#include <arpa/inet.h>
#include <sys/types.h>
#include <stdint.h>
#include <sys/socket.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#include "gamedata.h"

#define SERVER_ADDR htonl(INADDR_ANY)
#define MAX_CLIENTS 100
#define MAX_COMMAND_LINE_LENGTH 101

bool prefix(const char *pre, const char *str) {
  return strncmp(pre, str, strlen(pre)) == 0;
}

int main(int argc, char** argv) {

  if(argc < 2) {
    fprintf(stderr, "Give port number as $1\n");
    exit(255);
  }

  int sock_conn_d, sock_data_d;
  struct sockaddr_in server;

  if((sock_conn_d = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
    perror("server socket not created");
    exit(1);
  }

  memset(&server, 0, sizeof(server)); // zero the memory

  server.sin_family = AF_INET;
  server.sin_addr.s_addr = SERVER_ADDR;
  server.sin_port = htons(atoi(argv[1]));

  if(bind(sock_conn_d, (struct sockaddr*)&server, sizeof(server)) == -1) {
    perror("server socket not bound");
    exit(2);
  }

  while(true) {
    if(listen(sock_conn_d, MAX_CLIENTS) != 0) {
      perror("cannot listen on socket");
      close(sock_conn_d);
      exit(3);
    }

    printf("listening...\n");

    struct sockaddr_in client;
    socklen_t client_len = sizeof(client);
    sock_data_d = accept(sock_conn_d, (struct sockaddr*)&client, &client_len);

    if(sock_data_d == -1) {
      perror("cannot accept client");
      close(sock_conn_d);
      exit(4);
    }

    pid_t pid = fork();

    if(pid < 0) {
      perror("cannot fork for new client");
      exit(6);
    }
    else if(pid == 0) {
      gamedata_t *curr_data = gamedata_new();

      unsigned char command[MAX_COMMAND_LINE_LENGTH];
      FILE* in = fdopen(sock_data_d, "r");
      FILE* out = fdopen(dup(sock_data_d), "w");

      fprintf(out, "OK Connection establshed.\n");
      fflush(out);

      while(true) {
        fgets(command, MAX_COMMAND_LINE_LENGTH, in);

        union {
          unsigned int u;
          double d;
        } arg1;

        if(sscanf(command, "make %u\n", &(arg1.u)) == 1) {
          bool status = gamedata_make_pizzoccheri(curr_data, arg1.u);
          fprintf(out, status ? "OK Made.\n" : "KO 1 Insufficient resources.\n");
        }
        else if(prefix("sell", command)) {
          unsigned int sold = gamedata_sell_pizzoccheri(curr_data);
          fprintf(out, "OK %d sold.\n", sold);
        }
        else if(sscanf(command, "set price %lf\n", &(arg1.d)) == 1) {
          bool status = gamedata_set_unit_price(curr_data, arg1.d);
          fprintf(out, status ? "OK The price of one pizzocchero is now at %.02lf CHF.\n"
                  : "KO %.02lf CHF is not a valid price.\n", arg1.d);
        }
        else if(sscanf(command, "buy bitto %u", &(arg1.u)) == 1) {
          bool status = gamedata_buy_bitto(curr_data, arg1.u);
          fprintf(out, status ? "OK Purchased.\n" : "KO 2 Insufficient funds\n");
        }
        else if(sscanf(command, "buy flour %u", &(arg1.u)) == 1) {
          bool status = gamedata_buy_flour(curr_data, arg1.u);
          fprintf(out, status ? "OK Purchased.\n" : "KO 3 Insufficient funds\n");
        }
        else if(prefix("status", command)) {
          gamedata_print_status(curr_data, out);
        }
        else if(prefix("exit", command)) {
          fprintf(out, "OK Closing...\n");
          break;
        }
        else {
          fprintf(out, "KO 255 Syntax error\n");
        }

        fflush(out);
      }

      printf("closing data socket...\n");

      fclose(in);
      fclose(out);

      gamedata_delete(curr_data);

      printf("exiting...\n");
      exit(0);
    }
    // if father process just continue
  }
  close(sock_conn_d);
  exit(0);
}