using UnityEngine;

namespace Hallucinate.Game
{
    /// <summary>
    /// Pure logic for Elo rating calculations. 
    /// Follows the 1v1 competitive formula with dynamic K-factor.
    /// </summary>
    public static class EloSystem
    {
        public const int RATING_FLOOR = 100;
        public const int PLACEMENT_GAMES = 30;

        public static EloResult Calculate(
            int ratingA, int ratingB,
            int gamesPlayedA, int gamesPlayedB,
            float resultA) // 1=win, 0=lose, 0.5=draw
        {
            // 1. Expected Scores
            float eA = 1f / (1f + Mathf.Pow(10f, (ratingB - ratingA) / 400f));
            float eB = 1f - eA;

            // 2. K-Factors
            int kA = GetK(ratingA, gamesPlayedA);
            int kB = GetK(ratingB, gamesPlayedB);
            
            // 3. New Ratings
            int nA = Mathf.Max(RATING_FLOOR, Mathf.RoundToInt(ratingA + kA * (resultA - eA)));
            int nB = Mathf.Max(RATING_FLOOR, Mathf.RoundToInt(ratingB + kB * ((1f - resultA) - eB)));
            
            return new EloResult(nA, nB, nA - ratingA, nB - ratingB);
        }

        private static int GetK(int rating, int gamesPlayed)
        {
            if (gamesPlayed < PLACEMENT_GAMES) return 40;
            if (rating < 1200) return 32;
            if (rating < 2000) return 24;
            return 16;
        }

        public static string GetRank(int rating)
        {
            if (rating < 800) return "Iron";
            if (rating < 1000) return "Bronze";
            if (rating < 1200) return "Silver";
            if (rating < 1500) return "Gold";
            if (rating < 1800) return "Platinum";
            if (rating < 2100) return "Diamond";
            return "Master";
        }
        
        public static string GetRankColor(int rating)
        {
            if (rating < 800) return "#8A8A8A";  // Iron
            if (rating < 1000) return "#CD7F32"; // Bronze
            if (rating < 1200) return "#C0C0C0"; // Silver
            if (rating < 1500) return "#FFD700"; // Gold
            if (rating < 1800) return "#4DC8A0"; // Platinum
            if (rating < 2100) return "#7B6EE8"; // Diamond
            return "#E84D8A";                   // Master
        }
    }
}