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/* Author: Luis G. Torres */

#include "ompl/base/objectives/MinimaxObjective.h"

ompl::base::MinimaxObjective::MinimaxObjective(const SpaceInformationPtr &si) :
    OptimizationObjective(si)
{
}

ompl::base::Cost ompl::base::MinimaxObjective::stateCost(const State *s) const
{
    return Cost(1.0);
}

ompl::base::Cost ompl::base::MinimaxObjective::motionCost(const State *s1, const State *s2) const
{
    Cost worstCost = this->identityCost();

    int nd = si_->getStateSpace()->validSegmentCount(s1, s2);

    if (nd > 1)
    {
        State *test = si_->allocState();
        for (int j = 1; j < nd; ++j)
        {
            si_->getStateSpace()->interpolate(s1, s2, (double) j / (double) nd, test);
            Cost testStateCost = this->stateCost(test);
            if (this->isCostBetterThan(worstCost, testStateCost))
                worstCost = testStateCost;
        }
        si_->freeState(test);
    }

    // Lastly, check s2
    Cost lastCost = this->stateCost(s2);
    if (this->isCostBetterThan(worstCost, lastCost))
        worstCost = lastCost;

    return worstCost;
}

ompl::base::Cost ompl::base::MinimaxObjective::combineCosts(Cost c1, Cost c2) const
{
    if (this->isCostBetterThan(c1, c2))
        return c2;
    else
        return c1;
}
