#include "Runtime/CSortedLists.hpp"

#include "Runtime/World/CActor.hpp"

#include <algorithm>
#include <cassert>

namespace urde {
namespace {
template <typename T, typename S>
auto AccessElement(T& arr, S idx) -> typename T::reference {
  assert(std::size(arr) > static_cast<size_t>(idx) && idx >= 0);
  return arr[idx];
}

template <typename T, typename S>
auto AccessElement(const T& arr, S idx) -> typename T::const_reference {
  assert(std::size(arr) > static_cast<size_t>(idx) && idx >= 0);
  return arr[idx];
}
} // Anonymous namespace

CSortedListManager::CSortedListManager() { Reset(); }

void CSortedListManager::Reset() {
  x0_nodes.fill(SNode{});

  for (auto& list : xb000_sortedLists) {
    list.Reset();
  }
}

void CSortedListManager::AddToLinkedList(s16 nodeId, s16& headId, s16& tailId) const {
  if (headId == -1) {
    const_cast<SNode&>(AccessElement(x0_nodes, nodeId)).x28_next = headId;
    headId = nodeId;
    tailId = nodeId;
  } else {
    if (AccessElement(x0_nodes, nodeId).x28_next != -1)
      return;
    if (tailId == nodeId)
      return;
    const_cast<SNode&>(AccessElement(x0_nodes, nodeId)).x28_next = headId;
    headId = nodeId;
  }
}

void CSortedListManager::RemoveFromList(ESortedList list, s16 idx) {
  const auto listIndex = static_cast<size_t>(list);
  SSortedList& sl = xb000_sortedLists[listIndex];

  while (idx < sl.x800_size - 1) {
    AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx + 1)).x1c_selfIdxs[listIndex] = idx;
    AccessElement(sl.x0_ids, idx) = AccessElement(sl.x0_ids, idx + 1);
    ++idx;
  }

  --sl.x800_size;
}

void CSortedListManager::MoveInList(ESortedList list, s16 idx) {
  const auto listIndex = static_cast<size_t>(list);
  SSortedList& sl = xb000_sortedLists[listIndex];

  while (true) {
    if (idx > 0 && AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx - 1)).x4_box[listIndex] >
                       AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx)).x4_box[listIndex]) {
      AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx - 1)).x1c_selfIdxs[listIndex] = idx;
      AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx)).x1c_selfIdxs[listIndex] = idx - 1;
      std::swap(AccessElement(sl.x0_ids, idx), AccessElement(sl.x0_ids, idx - 1));
      --idx;
    } else {
      if (idx >= sl.x800_size - 1) {
        return;
      }
      if (AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx + 1)).x4_box[listIndex] >=
          AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx)).x4_box[listIndex]) {
        return;
      }
      AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx + 1)).x1c_selfIdxs[listIndex] = idx;
      AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx)).x1c_selfIdxs[listIndex] = idx + 1;
      std::swap(AccessElement(sl.x0_ids, idx), AccessElement(sl.x0_ids, idx + 1));
      ++idx;
    }
  }
}

void CSortedListManager::InsertInList(ESortedList list, SNode& node) {
  const auto listIndex = static_cast<size_t>(list);
  SSortedList& sl = xb000_sortedLists[listIndex];
  int insIdx = 0;

  for (int i = sl.x800_size; i > 0;) {
    /* Binary search cycle to find insert index */
    if (AccessElement(x0_nodes, AccessElement(sl.x0_ids, insIdx + i / 2)).x4_box[listIndex] < node.x4_box[listIndex]) {
      /* Upper */
      insIdx = insIdx + i / 2 + 1;
      i = i - i / 2 - 1;
    } else {
      /* Lower */
      i /= 2;
    }
  }

  /* Shift ids for insert */
  for (int i = sl.x800_size; i > insIdx; --i) {
    AccessElement(x0_nodes, AccessElement(sl.x0_ids, i - 1)).x1c_selfIdxs[listIndex] = i;
    AccessElement(sl.x0_ids, i) = AccessElement(sl.x0_ids, i - 1);
  }

  /* Do insert */
  AccessElement(sl.x0_ids, insIdx) = node.x0_actor->GetUniqueId().Value();
  node.x1c_selfIdxs[listIndex] = s16(insIdx);
  ++sl.x800_size;
}

s16 CSortedListManager::FindInListUpper(ESortedList list, float val) const {
  const auto listIndex = static_cast<size_t>(list);
  const SSortedList& sl = xb000_sortedLists[listIndex];
  int idx = 0;

  for (int i = sl.x800_size; i > 0;) {
    /* Binary search cycle to find index */
    if (!(val < AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx + i / 2)).x4_box[listIndex])) {
      /* Upper */
      idx = idx + i / 2 + 1;
      i = i - i / 2 - 1;
    } else {
      /* Lower */
      i /= 2;
    }
  }

  return idx;
}

s16 CSortedListManager::FindInListLower(ESortedList list, float val) const {
  const auto listIndex = static_cast<size_t>(list);
  const SSortedList& sl = xb000_sortedLists[listIndex];
  int idx = 0;

