#include "collectable_sim_ground.hpp"

#include <utility>
#include "../../../../config.h"

void CollectableSimGround::closeAllHoles()
{
    // Create one segment for the ground
    createSegment(-groundWidth / 2.f, groundWidth / 2.f);
}

void CollectableSimGround::createLayout(DepthHoleLayout &layout)
{
    if (!hasLayoutChanged(layout))
    {
        return;
    }
    currentLayoutHoles = layout.holes;
    segments.clear();

    if (currentLayoutHoles.empty())
    {
        closeAllHoles();
        return;
    }

    // Sort holes from left to right
    std::sort(currentLayoutHoles.begin(), currentLayoutHoles.end(),
              [](DepthHoleDescription a, DepthHoleDescription b)
              {
                  return a.x < b.x;
              });

    // Create segments for holes
    float leftCorner = -groundWidth / 2.f;
    float leftHoleId = -1;
    for (auto &hole: currentLayoutHoles)
    {
        auto rightCorner = hole.x - hole.width / 2.f;
        auto segment = createSegment(leftCorner, rightCorner);
        if (segment != nullptr)
        {
            segment->rightHoleId = hole.playerId;
            segment->leftHoleId = leftHoleId;
        }

        leftHoleId = hole.playerId;
        leftCorner = hole.x + hole.width / 2.f;
    }
    // Create segment for the right side
    auto segment = createSegment(leftCorner, groundWidth / 2.f);
    if (segment != nullptr)
    {
        segment->leftHoleId = leftHoleId;
    }
}

CollectableSimGround::CollectableSimGround(std::shared_ptr<b2World> world, float groundWidth)
        : world(std::move(world)), groundWidth(groundWidth)
{
    closeAllHoles();
}

void CollectableSimGround::setGroundWidth(float width)
{
    if (width <= 0)
    {
        throw std::runtime_error("Ground width must be greater than 0");
    }

    if (width == groundWidth)
    {
        return;
    }

    groundWidth = width;
    updateOuterSegmentsToWidth();
}

void CollectableSimGround::updateOuterSegmentsToWidth()
{
    auto outerSegments = getOuterSegments();
    auto borderPoints = groundWidth / 2.f;

    // Left segment
    if (outerSegments.left != nullptr)
    {
        auto leftSegment = outerSegments.left->body;
        auto leftCenter = leftSegment->getCenter();
        auto leftSize = leftSegment->getSize();
        auto rightPoint = leftCenter.x + leftSize.x / 2.f;

        createSegment(-borderPoints, rightPoint, outerSegments.left);
    }

    // Right segment
    if (outerSegments.right != nullptr)
    {
        auto rightSegment = outerSegments.right->body;
        auto rightCenter = rightSegment->getCenter();
        auto rightSize = rightSegment->getSize();
        auto leftPoint = rightCenter.x - rightSize.x / 2.f;

        createSegment(leftPoint, borderPoints, outerSegments.right);
    }
}

std::shared_ptr<CollectableSimGroundSegment> CollectableSimGround::createSegment(float leftCorner, float rightCorner,
                                                                                 std::shared_ptr<CollectableSimGroundSegment> segment)
{
    if (leftCorner > rightCorner)
    {
        // Segment would have negative width, don't create it and leave empty instead
        return segment;
    }

    if (segment == nullptr)
    {
        segment = std::make_shared<CollectableSimGroundSegment>(world);
        segments.push_back(segment);
    }

    auto center = sf::Vector2f((leftCorner + rightCorner) / 2.f, -COLLECTABLES_SIM_GROUND_THICKNESS / 2.f);
    auto size = sf::Vector2f(rightCorner - leftCorner, COLLECTABLES_SIM_GROUND_THICKNESS);

    segment->body->createSquare(b2_kinematicBody, center, size);

    return segment;
}

CollectableSimGround::SideSegments CollectableSimGround::getOuterSegments()
{
    SideSegments sideSegments;

    for (const auto &segment: segments)
    {
        if (segment->rightHoleId < 0)
        {
            sideSegments.right = segment;
        }

        if (segment->leftHoleId < 0)
        {
            sideSegments.left = segment;
        }

        if (sideSegments.left != nullptr && sideSegments.right != nullptr)
        {
            break;
        }
    }

    return sideSegments;
}

bool CollectableSimGround::hasLayoutChanged(DepthHoleLayout &layout)
{
    if (layout.holes.size() != currentLayoutHoles.size())
    {
        // Number of holes changed
        return true;
    }

    // Below here: Number of holes is the same
    if (currentLayoutHoles.empty())
    {
        // Both are empty, so no change
        return false;
    }

    // Sort holes from left to right
    std::sort(layout.holes.begin(), layout.holes.end(),
              [](DepthHoleDescription a, DepthHoleDescription b)
              {
                  return a.x < b.x;
              });

    // Compare holes
    for (int i = 0; i < layout.holes.size(); i++)
    {
        auto currentHole = currentLayoutHoles[i];
        auto newHole = layout.holes[i];

        if (newHole.x != currentHole.x ||
            newHole.width != currentHole.width)
        {
            // Hole changed
            return true;
        }
    }

    return false;
}