#include <iostream>
#include <string.h>
#include <stdlib.h>
#include "BMP.h"
using namespace std;

void usage(const char * progName);
void squashAndPadData(unsigned char * raw_data, unsigned char * padded_data,
                      int width, int height);

void usage(const char * progName)
{
    cout << "Usage: " << progName << " [options] <input-BMP-file>" << endl;
    cout << "  Options:" << endl;
    cout << "    -l threshold_level : set threshold level" << endl;
    exit(42);
}

int main(int argc, char * argv[])
{
    int argi;
    string inputFileName;
    string outputFileName;
    unsigned int threshold_level = 60;

    for (argi = 0; argi < argc; argi++)
    {
        if (!strcmp(argv[argi], "-l"))
        {
            if (argi >= argc - 1)
                usage(argv[0]);
            argi++;
            threshold_level = atoi(argv[argi]);
        }
        else
        {
            inputFileName = argv[argi];
            outputFileName = string(argv[argi], strlen(argv[argi]) - 4);
            outputFileName += "-edges.bmp";
        }
    }

    if (inputFileName == "")
        usage(argv[0]);

    BMP inputImage(inputFileName.c_str());
    int width = inputImage.getWidth();
    int height = inputImage.getHeight();
    int num_pixels = width * height;
    unsigned char * bmp_data =
        new unsigned char[num_pixels * 3];
    inputImage.read(bmp_data);

    unsigned char * padded_data =
        new unsigned char[(width + 2) * (height + 2)];
    squashAndPadData(bmp_data, padded_data, width, height);
    delete[] bmp_data;

    delete[] padded_data;
}

void squashAndPadData(unsigned char * raw_data, unsigned char * padded_data,
                      int width, int height)
{
    for (int i = 0; i < width + 2; i++)
        *padded_data++ = 0;
    for (int i = 0; i < height; i++)
    {
        *padded_data++ = 0;
        for (int j = 0; j < width; j++)
        {
            *padded_data++ = (raw_data[0] + raw_data[1] + raw_data[2]) / 3;
            raw_data += 3;
        }
        *padded_data++ = 0;
    }
    for (int i = 0; i < width + 2; i++)
        *padded_data++ = 0;
}