  for (int i = sl.x800_size; i > 0;) {
    /* Binary search cycle to find index */
    if (AccessElement(x0_nodes, AccessElement(sl.x0_ids, idx + i / 2)).x4_box[listIndex] < val) {
      /* Upper */
      idx = idx + i / 2 + 1;
      i = i - i / 2 - 1;
    } else {
      /* Lower */
      i /= 2;
    }
  }

  return idx;
}

s16 CSortedListManager::ConstructIntersectionArray(const zeus::CAABox& aabb) {
  const int minXa = FindInListLower(ESortedList::MinX, aabb.min.x());
  const int maxXa = FindInListUpper(ESortedList::MinX, aabb.max.x());
  const int minXb = FindInListLower(ESortedList::MaxX, aabb.min.x());
  const int maxXb = FindInListUpper(ESortedList::MaxX, aabb.max.x());
  const int xEnd = std::min(int(xb000_sortedLists[3].x800_size) - maxXb, minXa) + (maxXb + (maxXa - minXa) - minXb) / 2;

  const int minYa = FindInListLower(ESortedList::MinY, aabb.min.y());
  const int maxYa = FindInListUpper(ESortedList::MinY, aabb.max.y());
  const int minYb = FindInListLower(ESortedList::MaxY, aabb.min.y());
  const int maxYb = FindInListUpper(ESortedList::MaxY, aabb.max.y());
  const int yEnd = std::min(int(xb000_sortedLists[4].x800_size) - maxYb, minYa) + (maxYb + (maxYa - minYa) - minYb) / 2;

  const int minZa = FindInListLower(ESortedList::MinZ, aabb.min.z());
  const int maxZa = FindInListUpper(ESortedList::MinZ, aabb.max.z());
  const int minZb = FindInListLower(ESortedList::MaxZ, aabb.min.z());
  const int maxZb = FindInListUpper(ESortedList::MaxZ, aabb.max.z());
  const int zEnd = std::min(int(xb000_sortedLists[5].x800_size) - maxZb, minZa) + (maxZb + (maxZa - minZa) - minZb) / 2;

  if (xEnd < yEnd && xEnd < zEnd) {
    return CalculateIntersections(ESortedList::MinX, ESortedList::MaxX, minXa, maxXa, minXb, maxXb, ESortedList::MinY,
                                  ESortedList::MaxY, ESortedList::MinZ, ESortedList::MaxZ, aabb);
  } else if (yEnd < zEnd) {
    return CalculateIntersections(ESortedList::MinY, ESortedList::MaxY, minYa, maxYa, minYb, maxYb, ESortedList::MinX,
                                  ESortedList::MaxX, ESortedList::MinZ, ESortedList::MaxZ, aabb);
  } else {
    return CalculateIntersections(ESortedList::MinZ, ESortedList::MaxZ, minZa, maxZa, minZb, maxZb, ESortedList::MinX,
                                  ESortedList::MaxX, ESortedList::MinY, ESortedList::MaxY, aabb);
  }
}

s16 CSortedListManager::CalculateIntersections(ESortedList la, ESortedList lb, s16 a, s16 b, s16 c, s16 d,
                                               ESortedList slA, ESortedList slB, ESortedList slC, ESortedList slD,
                                               const zeus::CAABox& aabb) {
  const auto listAIndex = static_cast<size_t>(la);
  const auto listBIndex = static_cast<size_t>(lb);

  s16 headId = -1;
  s16 tailId = -1;
  for (int i = a; i < b; ++i) {
    AddToLinkedList(AccessElement(xb000_sortedLists[listAIndex].x0_ids, i), headId, tailId);
  }
  for (int i = c; i < d; ++i) {
    AddToLinkedList(AccessElement(xb000_sortedLists[listBIndex].x0_ids, i), headId, tailId);
  }

  if (a < xb000_sortedLists[listBIndex].x800_size - d) {
    for (int i = 0; i < a; ++i) {
      const s16 id = AccessElement(xb000_sortedLists[listAIndex].x0_ids, i);
      if (AccessElement(x0_nodes, id).x4_box[listBIndex] > aabb[listBIndex]) {
        AddToLinkedList(id, headId, tailId);
      }
    }
  } else {
    for (int i = d; i < xb000_sortedLists[listBIndex].x800_size; ++i) {
      const s16 id = AccessElement(xb000_sortedLists[listBIndex].x0_ids, i);
      if (AccessElement(x0_nodes, id).x4_box[listAIndex] < aabb[listAIndex]) {
        AddToLinkedList(id, headId, tailId);
      }
    }
  }

  for (s16* id = &headId; *id != -1;) {
    SNode& node = AccessElement(x0_nodes, *id);
    if (node.x4_box[size_t(slA)] > aabb[size_t(slB)] || node.x4_box[size_t(slB)] < aabb[size_t(slA)] ||
        node.x4_box[size_t(slC)] > aabb[size_t(slD)] || node.x4_box[size_t(slD)] < aabb[size_t(slC)]) {
      /* Not intersecting; remove from chain */
      *id = node.x28_next;
      node.x28_next = -1;
      continue;
    }
    id = &node.x28_next;
  }

