#ifndef GEOSPATIAL_QUERY_HPP
#define GEOSPATIAL_QUERY_HPP

#include "engine/approach.hpp"
#include "engine/bearing.hpp"
#include "engine/phantom_node.hpp"
#include "util/bearing.hpp"
#include "util/coordinate_calculation.hpp"
#include "util/rectangle.hpp"
#include "util/typedefs.hpp"
#include "util/web_mercator.hpp"

#include "osrm/coordinate.hpp"

#include <algorithm>
#include <cmath>
#include <iterator>
#include <memory>
#include <vector>

namespace osrm
{
namespace engine
{

inline std::pair<bool, bool> operator&&(const std::pair<bool, bool> &a,
                                        const std::pair<bool, bool> &b)
{
    return {a.first && b.first, a.second && b.second};
}

// Implements complex queries on top of an RTree and builds PhantomNodes from it.
//
// Only holds a weak reference on the RTree and coordinates!
template <typename RTreeT, typename DataFacadeT> class GeospatialQuery
{
    using EdgeData = typename RTreeT::EdgeData;
    using CoordinateList = typename RTreeT::CoordinateList;
    using CandidateSegment = typename RTreeT::CandidateSegment;

  public:
    GeospatialQuery(RTreeT &rtree_, const CoordinateList &coordinates_, DataFacadeT &datafacade_)
        : rtree(rtree_), coordinates(coordinates_), datafacade(datafacade_)
    {
    }

    std::vector<EdgeData> Search(const util::RectangleInt2D &bbox)
    {
        return rtree.SearchInBox(bbox);
    }

    // Returns max_results nearest PhantomNodes that are valid within the provided parameters.
    // Does not filter by small/big component!
    std::vector<PhantomNodeWithDistance>
    NearestPhantomNodes(const util::Coordinate input_coordinate,
                        const Approach approach,
                        const boost::optional<size_t> max_results,
                        const boost::optional<double> max_distance,
                        const boost::optional<Bearing> bearing_with_range,
                        const boost::optional<bool> use_all_edges) const
    {
        auto results = rtree.Nearest(
            input_coordinate,
            [this, approach, &input_coordinate, &bearing_with_range, &use_all_edges](
                const CandidateSegment &segment) {
                auto valid = CheckSegmentExclude(segment) &&
                             CheckApproach(input_coordinate, segment, approach) &&
                             (use_all_edges ? HasValidEdge(segment, *use_all_edges)
                                            : HasValidEdge(segment)) &&
                             (bearing_with_range ? CheckSegmentBearing(segment, *bearing_with_range)
                                                 : std::make_pair(true, true));
                return valid;
            },
            [this, &max_distance, &max_results, input_coordinate](const std::size_t num_results,
                                                                  const CandidateSegment &segment) {
                return (max_results && num_results >= *max_results) ||
                       (max_distance &&
                        CheckSegmentDistance(input_coordinate, segment, *max_distance));
            });

        return MakePhantomNodes(input_coordinate, results);
    }

    // Returns a list of phantom node candidates from the nearest location that are valid
    // within the provided parameters. If there is tie between equidistant locations,
    // we only pick candidates from one location.
    // If candidates do not include a node from a big component, an alternative list of candidates
    // from the nearest location which has nodes from a big component is returned.
    PhantomCandidateAlternatives NearestCandidatesWithAlternativeFromBigComponent(
        const util::Coordinate input_coordinate,
        const Approach approach,
        const boost::optional<double> max_distance,
        const boost::optional<Bearing> bearing_with_range,
        const boost::optional<bool> use_all_edges) const
    {
        bool has_nearest = false;
        bool has_big_component = false;
        Coordinate big_component_coord;
        double big_component_distance = std::numeric_limits<double>::max();
        Coordinate nearest_coord;
        auto results = rtree.Nearest(
            input_coordinate,
            [this,
             approach,
             &input_coordinate,
             &has_nearest,
             &has_big_component,
             &nearest_coord,
             &big_component_coord,
             &big_component_distance,
             &use_all_edges,
             &bearing_with_range](const CandidateSegment &segment) {
                auto is_big_component = !IsTinyComponent(segment);
                auto not_nearest =
                    has_nearest && segment.fixed_projected_coordinate != nearest_coord;
                auto not_big =
                    has_big_component && segment.fixed_projected_coordinate != big_component_coord;

