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

#ifndef ANIMTESTBED_ANIMGRAPH_H
#define ANIMTESTBED_ANIMGRAPH_H

#include "AnimGraphResource.h"

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

  std::vector<AnimNode*> m_nodes;
  std::vector<AnimNode*> m_eval_ordered_nodes;
  std::vector<std::vector<NodeInput> > m_node_inputs;
  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; }

  ~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 markActiveNodes();
  bool checkIsNodeActive(AnimNode* node) {
    return node->m_state != AnimNodeEvalState::Deactivated;
  }
  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;
    }
  }

  void* getOutput(const std::string& name) const;
  void* getInput(const std::string& name) const;

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

    std::vector<NodeInput>& node_inputs = m_node_inputs[node_index];
    for (size_t i = 0, n = node_inputs.size(); i < n; i++) {
      if (node_inputs[i].m_input_name == input_name) {
        return node_inputs[i].m_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;
  }

  static AnimGraph createFromResource(const AnimGraphResource& resource) {
    AnimGraph result;

    // create nodes
    for (int i = 0; i < resource.m_nodes.size(); i++) {
      const AnimNodeResource& node_resource = resource.m_nodes[i];
      AnimNode* node = AnimNodeFactory(node_resource.m_type_name.c_str());
      node->m_name = node_resource.m_name;
      node->m_node_type_name = node_resource.m_type_name;
      node->m_index = i;
      result.m_nodes.push_back(node);

      assert(node_resource.m_socket_accessor != nullptr);
      result.m_node_inputs.push_back(std::vector<NodeInput>());
      std::vector<NodeInput>& node_inputs = result.m_node_inputs.back();

      for (int j = 0, n = node_resource.m_socket_accessor->m_inputs.size();
           j < n;
           j++) {
        const Socket& input_socket =
            node_resource.m_socket_accessor->m_inputs[j];

        NodeInput input;
        input.m_node = nullptr;
        input.m_type = input_socket.m_type;
        input.m_input_name = input_socket.m_name;

        node_inputs.push_back(input);
      }
    }

    // Prepare graph inputs
    result.m_socket_accessor =
        AnimNodeAccessorFactory("BlendTree", result.m_nodes[0]);
    result.m_socket_accessor->m_outputs =
        resource.m_nodes[1].m_socket_accessor->m_outputs;
    result.m_socket_accessor->m_inputs =
        resource.m_nodes[0].m_socket_accessor->m_inputs;

    // inputs
    int input_block_size = 0;
    std::vector<Socket>& graph_inputs = result.getGraphInputs();
    for (int i = 0; i < graph_inputs.size(); i++) {
      input_block_size += sizeof(void*);
    }
    result.m_input_buffer = new char[input_block_size];
    memset(result.m_input_buffer, 0, input_block_size);

    int input_block_offset = 0;
    for (int i = 0; i < graph_inputs.size(); i++) {
      if (graph_inputs[i].m_type == SocketType::SocketTypeAnimation) {
      }
      graph_inputs[i].m_value.ptr =
          (void*)&result.m_input_buffer[input_block_offset];
      input_block_offset += sizeof(void*);
    }

    // outputs
    int output_block_size = 0;
    std::vector<Socket>& graph_outputs = result.getGraphOutputs();
    for (int i = 0; i < graph_outputs.size(); i++) {
      output_block_size += graph_outputs[i].m_type_size;
    }
    result.m_output_buffer = new char[output_block_size];
    memset(result.m_output_buffer, 0, output_block_size);

    int output_block_offset = 0;
    for (int i = 0; i < graph_outputs.size(); i++) {
      if (graph_outputs[i].m_type == SocketType::SocketTypeAnimation) {
      }
      graph_outputs[i].m_value.ptr =
          (void*)&result.m_output_buffer[output_block_offset];
      output_block_offset += graph_outputs[i].m_type_size;
    }

