// Copyright(C) 1999-2020, 2022 National Technology & Engineering Solutions
// of Sandia, LLC (NTESS).  Under the terms of Contract DE-NA0003525 with
// NTESS, the U.S. Government retains certain rights in this software.

#pragma once

#include "iotm_export.h"

// #######################  Start Clang Header Tool Managed Headers ########################
// clang-format off
#include <ctype.h>                                   // for toupper
#include <stddef.h>                                  // for size_t
#include <algorithm>                                 // for remove, etc
#include <iterator>                                  // for insert_iterator
#include <map>
#include <set>                                       // for set
#include <sstream>                                   // for operator<<, etc
#include <string>                                    // for basic_string, etc
#include <utility>                                   // for pair
#include <vector>                                    // for vector
#include <unordered_map>
#include <sstream>                       // for ostringstream
#include <iostream>
#include <functional>
#include <stdexcept>
#include <numeric>
#include <strings.h>

#include "Iotm_TextMeshFuncs.h"
#include "Iotm_TextMeshEntityGroup.h"

// clang-format on
// #######################   End Clang Header Tool Managed Headers  ########################
namespace Iotm {
  namespace text_mesh {

    using ErrorHandler = std::function<void(const std::ostringstream &)>;

    enum AssemblyType { ASSEMBLY, BLOCK, SIDESET, NODESET, INVALID_ASSEMBLY };

    inline std::ostream &operator<<(std::ostream &out, const AssemblyType &t)
    {
      switch (t) {
      case AssemblyType::ASSEMBLY: return out << "ASSEMBLY"; break;
      case AssemblyType::BLOCK: return out << "ELEMENT_BLOCK"; break;
      case AssemblyType::SIDESET: return out << "SIDESET"; break;
      case AssemblyType::NODESET: return out << "NODESET"; break;
      default: return out << "INVALID"; break;
      }
      return out << "INVALID[" << (unsigned)t << "]";
    }

    using AssemblyDataType = std::string;

    struct IOTM_EXPORT AssemblyData : public EntityGroupData<AssemblyDataType>
    {
      using DataType = AssemblyDataType;

      void         set_assembly_type(AssemblyType type_) { assemblyType = type_; }
      AssemblyType get_assembly_type() const { return assemblyType; }

    private:
      AssemblyType assemblyType = INVALID_ASSEMBLY;
    };

    template <typename EntityId> class Assemblies : public EntityGroup<AssemblyData>
    {
    public:
      using BaseClass = EntityGroup<AssemblyData>;

      Assemblies()
          : EntityGroup<AssemblyData>("ASSEMBLY", "ASSEMBLY_", {"BLOCK_", "SURFACE_", "NODELIST_"})
      {
      }

      bool is_cyclic(const std::string &assembly) const
      {
        initialize_graph();
        return check_for_cycle(assembly);
      }

      bool is_cyclic() const
      {
        for (const std::string &assembly : BaseClass::get_part_names())
          if (is_cyclic(assembly)) {
            return true;
          }

        return false;
      }

      std::vector<std::string> &&get_forward_traversal_list(const std::string &assembly) const
      {
        initialize_graph();
        fill_traversal(assembly);

        return std::move(m_traversalList);
      }

      std::vector<std::string> &&get_reverse_traversal_list(const std::string &assembly) const
      {
        initialize_graph();
        fill_traversal(assembly);
        std::reverse(m_traversalList.begin(), m_traversalList.end());

        return std::move(m_traversalList);
      }

    private:
      // Walk the tree without cyclic dependency
      void fill_traversal(const std::string &assembly) const
      {
        const AssemblyData *assemblyData = BaseClass::get_group_data(assembly);
        if (nullptr != assemblyData) {
          if (m_visitedNodes[assembly] == false) {
            m_visitedNodes[assembly] = true;
            m_traversalList.push_back(assembly);

            if (assemblyData->get_assembly_type() == AssemblyType::ASSEMBLY) {
              for (const std::string &member : assemblyData->data) {
                fill_traversal(member);
              }
            }
          }
        }
      }