                /**
                 *
                 *  Two reasons why we don't want this candidate:
                 *  1. A non-big component candidate that is not at the nearest location
                 *  2. A big component candidate that is not at the big location.
                 *
                 *  It's possible that 1. could end up having the same location as the nearest big
                 *  component node if we have yet to see one. However, we don't know this and it
                 *  could lead to buffering large numbers of candidates before finding the big
                 *  component location.
                 *  By filtering out 1. nodes, this does mean that the alternative list of
                 *  candidates will not have non-big component candidates. Given the alternative
                 *  list of big component candidates is meant as a backup choice, this seems
                 *  reasonable.
                 */
                if ((!is_big_component && not_nearest) || (is_big_component && not_big))
                {
                    return std::make_pair(false, false);
                }
                auto use_candidate =
                    CheckSegmentExclude(segment) &&
                    CheckApproach(input_coordinate, segment, approach) &&
                    (use_all_edges ? HasValidEdge(segment, *use_all_edges)
                                   : HasValidEdge(segment)) &&
                    (bearing_with_range ? CheckSegmentBearing(segment, *bearing_with_range)
                                        : std::make_pair(true, true));

                if (use_candidate.first || use_candidate.second)
                {
                    if (!has_nearest)
                    {
                        has_nearest = true;
                        nearest_coord = segment.fixed_projected_coordinate;
                    }
                    if (is_big_component && !has_big_component)
                    {
                        has_big_component = true;
                        big_component_coord = segment.fixed_projected_coordinate;
                        big_component_distance = GetSegmentDistance(input_coordinate, segment);
                    }
                }

                return use_candidate;
            },
            [this, &has_big_component, &max_distance, input_coordinate, &big_component_distance](
                const std::size_t /*num_results*/, const CandidateSegment &segment) {
                auto distance = GetSegmentDistance(input_coordinate, segment);
                auto further_than_big_component = distance > big_component_distance;
                auto no_more_candidates = has_big_component && further_than_big_component;
                auto too_far_away = max_distance && distance > *max_distance;

                // Time to terminate the search when:
                // 1. We've found a node from a big component and the next candidate is further away
                // than that node.
                // 2. We're further away from the input then our max allowed distance.
                return no_more_candidates || too_far_away;
            });

        return MakeAlternativeBigCandidates(input_coordinate, nearest_coord, results);
    }

  private:
    PhantomCandidateAlternatives
    MakeAlternativeBigCandidates(const util::Coordinate input_coordinate,
                                 const Coordinate nearest_coord,
                                 const std::vector<CandidateSegment> &results) const
    {
        if (results.size() == 0)
        {
            return std::make_pair(PhantomNodeCandidates{}, PhantomNodeCandidates{});
        }

        PhantomNodeCandidates nearest_phantoms;
        PhantomNodeCandidates big_component_phantoms;

