//
// Created by martin on 04.02.22.
//

#include "AnimGraphResource.h"

#include <fstream>

#include "3rdparty/json/json.hpp"

namespace AnimGraphCode {

using json = nlohmann::json;

//
// Socket <-> json
//
std::string sSocketTypeToStr(SocketType pin_type) {
  std::string result = "unknown";
  switch (pin_type) {
    case SocketType::SocketTypeBool:
      result = "Bool";
      break;
    case SocketType::SocketTypeAnimation:
      result = "Animation";
      break;
    case SocketType::SocketTypeFloat:
      result = "Float";
      break;
    case SocketType::SocketTypeVec3:
      result = "Vec3";
      break;
    case SocketType::SocketTypeQuat:
      result = "Quat";
      break;
    case SocketType::SocketTypeString:
      result = "String";
      break;
    default:
      result = "Unknown";
  }

  return result;
}

json sSocketToJson(const Socket& socket) {
  json result;
  result["name"] = socket.m_name;
  result["type"] = sSocketTypeToStr(socket.m_type);

  if (socket.m_value.ptr != nullptr) {
    if (socket.m_type == SocketType::SocketTypeBool) {
      result["value"] = *reinterpret_cast<bool*>(socket.m_value.ptr);
    } else if (socket.m_type == SocketType::SocketTypeAnimation) {
    } else if (socket.m_type == SocketType::SocketTypeFloat) {
      result["value"] = *reinterpret_cast<float*>(socket.m_value.ptr);
    } else if (socket.m_type == SocketType::SocketTypeVec3) {
      Vec3& vec3 = *reinterpret_cast<Vec3*>(socket.m_value.ptr);
      result["value"][0] = vec3[0];
      result["value"][1] = vec3[1];
      result["value"][2] = vec3[2];
    } else if (socket.m_type == SocketType::SocketTypeQuat) {
      Quat& quat = *reinterpret_cast<Quat*>(socket.m_value.ptr);
      result["value"][0] = quat[0];
      result["value"][1] = quat[1];
      result["value"][2] = quat[2];
      result["value"][3] = quat[3];
    } else if (socket.m_type == SocketType::SocketTypeString) {
      result["value"] = *reinterpret_cast<std::string*>(socket.m_value.ptr);
    } else {
      std::cerr << "Invalid socket type '" << static_cast<int>(socket.m_type)
                << "'." << std::endl;
    }
  }
  return result;
}

Socket sJsonToSocket(const json& json_data) {
  Socket result;
  result.m_type = SocketType::SocketTypeUndefined;
  result.m_value.ptr = nullptr;
  result.m_name = json_data["name"];

  std::string type_string = json_data["type"];

  if (type_string == "Bool") {
    result.m_type = SocketType::SocketTypeBool;
    result.m_type_size = sizeof(bool);
  } else if (type_string == "Animation") {
    result.m_type = SocketType::SocketTypeAnimation;
    result.m_type_size = sizeof(AnimData);
  } else if (type_string == "Float") {
    result.m_type = SocketType::SocketTypeFloat;
    result.m_type_size = sizeof(float);
  } else if (type_string == "Vec3") {
    result.m_type = SocketType::SocketTypeVec3;
    result.m_type_size = sizeof(Vec3);
  } else if (type_string == "Quat") {
    result.m_type = SocketType::SocketTypeQuat;
    result.m_type_size = sizeof(Quat);
  } else if (type_string == "String") {
    result.m_type = SocketType::SocketTypeString;
    result.m_type_size = sizeof(std::string);
  } else {
    std::cerr << "Invalid socket type '" << type_string << "'." << std::endl;
  }

  return result;
}

//
// AnimGraphNode <-> json
//
json sAnimGraphNodeToJson(const AnimNodeResource& node) {
  json result;

  result["name"] = node.m_name;
  result["type"] = "AnimNodeResource";
  result["node_type"] = node.m_type_name;

  for (size_t j = 0; j < 2; j++) {
    result["position"][j] = node.m_position[j];
  }

  for (size_t j = 0, n = node.m_socket_accessor->m_properties.size(); j < n;
       j++) {
    Socket& property = node.m_socket_accessor->m_properties[j];
    result["properties"][property.m_name] = sSocketToJson(property);
  }

  return result;
}

AnimNodeResource sAnimGraphNodeFromJson(const json& json_node) {
  AnimNodeResource result;

  result.m_name = json_node["name"];
  result.m_type_name = json_node["node_type"];
  result.m_position[0] = json_node["position"][0];
  result.m_position[1] = json_node["position"][1];

