/******************************************************************************
Copyright (c) 2018 Advanced Micro Devices, Inc. All rights reserved.

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.
*******************************************************************************/

#ifndef SRC_XML_XML_H_
#define SRC_XML_XML_H_

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <fstream>
#include <iostream>
#include <map>
#include <string>
#include <vector>

namespace xml {

class Xml {
 public:
  typedef std::vector<char> token_t;

  struct level_t;
  typedef std::vector<level_t*> node_vect_t;
  typedef std::list<level_t*> node_list_t;

  typedef node_vect_t nodes_t;
  typedef std::map<std::string, std::string> opts_t;
  struct level_t {
    std::string tag;
    nodes_t nodes;
    opts_t opts;
    const level_t* copy;
  };
  typedef std::vector<level_t*> nodes_vec_t;
  typedef std::map<std::string, nodes_vec_t> map_t;

  enum { DECL_STATE, BODY_STATE };

  static Xml* Create(const std::string& file_name, const Xml* obj = NULL) {
    Xml* xml = new Xml(file_name, obj);
    if (xml != NULL) {
      if (xml->Init() == false) {
        delete xml;
        xml = NULL;
      } else {
        const std::size_t pos = file_name.rfind('/');
        const std::string path = (pos != std::string::npos) ? file_name.substr(0, pos + 1) : "";

        xml->PreProcess();
        nodes_t incl_nodes;
        for (auto* node : xml->GetNodes("top.include")) {
          if (node->opts.find("touch") == node->opts.end()) {
            node->opts["touch"] = "";
            incl_nodes.push_back(node);
          }
        }
        for (auto* incl : incl_nodes) {
          const std::string& incl_name = path + incl->opts["file"];
          Xml* ixml = Create(incl_name, xml);
          if (ixml == NULL) {
            delete xml;
            xml = NULL;
            break;
          } else {
            delete ixml;
          }
        }
        if (xml) {
          xml->Process();
        }
      }
    }

    return xml;
  }

  static void Destroy(Xml* xml) { delete xml; }

  std::string GetName() { return file_name_; }

  void AddExpr(const std::string& full_tag, const std::string& name, const std::string& expr) {
    const std::size_t pos = full_tag.rfind('.');
    const std::size_t pos1 = (pos == std::string::npos) ? 0 : pos + 1;
    const std::string level_tag = full_tag.substr(pos1);
    level_t* level = new level_t;
    (*map_)[full_tag].push_back(level);
    level->tag = level_tag;
    level->opts["name"] = name;
    level->opts["expr"] = expr;
  }

  void AddConst(const std::string& full_tag, const std::string& name, const uint64_t& val) {
    std::ostringstream oss;
    oss << val;
    AddExpr(full_tag, name, oss.str());
  }

  nodes_t GetNodes(const std::string& global_tag) { return (*map_)[global_tag]; }

  template <class F> F ForEach(const F& f_i) {
    F f = f_i;
    if (map_) {
      for (auto& entry : *map_) {
        for (auto node : entry.second) {
          if (f.fun(entry.first, node) == false) break;
        }
      }
    }
    return f;
  }

  template <class F> F ForEach(const F& f_i) const {
    F f = f_i;
    if (map_) {
      for (auto& entry : *map_) {
        for (auto node : entry.second) {
          if (f.fun(entry.first, node) == false) break;
        }
      }
    }
    return f;
  }

  struct print_func {
    bool fun(const std::string& global_tag, level_t* node) {
      std::cout << global_tag << ":" << std::endl;
      for (auto& opt : node->opts) {
        std::cout << global_tag << "." << opt.first << " = " << opt.second << std::endl;
      }
      return true;
    }
  };

  void Print() const {
    std::cout << "XML file '" << file_name_ << "':" << std::endl;
    ForEach(print_func());
  }

 private:
  Xml(const std::string& file_name, const Xml* obj)
      : file_name_(file_name),
        file_line_(0),
        data_size_(0),
        index_(0),
        state_(BODY_STATE),
        comment_(false),
        included_(false),
        level_(NULL),
        map_(NULL) {
    if (obj != NULL) {
      map_ = obj->map_;
      level_ = obj->level_;
      included_ = true;
    }
  }

  struct delete_func {
    bool fun(const std::string&, level_t* node) {
      delete node;
      return true;
    }
  };

