#include "common.h"
#include <fcntl.h>
#include <semaphore.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

#define FAIL_TO_CLEANUP(cond, jmp_to)   \
    if (cond) {                         \
        perror(#cond);                  \
        ret = EXIT_FAILURE;             \
        goto jmp_to;                    \
    }

int main(void) {
    int ret = 0;
    int shm_fd = -1;
    void *shm_ptr = MAP_FAILED;
    sem_t *sem_c2s = SEM_FAILED;
    sem_t *sem_s2c = SEM_FAILED;

    FAIL_TO_CLEANUP((shm_fd = shm_open(SHM_NAME, O_RDWR, 0)) == -1, exit);
    FAIL_TO_CLEANUP(
            (shm_ptr = mmap(NULL, SHM_SIZE,
                            PROT_READ | PROT_WRITE,
                            MAP_SHARED, shm_fd, 0)) == MAP_FAILED,
            unmap_shared_mem);

    FAIL_TO_CLEANUP((sem_c2s = sem_open(SEM_C2S_NAME, 0)) == SEM_FAILED,
                    close_sem_c2s);
    FAIL_TO_CLEANUP((sem_s2c = sem_open(SEM_S2C_NAME, 0)) == SEM_FAILED,
                    close_sem_s2c);

    char filename[SHM_SIZE];
    FAIL_TO_CLEANUP(fgets(filename, sizeof(filename), stdin) == NULL, close_sem_s2c);

    size_t ln = strlen(filename);
    if (ln > 0 && filename[ln - 1] == '\n')
        filename[ln - 1] = '\0';

    memset(shm_ptr, 0, SHM_SIZE);
    strncpy((char *)shm_ptr, filename, SHM_SIZE - 1);

    FAIL_TO_CLEANUP(sem_post(sem_c2s) == -1, close_sem_s2c);

    FAIL_TO_CLEANUP(sem_wait(sem_s2c) == -1, close_sem_s2c);

    size_t len = strnlen((char *)shm_ptr, SHM_SIZE);
    FAIL_TO_CLEANUP(fwrite(shm_ptr, sizeof(char), len, stdout) != len, close_sem_s2c);
    fflush(stdout); // don't really care if fails

close_sem_s2c:
    sem_close(sem_s2c);
close_sem_c2s:
    sem_close(sem_c2s);
unmap_shared_mem:
    munmap(shm_ptr, SHM_SIZE);
close_shared_fd:
    close(shm_fd);
exit:
    return ret;
}