package com.infendro.hash.util

import com.infendro.bytes.ByteOrder
import com.infendro.bytes.ByteOrder.BIG_ENDIAN
import com.infendro.bytes.int.copyInto
import com.infendro.bytes.long.copyInto

internal class Buffer(val size: Int) {
    val value = ByteArray(size)
    var offset = 0

    val free: Int
        get() = size - offset

    fun isEmpty(): Boolean = offset == 0
    fun isNotEmpty(): Boolean = !isEmpty()
    fun isFull(): Boolean = offset == size

    fun reset() {
        value.fill(0x00)
        offset = 0
    }

    fun jumpTo(offset: Int) {
        this.offset = offset
    }

    fun append(byte: Byte) {
        value[offset++] = byte
    }

    fun append(bytes: ByteArray, startIndex: Int = 0, endIndex: Int = bytes.size) {
        bytes.copyInto(value, offset, startIndex, endIndex)
        offset += (endIndex - startIndex)
    }

    fun append(n: Int, order: ByteOrder = BIG_ENDIAN) {
        n.copyInto(value, offset, order = order)
        offset += 4
    }

    fun append(n: Long, order: ByteOrder = BIG_ENDIAN) {
        n.copyInto(value, offset, order = order)
        offset += 8
    }
}