PkmnLib.NET/Plugins/PkmnLib.Plugin.Gen7/Libraries/Gen7CaptureLibrary.cs

using System;
using PkmnLib.Dynamic.Libraries;
using PkmnLib.Static;

namespace PkmnLib.Plugin.Gen7.Libraries;

public class Gen7CaptureLibrary : ICaptureLibrary
{
    /// <inheritdoc />
    public CaptureResult TryCapture(IPokemon target, IItem captureItem, IBattleRandom random)
    {
        var maxHealth = target.BoostedStats.Hp;
        var currentHealth = target.CurrentHealth;
        var catchRate = target.Species.CaptureRate;

        byte bonusBall = 1;
        if (target.Library.ScriptResolver.TryResolveBattleItemScript(captureItem, out var script) &&
            script is PokeballScript pokeballScript)
        {
            bonusBall = pokeballScript.GetCatchRate(target);
        }

        byte bonusStatus = 1;
        target.RunScriptHook(x => x.ChangeCatchRateBonus(target, captureItem, ref bonusStatus));

        var modifiedCatchRate = (3.0 * maxHealth - 2.0 * currentHealth) * catchRate * bonusBall / (3.0 * maxHealth);
        modifiedCatchRate *= bonusStatus;

        var shakeProbability = 65536 / Math.Pow(255 / modifiedCatchRate, 0.1875);
        byte shakes = 0;
        if (modifiedCatchRate >= 255)
        {
            shakes = 4;
        }
        else
        {
            // FIXME: Implement critical capture
            for (var i = 0; i < 4; i++)
            {
                if (random.GetInt(0, 65536) < shakeProbability)
                {
                    shakes++;
                }
            }
        }
        var success = shakes >= 3;
        return new CaptureResult(success, shakes, false);
    }
}