        const auto add_to_candidates = [this, &input_coordinate](PhantomNodeCandidates &candidates,
                                                                 const EdgeData data) {
            auto candidate_it =
                std::find_if(candidates.begin(), candidates.end(), [&](const PhantomNode &node) {
                    return data.forward_segment_id.id == node.forward_segment_id.id &&
                           data.reverse_segment_id.id == node.reverse_segment_id.id;
                });
            if (candidate_it == candidates.end())
            {
                // First candidate from this segment
                candidates.push_back(MakePhantomNode(input_coordinate, data).phantom_node);
            }
            else
            {
                /**
                 *  Second candidate from this segment (there can be at most two).
                 *  We're snapping at the connection between two edges e1,e2 of the segment.
                 *
                 *        |     e1     |     e2     |
                 *        | --- f1 --> | --- f2 --> |
                 *        | <-- r1 --- | <-- r2 --- |
                 *
                 *  Most of the routing algorithms only support one candidate from each segment.
                 *  Therefore, we have to choose between e1 and e2.
                 *
                 *  It makes sense to pick one edge over another if that edge offers more
                 *  opportunities to act as a source or target for a route.
                 *
                 *  For consistency, we use the following logic:
                 *  "Pick e1 unless it makes sense to choose e2"
                 *
                 *  Representing edge enabled as a truth table:
                 *  f1 | r1 | f2 | r2 | selected
                 *  ____________________________
                 *  t  | t  | t  | t  | e1
                 *  t  | t  | t  | f  | e1
                 *  t  | t  | f  | t  | e1
                 *  t  | f  | t  | t  | e2
                 *  t  | f  | t  | f  | e1
                 *  t  | f  | f  | t  | e1
                 *  f  | t  | t  | t  | e2
                 *  f  | t  | t  | f  | e1
                 *  f  | t  | f  | t  | e1
                 *
                 *  The other rows in truth table don't appear as we discard an edge if both
                 *  forward and reverse are disabled.
                 *
                 **/
                if (candidate_it->fwd_segment_position < data.fwd_segment_position)
                {
                    if (data.forward_segment_id.enabled && data.reverse_segment_id.enabled &&
                        !(candidate_it->forward_segment_id.enabled &&
                          candidate_it->reverse_segment_id.enabled))
                    {
                        *candidate_it = MakePhantomNode(input_coordinate, data).phantom_node;
                    }
                }
                else
                {
                    if (!candidate_it->forward_segment_id.enabled ||
                        !candidate_it->reverse_segment_id.enabled ||
                        (data.forward_segment_id.enabled && data.reverse_segment_id.enabled))
                    {
                        *candidate_it = MakePhantomNode(input_coordinate, data).phantom_node;
                    }
                }
            }
        };

        std::for_each(results.begin(), results.end(), [&](const CandidateSegment &segment) {
            if (segment.fixed_projected_coordinate == nearest_coord)
            {
                add_to_candidates(nearest_phantoms, segment.data);
            }
            else
            {
                // Can only be from a big component for the alternative candidates
                add_to_candidates(big_component_phantoms, segment.data);
            }
        });
        return std::make_pair(std::move(nearest_phantoms), std::move(big_component_phantoms));
    }

    std::vector<PhantomNodeWithDistance>
    MakePhantomNodes(const util::Coordinate input_coordinate,
                     const std::vector<CandidateSegment> &results) const
    {
        std::vector<PhantomNodeWithDistance> distance_and_phantoms(results.size());
        std::transform(results.begin(),
                       results.end(),
                       distance_and_phantoms.begin(),
                       [this, &input_coordinate](const CandidateSegment &segment) {
                           return MakePhantomNode(input_coordinate, segment.data);
                       });
        return distance_and_phantoms;
    }

    PhantomNodeWithDistance MakePhantomNode(const util::Coordinate input_coordinate,
                                            const EdgeData &data) const
    {
        util::Coordinate point_on_segment;
        double ratio;
        const auto current_perpendicular_distance =
            util::coordinate_calculation::perpendicularDistance(coordinates[data.u],
                                                                coordinates[data.v],
                                                                input_coordinate,
                                                                point_on_segment,
                                                                ratio);

        // Find the node-based-edge that this belongs to, and directly
        // calculate the forward_weight, forward_offset, reverse_weight, reverse_offset

