package format.vox;

import format.vox.types.*;
import haxe.io.Bytes;
import haxe.io.BytesData;
import haxe.io.BytesInput;
import haxe.io.Input;

typedef VoxError = Any;

@:expose @:keep
class VoxReader {
	public static function read( data: BytesData, then: ?Vox -> ?VoxError -> Void ) {
		if (data == null) {
			then(null, 'Invalid input');
			return;
		}

		var input = new BytesInput(Bytes.ofData(data));

		if (input.readString(4) != 'VOX ') {
			then(null, 'Expected "VOX " header');
			return;
		}

		var version = i32(input);

		if (version != 150 && version != 200) {
			then(null, 'Unsupported version "$version"');
			return;
		}

		var vox = new Vox();
		vox.palette = DefaultPalette.map(VoxTools.transformColor);
		var state = { modelIndex: 0, sizeIndex: 0 }
		var nodeData: Array<NodeData> = [];

		readChunk(input, vox, nodeData, state);

		if (nodeData.length > 0) {
			vox.nodeGraph = buildNodeGraph(vox, nodeData, 0);
		}

		then(vox, null);
	}

	static function readChunk( input: Input, vox: Vox, nodeData: Array<NodeData>, state: State ) : Int {
		var chunkId = input.readString(4);
		#if haxe_format_vox_trace trace('chunk id = "${chunkId}"'); #end
		var contentSize = i32(input);
		#if haxe_format_vox_trace trace('content size = "${contentSize}"'); #end
		var childBytes  = i32(input);
		#if haxe_format_vox_trace trace('child bytes = "${childBytes}"'); #end

		switch chunkId {
			case 'MAIN':
			case 'PACK':
				var numModels = i32(input);
			case 'SIZE':
				vox.sizes[state.sizeIndex++] = {
					x :i32(input),
					y: i32(input),
					z: i32(input)
				}
			case 'XYZI':
				vox.models[state.modelIndex++] = [for (c in 0...i32(input)) readVoxel(input)];
			case 'RGBA':
				var palette = DefaultPalette;

				for (i in 0...255) {
					palette[i + 1] = input.readInt32();
				}

				input.readInt32();

				if (vox.palette != null) {
					#if haxe_format_vox_trace trace('vox.palette is already assigned'); #end
				}

				vox.palette = palette.map(VoxTools.transformColor);
			case 'MATL':
				var m = readMaterial(input);
				vox.materials[m.id] = m.props;
			case 'nTRN':
				var nodeId = i32(input); // 0 is root?
				var attributes = readDict(input);
				var childNodeId = i32(input);
				var reserved = i32(input);
				var layerId = i32(input);
				var numFrames = i32(input);
				var frames = [for (i in 0...numFrames) readDict(input)];
				#if haxe_format_vox_trace trace('$chunkId $nodeId $attributes $childNodeId $reserved $layerId $numFrames $frames'); #end
				nodeData[nodeId] = TransformNodeData(attributes, childNodeId, reserved, layerId, frames);
			case 'nSHP':
				var nodeId = i32(input);
				var attributes = readDict(input);
				var numModels = i32(input);
				var models: Array<Model> = [for (i in 0...numModels) { modelId: i32(input), attributes: readDict(input) }];
				#if haxe_format_vox_trace trace('$chunkId $nodeId $attributes $numModels $models'); #end
				nodeData[nodeId] = ShapeNodeData(attributes, models);
			case 'nGRP':
				var nodeId = i32(input);
				var attributes = readDict(input);
				var numChildren = i32(input);
				var children = [for (i in 0...numChildren) i32(input)];
				#if haxe_format_vox_trace trace('$chunkId $nodeId $attributes $numChildren $children'); #end
				nodeData[nodeId] = GroupNodeData(attributes, children);
			// case 'rOBJ': // TODO (DK) not defined in the docs (https://github.com/ephtracy/voxel-model/issues/19#issuecomment-380194831)
			// 	#if haxe_format_vox_trace trace('TODO (DK) chunk "${chunkId}" ($contentSize bytes)'); #end
			// 	input.read(contentSize);
			// case 'LAYR': // TODO (DK) not defined in the docs (https://github.com/ephtracy/voxel-model/issues/19#issuecomment-380194831)
			// 	#if haxe_format_vox_trace trace('TODO (DK) chunk "${chunkId}" ($contentSize bytes)'); #end
			// 	input.read(contentSize);
			default:
				#if haxe_format_vox_trace trace('skipping unsupported chunk "${chunkId}" ($contentSize bytes)'); #end
				input.read(contentSize);
		}

		var chunkSize = 4 + 4 + 4 + contentSize + childBytes;

		while (childBytes > 0) {
			childBytes -= readChunk(input, vox, nodeData, state);
		}

		return chunkSize;
	}

	static function buildNodeGraph( vox: Vox, nodeData: Array<NodeData>, nodeId: Int ) : Node {
		var n = nodeData[nodeId];

		return switch n {
			case TransformNodeData(att, childNodeId, r, l, fr):
				Transform(att, r, l, fr, buildNodeGraph(vox, nodeData, childNodeId));
			case GroupNodeData(att, children):
				Group(att, [for (childId in children) buildNodeGraph(vox, nodeData, childId)]);
			case ShapeNodeData(att, models):
				Shape(att, models);
		}
	}

	static inline function readVoxel( input: Input ) : Voxel
		return { x: byte(input), y: byte(input), z: byte(input), colorIndex: byte(input) }

	static inline function readMaterial( input: Input ) : { id: Int, props: Dict }
		return {
			id: i32(input),
			props: readDict(input),
		}

	static inline function readDict( input: Input ) : Dict
		return [for (i in 0...i32(input)) string(input) => string(input)];

	static inline function i32( input: Input ) : Int
		return input.readInt32();

	static inline function byte( input: Input ) : Int
		return input.readByte();

	static inline function string( input: Input ) : String
		return input.read(i32(input)).toString();

	// default palette from https://github.com/ephtracy/voxel-model/blob/master/MagicaVoxel-file-format-vox.txt
	public static var DefaultPalette(get, null): Array<Int>;

	static function get_DefaultPalette() return [
		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,
	];
}

private typedef State = {
	modelIndex: Int,
	sizeIndex: Int,
}

private enum NodeData {
	TransformNodeData( attributes: Dict, childNodeId: Int, reserved: Int, layerId: Int, frames: Array<Frame> );
	GroupNodeData( attributes: Dict, children: Array<Int> );
	ShapeNodeData( attributes: Dict, models: Array<Model> );
}