  return headId;
}

void CSortedListManager::BuildNearList(rstl::reserved_vector<TUniqueId, 1024>& out, const zeus::CVector3f& pos,
                                       const zeus::CVector3f& dir, float mag, const CMaterialFilter& filter,
                                       const CActor* actor) const {
  if (mag == 0.f)
    mag = 8000.f;
  const zeus::CVector3f ray = dir * mag;
  const zeus::CVector3f sum = ray + pos;
  zeus::CVector3f maxs(std::max(pos.x(), sum.x()), std::max(pos.y(), sum.y()), std::max(pos.z(), sum.z()));
  zeus::CVector3f mins(std::min(sum.x(), pos.x()), std::min(sum.y(), pos.y()), std::min(sum.z(), pos.z()));
  BuildNearList(out, zeus::CAABox(mins, maxs), filter, actor);
}

void CSortedListManager::BuildNearList(rstl::reserved_vector<TUniqueId, 1024>& out, const CActor& actor,
                                       const zeus::CAABox& aabb) const {
  const CMaterialFilter& filter = actor.GetMaterialFilter();
  s16 id = const_cast<CSortedListManager&>(*this).ConstructIntersectionArray(aabb);
  while (id != -1) {
    const SNode& node = AccessElement(x0_nodes, id);
    if (&actor != node.x0_actor && filter.Passes(node.x0_actor->GetMaterialList()) &&
        node.x0_actor->GetMaterialFilter().Passes(actor.GetMaterialList()))
      out.push_back(node.x0_actor->GetUniqueId());

    id = node.x28_next;
    const_cast<SNode&>(node).x28_next = -1;
  }
}

void CSortedListManager::BuildNearList(rstl::reserved_vector<TUniqueId, 1024>& out, const zeus::CAABox& aabb,
                                       const CMaterialFilter& filter, const CActor* actor) const {
  s16 id = const_cast<CSortedListManager&>(*this).ConstructIntersectionArray(aabb);
  while (id != -1) {
    const SNode& node = AccessElement(x0_nodes, id);
    if (actor != node.x0_actor && filter.Passes(node.x0_actor->GetMaterialList()))
      out.push_back(node.x0_actor->GetUniqueId());

    id = node.x28_next;
    const_cast<SNode&>(node).x28_next = -1;
  }
}

void CSortedListManager::Remove(const CActor* act) {
  SNode& node = AccessElement(x0_nodes, act->GetUniqueId().Value());
  if (!node.x2a_populated)
    return;

  RemoveFromList(ESortedList::MinX, node.x1c_selfIdxs[0]);
  RemoveFromList(ESortedList::MaxX, node.x1c_selfIdxs[3]);
  RemoveFromList(ESortedList::MinY, node.x1c_selfIdxs[1]);
  RemoveFromList(ESortedList::MaxY, node.x1c_selfIdxs[4]);
  RemoveFromList(ESortedList::MinZ, node.x1c_selfIdxs[2]);
  RemoveFromList(ESortedList::MaxZ, node.x1c_selfIdxs[5]);
  node.x2a_populated = false;
}

void CSortedListManager::Move(const CActor* act, const zeus::CAABox& aabb) {
  SNode& node = AccessElement(x0_nodes, act->GetUniqueId().Value());
  node.x4_box = aabb;

  MoveInList(ESortedList::MinX, node.x1c_selfIdxs[0]);
  MoveInList(ESortedList::MaxX, node.x1c_selfIdxs[3]);
  MoveInList(ESortedList::MinY, node.x1c_selfIdxs[1]);
  MoveInList(ESortedList::MaxY, node.x1c_selfIdxs[4]);
  MoveInList(ESortedList::MinZ, node.x1c_selfIdxs[2]);
  MoveInList(ESortedList::MaxZ, node.x1c_selfIdxs[5]);
}

void CSortedListManager::Insert(const CActor* act, const zeus::CAABox& aabb) {
  SNode& node = AccessElement(x0_nodes, act->GetUniqueId().Value());
  if (node.x2a_populated) {
    Move(act, aabb);
    return;
  }

  SNode newNode(act, aabb);
  InsertInList(ESortedList::MinX, newNode);
  InsertInList(ESortedList::MaxX, newNode);
  InsertInList(ESortedList::MinY, newNode);
  InsertInList(ESortedList::MaxY, newNode);
  InsertInList(ESortedList::MinZ, newNode);
  InsertInList(ESortedList::MaxZ, newNode);
  node = newNode;
}

bool CSortedListManager::ActorInLists(const CActor* act) const {
  if (!act)
    return false;
  const SNode& node = AccessElement(x0_nodes, act->GetUniqueId().Value());
  return node.x2a_populated;
}

} // namespace urde