  ~Xml() {
    if (included_ == false) {
      ForEach(delete_func());
      delete map_;
    }
  }

  bool Init() {
    fd_ = open(file_name_.c_str(), O_RDONLY);
    if (fd_ == -1) {
      // perror((std::string("open XML file ") + file_name_).c_str());
      return false;
    }

    if (map_ == NULL) {
      map_ = new map_t;
      if (map_ == NULL) return false;
      AddLevel("top");
    }

    return true;
  }

  void PreProcess() {
    uint32_t ind = 0;
    char buf[kBufSize];
    bool error = false;

    while (1) {
      const uint32_t pos = lseek(fd_, 0, SEEK_CUR);
      uint32_t size = read(fd_, buf, kBufSize);
      if (size <= 0) break;
      buf[size - 1] = '\0';

      if (strncmp(buf, "#include \"", 10) == 0) {
        for (ind = 0; (ind < size) && (buf[ind] != '\n'); ++ind) {}
        if (ind < size) {
          buf[ind] = '\0';
          size = ind;
          lseek(fd_, pos + ind + 1, SEEK_SET);
        }

        for (ind = 10; (ind < size) && (buf[ind] != '"'); ++ind) {}
        if (ind == size) {
          error = true;
          break;
        }
        buf[ind] = '\0';

        AddLevel("include");
        AddOption("file", &buf[10]);
        UpLevel();
      }
    }

    if (error) {
      fprintf(stderr, "XML PreProcess failed, line '%s'\n", buf);
      abort();
    }

    lseek(fd_, 0, SEEK_SET);
  }

  void Process() {
    token_t remainder;

    while (1) {
      token_t token = (remainder.size()) ? remainder : NextToken();
      remainder.clear();

      // token_t token1 = token;
      // token1.push_back('\0');
      // std::cout << ">>> " << &token1[0] << std::endl;

      // End of file
      if (token.size() == 0) break;

      switch (state_) {
        case BODY_STATE:
          if (token[0] == '<') {
            bool node_begin = true;
            unsigned ind = 1;
            if (token[1] == '/') {
              node_begin = false;
              ++ind;
            }

            unsigned i = ind;
            while (i < token.size()) {
              if (token[i] == '>') break;
              ++i;
            }
            for (unsigned j = i + 1; j < token.size(); ++j) remainder.push_back(token[j]);

            if (i == token.size()) {
              if (node_begin)
                state_ = DECL_STATE;
              else
                BadFormat(token);
              token.push_back('\0');
            } else {
              token[i] = '\0';
            }

            const char* tag = &token[ind];
            if (node_begin) {
              AddLevel(tag);
            } else {
              Inherit(GetOption("base"));

              if (strncmp(CurrentLevel().c_str(), tag, strlen(tag)) != 0) {
                token.back() = '>';
                BadFormat(token);
              }
              UpLevel();
            }
          } else {
            BadFormat(token);
          }
          break;
        case DECL_STATE:
          if (token[0] == '>') {
            state_ = BODY_STATE;
            for (unsigned j = 1; j < token.size(); ++j) remainder.push_back(token[j]);
            continue;
          } else {
            token.push_back('\0');
            unsigned j = 0;
            for (j = 0; j < token.size(); ++j)
              if (token[j] == '=') break;
            if (j == token.size()) BadFormat(token);
            token[j] = '\0';
            const std::string key = &token[0];
            const std::string value = &token[j + 1];
            AddOption(key, value);
          }
          break;
        default:
          std::cout << "XML parser error: wrong state: " << state_ << std::endl;
          abort();
      }
    }
  }

  bool SpaceCheck() const {
    bool cond = ((buffer_[index_] == ' ') || (buffer_[index_] == '\t'));
    return cond;
  }

  bool LineEndCheck() {
    bool found = false;
    if (buffer_[index_] == '\n') {
      buffer_[index_] = ' ';
      ++file_line_;
      found = true;
      comment_ = false;
    } else if (comment_ || (buffer_[index_] == '#')) {
      found = true;
      comment_ = true;
    }
    return found;
  }

