package huffman

import (
	. "huffman/internal/io"
	"io"
)

func Decode(reader io.ReadSeeker, writer io.Writer) {
	bufReader := NewBufferedReader(reader)
	bufWriter := NewBufferedWriter(writer)

	tree := DecodeTree(bufReader)

	if tree.Size == 1 {
		lg := int(bufReader.ReadByte())
		size := int(bufReader.ReadBits(lg))

		for i := 0; i < size; i++ {
			bufWriter.WriteByte(tree.Value)
		}
	} else {
		additionalBits := bufReader.ReadBits(3)
		bufReader.SetLastBitsSkip(int(additionalBits))

		curNode := tree
		for !bufReader.IsEOF() {
			if bufReader.ReadBit() == 0x0 {
				curNode = curNode.Left
			} else {
				curNode = curNode.Right
			}

			if curNode.IsTerminate() {
				bufWriter.WriteByte(curNode.Value)
				curNode = tree
			}
		}
	}

	bufWriter.Flush()
}