package cdkey

import "fmt"

type bitmap struct {
	size int
	set  int64
}

func newBitmap(size int, set int64) *bitmap {
	if size < 0 || size > 63 {
		panic("size must be between 0 and 63")
	}
	if size == 0 {
		size = 32
	}
	m := &bitmap{size: size, set: set}
	return m
}

func (m *bitmap) Get(index int) bool {
	return m.GetInt(index) != 0
}

func (m *bitmap) GetInt(index int) int64 {
	if index < 0 || index >= m.size {
		panic(fmt.Errorf("index out of range:%v", index))
	}

	if m.set&(1<<uint(index)) != 0 {
		return 1
	}
	return 0
}

func (m *bitmap) Set(index int, value bool) {
	if index < 0 || index >= m.size {
		panic(fmt.Errorf("index out of range:%v", index))
	}
	if value {
		m.set |= 1 << uint(index)
	} else {
		m.set &^= 1 << uint(index)
	}
}

func (m *bitmap) Clear() {
	m.set = 0
}

func (m *bitmap) toInt64() int64 {
	return m.set
}

func (m *bitmap) GetSize() int {
	return m.size
}