#region License
//   Copyright 2020 Kastellanos Nikolaos
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.
#endregion

using System;
using System.IO;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content.Pipeline;

namespace nkast.Aether.Content.Pipeline
{
    class VoxImporter
    {
        internal VoxelContent ImportVox(string filename, ContentImporterContext context)
        {
            VoxelContent output;
            using (Stream stream = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read))
            {
                using (BinaryReader reader = new BinaryReader(stream))
                {
                    ContentIdentity contentIdentity = new ContentIdentity(filename);
                    output = ImportVox(reader, contentIdentity, context);
                }
            }

            return output;
        }

        private VoxelContent ImportVox(BinaryReader reader, ContentIdentity contentIdentity, ContentImporterContext context)
        {
            VoxelContent output = null;

            VoxHeader header = new VoxHeader(reader);

            Chunk main = new Chunk(reader);
            if (main.ChunkId != Chunk.MAIN)
                throw new InvalidContentException("MAIN was expected");

            Chunk chunk = new Chunk(reader);
            if (chunk.ChunkId == Chunk.PACK)
                throw new InvalidContentException("PACK is not supported");

            Chunk chunkSIZE = chunk;
            if (chunkSIZE.ChunkId != Chunk.SIZE)
                throw new InvalidContentException("SIZE was expected");
            int sizeX = reader.ReadInt32();
            int sizeZ = reader.ReadInt32();
            int sizeY = reader.ReadInt32();


            Chunk chunkXYZI = new Chunk(reader);
            if (chunkXYZI.ChunkId != Chunk.XYZI)
                throw new InvalidContentException("XYZI was expected");
            int numVoxels = reader.ReadInt32();

            XYZI[] voxels = new XYZI[numVoxels];
            for (int i = 0; i < numVoxels; i++)
            {
                byte x = reader.ReadByte();
                byte z = reader.ReadByte();
                byte y = reader.ReadByte();
                byte ColorIndex = reader.ReadByte();
                z = (byte)(sizeZ - 1 - z);

                voxels[i].Point = new Point3(x, y, z);
                voxels[i].ColorIndex = ColorIndex;
            }

            uint[] palette = default_palette;
            if (reader.BaseStream.Position < reader.BaseStream.Length)
            {
                chunk = new Chunk(reader);

                if (chunk.ChunkId == Chunk.RGBA)
                {
                    palette = new UInt32[256];

                    // color [0-254] are mapped to palette index [1-255]
                    for (int i = 1; i < 256; i++)
                    {
                        palette[i] = reader.ReadUInt32();
                    }
                    // the last color is not mapped
                    reader.ReadUInt32();

                }
            }

            output = new VoxelContent()
            {
                GridSize = new Vector3(sizeX, sizeY, sizeZ),
                Voxels = voxels,
                Palette = palette,
            };

