using CounterStrikeSharp.API.Core;
using CounterStrikeSharp.API.Modules.UserMessages;

namespace Outnumbered.Engine;

// CS2 screen fade via the Fade user message. The exact message format is UNVERIFIED (hard to debug blind), so the send is
// wrapped: a wrong field name no-ops via onError instead of crashing. The blend/decision logic stays plugin-side.
internal static class ScreenFade
{
    public static int Pack(int r, int g, int b, int a) => r | (g << 8) | (b << 16) | (a << 24);

    public static void Send(CCSPlayerController p, int r, int g, int b, int a, bool clear, Action<Exception> onError)
    {
        try
        {
            // CUserMessageFade [106]: duration, hold_time, flags, color — all INT; color is one packed value (not nested clr).
            var msg = UserMessage.FromPartialName("Fade");
            msg.SetInt("duration", (int)(0.3f * 512));      // Q7.9 fixed point (seconds * 512); int, not float
            msg.SetInt("hold_time", 0);                     // FFADE_STAYOUT holds it until the next fade
            // hold a tint: FFADE_OUT|FFADE_STAYOUT. clear it: FFADE_IN|FFADE_PURGE (fades the held colour out + drops stayout).
            msg.SetInt("flags", clear ? (0x1 | 0x10) : (0x2 | 0x8));
            msg.SetInt("color", Pack(r, g, b, a));          // packed color32, R in the low byte
            msg.Send(p);
        }
        catch (Exception ex)
        {
            onError(ex);
        }
    }
}