text: // Copyright (c) 2016-2021 Thomas Fussell
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE
  //
  // @license: http://www.opensource.org/licenses/mit-license.php
  // @author: see AUTHORS file
  
  #pragma once
  
  #include <algorithm>
  #include <string>
  #include <unordered_map>
  
  #include <detail/default_case.hpp>
  #include <detail/external/include_libstudxml.hpp>
  #include <xlnt/packaging/relationship.hpp>
  #include <xlnt/styles/alignment.hpp>
  #include <xlnt/styles/border.hpp>
  #include <xlnt/styles/font.hpp>
  #include <xlnt/styles/fill.hpp>
  #include <xlnt/utils/exceptions.hpp>
  #include <xlnt/utils/variant.hpp>
  #include <xlnt/worksheet/pane.hpp>
  #include <xlnt/worksheet/page_setup.hpp>
  #include <xlnt/workbook/metadata_property.hpp>
  
  namespace xlnt {
  namespace detail {
  
  /// <summary>
  /// Returns the string representation of the underline style.
  /// </summary>
  std::string to_string(font::underline_style underline_style);
  
  /// <summary>
  /// Returns the string representation of the relationship type.
  /// </summary>
  std::string to_string(relationship_type t);
  
  std::string to_string(pattern_fill_type fill_type);
  
  std::string to_string(gradient_fill_type fill_type);
  
  std::string to_string(border_style border_style);
  
  std::string to_string(vertical_alignment vertical_alignment);
  
  std::string to_string(horizontal_alignment horizontal_alignment);
  
  std::string to_string(border_side side);
  
  std::string to_string(core_property prop);
  
  std::string to_string(extended_property prop);
  
  std::string to_string(variant::type type);
  
  std::string to_string(pane_corner corner);
  
  std::string to_string(target_mode mode);
  
  std::string to_string(pane_state state);
  
  std::string to_string(orientation state);
  
  template<typename T>
  static T from_string(const std::string &string_value);
  
  template<>
  font::underline_style from_string(const std::string &string)
  {
      if (string == "double") return font::underline_style::double_;
      if (string == "doubleAccounting") return font::underline_style::double_accounting;
      if (string == "single") return font::underline_style::single;
      if (string == "singleAccounting") return font::underline_style::single_accounting;
      if (string == "none") return font::underline_style::none;
  
      default_case(font::underline_style::none);
  }
  
  template<>
  relationship_type from_string(const std::string &string)
  {
      if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument")
          return relationship_type::office_document;
      else if (string == "http://schemas.openxmlformats.org/package/2006/relationships/metadata/thumbnail")
          return relationship_type::thumbnail;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/calcChain")
          return relationship_type::calculation_chain;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties")
          return relationship_type::extended_properties;
      else if (string == "http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties"
          || string == "http://schemas.openxmlformats.org/officedocument/2006/relationships/metadata/core-properties")
          return relationship_type::core_properties;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet")
          return relationship_type::worksheet;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings")
          return relationship_type::shared_string_table;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles")
          return relationship_type::stylesheet;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme")
          return relationship_type::theme;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/hyperlink")
          return relationship_type::hyperlink;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/chartsheet")
          return relationship_type::chartsheet;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/comments")
          return relationship_type::comments;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/vmlDrawing")
          return relationship_type::vml_drawing;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/custom-properties")
          return relationship_type::custom_properties;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/printerSettings")
          return relationship_type::printer_settings;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/connections")
          return relationship_type::connections;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/customProperty")
          return relationship_type::custom_property;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/customXmlMappings")
          return relationship_type::custom_xml_mappings;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/dialogsheet")
          return relationship_type::dialogsheet;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/drawing")
          return relationship_type::drawings;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/externalLinkPath")
          return relationship_type::external_workbook_references;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/pivotTable")
          return relationship_type::pivot_table;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/pivotCacheDefinition")
          return relationship_type::pivot_table_cache_definition;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/pivotCacheRecords")
          return relationship_type::pivot_table_cache_records;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/queryTable")
          return relationship_type::query_table;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/revisionHeaders")
          return relationship_type::shared_workbook_revision_headers;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedWorkbook")
          return relationship_type::shared_workbook;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/revisionLog")
          return relationship_type::revision_log;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/usernames")
          return relationship_type::shared_workbook_user_data;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/tableSingleCells")
          return relationship_type::single_cell_table_definitions;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/table")
          return relationship_type::table_definition;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/volatileDependencies")
          return relationship_type::volatile_dependencies;
      else if (string == "http://schemas.microsoft.com/office/2006/relationships/vbaProject")
          return relationship_type::vbaproject;
      else if (string == "http://schemas.openxmlformats.org/officeDocument/2006/relationships/image")
          return relationship_type::image;
  
