/* message.c */

#include "message.h"
#include "process.h"
#include "scheduler.h"
#include "string.h"
#include "tty3.h"
#include "types.h"

int get_mess_slot(int pid) {
  int id = pid - 1;
  int i;
  for (i = 0; i < MESSAGE_QUEUE_SIZE; i++) {
    if (!PCB_list[id].messages[i].priority) { return i; }
  }
  return -1;
}

int get_highest_mess(int pid) {
  int id = pid - 1;
  int highest = 0;
  int slot = -1;
  int i;
  for (i = 0; i < MESSAGE_QUEUE_SIZE; i++) {
    if (PCB_list[id].messages[i].priority > highest) {
      highest = PCB_list[id].messages[i].priority;
      slot = i;
    }
  }
  return slot;
}

int send_message(char *s, int prio, int recv_pid) {
  int recv_id = recv_pid - 1;
  int mess_id = get_mess_slot(recv_pid);
  if (mess_id == -1) {
    PCB_list[recv_id].status = CRASHED;
    return ERROR_SEND;
  }
  else {
    string_memcpy(PCB_list[recv_id].messages[mess_id].data, s);
    PCB_list[recv_id].messages[mess_id].priority = prio;
    PCB_list[recv_id].messages[mess_id].receiver_pid = recv_pid;
    PCB_list[recv_id].messages[mess_id].sender_pid = get_running() + 1;
    return OK_SEND;
  }
}

int receive_message() {
  int pid = get_running() + 1;
  int start_counter = 0;
  while (start_counter++ < RECEIVE_WAIT_MAX) {
    int mess_id = get_highest_mess(pid);
    if (mess_id != -1) {
      get_message(pid, mess_id);
      return OK_RECEIVE;
    }
  }
  return RECEIVE_TIME_OUT;
}
void get_message(int pid, int mess_id) {
  int id = pid - 1;
  print_message(pid, mess_id);
  string_memcpy(PCB_list[id].current_message.data, PCB_list[id].messages[mess_id].data);
  PCB_list[id].current_message.priority = PCB_list[id].messages[mess_id].priority;
  PCB_list[id].current_message.sender_pid = PCB_list[id].messages[mess_id].sender_pid;
  PCB_list[id].current_message.receiver_pid = PCB_list[id].messages[mess_id].receiver_pid;
  erase_message(pid, mess_id);
}

void erase_message(int pid, int mess_id) {
  int id = pid - 1;
  string_memcpy(PCB_list[id].messages[mess_id].data, "");
  PCB_list[id].messages[mess_id].priority = 0;
  PCB_list[id].messages[mess_id].sender_pid = 0;
  PCB_list[id].messages[mess_id].receiver_pid = 0;
}

void erase_all_messages(int pid) {
  int id = pid - 1;
  int i;
  for (i = 0; i < MESSAGE_QUEUE_SIZE; i++) { erase_message(pid, i); }
  string_memcpy(PCB_list[id].current_message.data, "");
  PCB_list[id].current_message.priority = 0;
  PCB_list[id].current_message.sender_pid = 0;
  PCB_list[id].current_message.receiver_pid = 0;
}

void print_message(int process_pid, int message_id) {
  int process_id = process_pid - 1;
  print_int(PCB_list[process_id].messages[message_id].sender_pid);
  print_string(" -> ");
  print_int(PCB_list[process_id].messages[message_id].receiver_pid);
  print_string(": ");
  print_string(PCB_list[process_id].messages[message_id].data);
  NEWLINE;
}