  result.m_anim_node = AnimNodeFactory(result.m_type_name);
  result.m_socket_accessor =
      AnimNodeAccessorFactory(result.m_type_name, result.m_anim_node);

  for (size_t j = 0, n = result.m_socket_accessor->m_properties.size(); j < n;
       j++) {
    Socket& property = result.m_socket_accessor->m_properties[j];
    json json_property = json_node["properties"][property.m_name];

    if (sSocketTypeToStr(property.m_type) == json_property["type"]) {
      if (property.m_type == SocketType::SocketTypeBool) {
        result.m_socket_accessor->SetProperty<bool>(
            property.m_name,
            json_property["value"]);
      } else if (property.m_type == SocketType::SocketTypeAnimation) {
      } else if (property.m_type == SocketType::SocketTypeFloat) {
        result.m_socket_accessor->SetProperty<float>(
            property.m_name,
            json_property["value"]);
      } else if (property.m_type == SocketType::SocketTypeVec3) {
        Vec3* property_vec3 = reinterpret_cast<Vec3*>(property.m_value.ptr);
        (*property_vec3)[0] = json_property["value"][0];
        (*property_vec3)[1] = json_property["value"][1];
        (*property_vec3)[2] = json_property["value"][2];
      } else if (property.m_type == SocketType::SocketTypeQuat) {
        Quat* property_quat = reinterpret_cast<Quat*>(property.m_value.ptr);
        (*property_quat)[0] = json_property["value"][0];
        (*property_quat)[1] = json_property["value"][1];
        (*property_quat)[2] = json_property["value"][2];
        (*property_quat)[3] = json_property["value"][3];
      } else if (property.m_type == SocketType::SocketTypeString) {
        result.m_socket_accessor->SetProperty<std::string>(
            property.m_name,
            json_property["value"]);
      } else {
        std::cerr << "Invalid type for property '" << property.m_name
                  << "'. Cannot parse json to type '"
                  << static_cast<int>(property.m_type) << std::endl;
        break;
      }
    } else {
      std::cerr << "Invalid type for property '" << property.m_name
                << "': expected " << sSocketTypeToStr(property.m_type)
                << " but got " << json_property["type"] << std::endl;
    }
  }

  return result;
}

//
// AnimGraphConnection <-> Json
//
json sAnimGraphConnectionToJson(const AnimGraphConnection& connection) {
  json result;

  result["type"] = "AnimGraphConnection";

  result["source_node_index"] = connection.m_source_node_index;
  result["source_socket_index"] = connection.m_source_socket_index;

  result["target_node_index"] = connection.m_target_node_index;
  result["target_socket_index"] = connection.m_target_socket_index;

  return result;
}

AnimGraphConnection sAnimGraphConnectionFromJson(const json& json_node) {
  AnimGraphConnection connection;

  connection.m_source_node_index = json_node["source_node_index"];
  connection.m_source_socket_index = json_node["source_socket_index"];

  connection.m_target_node_index = json_node["target_node_index"];
  connection.m_target_socket_index = json_node["target_socket_index"];

  return connection;
}

void AnimGraphResource::clear() {
  m_name = "";

  clearNodes();
  m_connections.clear();

  initGraphConnectors();
}

void AnimGraphResource::clearNodes() {
  for (size_t i = 0; i < m_nodes.size(); i++) {
    delete m_nodes[i].m_socket_accessor;
    m_nodes[i].m_socket_accessor = nullptr;
    delete m_nodes[i].m_anim_node;
    m_nodes[i].m_anim_node = nullptr;
  }
  m_nodes.clear();
}

void AnimGraphResource::initGraphConnectors() {
  m_nodes.push_back(AnimNodeResourceFactory("BlendTree"));
  m_nodes[0].m_name = "Outputs";
  m_nodes.push_back(AnimNodeResourceFactory("BlendTree"));
  m_nodes[1].m_name = "Inputs";
}

bool AnimGraphResource::saveToFile(const char* filename) const {
  json result;

  result["name"] = m_name;
  result["type"] = "AnimGraphResource";

  for (size_t i = 0; i < m_nodes.size(); i++) {
    const AnimNodeResource& node = m_nodes[i];
    result["nodes"][i] = sAnimGraphNodeToJson(node);
  }

  for (size_t i = 0; i < m_connections.size(); i++) {
    const AnimGraphConnection& connection = m_connections[i];
    result["connections"][i] = sAnimGraphConnectionToJson(connection);
  }

