//
// Created by martin on 25.03.22.
//

#ifndef ANIMTESTBED_ANIMGRAPH_H
#define ANIMTESTBED_ANIMGRAPH_H

#include "AnimGraphData.h"
#include "AnimGraphNodes.h"

struct AnimDataWorkBuffer {
  std::vector<AnimData> m_eval_anim_data;
  std::vector<AnimData*> m_available_data;

  AnimDataWorkBuffer(size_t stack_size) {
    m_eval_anim_data.resize(stack_size);
    m_available_data.resize(stack_size);

    for (size_t i = 0; i < stack_size; i++) {
      m_available_data[i] = &m_eval_anim_data[i];
    }
  }

  void push(AnimData* anim_data) {
    assert (m_available_data.size() < m_eval_anim_data.size());
    m_available_data.push_back(anim_data);
  }

  void pop() {
    assert (m_available_data.size() > 0);
    m_available_data.pop_back();
  }

  AnimData* peek() {
    return m_available_data.back();
  }
};

//
// AnimGraph (Runtime)
//
struct AnimGraph {
  AnimData m_local_transforms;

  std::vector<AnimNode*> m_nodes;
  std::vector<AnimNode*> m_eval_ordered_nodes;
  std::vector<std::vector<AnimGraphConnection> > m_node_input_connections;
  std::vector<std::vector<AnimGraphConnection> > m_node_output_connections;
  NodeSocketAccessorBase* m_socket_accessor;
  char* m_input_buffer = nullptr;
  char* m_output_buffer = nullptr;

  std::vector<Socket>& getGraphOutputs() { return m_socket_accessor->m_inputs; }
  std::vector<Socket>& getGraphInputs() { return m_socket_accessor->m_outputs; }

  AnimDataWorkBuffer m_anim_data_work_buffer = AnimDataWorkBuffer(5);

  ~AnimGraph() {
    delete[] m_input_buffer;
    delete[] m_output_buffer;

    for (int i = 0; i < m_nodes.size(); i++) {
      delete m_nodes[i];
    }

    delete m_socket_accessor;
  }

  void updateOrderedNodes();
  void updateOrderedNodesRecursive(int node_index);
  void markActiveNodes();
  bool checkIsNodeActive(AnimNode* node) {
    return node->m_state != AnimNodeEvalState::Deactivated;
  }


  void evalInputNode();
  void prepareNodeEval(size_t node_index);
  void finishNodeEval(size_t node_index);
  void evalOutputNode();

  void evalSyncTracks();
  void updateTime(float dt);
  void evaluate();
  void reset() {
    for (size_t i = 0, n = m_nodes.size(); i < n; i++) {
      m_nodes[i]->m_time_now = 0.f;
      m_nodes[i]->m_time_last = 0.f;
      m_nodes[i]->m_state = AnimNodeEvalState::Undefined;
    }
  }

  Socket* getInputSocket(const std::string& name);
  Socket* getOutputSocket(const std::string& name);

  const Socket* getInputSocket(const std::string& name) const;
  const Socket* getOutputSocket(const std::string& name) const;

  void* getInputPtr(const std::string& name) const {
    const Socket* input_socket = getInputSocket(name);
    if (input_socket != nullptr) {
      return input_socket->m_value.ptr;
    }

    return nullptr;
  }

  int getNodeEvalOrderIndex(const AnimNode* node) {
    for (size_t i = 0, n = m_eval_ordered_nodes.size(); i < n; i++) {
      if (m_eval_ordered_nodes[i] == node) {
        return i;
      }
    }

    return -1;
  }
  const AnimNode* getAnimNodeForInput (
      size_t node_index,
      const std::string& input_name) const {
    assert(node_index < m_nodes.size());

    const std::vector<AnimGraphConnection>& input_connection = m_node_input_connections[node_index];
    for (size_t i = 0, n = input_connection.size(); i < n; i++) {
      if (input_connection[i].m_target_socket.m_name == input_name) {
        return input_connection[i].m_source_node;
      }
    }

    return nullptr;
  }

  AnimNode* getAnimNode(const char* name) {
    for (size_t i = 0; i < m_nodes.size(); i++) {
      if (m_nodes[i]->m_name == name) {
        return m_nodes[i];
      }
    }

    return nullptr;
  }

  size_t getAnimNodeIndex (AnimNode* node) {
    for (size_t i = 0; i < m_nodes.size(); i++) {
      if (m_nodes[i] == node) {
        return i;
      }
    }

    return -1;
  }
};

#endif  //ANIMTESTBED_ANIMGRAPH_H