
    }
}