// Server code which contains a name/email pairs and will fulfill
// requests from a client through FIFOs.
#include <errno.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

// data the server has and clients want: pairings of name and email
char *data[][2] = {
    {"Chris Kauffman", "kauffman@umn.edu"},
    {"Christopher Jonathan", "jonat003@umn.edu"},
    {"Amy Larson", "larson@cs.umn.edu"},
    {"Chris Dovolis", "dovolis@cs.umn.edu"},
    {"Dan Knights", "knights@cs.umn.edu"},
    {"George Karypis", "karypis@cs.umn.edu"},
    {"Steven Jensen", "sjensen@cs.umn.edu"},
    {"Daniel Keefe", "dfk@umn.edu"},
    {"Michael W. Whalen", "whalen@cs.umn.edu"},
    {"Catherine Qi Zhao", "qzhao@umn.edu"},
    {"Dan Challou", "challou@cs.umn.edu"},
    {"Steven Wu", "zsw@umn.edu"},
    {"Michael Steinbach", "steinbac@cs.umn.edu"},
    {"Jon Weissman", "jon@cs.umn.edu"},
    {"Victoria Interrante", "interran@cs.umn.edu"},
    {"Shana Watters", "watt0087@umn.edu"},
    {"James Parker", "jparker@cs.umn.edu"},
    {"James Moen", "moen0017@cs.umn.edu"},
    {"Daniel Giesel", "giese138@umn.edu"},
    {"Jon Read", "readx028@umn.edu"},
    {"Sara Stokowski", "stoko004@umn.edu"},
    {NULL, NULL},
};

// structure to store a lookup_t. client fills in with name, server
// fills in email if found in
typedef struct {
  int pid;
  char name[256];
  char email[256];
} lookup_t;

int main() {
  setvbuf(stdout, NULL, _IONBF, 0);
  printf("starting server\n");

  remove("requests.fifo");
  remove("completions.fifo");
  remove("data.fifo");
  printf("SERVER: removed old fifos\n");

  mkfifo("requests.fifo", S_IRUSR | S_IWUSR);
  mkfifo("completions.fifo", S_IRUSR | S_IWUSR);
  mkfifo("data.fifo", S_IRUSR | S_IWUSR);
  printf("SERVER: created new fifos\n");

  int requests_fd = open(
      "requests.fifo", O_RDWR); // open read/write in case server hasn't started
  int completions_fd =
      open("completions.fifo",
           O_RDWR); // open read or write only may cause hangs if the
  int data_fd =
      open("data.fifo", O_RDWR); // other end of the pipe has not be openened
  printf("SERVER: opened FIFOs, listening\n");

  while (1) {
    lookup_t request;
    read(requests_fd, &request, sizeof(lookup_t));
    printf("%d B SERVER: received request {pid=%d  name=\"%s\" }\n",
           request.pid, request.pid, request.name);
    char *name = request.name;
    int found = 0;
    for (int i = 0; data[i][0] != NULL; i++) {
      if (strcmp(name, data[i][0]) == 0) {
        strcpy(request.email, data[i][1]);
        found = 1;
      }
    }
    if (!found) {
      strcpy(request.email, "NOT FOUND");
    }
    printf(
        "%d B SERVER: filling request {pid=%d  name=\"%s\"  email=\"%s\" }\n",
        request.pid, request.pid, request.name, request.email);
    write(data_fd, &request, sizeof(request));
    printf("%d B SERVER: signaling pid %d\n", request.pid, request.pid);
    kill(request.pid, SIGCONT);
    int done_pid = -1;
    read(completions_fd, &done_pid, sizeof(int));
    printf("%d E SERVER: %d completion\n", done_pid, done_pid);
    if (request.pid != done_pid) {
      printf("Server Problems: PID %d vs %d", request.pid, done_pid);
    }
  }

  exit(0);
}