#include "xmake.h"

#include <cstdlib>
#include <filesystem>
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <string>
#include <vector>

#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>
#include <boost/process.hpp>

#include <fmt/format.h>

namespace fs = std::filesystem;
namespace bp = boost::process;
namespace pt = boost::property_tree;
using namespace std::string_literals;

namespace {
 const fs::path XMakefile{"XMakefile"};

 void usage()
 {
  std::cout << "Usage: xmake <target>" << std::endl;
 }

 std::string get_target(pt::ptree& ptree) {
  return ptree.get<std::string>("xmake.build.name");
 }
 
 std::vector<std::string> get_sources(pt::ptree& ptree) {
  std::vector<std::string> sources;
  for (pt::ptree::value_type &v: ptree.get_child("xmake.build")) {
   if (v.first == "source")
    sources.push_back(v.second.data());
  }
  return sources;
 }

 std::vector<std::string> get_objects(pt::ptree& ptree) {
  std::vector<std::string> objects{get_sources(ptree)};
  for (auto &i: objects) {
   fs::path p{i};
   p.replace_extension("o");
   i = p.string();
  }
  return objects;
 }

 void build(pt::ptree& ptree) {
  std::string target{get_target(ptree)};

  std::vector<std::string> sources{get_sources(ptree)};

  std::cout << "Target: " << target << std::endl;

  std::cout << "Sources: " << std::endl;
  for (auto &i: sources) {
   std::cout << "  " << i << std::endl;
  }

  std::vector<std::string> commands;
  // compile
  for (auto &i: sources) {
   fs::path p{i};
   fs::path p_obj{i};
   p_obj.replace_extension("o");
   commands.push_back(fmt::format("g++ -std=c++17 -c {} -o {}", p.string(), p_obj.string()));
  }
  // link
  std::string link_command{"g++"};
  std::vector<std::string> objects{get_objects(ptree)};
  for (auto &i: objects) {
   link_command += fmt::format(" {}", i);
  }
  link_command += " -lfmt";
  link_command += fmt::format(" -o {}", target);
  commands.push_back(link_command);

  std::cout << "Commands: " << std::endl;
  for (auto &i: commands) {
   std::cout << "  " << i << std::endl;
  }

  std::cout << "Running commands: " << std::endl;
  for (auto &i: commands) {
   std::cout << i << std::endl;
   int result{system(i.c_str())};
   if (result != 0) {
    throw std::runtime_error(fmt::format("Error {}", result));
   }
  }
 }

 void clean(pt::ptree& ptree) {
  std::vector<std::string> cleanlist{get_objects(ptree)};
  cleanlist.push_back(get_target(ptree));

  std::vector<std::string> commands;
  for (auto &i: cleanlist) {
   commands.push_back(fmt::format("rm -f {}", i));
  }

  std::cout << "Running commands: " << std::endl;
  for (auto &i: commands) {
   std::cout << i << std::endl;
   int result{system(i.c_str())};
   if (result != 0) {
    throw std::runtime_error(fmt::format("Error {}", result));
   }
  }
 }
}

int xmake(int argc, char* argv[])
{
 try {
  pt::ptree ptree;
  pt::read_xml(XMakefile, ptree, pt::xml_parser::no_comments | pt::xml_parser::trim_whitespace);

  std::string action{"default"};

  if (argc == 1) { // default action
  } else if (argc == 2) {
   action = argv[1];
  } else {
   std::cerr << "Invalid arguments." << std::endl;
   usage;
   exit(1);
  }

  if (action == "default"s || action == "build") { // build
   build(ptree);
  } else if (action == "clean") {
   clean(ptree);
  } else if (action == "install") {
   throw std::runtime_error("unimplemented");
  } else if (action == "rebuild") {
   throw std::runtime_error("unimplemented");
  } else if (action == "run") {
   throw std::runtime_error("unimplemented");
  } else {
   std::cerr << "Invalid action: " << action << std::endl;
   usage;
   exit(1);
  }


 } catch (const std::exception& ex) {
  std::cerr << "xmake: " << ex.what() << std::endl;
  return 1;
 }

 return 0;
}