  token_t NextToken() {
    token_t token;
    bool in_string = false;
    bool special_symb = false;

    while (1) {
      if (data_size_ == 0) {
        data_size_ = read(fd_, buffer_, kBufSize);
        if (data_size_ <= 0) break;
      }

      if (token.empty()) {
        while ((index_ < data_size_) && (SpaceCheck() || LineEndCheck())) {
          ++index_;
        }
      }
      while ((index_ < data_size_) && (in_string || !(SpaceCheck() || LineEndCheck()))) {
        const char symb = buffer_[index_];
        bool skip_symb = false;

        switch (symb) {
          case '\\':
            if (special_symb) {
              special_symb = false;
            } else {
              special_symb = true;
              skip_symb = true;
            }
            break;
          case '"':
            if (special_symb) {
              special_symb = false;
            } else {
              in_string = !in_string;
              if (!in_string) {
                buffer_[index_] = ' ';
                --index_;
              }
              skip_symb = true;
            }
            break;
        }

        if (!skip_symb) token.push_back(symb);
        ++index_;
      }

      if (index_ == data_size_) {
        index_ = 0;
        data_size_ = 0;
      } else {
        if (special_symb || in_string) BadFormat(token);
        break;
      }
    }

    return token;
  }

  void BadFormat(token_t token) {
    token.push_back('\0');
    std::cout << "Error: " << file_name_ << ", line " << file_line_ << ", bad XML token '"
              << &token[0] << "'" << std::endl;
    abort();
  }

  void AddLevel(const std::string& tag) {
    level_t* level = new level_t{};
    level->tag = tag;
    if (level_) {
      level_->nodes.push_back(level);
      stack_.push_back(level_);
    }
    level_ = level;

    std::string global_tag = GlobalTag(tag);
    (*map_)[global_tag].push_back(level_);
  }

  void UpLevel() {
    level_ = stack_.back();
    stack_.pop_back();
  }

  void Copy(const level_t* from, level_t* to) {
    level_t* level = to;
    if (level == NULL) {
      AddLevel(from->tag);
      level = level_;
    }
    level->copy = from;
    level->opts = from->opts;

    for (auto node : from->nodes) {
      bool found = false;
      const std::string name = GetOption("name", node);
      const std::string global_tag = GlobalTag(level->tag) + "." + node->tag;
      for (auto item : (*map_)[global_tag]) {
        if ((name == GetOption("name", item)) || (node == item->copy)) {
          found = true;
          break;
        }
      }
      if (found == false) Copy(node, NULL);
    }

    if (to == NULL) UpLevel();
  }

  void Inherit(const std::string& tag) {
    if (!tag.empty()) {
      const std::string global_tag = GlobalTag(tag);
      auto it = map_->find(global_tag);
      if (it == map_->end()) {
        fprintf(stderr, "Node \"%s\": Base not found \"%s\"\n", level_->tag.c_str(), tag.c_str());
        abort();
      }
      for (auto node : it->second) {
        Copy(node, level_);
      }
    }
  }

  std::string CurrentLevel() const { return level_->tag; }

  std::string GlobalTag(const std::string& tag) const {
    std::string global_tag;
    for (level_t* level : stack_) {
      global_tag += level->tag + ".";
    }
    global_tag += tag;
    return global_tag;
  }

  void AddOption(const std::string& key, const std::string& value) {
    level_->opts[key] = value;
  }
  std::string GetOption(const std::string& key, const level_t* level = NULL) {
    level = (level != NULL) ? level : level_;
    auto it = level->opts.find(key);
    return (it != level->opts.end()) ? it->second : "";
  }

  const std::string file_name_;
  unsigned file_line_;
  int fd_;

  static const size_t kBufSize = 256;
  char buffer_[kBufSize];

  unsigned data_size_;
  unsigned index_;
  unsigned state_;
  bool comment_;
  std::vector<level_t*> stack_;
  bool included_;
  level_t* level_;
  map_t* map_;
};

}  // namespace xml

#endif  // SRC_XML_XML_H_