#include "random_graph_generator.h"

random_graph_generator::random_graph_generator(
  size_t number_of_edges, size_t number_of_nodes,
  random_attribute_generator edge_generator,
  random_attribute_generator node_generator,
  std::map<std::string, Attribute> default_values_edge_attributes,
  std::map<std::string, Attribute> default_values_node_attributes
)
  : _template_node_attributes(default_values_node_attributes), _template_edge_attributes(default_values_edge_attributes), _number_of_nodes(number_of_nodes), _number_of_edges(number_of_edges), _node_generator(node_generator), _edge_generator(edge_generator) {}

Graph random_graph_generator::next_acyclic(){
  Graph g (this->_template_edge_attributes, this->_template_node_attributes);
  while(!random_graph_generator::grow_random_acyclic(g, this->_number_of_nodes, this->_number_of_edges, this->_edge_generator, this->_node_generator).first){
    std::cout << "generation failed; retrying!" << std::endl;
  }
  return g;
}

Graph random_graph_generator::next(){
  Graph g (this->_template_edge_attributes, this->_template_node_attributes);
  while(!random_graph_generator::grow_random(g, this->_number_of_nodes, this->_number_of_edges, this->_edge_generator, this->_node_generator).first){
    std::cout << "generation failed; retrying!" << std::endl;
  }
  return g;
}

std::pair<std::pair<Node*, Node*>,Graph> random_graph_generator::next_acyclic_2_tips(){
  Graph g (this->_template_edge_attributes, this->_template_node_attributes);
  while(!random_graph_generator::grow_random_acyclic(g, this->_number_of_nodes, this->_number_of_edges, this->_edge_generator, this->_node_generator).first){
    std::cout << "generation failed; retrying!" << std::endl;
  }
  auto tips = g.tip_fringes(this->_edge_generator, this->_node_generator);
  return {tips, std::move(g)};
}

std::pair<bool, Attribute> random_graph_generator::node_template(const std::string& attr) const{
  auto search = this->_template_node_attributes.find(attr);
  if(search == this->_template_node_attributes.end()){
    return {false, {fix, 0}};
  }
  return {true, search->second};
}

std::pair<bool, Attribute> random_graph_generator::edge_template(const std::string& attr) const {
  auto search = this->_template_edge_attributes.find(attr);
  if(search == this->_template_edge_attributes.end()){
    return {false, {fix, 0}};
  }
  return {true, search->second};
}

Attribute random_graph_generator::edge_template_throwing(const std::string& attr){
  auto search = this->_template_edge_attributes.find(attr);
  if(search == this->_template_edge_attributes.end()){
    std::stringstream text;
    text << "\"" << attr << "\" is not defined by default for Edges generated by this Generator";
    throw std::range_error(text.str());
  }
  return search->second;
}

Attribute random_graph_generator::node_template_throwing(const std::string& attr){
  auto search = this->_template_node_attributes.find(attr);
  if(search == this->_template_node_attributes.end()){
    std::stringstream text;
    text << "\"" << attr << "\" is not defined by default for Nodes generated by this Generator";
    throw std::range_error(text.str());
  }
  return search->second;
}

std::pair<bool, std::pair<std::vector<Node*>, std::vector<Edge*>>> random_graph_generator::grow_random(Graph& g, size_t number_of_nodes, size_t number_of_edges, random_attribute_generator& edge_attribute_generator, random_attribute_generator& node_attribute_generator){
  std::vector<Node*> added_nodes;
  std::vector<Edge*> added_edges;
  added_nodes.reserve(number_of_nodes);
  added_edges.reserve(number_of_edges);

  for(size_t i = 0; i < number_of_nodes; ++i){
    std::stringstream name;
    name << g.size().first;
    added_nodes.push_back(g.add_node(name.str(), node_attribute_generator.next()));
  }
  random_set_element_generator<Node*> rand_stream (&g.nodes());

  Node* n1;
  Node* n2;
  for(size_t i = 0; i < number_of_edges; ++i){
    size_t attempt = 0;
    redo:
    if(attempt > g.nodes().size()*g.nodes().size()*g.nodes().size()){
      goto failed;
    };

    try{
      rand_stream >> n1;
      rand_stream >> n2;
    }catch (std::range_error& e){
      goto failed;
    }

    {
      auto existing_path = g.directed_admissible_st_path(n1, n2);
      if(existing_path.first && existing_path.second.number_of_edges() <= 1) {
        attempt++;
        goto redo;
      }
    }

    std::stringstream name;
    name << n1->description() << "_" << n2->description();
    added_edges.push_back(g.add_edge(n1, n2, name.str(), edge_attribute_generator.next()));
  }
  return {true,{added_nodes, added_edges}};

  failed:
  /*
    cleanup: restore state; due to failure: remove the already added components
  */
  for(Edge* e : added_edges){
    g.remove_edge(e);
  }
  for(Node* n : added_nodes){
    g.remove_node(n);
  }
  return {false,{{},{}}};
}

//TODO: add generate_random_edge and random node to node, edge and use additional parameters to generate random attributes for edges, nodes
std::pair<bool, std::pair<std::vector<Node*>, std::vector<Edge*>>> random_graph_generator::grow_random_acyclic(Graph& g, size_t number_of_nodes, size_t number_of_edges, random_attribute_generator& edge_attribute_generator, random_attribute_generator& node_attribute_generator){
  std::vector<Node*> added_nodes;
  std::vector<Edge*> added_edges;
  added_nodes.reserve(number_of_nodes);
  added_edges.reserve(number_of_edges);

  for(size_t i = 0; i < number_of_nodes; ++i){
    std::stringstream name;
    name << g.size().first;
    added_nodes.push_back(g.add_node(name.str(), node_attribute_generator.next()));
  }
  random_set_element_generator<Node*> rand_stream (&g.nodes());

  Node* n1;
  Node* n2;
  for(size_t i = 0; i < number_of_edges; ++i){
    size_t attempt = 0;
    redo:
    if(attempt > g.nodes().size()*g.nodes().size()*g.nodes().size()){
      goto failed;
    };

    try{
      rand_stream >> n1;
      rand_stream >> n2;
    }catch (std::range_error& e){
      goto failed;
    }

    if(n1 == n2 || g.directed_admissible_st_path(n2, n1).first || g.directed_admissible_st_path(n1, n2).second.number_of_edges() == 1) {
      attempt++;
      goto redo;
    }

    std::stringstream name;
    name << n1->description() << "_" << n2->description();
    added_edges.push_back(g.add_edge(n1, n2, name.str(), edge_attribute_generator.next()));
  }
  return {true,{added_nodes, added_edges}};

  failed:
  /*
    cleanup: restore state; due to failure: remove the already added components
  */
  for(Edge* e : added_edges){
    g.remove_edge(e);
  }
  for(Node* n : added_nodes){
    g.remove_node(n);
  }
  return {false,{{},{}}};
}