using System.Collections.Generic;
using UnityEngine;

namespace MSCO
{
    /// <summary>
    /// Kleine Hinweise oben rechts (unter der Ping-Anzeige), z.B. "Bob joined" / "Bob left".
    /// Gleiten von rechts herein, bleiben ein paar Sekunden und blenden dann aus. Höchstens 4 gleichzeitig.
    /// </summary>
    public class Toasts
    {
        const float Lifetime = 4.5f;
        const float SlideIn = 0.25f;
        const float FadeOut = 0.6f;
        const float Width = 250f;
        const float Height = 36f;
        const int MaxShown = 4;

        class Toast
        {
            public string Text;
            public string Detail;
            public Color Dot;
            public float Start;
        }

        readonly List<Toast> toasts = new List<Toast>();
        GUIStyle box, title, detail;
        Texture2D dotTex;

        public void Add(string text, string detail, Color dot)
        {
            toasts.Add(new Toast { Text = text, Detail = detail, Dot = dot, Start = Time.realtimeSinceStartup });
            if (toasts.Count > MaxShown) toasts.RemoveAt(0);
        }

        public void Draw()
        {
            if (toasts.Count == 0) return;
            EnsureStyles();
            float now = Time.realtimeSinceStartup;
            toasts.RemoveAll(t => now - t.Start > Lifetime);

            Color before = GUI.color;
            float y = 40f; // unter der Ping-Anzeige
            for (int i = toasts.Count - 1; i >= 0; i--) // neueste oben
            {
                Toast t = toasts[i];
                float age = now - t.Start;
                float slide = Mathf.Clamp01(age / SlideIn);
                slide = 1f - (1f - slide) * (1f - slide); // weich abbremsen
                float alpha = Mathf.Clamp01((Lifetime - age) / FadeOut);

                var r = new Rect(Screen.width - 12 - Width + (1f - slide) * (Width + 20f), y, Width, Height);
                GUI.color = new Color(1f, 1f, 1f, alpha);
                UiTheme.DrawShadow(r);
                GUI.Box(r, GUIContent.none, box);

                GUI.color = new Color(t.Dot.r, t.Dot.g, t.Dot.b, alpha);
                GUI.DrawTexture(new Rect(r.x + 14, r.y + Height / 2f - 4, 8, 8), dotTex);

                GUI.color = new Color(1f, 1f, 1f, alpha);
                GUI.Label(new Rect(r.x + 32, r.y, r.width - 40, Height), t.Text, title);
                if (!string.IsNullOrEmpty(t.Detail))
                {
                    float w = title.CalcSize(new GUIContent(t.Text)).x;
                    GUI.Label(new Rect(r.x + 32 + w + 6, r.y, r.width - 46 - w, Height), t.Detail, detail);
                }
                y += Height + 6f;
            }
            GUI.color = before;
        }

        void EnsureStyles()
        {
            if (box != null && box.normal.background != null) return;
            box = UiTheme.Card(new Color(0.06f, 0.06f, 0.07f, 0.92f), 6);
            title = new GUIStyle(GUI.skin.label) { fontSize = 13, fontStyle = FontStyle.Bold, alignment = TextAnchor.MiddleLeft };
            title.normal.textColor = Color.white;
            title.wordWrap = false;
            detail = new GUIStyle(title) { fontStyle = FontStyle.Normal, fontSize = 12 };
            detail.normal.textColor = UiTheme.Muted;
            dotTex = RoundDot(16);
        }

        static Texture2D RoundDot(int size)
        {
            var t = new Texture2D(size, size, TextureFormat.ARGB32, false);
            float c = (size - 1) / 2f;
            for (int x = 0; x < size; x++)
                for (int y = 0; y < size; y++)
                {
                    float d = Mathf.Sqrt((x - c) * (x - c) + (y - c) * (y - c));
                    t.SetPixel(x, y, new Color(1f, 1f, 1f, Mathf.Clamp01(c + 0.5f - d)));
                }
            t.Apply();
            t.hideFlags = HideFlags.HideAndDontSave;
            return t;
        }
    }
}