// Copyright (c) 2026 Charles KWON OhJun (charleskwonohjun@gmail.com)
// All rights reserved.

// Bit operation functions using Go's native operators.
// HB_BITAND, HB_BITOR, HB_BITXOR, HB_BITSHIFT, HB_BITNOT,
// HB_BITTEST, HB_BITSET, HB_BITRESET

package hbrtl

import "five/hbrt"

// HB_BITAND(nVal1, nVal2 [, nValN...]) → nResult
func HbBitAnd(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()
	result := t.Local(1).AsLong()
	for i := 2; i <= nParams; i++ {
		result &= t.Local(i).AsLong()
	}
	t.RetLong(result)
}

// HB_BITOR(nVal1, nVal2 [, nValN...]) → nResult
func HbBitOr(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()
	result := t.Local(1).AsLong()
	for i := 2; i <= nParams; i++ {
		result |= t.Local(i).AsLong()
	}
	t.RetLong(result)
}

// HB_BITXOR(nVal1, nVal2 [, nValN...]) → nResult
func HbBitXor(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()
	result := t.Local(1).AsLong()
	for i := 2; i <= nParams; i++ {
		result ^= t.Local(i).AsLong()
	}
	t.RetLong(result)
}

// HB_BITNOT(nVal) → nResult
func HbBitNot(t *hbrt.Thread) {
	t.Frame(1, 0)
	defer t.EndProc()
	t.RetLong(^t.Local(1).AsLong())
}

// HB_BITSHIFT(nVal, nShift) → nResult
// nShift > 0: left shift, nShift < 0: right shift
func HbBitShift(t *hbrt.Thread) {
	t.Frame(2, 0)
	defer t.EndProc()
	val := t.Local(1).AsLong()
	shift := t.Local(2).AsLong()
	if shift >= 0 {
		t.RetLong(val << uint(shift))
	} else {
		t.RetLong(val >> uint(-shift))
	}
}

// HB_BITTEST(nVal, nBit) → lSet
func HbBitTest(t *hbrt.Thread) {
	t.Frame(2, 0)
	defer t.EndProc()
	val := t.Local(1).AsLong()
	bit := uint(t.Local(2).AsLong())
	t.RetBool((val & (1 << bit)) != 0)
}

// HB_BITSET(nVal, nBit) → nResult
func HbBitSet(t *hbrt.Thread) {
	t.Frame(2, 0)
	defer t.EndProc()
	val := t.Local(1).AsLong()
	bit := uint(t.Local(2).AsLong())
	t.RetLong(val | (1 << bit))
}

// HB_BITRESET(nVal, nBit) → nResult
func HbBitReset(t *hbrt.Thread) {
	t.Frame(2, 0)
	defer t.EndProc()
	val := t.Local(1).AsLong()
	bit := uint(t.Local(2).AsLong())
	t.RetLong(val &^ (1 << bit))
}