using System.Collections.Generic;
using System.IO;
using UnityEngine;
using UnityEngine.UI;
using Random = UnityEngine.Random;

public class EvolutionController : MonoBehaviour {
    
    public int generationTimeInSeconds;
    public int populationSize;
    public GameObject agentPrefab;
    public Transform target;

    public Text informationText;
    public Slider timeSlider;
    
    private int _currentGeneration;
    private List<Agent> _agents;
    private float _startTime;
    private float _lastScore;
    
    private void Start() {
        _agents = new List<Agent>();
        StartGeneration();
    }

    private void Update() {
        if (_agents.Count == 0) return;
        
        if (Time.time - _startTime > generationTimeInSeconds) {
            _startTime = Time.time;
            StartGeneration();
        }
        _agents.Sort((agent, agent1) => agent1.Network.CompareTo(agent.Network));
        
        informationText.text = $"Generation: {_currentGeneration}\n" +
                               $"Time: {(Time.time - _startTime).ToString("F1")}\n" +
                               $"Population: {_agents.Count}\n" +
                               $"Time scale: {Time.timeScale}\n" +
                               $"Score: {_agents[0].Network.GetScore()}\n" +
                               $"Last score: {_lastScore}";
    }

    private void StartGeneration() {
        for (int i = 0; i < transform.childCount; i++) {
            Destroy(transform.GetChild(i).gameObject);
        }
        
        NeuralNetwork bestNetwork = null;
        if (_currentGeneration > 0) {
            _agents.Sort((agent, agent1) => agent1.Network.CompareTo(agent.Network));
            bestNetwork = _agents[0].Network;
            _lastScore = bestNetwork.GetScore();
        }

        target.position = new Vector2(Random.Range(-10, 10), Random.Range(-5, 5));
        
        _agents.Clear();
        for (int i = 0; i < populationSize; i++) {
            GameObject agent = Instantiate(agentPrefab, Vector3.zero, Quaternion.identity);
            agent.transform.SetParent(transform);
            Agent agentController = agent.AddComponent<Agent>();
            agentController.Initialize(target, bestNetwork);
            _agents.Add(agentController);
        }
        _currentGeneration++;
    }
    
    public void ChangeTimeMultipler() {
        Time.timeScale = timeSlider.value;
    }
}