  // Graph inputs and outputs
  {
    const AnimNodeResource& graph_output_node = m_nodes[0];
    const std::vector<Socket> graph_inputs =
        graph_output_node.m_socket_accessor->m_inputs;
    for (size_t i = 0; i < graph_inputs.size(); i++) {
      result["nodes"][0]["inputs"][i] = sSocketToJson(graph_inputs[i]);
    }

    const AnimNodeResource& graph_input_node = m_nodes[1];
    const std::vector<Socket> graph_outputs =
        graph_input_node.m_socket_accessor->m_outputs;
    for (size_t i = 0; i < graph_outputs.size(); i++) {
      result["nodes"][1]["outputs"][i] = sSocketToJson(graph_outputs[i]);
    }
  }

  std::ofstream output_file;
  output_file.open(filename);
  output_file << to_string(result) << std::endl;
  output_file.close();

  return true;
}

bool AnimGraphResource::loadFromFile(const char* filename) {
  std::ifstream input_file;
  input_file.open(filename);
  std::stringstream buffer;
  buffer << input_file.rdbuf();

  json json_data = json::parse(buffer.str(), nullptr, false);
  if (json_data.is_discarded()) {
    std::cerr << "Error parsing json of file '" << filename << "'."
              << std::endl;
  }

  if (json_data["type"] != "AnimGraphResource") {
    std::cerr
        << "Invalid json object. Expected type 'AnimGraphResource' but got '"
        << json_data["type"] << "'." << std::endl;
  }

  clear();
  clearNodes();

  m_name = json_data["name"];
  for (size_t i = 0; i < json_data["nodes"].size(); i++) {
    const json& json_node = json_data["nodes"][i];
    if (json_node["type"] != "AnimNodeResource") {
      std::cerr
          << "Invalid json object. Expected type 'AnimNodeResource' but got '"
          << json_node["type"] << "'." << std::endl;
      return false;
    }

    AnimNodeResource node = sAnimGraphNodeFromJson(json_node);
    m_nodes.push_back(node);
  }

  for (size_t i = 0; i < json_data["connections"].size(); i++) {
    const json& json_connection = json_data["connections"][i];
    if (json_connection["type"] != "AnimGraphConnection") {
      std::cerr << "Invalid json object. Expected type 'AnimGraphConnection' "
                   "but got '"
                << json_connection["type"] << "'." << std::endl;
      return false;
    }

    AnimGraphConnection connection =
        sAnimGraphConnectionFromJson(json_connection);
    m_connections.push_back(connection);
  }

  const json& graph_outputs = json_data["nodes"][0]["inputs"];
  for (size_t i = 0; i < graph_outputs.size(); i++) {
    AnimNodeResource& graph_node = m_nodes[0];
    graph_node.m_socket_accessor->m_inputs.push_back(
        sJsonToSocket(graph_outputs[i]));
  }

  const json& graph_inputs = json_data["nodes"][1]["outputs"];
  for (size_t i = 0; i < graph_inputs.size(); i++) {
    AnimNodeResource& graph_node = m_nodes[1];
    graph_node.m_socket_accessor->m_outputs.push_back(
        sJsonToSocket(graph_inputs[i]));
  }

  return true;
}

void AnimGraph::UpdateOrderedNodes() {
  std::vector<int> node_index_stack;
  node_index_stack.push_back(0);

  m_ordered_nodes.clear();

  while (node_index_stack.size() > 0) {
    std::vector<AnimNodeInput>& node_inputs = m_node_inputs[node_index_stack.back()];
    node_index_stack.pop_back();

    for (size_t i = 0, n = node_inputs.size(); i < n; i++) {
      AnimNode* input_node = node_inputs[i].m_node;
      if (input_node == nullptr) {
        continue;
      }

      int input_node_index = getAnimNodeIndex(input_node);
      bool is_node_processed = false;
      for (size_t j = 0, m = m_ordered_nodes.size(); j < m; j++) {
        if (m_ordered_nodes[j] == input_node) {
          is_node_processed = true;
          break;
        }
      }

      if (is_node_processed) {
        continue;
      }

      m_ordered_nodes.push_back(input_node);
      node_index_stack.push_back(input_node_index);
    }
  }
}

void AnimGraph::MarkActiveNodes() {
  m_frame_counter++;

  // TODO: start from output and trigger updating of the frame counter.
}

void* AnimGraph::GetOutput(const std::string& name) const {
  Socket* socket = m_socket_accessor->FindInputSocket(name);
  if (socket == nullptr) {
    return nullptr;
  }

  return socket->m_value.ptr;
}

void* AnimGraph::GetInput(const std::string& name) const {
  Socket* socket = m_socket_accessor->FindOutputSocket(name);
  if (socket == nullptr) {
    return nullptr;
  }

  return *(socket->m_value.ptr_ptr);
}

}