        BOOST_ASSERT(data.forward_segment_id.enabled || data.reverse_segment_id.enabled);
        BOOST_ASSERT(!data.reverse_segment_id.enabled ||
                     datafacade.GetGeometryIndex(data.forward_segment_id.id).id ==
                         datafacade.GetGeometryIndex(data.reverse_segment_id.id).id);
        const auto geometry_id = datafacade.GetGeometryIndex(data.forward_segment_id.id).id;
        const auto component_id = datafacade.GetComponentID(data.forward_segment_id.id);

        const auto forward_weights = datafacade.GetUncompressedForwardWeights(geometry_id);
        const auto reverse_weights = datafacade.GetUncompressedReverseWeights(geometry_id);

        const auto forward_durations = datafacade.GetUncompressedForwardDurations(geometry_id);
        const auto reverse_durations = datafacade.GetUncompressedReverseDurations(geometry_id);

        const auto forward_geometry = datafacade.GetUncompressedForwardGeometry(geometry_id);

        const auto forward_weight_offset =
            // NOLINTNEXTLINE(bugprone-fold-init-type)
            alias_cast<EdgeWeight>(
                std::accumulate(forward_weights.begin(),
                                forward_weights.begin() + data.fwd_segment_position,
                                SegmentWeight{0}));

        const auto forward_duration_offset =
            // NOLINTNEXTLINE(bugprone-fold-init-type)
            alias_cast<EdgeDuration>(
                std::accumulate(forward_durations.begin(),
                                forward_durations.begin() + data.fwd_segment_position,
                                SegmentDuration{0}));

        EdgeDistance forward_distance_offset = {0};
        // Sum up the distance from the start to the fwd_segment_position
        for (auto current = forward_geometry.begin();
             current < forward_geometry.begin() + data.fwd_segment_position;
             ++current)
        {
            forward_distance_offset +=
                to_alias<EdgeDistance>(util::coordinate_calculation::greatCircleDistance(
                    datafacade.GetCoordinateOfNode(*current),
                    datafacade.GetCoordinateOfNode(*std::next(current))));
        }

        BOOST_ASSERT(data.fwd_segment_position <
                     std::distance(forward_durations.begin(), forward_durations.end()));

        EdgeWeight forward_weight =
            alias_cast<EdgeWeight>(forward_weights[data.fwd_segment_position]);
        EdgeDuration forward_duration =
            alias_cast<EdgeDuration>(forward_durations[data.fwd_segment_position]);
        EdgeDistance forward_distance =
            to_alias<EdgeDistance>(util::coordinate_calculation::greatCircleDistance(
                datafacade.GetCoordinateOfNode(forward_geometry(data.fwd_segment_position)),
                point_on_segment));

        const auto reverse_weight_offset = alias_cast<EdgeWeight>(
            std::accumulate(reverse_weights.begin(),
                            reverse_weights.end() - data.fwd_segment_position - 1,
                            SegmentWeight{0}));

        const auto reverse_duration_offset = alias_cast<EdgeDuration>(
            std::accumulate(reverse_durations.begin(),
                            reverse_durations.end() - data.fwd_segment_position - 1,
                            SegmentDuration{0}));

        EdgeDistance reverse_distance_offset = {0};
        // Sum up the distance from just after the fwd_segment_position to the end
        for (auto current = forward_geometry.begin() + data.fwd_segment_position + 1;
             current != std::prev(forward_geometry.end());
             ++current)
        {
            reverse_distance_offset +=
                to_alias<EdgeDistance>(util::coordinate_calculation::greatCircleDistance(
                    datafacade.GetCoordinateOfNode(*current),
                    datafacade.GetCoordinateOfNode(*std::next(current))));
        }

        EdgeWeight reverse_weight = alias_cast<EdgeWeight>(
            reverse_weights[reverse_weights.size() - data.fwd_segment_position - 1]);
        EdgeDuration reverse_duration = alias_cast<EdgeDuration>(
            reverse_durations[reverse_durations.size() - data.fwd_segment_position - 1]);
        EdgeDistance reverse_distance =
            to_alias<EdgeDistance>(util::coordinate_calculation::greatCircleDistance(
                point_on_segment,
                datafacade.GetCoordinateOfNode(forward_geometry(data.fwd_segment_position + 1))));

        ratio = std::min(1.0, std::max(0.0, ratio));
        if (data.forward_segment_id.id != SPECIAL_SEGMENTID)
        {
            forward_weight = to_alias<EdgeWeight>(from_alias<double>(forward_weight) * ratio);
            forward_duration = to_alias<EdgeDuration>(from_alias<double>(forward_duration) * ratio);
        }
        if (data.reverse_segment_id.id != SPECIAL_SEGMENTID)
        {
            reverse_weight -= to_alias<EdgeWeight>(from_alias<double>(reverse_weight) * ratio);
            reverse_duration -=
                to_alias<EdgeDuration>(from_alias<double>(reverse_duration) * ratio);
        }