      // ECMA 376-4 Part 1 Section 9.1.7 says consumers shall not fail to load
      // a document with unknown relationships.
      return relationship_type::unknown;
  }
  
  template<>
  pattern_fill_type from_string(const std::string &string)
  {
  #pragma clang diagnostic push
  #pragma clang diagnostic ignored "-Wexit-time-destructors"
      static std::unordered_map<std::string, pattern_fill_type> patternFill {
          {"darkdown", pattern_fill_type::darkdown },
          { "darkgray", pattern_fill_type::darkgray },
          { "darkgrid", pattern_fill_type::darkgrid },
          { "darkhorizontal", pattern_fill_type::darkhorizontal },
          { "darktrellis", pattern_fill_type::darktrellis },
          { "darkup", pattern_fill_type::darkup },
          { "darkvertical", pattern_fill_type::darkvertical },
          { "gray0625", pattern_fill_type::gray0625 },
          { "gray125", pattern_fill_type::gray125 },
          { "lightdown", pattern_fill_type::lightdown },
          { "lightgray", pattern_fill_type::lightgray },
          { "lightgrid", pattern_fill_type::lightgrid },
          { "lighthorizontal", pattern_fill_type::lighthorizontal },
          { "lighttrellis", pattern_fill_type::lighttrellis },
          { "lightup", pattern_fill_type::lightup },
          { "lightvertical", pattern_fill_type::lightvertical },
          { "mediumgray", pattern_fill_type::mediumgray },
          { "none", pattern_fill_type::none },
          { "solid", pattern_fill_type::solid }
      };
  #pragma clang diagnostic pop
      
      auto toLower = [](std::string str) {
          auto bg = std::begin (str);
          auto en = std::end (str);
          std::transform(bg, en, bg, 
                         [](char c) {
                          // static cast to avoid int -> char narrowing warning
                             return static_cast<char>(tolower(c)); 
                         });
  
          return str;
      };
  
      auto patternLookup = [](const std::string& key) {
          auto entry = patternFill.find (key);
          if (entry != std::end (patternFill)) {
              return entry->second;
          }
          else {
              // Note: there won't be an error if there is an unsupported pattern
              return pattern_fill_type::none;
          }
      };
  
      std::string lowerString {toLower (string) };
  
      return patternLookup (lowerString);
  }
  
  template<>
  gradient_fill_type from_string(const std::string &string)
  {
      if (string == "linear") return gradient_fill_type::linear;
      else if (string == "path") return gradient_fill_type::path;
  
      default_case(gradient_fill_type::linear);
  }
  
  template<>
  border_style from_string(const std::string &string)
  {
      if (string == "dashDot") return border_style::dashdot;
      else if (string == "dashDotDot") return border_style::dashdotdot;
      else if (string == "dashed") return border_style::dashed;
      else if (string == "dotted") return border_style::dotted;
      else if (string == "double") return border_style::double_;
      else if (string == "hair") return border_style::hair;
      else if (string == "medium") return border_style::medium;
      else if (string == "mediumDashdot") return border_style::mediumdashdot;
      else if (string == "mediumDashDotDot") return border_style::mediumdashdotdot;
      else if (string == "mediumDashed") return border_style::mediumdashed;
      else if (string == "none") return border_style::none;
      else if (string == "slantDashDot") return border_style::slantdashdot;
      else if (string == "thick") return border_style::thick;
      else if (string == "thin") return border_style::thin;
  
      default_case(border_style::dashdot);
  }
  
  template<>
  vertical_alignment from_string(const std::string &string)
  {
      if (string == "bottom") return vertical_alignment::bottom;
      else if (string == "center") return vertical_alignment::center;
      else if (string == "distributed") return vertical_alignment::distributed;
      else if (string == "justify") return vertical_alignment::justify;
      else if (string == "top") return vertical_alignment::top;
  
      default_case(vertical_alignment::top);
  }
  
  template<>
  horizontal_alignment from_string(const std::string &string)
  {
      if (string == "center") return horizontal_alignment::center;
      else if (string == "centerContinuous") return horizontal_alignment::center_continuous;
      else if (string == "distributed") return horizontal_alignment::distributed;
      else if (string == "fill") return horizontal_alignment::fill;
      else if (string == "general") return horizontal_alignment::general;
      else if (string == "justify") return horizontal_alignment::justify;
      else if (string == "left") return horizontal_alignment::left;
      else if (string == "right") return horizontal_alignment::right;
  
