package com.mojang.blaze3d.buffers;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;

@Environment(EnvType.CLIENT)
public abstract class GpuBuffer implements AutoCloseable {
	public static final int USAGE_MAP_READ = 1;
	public static final int USAGE_MAP_WRITE = 2;
	public static final int USAGE_HINT_CLIENT_STORAGE = 4;
	public static final int USAGE_COPY_DST = 8;
	public static final int USAGE_COPY_SRC = 16;
	public static final int USAGE_VERTEX = 32;
	public static final int USAGE_INDEX = 64;
	public static final int USAGE_UNIFORM = 128;
	public static final int USAGE_UNIFORM_TEXEL_BUFFER = 256;
	@GpuBuffer.Usage
	private final int usage;
	private final long size;
	private final GpuBufferSlice defaultSlice;

	public GpuBuffer(@GpuBuffer.Usage final int usage, final long size) {
		this.size = size;
		this.usage = usage;
		this.defaultSlice = new GpuBufferSlice(this, 0L, size);
	}

	public long size() {
		return this.size;
	}

	@GpuBuffer.Usage
	public int usage() {
		return this.usage;
	}

	public abstract boolean isClosed();

	public abstract void close();

	public GpuBufferSlice slice(final long offset, final long length) {
		if (offset >= 0L && length >= 0L && offset + length <= this.size) {
			return new GpuBufferSlice(this, offset, length);
		} else {
			throw new IllegalArgumentException("Offset of " + offset + " and length " + length + " would put new slice outside buffer's range (of 0," + length + ")");
		}
	}

	public GpuBufferSlice slice() {
		return this.defaultSlice;
	}

	public GpuBufferSlice.MappedView map(final boolean read, final boolean write) {
		return this.map(0L, this.size, read, write);
	}

	public abstract GpuBufferSlice.MappedView map(final long offset, final long length, final boolean read, final boolean write);

	@Retention(RetentionPolicy.CLASS)
	@Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE, ElementType.METHOD, ElementType.TYPE_USE})
	@Environment(EnvType.CLIENT)
	public @interface Usage {
	}
}