        // check phantom node segments validity
        auto areSegmentsValid = [](auto first, auto last) -> bool {
            return std::find(first, last, INVALID_SEGMENT_WEIGHT) == last;
        };
        bool is_forward_valid_source =
            areSegmentsValid(forward_weights.begin(), forward_weights.end());
        bool is_forward_valid_target = areSegmentsValid(
            forward_weights.begin(), forward_weights.begin() + data.fwd_segment_position + 1);
        bool is_reverse_valid_source =
            areSegmentsValid(reverse_weights.begin(), reverse_weights.end());
        bool is_reverse_valid_target = areSegmentsValid(
            reverse_weights.begin(), reverse_weights.end() - data.fwd_segment_position);

        auto transformed = PhantomNodeWithDistance{
            PhantomNode{data,
                        component_id,
                        forward_weight,
                        reverse_weight,
                        forward_weight_offset,
                        reverse_weight_offset,
                        forward_distance,
                        reverse_distance,
                        forward_distance_offset,
                        reverse_distance_offset,
                        forward_duration,
                        reverse_duration,
                        forward_duration_offset,
                        reverse_duration_offset,
                        is_forward_valid_source,
                        is_forward_valid_target,
                        is_reverse_valid_source,
                        is_reverse_valid_target,
                        point_on_segment,
                        input_coordinate,
                        static_cast<unsigned short>(util::coordinate_calculation::bearing(
                            coordinates[data.u], coordinates[data.v]))},
            current_perpendicular_distance};

        return transformed;
    }

    double GetSegmentDistance(const Coordinate input_coordinate,
                              const CandidateSegment &segment) const
    {
        BOOST_ASSERT(segment.data.forward_segment_id.id != SPECIAL_SEGMENTID ||
                     !segment.data.forward_segment_id.enabled);
        BOOST_ASSERT(segment.data.reverse_segment_id.id != SPECIAL_SEGMENTID ||
                     !segment.data.reverse_segment_id.enabled);

        Coordinate wsg84_coordinate =
            util::web_mercator::toWGS84(segment.fixed_projected_coordinate);

        return util::coordinate_calculation::greatCircleDistance(input_coordinate,
                                                                 wsg84_coordinate);
    }

    bool CheckSegmentDistance(const Coordinate input_coordinate,
                              const CandidateSegment &segment,
                              const double max_distance) const
    {
        return GetSegmentDistance(input_coordinate, segment) > max_distance;
    }

    std::pair<bool, bool> CheckSegmentExclude(const CandidateSegment &segment) const
    {
        std::pair<bool, bool> valid = {true, true};

        if (segment.data.forward_segment_id.enabled &&
            datafacade.ExcludeNode(segment.data.forward_segment_id.id))
        {
            valid.first = false;
        }

        if (segment.data.reverse_segment_id.enabled &&
            datafacade.ExcludeNode(segment.data.reverse_segment_id.id))
        {
            valid.second = false;
        }

        return valid;
    }

    std::pair<bool, bool> CheckSegmentBearing(const CandidateSegment &segment,
                                              const Bearing filter_bearing) const
    {
        BOOST_ASSERT(segment.data.forward_segment_id.id != SPECIAL_SEGMENTID ||
                     !segment.data.forward_segment_id.enabled);
        BOOST_ASSERT(segment.data.reverse_segment_id.id != SPECIAL_SEGMENTID ||
                     !segment.data.reverse_segment_id.enabled);

        const double forward_edge_bearing = util::coordinate_calculation::bearing(
            coordinates[segment.data.u], coordinates[segment.data.v]);

