// SPDX-License-Identifier: GPL-3.0-or-later
#include <catch2/catch_test_macros.hpp>
#include <iostream>
#include <sstream>

#include "node.h"

int get_node_id(node *n) {
  // TODO: ensure the test calling this starts at node_id 0 (currently this is
  // undefined based on order the tests are run)
  // for the time being, this gets the offset
  int id = std::stoi(n->get_name().substr(5));
  // this tests if the node id was correctly extracted
  REQUIRE(n->get_name() == "node_" + std::to_string(id));
  return id;
}

TEST_CASE("Name") {
  node *n = new node("test");
  REQUIRE(n->get_name() == "test");
  n->set_name("foo");
  REQUIRE(n->get_name() == "foo");
  delete n;
}

TEST_CASE("Number of children") {
  node *n = new node("test");
  REQUIRE(n->get_nr_children() == 0);
  for (std::size_t i = 0; i < 20; i++) {
    node *child = new node("child");
    n->add_child(child);
  }
  REQUIRE(n->get_nr_children() == 20);
  delete n;
}

TEST_CASE("Get children") {
  node *n = new node("test");
  REQUIRE(n->get_nr_children() == 0);
  for (std::size_t i = 0; i < 5; i++) {
    n->add_child(new node("child " + std::to_string(i)));
  }
  for (std::size_t i = 0; i < 5; i++) {
    REQUIRE(n->get_child(i)->get_name() == "child " + std::to_string(i));
  }
  delete n;
}

TEST_CASE("Global node counting") {
  node *n = new node();

  const int node_id_start = get_node_id(n);

  for (std::size_t i = 0; i < 5; i++) {
    n->add_child(new node());
  }
  n->add_child(new node("explicit name"));
  for (std::size_t i = 0; i < 5; i++) {
    REQUIRE(n->get_child(i)->get_name() ==
            "node_" + std::to_string(node_id_start + 1 + i));
  }
  REQUIRE(n->get_child(5)->get_name() == "explicit name");
  delete n;
}

TEST_CASE("Create complete tree") {
  const std::size_t nr_child_nodes = 2;
  const unsigned int tree_depth = 4;
  node *t = create_complete_tree(nr_child_nodes, tree_depth);

  int count = get_node_id(t);

  REQUIRE(t->get_name() == "node_" + std::to_string(count++));

  // this is very verbose,
  // but without a serialisation,
  // there is no other good way I could find (that does not also implement the
  // logic to test).
  REQUIRE(t->get_child(0)->get_name() == "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(0)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(0)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(1)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(0)->get_child(1)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_name() == "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(0)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(0)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(1)->get_child(0)->get_name() ==
          "node_" + std::to_string(count++));
  REQUIRE(t->get_child(1)->get_child(1)->get_child(1)->get_name() ==
          "node_" + std::to_string(count++));

  REQUIRE(t->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(0)->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(0)->get_child(0)->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(0)->get_child(1)->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(1)->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(1)->get_child(0)->get_nr_children() == nr_child_nodes);
  REQUIRE(t->get_child(1)->get_child(1)->get_nr_children() == nr_child_nodes);

  delete t;
}

TEST_CASE("Print complete tree") {
  const std::size_t nr_child_nodes = 2;
  const unsigned int tree_depth = 4;
  node *t = create_complete_tree(nr_child_nodes, tree_depth);

  int count = get_node_id(t);

  std::stringstream output;
  t->print(output);

  std::stringstream expected;
  expected << "node_" << count++ << std::endl;
  for (size_t i = 0; i < 2; i++) {
    expected << "\tnode_" << count++ << std::endl;
    for (size_t j = 0; j < 2; j++) {
      expected << "\t\tnode_" << count++ << std::endl;
      for (size_t k = 0; k < 2; k++) {
        expected << "\t\t\tnode_" << count++ << std::endl;
      }
    }
  }
  REQUIRE(output.str() == expected.str());

  delete t;
}

TEST_CASE("Print stream overload") {
  node n("foo");

  std::stringstream output1;
  n.print(output1);

  std::stringstream output2;
  output2 << n;

  REQUIRE(output1.str() == output2.str());
}

TEST_CASE("Cycle detection") {
  node *n = new node("foo");
  n->add_child(new node("bar"));
  n->get_child(0)->add_child(n);

  std::stringstream output;
  output << n->print_recursive();

  REQUIRE(output.str() == "foo\n\tbar [↝ foo]\n");

  delete n;
}

TEST_CASE("Cycle detection (iterative)") {
  node *n = new node("foo");
  n->add_child(new node("bar"));
  n->get_child(0)->add_child(n);

  std::stringstream output;
  output << n->print_iterative();

  REQUIRE(output.str() == "foo\n\tbar [↝ foo]\n");

  delete n;
}

TEST_CASE("Very short cycle detection") {
  node *n = new node("foo");
  n->add_child(n);

  std::stringstream output;
  output << n->print_recursive();

  REQUIRE(output.str() == "foo [↝ foo]\n");

  delete n;
}

TEST_CASE("Very short cycle detection (iterative)") {
  node *n = new node("foo");
  n->add_child(n);

  std::stringstream output;
  output << n->print_iterative();

  REQUIRE(output.str() == "foo [↝ foo]\n");

  delete n;
}

TEST_CASE("Equivalence of iterative and recursive print") {
  node *n = new node();
  REQUIRE(n->print_recursive() == n->print_iterative());
  delete n;

  node *r = new node("foo");
  r->add_child(new node("bar"));
  r->get_child(0)->add_child(r);
  REQUIRE(r->print_recursive() == r->print_iterative());
  delete r;

  node *t = create_complete_tree(2, 4);
  REQUIRE(t->print_recursive() == t->print_iterative());
  delete t;
}