      bool check_for_cycle(const std::string &assembly) const
      {
        bool                isCyclic     = false;
        const AssemblyData *assemblyData = BaseClass::get_group_data(assembly);
        if (nullptr != assemblyData) {
          if (m_visitedNodes[assembly] == true) {
            isCyclic = true;
          }
          else {
            m_visitedNodes[assembly] = true;

            if (assemblyData->get_assembly_type() == AssemblyType::ASSEMBLY) {
              for (const std::string &member : assemblyData->data) {
                isCyclic |= check_for_cycle(member);
              }
            }
          }
        }
        return isCyclic;
      }

      void initialize_graph() const
      {
        m_traversalList.clear();
        m_traversalList.reserve(BaseClass::size());

        for (const std::string &name : BaseClass::get_part_names()) {
          m_visitedNodes[name] = false;
        }
      }

      mutable std::unordered_map<std::string, bool> m_visitedNodes;
      mutable std::vector<std::string>              m_traversalList;
    };

    class IOTM_EXPORT AssemblyParser
    {
    public:
      AssemblyParser() : m_assemblyType(INVALID_ASSEMBLY)
      {
        ErrorHandler errorHandler = [](const std::ostringstream &errmsg) {
          default_error_handler(errmsg);
        };
        set_error_handler(errorHandler);
      }

      void set_error_handler(ErrorHandler errorHandler) { m_errorHandler = errorHandler; }

      std::string get_name() { return m_name; }

      AssemblyType get_assembly_type() const { return m_assemblyType; }

      const std::vector<std::string> &get_assembly_data() { return m_members; }

      // Expected format for assembly string data is:
      // "name=<name>; type=<assembly|block|sideset|nodeset>; member=member_1,...,member_n;"
      // Only type keyword is required
      void parse(const std::string &parseData)
      {
        auto options = get_tokens(parseData, ";");

        for (const auto &option : options) {
          parse_option_group(option);
        }
      }

      void verify_parse() const
      {
        if (m_assemblyType == INVALID_ASSEMBLY) {
          std::ostringstream errmsg;
          errmsg << "Error!  Assembly with name: " << m_name << " does not have a defined type.";
          m_errorHandler(errmsg);
        }
      }

    private:
      void parse_option(std::string optionName, const std::string &optionValue)
      {
        convert_to_lower_case(optionName);

        if (optionName == "name") {
          parse_name(optionValue);
        }
        else if (optionName == "type") {
          parse_assembly_type(optionValue);
        }
        else if (optionName == "member") {
          parse_assembly_members(optionValue);
        }
        else {
          std::ostringstream errmsg;
          errmsg << "Unrecognized assembly option: " << optionName;
          m_errorHandler(errmsg);
        }
      }

      void parse_option_group(const std::string &option)
      {
        if (!option.empty()) {
          auto optionTokens = get_tokens(option, "=");

          if (optionTokens.size() != 2) {
            std::ostringstream errmsg;
            errmsg << "Unrecognized assembly option: " << option;
            m_errorHandler(errmsg);
          }

          parse_option(optionTokens[0], optionTokens[1]);
        }
      }

      void parse_name(const std::string &data) { m_name = data; }

      void parse_assembly_type(std::string type)
      {
        convert_to_lower_case(type);

        if (type == "assembly") {
          m_assemblyType = ASSEMBLY;
        }
        else if (type == "block") {
          m_assemblyType = BLOCK;
        }
        else if (type == "sideset") {
          m_assemblyType = SIDESET;
        }
        else if (type == "nodeset") {
          m_assemblyType = NODESET;
        }
        else {
          std::ostringstream errmsg;
          errmsg << "Unrecognized assembly type: " << type;
          m_errorHandler(errmsg);
        }
      }

      void parse_assembly_members(const std::string &data)
      {
        std::vector<std::string> assemblyData = get_tokens(data, ",");
        for (std::string &member : assemblyData) {
          convert_to_upper_case(member);
        }

        m_members = assemblyData;
      }

      std::vector<std::string> m_members{};
      std::string              m_name{};
      AssemblyType             m_assemblyType{INVALID_ASSEMBLY};
      ErrorHandler             m_errorHandler;
    };

  } // namespace text_mesh
} // namespace Iotm