#include <iostream>
#include <fstream>
using namespace std;

#include "apstring.h"
#include "bitops.h"
#include "globals.h"

Tree * readTree(ibstream & input)
// pre: inorder traversal of tree stored in input    
// post: read tree and return root 
{
    int val;
    Tree * left;
    Tree * right;
    
    if (input.readbits(1,val))         // read a bit
    {
        if (val == 0)                  // internal node, read subtrees
        {
            left = readTree(input);
            right = readTree(input);
            return new Tree(0,0,left,right);
        }
        else                           // leaf, read value 
        {
            input.readbits(BITS_PER_WORD + 1,val);
            return new Tree(val,0,0,0);
        }       
    }
    return 0;   // should never reach this if file is ok
}

int main(int argc, char * argv[])
{
    apstring filename;
    if (argc > 1)
    {
        filename = argv[1];
	if (argc == 3)
	{
	    setsize(atoi(argv[2]));
	}	
    }
    else
    {
        cout << "Enter filename: ";
        cin >> filename;
    }
    ibstream input(filename.c_str());
    apstring outname = filename + ".unhf";
    obstream output(outname.c_str());

    Tree * root = readTree(input);
    Tree * current = root;
    int val;
        
    while (input.readbits(1,val))      // reading a bit succeeds
    {
        if (val == 0)                  // read a zero, go left
        {
            current = current->left;
        }
        else
        {
            current = current->right;
        }
        if (current->left == 0 && current->right == 0)  // at a leaf?
        {
            if (current->info == PSEUDO_EOF)            // all done, stop
            {
                break;
            }
            else                                        // write the char
            {
                output.writebits(BITS_PER_WORD, current->info);
            }
            current = root;
        }
    }
    return 0;
}