      default_case(horizontal_alignment::general);
  }
  template<>
  border_side from_string(const std::string &string)
  {
      if (string == "bottom") return border_side::bottom;
      else if (string == "diagonal") return border_side::diagonal;
      else if (string == "right") return border_side::end;
      else if (string == "horizontal") return border_side::horizontal;
      else if (string == "left") return border_side::start;
      else if (string == "top") return border_side::top;
      else if (string == "vertical") return border_side::vertical;
  
      default_case(border_side::bottom);
  }
  
  template<>
  core_property from_string(const std::string &string)
  {
      if (string == "category") return core_property::category;
      else if (string == "contentStatus") return core_property::content_status;
      else if (string == "created") return core_property::created;
      else if (string == "creator") return core_property::creator;
      else if (string == "description") return core_property::description;
      else if (string == "identifier") return core_property::identifier;
      else if (string == "keywords") return core_property::keywords;
      else if (string == "language") return core_property::language;
      else if (string == "lastModifiedBy") return core_property::last_modified_by;
      else if (string == "lastPrinted") return core_property::last_printed;
      else if (string == "modified") return core_property::modified;
      else if (string == "revision") return core_property::revision;
      else if (string == "subject") return core_property::subject;
      else if (string == "title") return core_property::title;
      else if (string == "version") return core_property::version;
  
      default_case(core_property::category);
  }
  
  template<>
  extended_property from_string(const std::string &string)
  {
      if (string == "Application") return extended_property::application;
      else if (string == "AppVersion") return extended_property::app_version;
      else if (string == "Characters") return extended_property::characters;
      else if (string == "CharactersWithSpaces") return extended_property::characters_with_spaces;
      else if (string == "Company") return extended_property::company;
      else if (string == "DigSig") return extended_property::dig_sig;
      else if (string == "DocSecurity") return extended_property::doc_security;
      else if (string == "HeadingPairs") return extended_property::heading_pairs;
      else if (string == "HiddenSlides") return extended_property::hidden_slides;
      else if (string == "HyperlinksChanged") return extended_property::hyperlinks_changed;
      else if (string == "HyperlinkBase") return extended_property::hyperlink_base;
      else if (string == "HLinks") return extended_property::h_links;
      else if (string == "Lines") return extended_property::lines;
      else if (string == "LinksUpToDate") return extended_property::links_up_to_date;
      else if (string == "Manager") return extended_property::manager;
      else if (string == "MMClips") return extended_property::m_m_clips;
      else if (string == "Notes") return extended_property::notes;
      else if (string == "Pages") return extended_property::pages;
      else if (string == "Paragraphs") return extended_property::paragraphs;
      else if (string == "PresentationFormat") return extended_property::presentation_format;
      else if (string == "ScaleCrop") return extended_property::scale_crop;
      else if (string == "SharedDoc") return extended_property::shared_doc;
      else if (string == "Slides") return extended_property::slides;
      else if (string == "Template") return extended_property::template_;
      else if (string == "TitlesOfParts") return extended_property::titles_of_parts;
      else if (string == "TotalTime") return extended_property::total_time;
      else if (string == "Words") return extended_property::words;
  
      default_case(extended_property::application);
  }
  
  /*
  template<>
  variant::type from_string(const std::string &string)
  {
      if (string == "bool") return variant::type::boolean;
      else if (string == "date") return variant::type::date;
      else if (string == "i4") return variant::type::i4;
      else if (string == "lpstr") return variant::type::lpstr;
      else if (string == "null") return variant::type::null;
      else if (string == "vector") return variant::type::vector;
  
      default_case(variant::type::null);
  }
  */
  
  template<>
  xlnt::pane_state from_string(const std::string &string)
  {
      if (string == "frozen") return xlnt::pane_state::frozen;
      else if (string == "frozenSplit") return xlnt::pane_state::frozen_split;
      else if (string == "split") return xlnt::pane_state::split;
  
      default_case(xlnt::pane_state::frozen);
  }
  
  template<>
  target_mode from_string(const std::string &string)
  {
      if (string == "Internal") return target_mode::internal;
      else if (string == "External") return target_mode::external;
  
      default_case(target_mode::internal);
  }
  
  template<>
  pane_corner from_string(const std::string &string)
  {
      if (string == "bottomLeft") return pane_corner::bottom_left;
      else if (string == "bottomRight") return pane_corner::bottom_right;
      else if (string == "topLeft") return pane_corner::top_left;
      else if (string == "topRight") return pane_corner::top_right;
  
      default_case(pane_corner::bottom_left);
  }
  
  template <>
  orientation from_string(const std::string &string)
  {
      if (string == "default") return orientation::default_orientation;
      else if (string == "landscape") return orientation::landscape;
      else if (string == "portrait") return orientation::portrait;
      default_case(orientation::default_orientation);
  }
  