            return output;
        }
        
        readonly uint[] default_palette = new uint[]
        {
            0x00000000, 0xffffffff, 0xffccffff, 0xff99ffff, 0xff66ffff, 0xff33ffff, 0xff00ffff, 0xffffccff, 0xffccccff, 0xff99ccff, 0xff66ccff, 0xff33ccff, 0xff00ccff, 0xffff99ff, 0xffcc99ff, 0xff9999ff,
            0xff6699ff, 0xff3399ff, 0xff0099ff, 0xffff66ff, 0xffcc66ff, 0xff9966ff, 0xff6666ff, 0xff3366ff, 0xff0066ff, 0xffff33ff, 0xffcc33ff, 0xff9933ff, 0xff6633ff, 0xff3333ff, 0xff0033ff, 0xffff00ff,
            0xffcc00ff, 0xff9900ff, 0xff6600ff, 0xff3300ff, 0xff0000ff, 0xffffffcc, 0xffccffcc, 0xff99ffcc, 0xff66ffcc, 0xff33ffcc, 0xff00ffcc, 0xffffcccc, 0xffcccccc, 0xff99cccc, 0xff66cccc, 0xff33cccc,
            0xff00cccc, 0xffff99cc, 0xffcc99cc, 0xff9999cc, 0xff6699cc, 0xff3399cc, 0xff0099cc, 0xffff66cc, 0xffcc66cc, 0xff9966cc, 0xff6666cc, 0xff3366cc, 0xff0066cc, 0xffff33cc, 0xffcc33cc, 0xff9933cc,
            0xff6633cc, 0xff3333cc, 0xff0033cc, 0xffff00cc, 0xffcc00cc, 0xff9900cc, 0xff6600cc, 0xff3300cc, 0xff0000cc, 0xffffff99, 0xffccff99, 0xff99ff99, 0xff66ff99, 0xff33ff99, 0xff00ff99, 0xffffcc99,
            0xffcccc99, 0xff99cc99, 0xff66cc99, 0xff33cc99, 0xff00cc99, 0xffff9999, 0xffcc9999, 0xff999999, 0xff669999, 0xff339999, 0xff009999, 0xffff6699, 0xffcc6699, 0xff996699, 0xff666699, 0xff336699,
            0xff006699, 0xffff3399, 0xffcc3399, 0xff993399, 0xff663399, 0xff333399, 0xff003399, 0xffff0099, 0xffcc0099, 0xff990099, 0xff660099, 0xff330099, 0xff000099, 0xffffff66, 0xffccff66, 0xff99ff66,
            0xff66ff66, 0xff33ff66, 0xff00ff66, 0xffffcc66, 0xffcccc66, 0xff99cc66, 0xff66cc66, 0xff33cc66, 0xff00cc66, 0xffff9966, 0xffcc9966, 0xff999966, 0xff669966, 0xff339966, 0xff009966, 0xffff6666,
            0xffcc6666, 0xff996666, 0xff666666, 0xff336666, 0xff006666, 0xffff3366, 0xffcc3366, 0xff993366, 0xff663366, 0xff333366, 0xff003366, 0xffff0066, 0xffcc0066, 0xff990066, 0xff660066, 0xff330066,
            0xff000066, 0xffffff33, 0xffccff33, 0xff99ff33, 0xff66ff33, 0xff33ff33, 0xff00ff33, 0xffffcc33, 0xffcccc33, 0xff99cc33, 0xff66cc33, 0xff33cc33, 0xff00cc33, 0xffff9933, 0xffcc9933, 0xff999933,
            0xff669933, 0xff339933, 0xff009933, 0xffff6633, 0xffcc6633, 0xff996633, 0xff666633, 0xff336633, 0xff006633, 0xffff3333, 0xffcc3333, 0xff993333, 0xff663333, 0xff333333, 0xff003333, 0xffff0033,
            0xffcc0033, 0xff990033, 0xff660033, 0xff330033, 0xff000033, 0xffffff00, 0xffccff00, 0xff99ff00, 0xff66ff00, 0xff33ff00, 0xff00ff00, 0xffffcc00, 0xffcccc00, 0xff99cc00, 0xff66cc00, 0xff33cc00,
            0xff00cc00, 0xffff9900, 0xffcc9900, 0xff999900, 0xff669900, 0xff339900, 0xff009900, 0xffff6600, 0xffcc6600, 0xff996600, 0xff666600, 0xff336600, 0xff006600, 0xffff3300, 0xffcc3300, 0xff993300,
            0xff663300, 0xff333300, 0xff003300, 0xffff0000, 0xffcc0000, 0xff990000, 0xff660000, 0xff330000, 0xff0000ee, 0xff0000dd, 0xff0000bb, 0xff0000aa, 0xff000088, 0xff000077, 0xff000055, 0xff000044,
            0xff000022, 0xff000011, 0xff00ee00, 0xff00dd00, 0xff00bb00, 0xff00aa00, 0xff008800, 0xff007700, 0xff005500, 0xff004400, 0xff002200, 0xff001100, 0xffee0000, 0xffdd0000, 0xffbb0000, 0xffaa0000,
            0xff880000, 0xff770000, 0xff550000, 0xff440000, 0xff220000, 0xff110000, 0xffeeeeee, 0xffdddddd, 0xffbbbbbb, 0xffaaaaaa, 0xff888888, 0xff777777, 0xff555555, 0xff444444, 0xff222222, 0xff111111
        };
    }
}