#include "srv.h"
#include "tplr.h"
#include <cstdlib>
#include <ctime>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <cstring>
#include <iostream>
#include <algorithm>

Server::Server(int port, const std::vector<std::string>* questions, size_t n, const std::map<std::string, std::string>* templates)
  : port(port), questions(questions), n(n), templates(templates) {
  std::srand(std::time(nullptr));
}

std::string Server::getRandomQuestion() {
  if (questions->size() == recentQuestions.size()) {
    recentQuestions.clear();
  }
  
  int index;
  bool unique;

  do {
    index = std::rand() % questions->size();
    unique = std::find(recentQuestions.begin(), recentQuestions.end(), index) == recentQuestions.end();
  } while (!unique);

  recentQuestions.push_back(index);
  if (recentQuestions.size() > n) {
    recentQuestions.pop_front();
  }

  return (*questions)[index];
}

void Server::handleRequest(int client_socket) {
  char buffer[1024] = {0};
  read(client_socket, buffer, sizeof(buffer));

  std::string request(buffer);
  std::string response;

  if (request.find("GET /q") == 0) {
    std::string question = getRandomQuestion();
    std::map<std::string, std::string> context = {{"QUESTION", question}};
    response = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n" + renderTemplate(templates->at("tpl/tpl_q.html"), context);
  } else if (request.find("GET /about") == 0) {
    response = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n" + templates->at("tpl/tpl_about.html");
  } else {
    response = "HTTP/1.1 404 Not Found\r\nContent-Type: text/plain\r\n\r\n404 Not Found";
  }

  send(client_socket, response.c_str(), response.size(), 0);
  close(client_socket);
}

void Server::run() {
  int server_fd;
  struct sockaddr_in address;
  int opt = 1;
  int addrlen = sizeof(address);

  if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
    perror("Ошибка создания сокета");
    exit(EXIT_FAILURE);
  }

  if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt))) {
    perror("Ошибка настройки сокета");
    exit(EXIT_FAILURE);
  }
  address.sin_family = AF_INET;
  address.sin_addr.s_addr = INADDR_ANY;
  address.sin_port = htons(port);

  if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
    perror("Ошибка привязки сокета");
    exit(EXIT_FAILURE);
  }
  
  if (listen(server_fd, 3) < 0) {
    perror("Ошибка при прослушивании");
    exit(EXIT_FAILURE);
  }

  while (true) {
    int client_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen);
    if (client_socket < 0) {
      perror("Ошибка при принятии соединения");
      exit(EXIT_FAILURE);
    }
    handleRequest(client_socket);
  }
}