using System.Collections.Generic;
using UnityEngine;
using TMPro;
using System.Linq;

public class RaceManager : MonoBehaviour
{
    [SerializeField] private GameObject leaderboardUI;
    [SerializeField] private Transform leaderboardContent;
    [SerializeField] private GameObject leaderboardEntryPrefab;
    [SerializeField] private GameObject waitingText;
    [SerializeField] private int totalCars = 4;

    private List<(VehicleController car, string name)> finishOrder = new();
    private HashSet<VehicleController> finishedCars = new();
    private List<VehicleTracker> activeTrackers = new();
    private bool leaderboardShown = false;
    public int TotalCars => totalCars;


    public void RegisterTracker(VehicleTracker tracker)
    {
        if (!activeTrackers.Contains(tracker))
            activeTrackers.Add(tracker);
    }

    public void RegisterFinish(VehicleController car)
    {
        if (finishedCars.Contains(car)) return;

        string displayName = car.isAIControlled
            ? car.GetComponentInChildren<TextMeshProUGUI>().text
            : GameConstants.PlayerName;

        finishOrder.Add((car, displayName));
        finishedCars.Add(car);

        if (!leaderboardShown && !car.isAIControlled)
        {
            leaderboardShown = true;
            ShowLeaderboard(); // Show first time (player triggered)
            waitingText?.SetActive(true);
        }
        else if (leaderboardShown)
        {
            UpdateLeaderboard(); // Add AI progressively
        }

        if (finishedCars.Count >= totalCars)
        {
            waitingText?.SetActive(false);
        }
    }

    public bool HasFinished(VehicleController car)
    {
        return finishedCars.Contains(car);
    }

    public int GetCurrentPosition(VehicleTracker tracker)
    {
        VehicleController car = tracker.GetComponent<VehicleController>();

        if (HasFinished(car))
        {
            return finishOrder.FindIndex(f => f.car == car) + 1;
        }

        var sorted = activeTrackers
            .Where(t => !HasFinished(t.GetComponent<VehicleController>()))
            .OrderByDescending(t => t.GetDistance())
            .ToList();

        return finishOrder.Count + sorted.IndexOf(tracker) + 1;
    }

    private void ShowLeaderboard()
    {
        leaderboardUI.SetActive(true);
        UpdateLeaderboard();
    }

    private void UpdateLeaderboard()
    {
        foreach (Transform child in leaderboardContent)
        {
            Destroy(child.gameObject);
        }

        string playerName = GameConstants.PlayerName;

        for (int i = 0; i < finishOrder.Count; i++)
        {
            GameObject entry = Instantiate(leaderboardEntryPrefab, leaderboardContent);
            TextMeshProUGUI text = entry.GetComponentInChildren<TextMeshProUGUI>();

            if (text != null)
            {
                string name = finishOrder[i].name;
                if (name == playerName)
                {
                    text.text = $"<b>{i + 1}. {name}</b>";
                    text.color = Color.yellow;
                }
                else
                {
                    text.text = $"{i + 1}. {name}";
                    text.color = Color.white;
                }
            }
        }
    }
}