using Steamworks;
using UnityEngine;

namespace Ashwild.Network
{
    /// <summary>
    /// Turns a Steam avatar image handle into a Unity Sprite. Steam hands us raw RGBA pixels
    /// laid out top-to-bottom, whereas Unity textures are bottom-to-top, so the rows are flipped
    /// while copying. Returns null for any invalid/empty handle so callers can fall back cleanly.
    /// </summary>
    public static class SteamAvatarUtil
    {
        /// <summary>
        /// Builds a Sprite from a Steam image handle (e.g. from GetLargeFriendAvatar).
        /// </summary>
        public static Sprite BuildSprite(int imageHandle)
        {
            if (imageHandle <= 0) return null;
            if (!SteamUtils.GetImageSize(imageHandle, out uint width, out uint height)) return null;
            if (width == 0 || height == 0) return null;

            int w = (int)width;
            int h = (int)height;

            byte[] buffer = new byte[w * h * 4];
            if (!SteamUtils.GetImageRGBA(imageHandle, buffer, buffer.Length)) return null;

            // Flip vertically: Steam rows run top→bottom, Unity expects bottom→top.
            Color32[] pixels = new Color32[w * h];
            for (int y = 0; y < h; y++)
            {
                int srcRow = (h - 1 - y) * w * 4;
                int dstRow = y * w;
                for (int x = 0; x < w; x++)
                {
                    int s = srcRow + x * 4;
                    pixels[dstRow + x] = new Color32(buffer[s], buffer[s + 1], buffer[s + 2], buffer[s + 3]);
                }
            }

            Texture2D texture = new Texture2D(w, h, TextureFormat.RGBA32, false, true)
            {
                wrapMode = TextureWrapMode.Clamp
            };
            texture.SetPixels32(pixels);
            texture.Apply(false, false);

            return Sprite.Create(texture, new Rect(0f, 0f, w, h), new Vector2(0.5f, 0.5f), 100f);
        }
    }
}