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/* Author: Ioan Sucan */

#include "ompl/base/samplers/MaximizeClearanceValidStateSampler.h"
#include "ompl/base/SpaceInformation.h"

ompl::base::MaximizeClearanceValidStateSampler::MaximizeClearanceValidStateSampler(const SpaceInformation *si)
  : ValidStateSampler(si), sampler_(si->allocStateSampler()), improveAttempts_(3), work_(si->allocState())
{
    name_ = "max_clearance";
    params_.declareParam<unsigned int>("nr_improve_attempts",
                                       [this](unsigned int n)
                                       {
                                           setNrImproveAttempts(n);
                                       },
                                       [this]
                                       {
                                           return getNrImproveAttempts();
                                       });
}

ompl::base::MaximizeClearanceValidStateSampler::~MaximizeClearanceValidStateSampler()
{
    si_->freeState(work_);
}

bool ompl::base::MaximizeClearanceValidStateSampler::sample(State *state)
{
    unsigned int attempts = 0;
    bool valid = false;
    double dist = 0.0;
    do
    {
        sampler_->sampleUniform(state);
        valid = si_->getStateValidityChecker()->isValid(state, dist);
        ++attempts;
    } while (!valid && attempts < attempts_);

    if (valid)
    {
        bool validW = false;
        double distW = 0.0;
        attempts = 0;
        while (attempts < improveAttempts_)
        {
            sampler_->sampleUniform(work_);
            validW = si_->getStateValidityChecker()->isValid(work_, distW);
            ++attempts;
            if (validW && distW > dist)
            {
                dist = distW;
                si_->copyState(state, work_);
            }
        }
        return true;
    }
    else
        return false;
}

bool ompl::base::MaximizeClearanceValidStateSampler::sampleNear(State *state, const State *near, const double distance)
{
    unsigned int attempts = 0;
    bool valid = false;
    double dist = 0.0;
    do
    {
        sampler_->sampleUniformNear(state, near, distance);
        valid = si_->getStateValidityChecker()->isValid(state, dist);
        ++attempts;
    } while (!valid && attempts < attempts_);

    if (valid)
    {
        bool validW = false;
        double distW = 0.0;
        attempts = 0;
        while (attempts < improveAttempts_)
        {
            sampler_->sampleUniformNear(work_, near, distance);
            validW = si_->getStateValidityChecker()->isValid(work_, distW);
            ++attempts;
            if (validW && distW > dist)
            {
                dist = distW;
                si_->copyState(state, work_);
            }
        }
        return true;
    }
    else
        return false;
}