        const double backward_edge_bearing = (forward_edge_bearing + 180) > 360
                                                 ? (forward_edge_bearing - 180)
                                                 : (forward_edge_bearing + 180);

        const bool forward_bearing_valid =
            util::bearing::CheckInBounds(
                std::round(forward_edge_bearing), filter_bearing.bearing, filter_bearing.range) &&
            segment.data.forward_segment_id.enabled;
        const bool backward_bearing_valid =
            util::bearing::CheckInBounds(
                std::round(backward_edge_bearing), filter_bearing.bearing, filter_bearing.range) &&
            segment.data.reverse_segment_id.enabled;
        return std::make_pair(forward_bearing_valid, backward_bearing_valid);
    }

    /**
     * Checks to see if the edge weights are valid.  We might have an edge,
     * but a traffic update might set the speed to 0 (weight == INVALID_SEGMENT_WEIGHT).
     * which means that this edge is not currently traversable.  If this is the case,
     * then we shouldn't snap to this edge.
     */
    std::pair<bool, bool> HasValidEdge(const CandidateSegment &segment,
                                       const bool use_all_edges = false) const
    {

        bool forward_edge_valid = false;
        bool reverse_edge_valid = false;

        const auto &data = segment.data;
        BOOST_ASSERT(data.forward_segment_id.enabled);
        BOOST_ASSERT(data.forward_segment_id.id != SPECIAL_NODEID);
        const auto geometry_id = datafacade.GetGeometryIndex(data.forward_segment_id.id).id;

        const auto forward_weights = datafacade.GetUncompressedForwardWeights(geometry_id);
        if (forward_weights[data.fwd_segment_position] != INVALID_SEGMENT_WEIGHT)
        {
            forward_edge_valid = data.forward_segment_id.enabled;
        }

        const auto reverse_weights = datafacade.GetUncompressedReverseWeights(geometry_id);
        if (reverse_weights[reverse_weights.size() - data.fwd_segment_position - 1] !=
            INVALID_SEGMENT_WEIGHT)
        {
            reverse_edge_valid = data.reverse_segment_id.enabled;
        }

        forward_edge_valid = forward_edge_valid && (data.is_startpoint || use_all_edges);
        reverse_edge_valid = reverse_edge_valid && (data.is_startpoint || use_all_edges);

        return std::make_pair(forward_edge_valid, reverse_edge_valid);
    }

    bool IsTinyComponent(const CandidateSegment &segment) const
    {
        const auto &data = segment.data;
        BOOST_ASSERT(data.forward_segment_id.enabled || data.reverse_segment_id.enabled);
        BOOST_ASSERT(data.forward_segment_id.id != SPECIAL_NODEID);
        return datafacade.GetComponentID(data.forward_segment_id.id).is_tiny;
    }

    std::pair<bool, bool> CheckApproach(const util::Coordinate &input_coordinate,
                                        const CandidateSegment &segment,
                                        const Approach approach) const
    {
        bool isOnewaySegment =
            !(segment.data.forward_segment_id.enabled && segment.data.reverse_segment_id.enabled);
        if (!isOnewaySegment && approach == Approach::CURB)
        {
            // Check the counter clockwise
            //
            //                  input_coordinate
            //                       |
            //                       |
            // segment.data.u ---------------- segment.data.v

            bool input_coordinate_is_at_right = !util::coordinate_calculation::isCCW(
                coordinates[segment.data.u], coordinates[segment.data.v], input_coordinate);

            if (datafacade.IsLeftHandDriving(segment.data.forward_segment_id.id))
                input_coordinate_is_at_right = !input_coordinate_is_at_right;

            return std::make_pair(input_coordinate_is_at_right, (!input_coordinate_is_at_right));
        }
        return std::make_pair(true, true);
    }

    const RTreeT &rtree;
    const CoordinateList &coordinates;
    DataFacadeT &datafacade;
};
} // namespace engine
} // namespace osrm

#endif