    // connect the nodes
    for (int i = 0; i < resource.m_connections.size(); i++) {
      const AnimGraphConnection& connection = resource.m_connections[i];
      std::string source_node_type = "";
      std::string target_node_type = "";
      std::string source_node_name = "";
      std::string target_node_name = "";
      AnimNode* source_node = nullptr;
      AnimNode* target_node = nullptr;
      NodeSocketAccessorBase* source_node_accessor = nullptr;
      NodeSocketAccessorBase* target_node_accessor = nullptr;
      SocketType source_type;
      SocketType target_type;
      size_t source_socket_index = -1;
      size_t target_socket_index = -1;

      if (connection.m_source_node != nullptr) {
        size_t node_index = resource.getNodeIndex(*connection.m_source_node);
        if (node_index == -1) {
          std::cerr << "Could not find source node index." << std::endl;
          continue;
        }
        source_node = result.m_nodes[node_index];
        source_node_name = source_node->m_name;
        source_node_type = source_node->m_node_type_name;
        if (node_index == 1) {
          source_node_accessor = result.m_socket_accessor;
        } else {
          source_node_accessor =
              AnimNodeAccessorFactory(source_node_type, source_node);
        }
      }

      if (connection.m_target_node != nullptr) {
        size_t node_index = resource.getNodeIndex(*connection.m_target_node);
        if (node_index == -1) {
          std::cerr << "Could not find source node index." << std::endl;
          continue;
        }
        target_node = result.m_nodes[node_index];
        target_node_name = target_node->m_name;
        target_node_type = target_node->m_node_type_name;
        if (node_index == 0) {
          target_node_accessor = result.m_socket_accessor;
        } else {
          target_node_accessor =
              AnimNodeAccessorFactory(target_node_type, target_node);
        }
      }

      assert(source_node != nullptr);
      assert(target_node != nullptr);

      //
      // Map resource node sockets to graph instance node sockets
      //
      if (connection.m_source_socket == nullptr) {
        std::cerr << "Invalid source socket for connection " << i << "."
                  << std::endl;
        continue;
      }

      if (connection.m_target_socket == nullptr) {
        std::cerr << "Invalid source socket for connection " << i << "."
                  << std::endl;
        continue;
      }

      source_socket_index = source_node_accessor->GetOutputIndex(
          connection.m_source_socket->m_name);
      if (source_socket_index == -1) {
        std::cerr << "Invalid source socket "
                  << connection.m_source_socket->m_name << " for node "
                  << connection.m_source_node->m_name << "." << std::endl;
        continue;
      }
      const Socket* source_socket =
          &source_node_accessor->m_outputs[source_socket_index];

      target_socket_index = target_node_accessor->GetInputIndex(
          connection.m_target_socket->m_name);
      if (target_socket_index == -1) {
        std::cerr << "Invalid target socket "
                  << connection.m_target_socket->m_name << " for node "
                  << connection.m_target_node->m_name << "." << std::endl;
        continue;
      }
      const Socket* target_socket =
          &target_node_accessor->m_inputs[target_socket_index];

      if (source_socket->m_type != target_socket->m_type) {
        std::cerr << "Cannot connect sockets: invalid types!" << std::endl;
      }

      //
      // Wire up outputs to inputs.
      //
      (*source_socket->m_value.ptr_ptr) = target_socket->m_value.ptr;

      size_t target_node_index = target_node->m_index;

      std::vector<NodeInput>& node_inputs =
          result.m_node_inputs[target_node_index];
      for (int j = 0, n = node_inputs.size(); j < n; j++) {
        if (node_inputs[j].m_input_name == target_socket->m_name) {
          node_inputs[j].m_node = source_node;
        }
      }

      if (target_node_accessor != result.m_socket_accessor) {
        delete target_node_accessor;
      }

      if (source_node_accessor != result.m_socket_accessor) {
        delete source_node_accessor;
      }
    }

    result.updateOrderedNodes();
    result.reset();

    return result;
  }
};

#endif  //ANIMTESTBED_ANIMGRAPH_H