#include "Reader.h"

#include <ctime>
#include <limits>
#include <tuple>
#include <vector>

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


static constexpr long double SCALE {.0001};
static constexpr long double EXTENT {20000};


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


std::tuple<std::vector<Grid>, Timeline>
Reader::read(Source& source)
{
    std::vector<Grid> grids;
    std::time_t start {std::numeric_limits<std::time_t>::max()};
    std::time_t end {0};
    for (auto& km : source.killmails()) {
        if (km.time < start) start = km.time;
        if (end < km.time) end = km.time;
        auto& grid = find_grid_for(grids, km.position);
        grid.wrecks.push_back(Wreck{Vector3{0, 0, 0}, km, 0, source.team(km.owner)});
    }
    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),
            };
            wreck.time = static_cast<double>(wreck.killmail.time - start);
        }
        grid.origin = average;
    }
    Timeline timeline(start, end);
    return {grids, timeline};
}


Grid&
find_grid_for(std::vector<Grid>& grids, const LongVector3& position)
{
    for (auto& grid : grids)
        for (auto& wreck : grid.wrecks)
            if (dist(position, wreck.killmail.position) < EXTENT)
                return grid;
    grids.push_back(Grid{});
    return grids.back();
}