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import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.tileentity.TileEntity;

public class ModEnergyStorage {

    private long energy;
    private long capacity;
    private long maxReceive;
    private long maxExtract;

    /**
     * Initialise an energy storage.
     *
     * @param capacity The capacity of the energy storage
     */
    public ModEnergyStorage(long capacity) {
        this(capacity, capacity, capacity, 0);
    }

    /**
     * Initialise an energy storage.
     *
     * @param capacity    The capacity of the energy storage
     * @param maxTransfer The maximum amount of energy which can be received and
     *                    extracted
     */
    public ModEnergyStorage(long capacity, long maxTransfer) {
        this(capacity, maxTransfer, maxTransfer, 0);
    }

    /**
     * Initialise an energy storage
     *
     * @param capacity   The capacity of the energy storage
     * @param maxReceive The maximum amount of energy which can be received
     * @param maxExtract The maximum amount of energy which can be extracted
     */
    public ModEnergyStorage(long capacity, long maxReceive, long maxExtract) {
        this(capacity, maxReceive, maxExtract, 0);
    }

    /**
     * Initialise an energy storage
     *
     * @param capacity   The capacity of the energy storage
     * @param maxReceive The maximum amount of energy which can be received
     * @param maxExtract The maximum amount of energy which can be extracted
     * @param energy     The energy inside of the energy storage
     */
    public ModEnergyStorage(long capacity, long maxReceive, long maxExtract, long energy) {
        this.capacity = capacity;
        this.maxReceive = maxReceive;
        this.maxExtract = maxExtract;
        this.energy = Math.max(0, Math.min(capacity, energy));
    }

    /**
     * Give energy to the energy storage
     *
     * @param maxReceive The amount of energy to give
     * @param simulate   Whether it is a simulation - if so, no energy will actually be
     *                   given
     * @return The amount of energy which was received
     */
    public long receiveEnergy(long maxReceive, boolean simulate) {
        if (!canReceive())
            return 0;

        long energyReceived = Math.min(this.capacity - this.energy, Math.min(this.maxReceive, maxReceive));
        if (!simulate)
            this.energy += energyReceived;
        return energyReceived;
    }

    /**
     * Take energy from the energy storage
     *
     * @param maxExtract The amount of energy to take
     * @param simulate   Whether it is a simulation - if so, no energy will actually be
     *                   taken
     * @return The amount of energy which was extracted
     */
    public long extractEnergy(long maxExtract, boolean simulate) {
        if (!canExtract())
            return 0;

        long energyExtracted = Math.min(this.energy, Math.min(this.maxExtract, maxExtract));
        if (!simulate)
            this.energy -= energyExtracted;
        return energyExtracted;
    }

    /**
     * For use only inside your {@link TileEntity}
     *
     * @param maxExtract How much you want to extract
     * @param simulate   Whether it is a simulation
     * @return The amount of energy taken
     */
    public long extractEnergyInternal(long maxExtract, boolean simulate) {
        long before = this.maxExtract;
        this.maxExtract = Long.MAX_VALUE;

        long toReturn = this.extractEnergy(maxExtract, simulate);

        this.maxExtract = before;
        return toReturn;
    }

    /**
     * For use only inside your {@link TileEntity}
     *
     * @param maxReceive How much you want to give
     * @param simulate   Whether it is a simulation
     * @return The amount of energy given
     */
    public long receiveEnergyInternal(long maxReceive, boolean simulate) {
        long before = this.maxReceive;
        this.maxReceive = Long.MAX_VALUE;

        long toReturn = this.receiveEnergy(maxReceive, simulate);

        this.maxReceive = before;
        return toReturn;
    }

    /**
     * Read and set all values from the data inside the given
     * {@link NBTTagCompound}
     *
     * @param nbt The {@link NBTTagCompound} with all the data
     */
    public void readFromNBT(NBTTagCompound nbt) {
        this.energy = nbt.getInteger("Energy");
        this.capacity = nbt.getInteger("Capacity");
        this.maxReceive = nbt.getInteger("MaxReceive");
        this.maxExtract = nbt.getInteger("MaxExtract");
    }

    /**
     * Write all of the data to the {@link NBTTagCompound} provided
     *
     * @param nbt The {@link NBTTagCompound} to write to
     */
    public void writeToNBT(NBTTagCompound nbt) {
        nbt.setLong("Energy", this.energy);
        nbt.setLong("Capacity", this.capacity);
        nbt.setLong("MaxReceive", this.maxReceive);
        nbt.setLong("MaxExtract", this.maxExtract);
    }

    /**
     * Set the current energy
     *
     * @param energy The energy to set
     * @return The {@link ModEnergyStorage} with the new energy
     */
    public ModEnergyStorage setEnergyStored(long energy) {
        this.energy = energy;
        return this;
    }

    /**
     * Set the current capacity
     *
     * @param capacity The capacity to set
     * @return The {@link ModEnergyStorage} with the new capacity
     */
    public ModEnergyStorage setCapacity(long capacity) {
        this.capacity = capacity;
        return this;
    }

    /**
     * Set the current max transfer
     *
     * @param transfer The max transfer to set
     * @return The {@link ModEnergyStorage} with the new max transfer
     */
    public ModEnergyStorage setMaxTransfer(long transfer) {
        this.maxReceive = transfer;
        this.maxExtract = transfer;
        return this;
    }

    /**
     * Set the current max receive
     *
     * @param maxReceive The max receive to set
     * @return The {@link ModEnergyStorage} with the new max receive
     */
    public ModEnergyStorage setMaxReceive(long maxReceive) {
        this.maxReceive = maxReceive;
        return this;
    }

    /**
     * Set the current max extract
     *
     * @param maxExtract The max extract to set
     * @return The {@link ModEnergyStorage} with the new max extract
     */
    public ModEnergyStorage setMaxExtract(long maxExtract) {
        this.maxExtract = maxExtract;
        return this;
    }

    /**
     * Get the maximum energy this can extract and receive
     *
     * @return The max transfer
     */
    public long getMaxTransfer() {
        return this.maxReceive == this.maxExtract ? this.maxReceive : Math.max(this.maxReceive, this.maxExtract);
    }

    /**
     * Get the maximum energy this can receive
     *
     * @return The maximum energy this can receive
     */
    public long getMaxReceive() {
        return this.maxReceive;
    }

    /**
     * Get the maximum energy that can be extracted
     *
     * @return The maximum energy that can be extracted
     */
    public long getMaxExtract() {
        return this.maxExtract;
    }

    /**
     * Get the energy inside of the energy storage
     *
     * @return The energy inside of the energy storage
     */
    public long getEnergyStored() {
        return this.energy;
    }

    /**
     * Get the maximum amount of energy in the energy storage
     *
     * @return The maximum amount of energy in the energy storage
     */
    public long getMaxEnergyStored() {
        return this.capacity;
    }

    /**
     * @return whether you can take energy from the energy storage
     */
    public boolean canExtract() {
        return this.maxExtract > 0;
    }

    /**
     * @return whether you can give energy to the energy storage
     */
    public boolean canReceive() {
        return this.maxReceive > 0;
    }

}