  } // namespace detail
  } // namespace xlnt
  
  namespace xml {
  
  template <>
  struct value_traits<xlnt::font::underline_style>
  {
      static xlnt::font::underline_style parse(std::string underline_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::font::underline_style>(underline_string);
      }
  
      static std::string serialize(xlnt::font::underline_style underline_style, const serializer &)
      {
          return xlnt::detail::to_string(underline_style);
      }
  };
  
  template <>
  struct value_traits<xlnt::relationship_type>
  {
      static xlnt::relationship_type parse(std::string relationship_type_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::relationship_type>(relationship_type_string);
      }
  
      static std::string serialize(xlnt::relationship_type type, const serializer &)
      {
          return xlnt::detail::to_string(type);
      }
  };
  
  template <>
  struct value_traits<xlnt::pattern_fill_type>
  {
      static xlnt::pattern_fill_type parse(std::string fill_type_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::pattern_fill_type>(fill_type_string);
      }
  
      static std::string serialize(xlnt::pattern_fill_type fill_type, const serializer &)
      {
          return xlnt::detail::to_string(fill_type);
      }
  };
  
  template <>
  struct value_traits<xlnt::gradient_fill_type>
  {
      static xlnt::gradient_fill_type parse(std::string fill_type_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::gradient_fill_type>(fill_type_string);
      }
  
      static std::string serialize(xlnt::gradient_fill_type fill_type, const serializer &)
      {
          return xlnt::detail::to_string(fill_type);
      }
  };
  
  template <>
  struct value_traits<xlnt::border_style>
  {
      static xlnt::border_style parse(std::string style_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::border_style>(style_string);
      }
  
      static std::string
      serialize (xlnt::border_style style, const serializer &)
      {
          return xlnt::detail::to_string(style);
      }
  };
  
  template <>
  struct value_traits<xlnt::vertical_alignment>
  {
      static xlnt::vertical_alignment parse(std::string alignment_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::vertical_alignment>(alignment_string);
      }
  
      static std::string serialize (xlnt::vertical_alignment alignment, const serializer &)
      {
          return xlnt::detail::to_string(alignment);
      }
  };
  
  template <>
  struct value_traits<xlnt::horizontal_alignment>
  {
      static xlnt::horizontal_alignment parse(std::string alignment_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::horizontal_alignment>(alignment_string);
      }
  
      static std::string serialize(xlnt::horizontal_alignment alignment, const serializer &)
      {
          return xlnt::detail::to_string(alignment);
      }
  };
  
  template <>
  struct value_traits<xlnt::border_side>
  {
      static xlnt::border_side parse(std::string side_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::border_side>(side_string);
      }
  
      static std::string serialize(xlnt::border_side side, const serializer &)
      {
          return xlnt::detail::to_string(side);
      }
  };
  
  template <>
  struct value_traits<xlnt::target_mode>
  {
      static xlnt::target_mode parse(std::string mode_string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::target_mode>(mode_string);
      }
  
      static std::string serialize(xlnt::target_mode mode, const serializer &)
      {
          return xlnt::detail::to_string(mode);
      }
  };
  
  template <>
  struct value_traits<xlnt::pane_state>
  {
      static xlnt::pane_state parse(std::string string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::pane_state>(string);
      }
  
      static std::string serialize(xlnt::pane_state state, const serializer &)
      {
          return xlnt::detail::to_string(state);
      }
  };
  
  template <>
  struct value_traits<xlnt::pane_corner>
  {
      static xlnt::pane_corner parse(std::string string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::pane_corner>(string);
      }
  
      static std::string serialize(xlnt::pane_corner corner, const serializer &)
      {
          return xlnt::detail::to_string(corner);
      }
  };
  
  template <>
  struct value_traits<xlnt::core_property>
  {
      static xlnt::core_property parse(std::string string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::core_property>(string);
      }
  
      static std::string serialize(xlnt::core_property corner, const serializer &)
      {
          return xlnt::detail::to_string(corner);
      }
  };
  
  template <>
  struct value_traits<xlnt::extended_property>
  {
      static xlnt::extended_property parse(std::string string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::extended_property>(string);
      }
  
      static std::string serialize(xlnt::extended_property corner, const serializer &)
      {
          return xlnt::detail::to_string(corner);
      }
  };
  
  template <>
  struct value_traits<xlnt::orientation>
  {
      static xlnt::orientation parse(std::string string, const parser &)
      {
          return xlnt::detail::from_string<xlnt::orientation>(string);
      }
  
      static std::string serialize(xlnt::orientation orientation, const serializer &)
      {
          return xlnt::detail::to_string(orientation);
      }
  };
  
  } // namespace xml
  
  
  