/**
 * @file findContours.cpp
 * @brief mex interface for findContours
 * @author Kota Yamaguchi
 * @date 2011
 */
#include "mexopencv.hpp"
using namespace std;
using namespace cv;

/** Mode of the contour retrieval algorithm for option processing
 */
const ConstMap<std::string,int> ContourMode = ConstMap<std::string,int>
    ("External",cv::RETR_EXTERNAL)    //!< retrieve only the most external (top-level) contours
    ("List",    cv::RETR_LIST)        //!< retrieve all the contours without any hierarchical information
    ("CComp",    cv::RETR_CCOMP)        //!< retrieve the connected components (that can possibly be nested)
    ("Tree",    cv::RETR_TREE);     //!< retrieve all the contours and the whole hierarchy

/** Type of the contour approximation algorithm for option processing
 */
const ConstMap<std::string,int> ContourType = ConstMap<std::string,int>
    ("None",        cv::CHAIN_APPROX_NONE)
    ("Simple",        cv::CHAIN_APPROX_SIMPLE)
    ("TC89_L1",        cv::CHAIN_APPROX_TC89_L1)
    ("TC89_KCOS",    cv::CHAIN_APPROX_TC89_KCOS);

/**
 * Main entry called from Matlab
 * @param nlhs number of left-hand-side arguments
 * @param plhs pointers to mxArrays in the left-hand-side
 * @param nrhs number of right-hand-side arguments
 * @param prhs pointers to mxArrays in the right-hand-side
 */
void mexFunction( int nlhs, mxArray *plhs[],
                  int nrhs, const mxArray *prhs[] )
{
    // Check the number of arguments
    if (nrhs<1 || ((nrhs%2)!=1) || nlhs>2)
        mexErrMsgIdAndTxt("mexopencv:error","Wrong number of arguments");
    
    // Argument vector
    vector<MxArray> rhs(prhs,prhs+nrhs);
    Mat image(rhs[0].toMat(CV_8U));
    vector<vector<Point> > contours;
    vector<Vec4i> hierarchy;
    int mode = CV_RETR_EXTERNAL;
    int method = CV_CHAIN_APPROX_NONE;
    Point offset;
    for (int i=1; i<nrhs; i+=2) {
        string key = rhs[i].toString();
        if (key=="Mode")
            mode = ContourMode[rhs[i+1].toString()];
        else if (key=="Method")
            method = ContourType[rhs[i+1].toString()];
        else if (key=="Offset")
            offset = rhs[i+1].toPoint();
        else
            mexErrMsgIdAndTxt("mexopencv:error","Unrecognized option");
    }
    
    // Process
    findContours(image, contours, hierarchy, mode, method, offset);
    plhs[0] = MxArray(contours);
    if (nlhs > 1) {
        vector<Mat> vc(hierarchy.size());
        for (int i=0;i<vc.size();++i)
            vc[i] = Mat(1,4,CV_32SC1,&hierarchy[i][0]);
        plhs[1] = MxArray(vc);
    }
}