/**
 * Copyright (C) 2016 Aaron Ball <nullspoon@oper.io>
 *
 * Ircbot is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Ircbot is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ircbot.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

/* Networking libs */
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>


// For trapping Ctrl+c
#include <signal.h>

#include "common.h"

#define buflen 512

static int socket_desc;

int newconn(char* addr, char* port) {
  int status;
  int socket_desc;
  struct addrinfo hints, *p;
  struct addrinfo *servinfo;

  // Ensure our struct is empty
  memset(&hints, 0, sizeof(hints));

  // Set hints struct
  hints.ai_flags    = AI_PASSIVE;
  hints.ai_family   = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;

  if((status = getaddrinfo(addr, port, &hints, &servinfo)) != 0) {
    fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(status));
    exit(1);
  }

  // Iterrate the dns entries
  for(p = servinfo;p != NULL; p = p->ai_next) {
    // Attempt to create socket
    socket_desc = socket(p->ai_family, p->ai_socktype, p->ai_protocol);

    // If socket creation failed, skip entry
    if (socket_desc == -1) continue;

    // Attempt to connect. If successful, break out of loop
    if (connect(socket_desc, p->ai_addr, p->ai_addrlen) != -1) break;
  }

  return socket_desc;
}


int recv_line(int sockd, char* out) {
  int i = 0;
  char c = '\0';

  while(c != '\n') {
    recv(sockd, &c, 1, 0);
    out[i] = c;
    i++;
  }
  out[i] = '\0';
  return i;
}


char* irc_get_msg(char* str, char* buf ) {
  int i = 2;
  int bufi = 0;
  // Place the start cursor
  while(i < strlen(str)) {
    if(str[i] == ':') {
      i++;
      printf("Found beginning of message at index %d\n", i);
      break;
    }
    i++;
  }

  while(str[i] != '\r' && str[i] != '\n' && str[i] != '\0') {
    buf[bufi] = str[i];
    bufi++;
    i++;
  }

  buf[bufi] = '\0';
  return buf;
}


int doloop(int sockd, int ret, char* chan) {
  char buf[buflen];
  char resp[buflen];
  char msg[1024];
  int len;

  while(1) {
    len = recv_line(sockd, buf);
    if(len == 0) continue;

    if(strncmp(buf, "PING", 4) == 0) {
      sprintf(&resp[0], "PONG %s", &buf[5]);
      printf("pong: %s", resp);
      send(sockd, resp, strlen(resp), 0);
      if(ret == 1) return 0;
    } else if(strstr(buf, "ircbot quit") != NULL) {
      // Quit command
      break;
    } else if(strstr(buf, "ircbot say ") != NULL) {
      // The say command
      irc_get_msg(buf, msg);
      sprintf(&resp[0], "PRIVMSG %s :%s\n", chan, &msg[11]);
      printf("Say command received. Saying \"%s\"\n", &msg[11]);
      send(sockd, resp, strlen(resp), 0);
    } else if(strstr(buf, "ircbot meaning of life") != NULL) {
      // The mol command
      sprintf(&resp[0], "PRIVMSG %s :%d\n", chan, 42);
      send(sockd, resp, strlen(resp), 0);
    } else if(strstr(buf, "Looking up your hostname") != NULL) {
      // Receive next line
      recv_line(sockd, buf);
      printf(buf);
      break;
    } else if(strstr(buf, "Nickname is already in use.") != NULL) {
      // We can't proceed if nickname is already in use.
      printf(buf);
      return -1;
    }

    printf(buf);
    //len = 0;
  }

  return 0;
}


int irc_auth(int sockd, char* nick, char* user, char* chan) {
  int status;
  char nickstr[buflen];
  char userstr[buflen];
  char joinstr[buflen];

  // Compose NICK statement
  sprintf(nickstr, "NICK %s\n", nick);
  // Compose NICK statement
  sprintf(userstr, "USER %s 0 * : %s\n", nick, user);
  // Compose the JOIN statement
  sprintf(joinstr, "JOIN %s\n", chan);

  // Wait for hostname identification
  doloop(sockd, 1, chan);

  // Send NICK command
  send(sockd, nickstr, strlen(nickstr), 0);
  printf("%s\n", nickstr);

  // Send USER command
  send(sockd, userstr, strlen(userstr), 0);
  printf("%s\n", userstr);

  // Wait for ping and send pong response
  printf("Waiting for initial ping\n");
  status = doloop(sockd, 1, chan);
  if(status == -1) return -1;

  // Send JOIN command
  printf("Joining channel %s\n", chan);
  send(sockd, joinstr, strlen(joinstr), 0);

  printf("Entering main watcher loop\n");
  doloop(sockd, 0, chan);

  // send quit message
  char quitstr[512];
  sprintf(quitstr, "QUIT :Blowing this popsicle stand\n");
  send(sockd, quitstr, strlen(quitstr), 0);
  close(sockd);

  return 0;
}

void quit(int signal) {
  char quitstr[512];
  sprintf(quitstr, "QUIT :Force quit!\n");
  send(socket_desc, quitstr, strlen(quitstr), 0);
  printf("\n\nQuitting, signal %d\n\n\n", signal);

  //doloop(socket_desc, 1);
  close(socket_desc);
  exit(128 + signal);
}


int main(int argc, char* argv[]) {
  char *server = argv[1];
  char *port = argv[2];
  char *nick = argv[3];
  char *chan = argv[4];
  int status;

  if(argc < 4) {
    printf("\nERROR: Irc server, port, and nick required to connect\n\n");
    printf("Usage:\n  ircbot irc.server.tld 6667 jcricket\n\n");
    return 1;
  }

  //int socket_desc;

  socket_desc = newconn(server, port);

  if(socket_desc == -1) {
    printf("Connection error\n");
    return 1;
  }

  signal(SIGINT, quit);


  status = irc_auth(socket_desc, nick, nick, chan);
  if(status == -1) return 1;

  // Cleanup
  close(socket_desc);

  return 0;
}