/*M///////////////////////////////////////////////////////////////////////////////////////
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//  copy or use the software.
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//
//                          License Agreement
//                For Open Source Computer Vision Library
//
// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
// Copyright (C) 2009, Willow Garage Inc., all rights reserved.
// Third party copyrights are property of their respective owners.
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// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
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//   * Redistribution's of source code must retain the above copyright notice,
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//     derived from this software without specific prior written permission.
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// This software is provided by the copyright holders and contributors "as is" and
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// loss of use, data, or profits; or business interruption) however caused
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//M*/

#include <iostream>
#include <fstream>
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/stitching.hpp"

using namespace std;
using namespace cv;

bool try_use_gpu = false;
Stitcher::Mode mode = Stitcher::PANORAMA;
vector<Mat> imgs;
string result_name = "result.jpg";

void printUsage();
int parseCmdArgs(int argc, char** argv);

int main(int argc, char* argv[])
{
    int retval = parseCmdArgs(argc, argv);
    if (retval) return -1;

    Mat pano;
    Ptr<Stitcher> stitcher = Stitcher::create(mode, try_use_gpu);
    Stitcher::Status status = stitcher->stitch(imgs, pano);

    if (status != Stitcher::OK)
    {
        cout << "Can't stitch images, error code = " << int(status) << endl;
        return -1;
    }

    imwrite(result_name, pano);
    return 0;
}


void printUsage()
{
    cout <<
        "Images stitcher.\n\n"
        "stitching img1 img2 [...imgN]\n\n"
        "Flags:\n"
        "  --try_use_gpu (yes|no)\n"
        "      Try to use GPU. The default value is 'no'. All default values\n"
        "      are for CPU mode.\n"
        "  --mode (panorama|scans)\n"
        "      Determines configuration of stitcher. The default is 'panorama',\n"
        "      mode suitable for creating photo panoramas. Option 'scans' is suitable\n"
        "      for stitching materials under affine transformation, such as scans.\n"
        "  --output <result_img>\n"
        "      The default is 'result.jpg'.\n";
}


int parseCmdArgs(int argc, char** argv)
{
    if (argc == 1)
    {
        printUsage();
        return -1;
    }
    for (int i = 1; i < argc; ++i)
    {
        if (string(argv[i]) == "--help" || string(argv[i]) == "/?")
        {
            printUsage();
            return -1;
        }
        else if (string(argv[i]) == "--try_use_gpu")
        {
            if (string(argv[i + 1]) == "no")
                try_use_gpu = false;
            else if (string(argv[i + 1]) == "yes")
                try_use_gpu = true;
            else
            {
                cout << "Bad --try_use_gpu flag value\n";
                return -1;
            }
            i++;
        }
        else if (string(argv[i]) == "--output")
        {
            result_name = argv[i + 1];
            i++;
        }
        else if (string(argv[i]) == "--mode")
        {
            if (string(argv[i + 1]) == "panorama")
                mode = Stitcher::PANORAMA;
            else if (string(argv[i + 1]) == "scans")
                mode = Stitcher::SCANS;
            else
            {
                cout << "Bad --mode flag value\n";
                return -1;
            }
            i++;
        }
        else
        {
            Mat img = imread(argv[i]);
            if (img.empty())
            {
                cout << "Can't read image '" << argv[i] << "'\n";
                return -1;
            }
            imgs.push_back(img);
        }
    }
    return 0;
}