#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <wait.h>
#include <stdlib.h>


#include "array.h"
#include "builtins.h"

void handle(int sig) {
    /* Do nothing. */
}


void builtin_wait(process p) {

    struct sigaction handler;
    handler.sa_handler = handle;
    sigemptyset(&handler.sa_mask);
    handler.sa_flags = 0;
    bool error = false;
    pid_t *pids;
    arrayInit(pids);
    size_t i = 1;
    while (!error && p.argv[i] != NULL) {
        char *end;
        pid_t tmp = strtol(p.argv[i], &end, 10);
        if (*end != '\0') {
            fprintf(stderr, "Not a valid pid: %s", p.argv[i]);
            error = true;
            break;
        }
        arrayPush(pids) = tmp;
        ++i;
    }

    if (!error) {
        while (!arrayIsEmpty(pids)) {
            int status;
            pid_t current_pid = arrayPop(pids);
            printf("Waiting for %ld...\n", (long)current_pid);
            // install signal handler without SA_RESTART, so waitpid gets interrupted
            sigaction(SIGINT, &handler, NULL);
            if (waitpid(current_pid, &status, WUNTRACED) < 0) {
                if (EINTR == errno) {
                    // cancelled by ctrl-c
                } else {
                    perror("Could not wait on process");
                }
            } else {
                printf("[%i] TERMINATED\n", current_pid);
                if (WIFEXITED(status)) {
                    printf("[%i] exited normally with status: %i\n", current_pid,
                           WEXITSTATUS(status));
                } else if (WIFSTOPPED(status)) {
                    printf("[%i] was stopped by signal: %s\n", current_pid,
                           strsignal(WSTOPSIG(status)));
                } else if (WIFSIGNALED(status)) {
                    printf("[%i] was terminated by signal: %s\n", current_pid,
                           strsignal(WTERMSIG(status)));
                } else {
                    printf("[%i] exited (not sure why), exit status: %i\n", current_pid,
                           WEXITSTATUS(status));
                }
            }
            signal(SIGINT, SIG_DFL);
        }
    }

    arrayRelease(pids);
}