/**
 * Eugene Marinelli
 * 18-549 - Healthnet
 * 2/22/08
 *
 * Gumstix->PC upload server.
 *
 * Based on http://cs.baylor.edu/~donahoo/practical/CSockets/textcode.html
 */

#include <arpa/inet.h>
#include <signal.h>
#include <sqlite3.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>

#define MAXPENDING 5

static int servSock;
static int clntSock;

static sqlite3* db_conn;

static void exit_handler(int x) {
  if (db_conn) {
    sqlite3_close(db_conn);
  }

  if (servSock) {
    close(servSock);
  }

  if (clntSock) {
    close(clntSock);
  }

  exit(1);
}

static int db_select_callback(void* client_socket, int num_cols, char** results, char** colnames) {
  int sock = (int)client_socket;

  char buf[80] = "";

  int i;
  for (i = 0; i < num_cols; i++) {
    strcat(buf, results[i]);

    if (i < num_cols-1) {
      strcat(buf, ",");
    }
  }

  strcat(buf, ";");

  if (send(sock, buf, strlen(buf), 0) == -1) {
    perror("send");
    return -1;
  } else {
    return 0;
  }
}

int main(int argc, char *argv[]) {
  signal(SIGINT, exit_handler);

  if (argc != 3) {
    fprintf(stderr, "Usage: %s <port> <db filename>\n", argv[0]);
    exit(1);
  }

  unsigned short echoServPort = atoi(argv[1]);
  char* db_filename = argv[2];

  if ((servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
    perror("socket");
    exit(1);
  }

  struct sockaddr_in echoServAddr;
  memset(&echoServAddr, 0, sizeof(echoServAddr));
  echoServAddr.sin_family = AF_INET;
  echoServAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  echoServAddr.sin_port = htons(echoServPort);

  if (bind(servSock, (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0) {
    perror("bind");
    exit(1);
  }

  if (listen(servSock, MAXPENDING) < 0) {
    perror("listen");
    exit(1);
  }

  // Initialize database.
  int ret;
  if ((ret = sqlite3_open(db_filename, &db_conn)) != SQLITE_OK) {
    fprintf(stderr, "sqlite3_open failed: error code %d\n", ret);
  }

  while (1) {
    struct sockaddr_in echoClntAddr;
    unsigned clntLen = sizeof(echoClntAddr);

    /* Wait for client connection. */
    if ((clntSock = accept(servSock, (struct sockaddr *) &echoClntAddr, &clntLen)) < 0) {
      printf("accept() failed\n");
      exit(1);
    }

    fprintf(stderr, "Handling client %s\n", inet_ntoa(echoClntAddr.sin_addr));

    fprintf(stderr, "Loading data from database %s...\n", db_filename);

//    int bytes_recv = recv(clntSock, buf, 80, 0);
//    printf("%d bytes received\n", bytes_recv);

    printf("Querying and uploading data...\n");

    /* Callback writes results to client socket. */
    char err_buf[80];
    int ret = sqlite3_exec(db_conn, "select * from bodystats", db_select_callback, (void*)clntSock,
                           (char**)&err_buf);
    if (ret != SQLITE_OK) {
      fprintf(stderr, "sqlite3_exec failed: %s\n", err_buf);
      exit_handler(1);
    }

    printf("Data uploaded.\n");
    if (close(clntSock) == -1) {
      perror("close");
      exit_handler(1);
    }
  }
}