RedControl/src/main/java/net/brokenmoon/redcontrol/blockentities/DriveEntity.java

package net.brokenmoon.redcontrol.blockentities;

import com.simon816.j65el02.device.DiskDriver;
import net.brokenmoon.redcontrol.RedControl;
import net.brokenmoon.redcontrol.api.DriveFactory;
import net.brokenmoon.redcontrol.api.Peripheral;
import net.brokenmoon.redcontrol.item.FloppyDisk;
import net.minecraft.block.BlockState;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NbtCompound;
import net.minecraft.text.Style;
import net.minecraft.text.Text;
import net.minecraft.util.ActionResult;
import net.minecraft.util.Hand;
import net.minecraft.util.math.BlockPos;

import java.net.URI;
import java.nio.ByteBuffer;
import java.util.UUID;

import static net.minecraft.item.ItemStack.DISPLAY_KEY;
import static net.minecraft.item.ItemStack.NAME_KEY;

public class DriveEntity extends Peripheral {

    private static final int SECTOR_SIZE = 0x80;

    private DiskDriver driver = null;
    private ByteBuffer buffer = null;

    private int sector;
    private int command;

    private ItemStack disk = ItemStack.EMPTY;

    public DriveEntity(BlockPos pos, BlockState state) {
        super(RedControl.DRIVE_BLOCK_ENTITY, pos, state, 2);

        this.buffer = ByteBuffer.allocateDirect(SECTOR_SIZE);
    }

    @Override
    public void write(int address, int data) {
        if(driver != null) {
            switch (address) {
                case 0x80: // Sector number (lo)
                    this.sector = (this.sector & 0xff00) | data;
                    break;
                case 0x81: // Sector number (hi)
                    this.sector = (data << 8) | (this.sector & 0xff);
                    break;
                case 0x82: // Disk command
                    this.command = data;
                    break;
                default: // Disk sector buffer
                    if (address >= 0 && address <= 0x7f) {
                        this.buffer.put(address, (byte) data);
                    }
            }
        }
    }


    @Override
    public int read(int address) {
        if(driver != null) {
            switch (address) {
                case 0x80: // Sector number (lo)
                    return this.sector & 0xff;
                case 0x81: // Sector number (hi)
                    return (this.sector >> 8) & 0xff;
                case 0x82: // Disk command
                    return this.command;
                default: // Disk sector buffer
                    if (address >= 0 && address <= 0x7f) {
                        return this.buffer.get(address);
                    }
                    return 0;
            }
        }
        return 0;
    }

    @Override
    public void update() {
        if(driver != null) {
            try {
                switch (this.command) {
                    case 0x01: // Read Disk Name
                        this.buffer.clear();
                        this.buffer.put(driver.getDriveName());
                        this.command = 0;
                        break;
                    case 0x02: // Write Disk Name
                        this.buffer.position(0);
                        byte[] diskName = new byte[SECTOR_SIZE];
                        this.buffer.get(diskName);
                        NbtCompound sub_nbt = new NbtCompound();
                        sub_nbt.putString(NAME_KEY, Text.Serialization.toJsonString(Text.literal(new String(diskName).trim()).setStyle(Style.EMPTY.withItalic(false))));
                        this.disk.setSubNbt(DISPLAY_KEY, sub_nbt);
                        this.driver.writeDiskName(diskName);
                        this.command = 0;
                        break;
                    case 0x03: // Read Disk Serial
                        this.buffer.clear();
                        this.buffer.put(driver.getDriveSerial());
                        this.command = 0;
                        break;
                    case 0x04: // Read Disk Sector
                        if (this.sector >= 0x800) {
                            this.command = 0xff;
                            break;
                        }
                        this.driver.seek(this.sector << 7);
                        this.buffer.position(0);
                        this.driver.read(this.buffer);
                        this.command = 0;
                        break;
                    case 0x05: // Write Disk Sector
                        if (this.sector >= 0x800) {
                            this.command = 0xff;
                            break;
                        }
                        this.driver.seek(this.sector << 7);
                        this.buffer.position(0);
                        this.driver.write(this.buffer);
                        this.command = 0;
                        break;
                }
            } catch (Exception e) {
                this.command = 0xff;
                //e.printStackTrace();
            }
        }
    }

    public ActionResult onUse(PlayerEntity player, Hand hand) {
        if(!world.isClient) {
            if (disk == ItemStack.EMPTY && player.getStackInHand(hand).getItem() instanceof FloppyDisk) {
                return loadDisk(player, hand);
            } else if (player.getStackInHand(hand) == ItemStack.EMPTY) {
                return ejectDisk(player, hand);
            }
        }
        return ActionResult.PASS;
    }

    private ActionResult ejectDisk(PlayerEntity player, Hand hand) {
        player.setStackInHand(hand, disk.copy());
        disk = ItemStack.EMPTY;
        this.driver = null;
        this.buffer = null;
        markDirty();
        return ActionResult.SUCCESS;
    }

    private ActionResult loadDisk(PlayerEntity player, Hand hand) {
        disk = player.getStackInHand(hand).copy();
        player.setStackInHand(hand, ItemStack.EMPTY);
        if(!disk.hasNbt()){
            NbtCompound newNbt = new NbtCompound();
            String newUUID = UUID.randomUUID().toString();
            newNbt.putString("uri", "save://" + newUUID + ".img");
            newNbt.putString("serial", newUUID);
            disk.setNbt(newNbt);
        }
        this.driver = DriveFactory.INSTANCE.createDriver(URI.create(disk.getNbt().getString("uri")), String.valueOf(disk.getName()), disk.getNbt().getString("serial"));
        this.buffer = ByteBuffer.allocateDirect(SECTOR_SIZE);
        markDirty();
        return ActionResult.SUCCESS;
    }

    @Override
    protected void writeNbt(NbtCompound nbt) {
        //SUPER DUPER NOT DONE TODO: FINISH THIS.
        NbtCompound compound = new NbtCompound();
        disk.writeNbt(compound);
        nbt.put("item",compound);
        super.writeNbt(nbt);
    }

    @Override
    public void readNbt(NbtCompound nbt) {
        disk = ItemStack.fromNbt(nbt.getCompound("item"));
        super.readNbt(nbt);
    }
}