#include "Reader.h"

#include <cmath>
#include <vector>

#include "Grid.h"
#include "LongVector3.h"
#include "Source.h"
#include "Wreck.h"


static constexpr long double SCALE {.0001};
static constexpr long double EXTENT {1000 * 50000};


static Grid& find_grid_for(std::vector<Grid>& grids, const LongVector3& position);


std::vector<Grid>
Reader::read(Source& source)
{
    std::vector<Grid> grids;
    for (auto& km : source.killmails()) {
        auto& grid = find_grid_for(grids, km.position);
        grid.wrecks.push_back(Wreck{Vector3{0, 0, 0}, km});
    }
    for (auto& grid : grids) {
        LongVector3 average {0, 0, 0};
        for (const auto& wreck : grid.wrecks) {
            average.x += wreck.killmail.position.x;
            average.y += wreck.killmail.position.y;
            average.z += wreck.killmail.position.z;
        }
        const auto killmails = grid.wrecks.size();
        average.x /= killmails;
        average.y /= killmails;
        average.z /= killmails;
        for (auto& wreck : grid.wrecks) {
            wreck.position = {
                static_cast<float>((wreck.killmail.position.x - average.x) * SCALE),
                static_cast<float>((wreck.killmail.position.y - average.y) * SCALE),
                static_cast<float>((wreck.killmail.position.z - average.z) * SCALE),
            };
        }
        grid.origin = average;
    }
    return grids;
}


Grid&
find_grid_for(std::vector<Grid>& grids, const LongVector3& position)
{
    for (auto& grid : grids) {
        for (auto& wreck : grid.wrecks) {
            const long double dist =
                std::sqrt(
                    std::pow(position.x - wreck.killmail.position.x, 2) +
                    std::pow(position.y - wreck.killmail.position.y, 2) +
                    std::pow(position.z - wreck.killmail.position.z, 2));
            if (dist < EXTENT)
                return grid;
        }
    }
    grids.push_back(Grid{});
    return grids.back();
}