Этап 2

Minint.Core/Models/MinintDocument.cs

@@ -0,0 +1,53 @@
+namespace Minint.Core.Models;
+
+/// <summary>
+/// A single document (frame) within a container.
+/// Has its own palette shared by all layers, plus a list of layers.
+/// </summary>
+public sealed class MinintDocument
+{
+    public string Name { get; set; }
+
+    /// <summary>
+    /// Delay before showing the next frame during animation playback (ms).
+    /// </summary>
+    public uint FrameDelayMs { get; set; }
+
+    /// <summary>
+    /// Document palette. Index 0 is always <see cref="RgbaColor.Transparent"/>.
+    /// All layers reference colors by index into this list.
+    /// </summary>
+    public List<RgbaColor> Palette { get; }
+
+    public List<MinintLayer> Layers { get; }
+
+    public MinintDocument(string name)
+    {
+        Name = name;
+        FrameDelayMs = 100;
+        Palette = [RgbaColor.Transparent];
+        Layers = [];
+    }
+
+    /// <summary>
+    /// Constructor for deserialization — accepts pre-built palette and layers.
+    /// </summary>
+    public MinintDocument(string name, uint frameDelayMs, List<RgbaColor> palette, List<MinintLayer> layers)
+    {
+        Name = name;
+        FrameDelayMs = frameDelayMs;
+        Palette = palette;
+        Layers = layers;
+    }
+
+    /// <summary>
+    /// Returns the number of bytes needed to store a single palette index on disk.
+    /// </summary>
+    public int IndexByteWidth => Palette.Count switch
+    {
+        <= 255 => 1,
+        <= 65_535 => 2,
+        <= 16_777_215 => 3,
+        _ => 4
+    };
+}