#define FUSE_USE_VERSION 26
/* ---------------------------------------------------------------------------- */

#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

#include "myfs_tools.h"
/* ---------------------------------------------------------------------------- */

static const char *hello_str = "Hello World!\n";
/* ---------------------------------------------------------------------------- */

static int myfs_getattr(const char *path, struct stat *stbuf) {
    int res = 0;

    memset(stbuf, 0, sizeof(struct stat));
    if (strcmp(path, "/") == 0) {
        stbuf->st_mode = S_IFDIR | 0755;
        stbuf->st_nlink = 2;
    } else if(myfs_file_exists(path)) {
        char* fullpath = myfs_file_full_path(path);
        stat(fullpath, stbuf);
        free(fullpath);
    } else
        res = -ENOENT;

    return res;
}
/* ---------------------------------------------------------------------------- */

static int myfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
             off_t offset, struct fuse_file_info *fi) {
    (void) offset;
    (void) fi;

    if (strcmp(path, "/") != 0)
        return -ENOENT;

    filler(buf, ".", NULL, 0);
    filler(buf, "..", NULL, 0);  
    
    // open dir
    char* dirname = myfs_dir_get_fuse_home_path();
    DIR* dirptr = myfs_dir_open(dirname);
    free(dirname);
    if(dirptr == NULL)
        return -errno;
    
    // read dir content
    while(1) {
        struct dirent * entry = myfs_dir_read(dirptr);
        if(!entry) break;
        filler(buf, entry->d_name, NULL, 0);
    }
    
    // close dir
    myfs_dir_close(dirptr);

    return 0;
}
/* ---------------------------------------------------------------------------- */

static int myfs_open(const char *path, struct fuse_file_info *fi) {

    if(myfs_file_exists(path) == 0)
        return -ENOENT;

    if ((fi->flags & 3) != O_RDONLY)
        return -EACCES;

    return 0;
}
/* ---------------------------------------------------------------------------- */

static int myfs_read(const char *path, char *outputbuf, size_t size, off_t offset,
              struct fuse_file_info *fi) {

    pid_t pid;
    int pfd[2], i;
    char offbuf[1];
    ssize_t nread;
    ssize_t totalread = 0;
    
    (void) fi;
     
    pipe(pfd);
    pid = fork();
    
    // child process
    if(pid == 0) {
        dup2(pfd[1],STDOUT_FILENO);
        close(pfd[0]);
        close(pfd[1]);
        char* fullpath = myfs_file_full_path(path);
        execlp(fullpath, fullpath, NULL);
        // on error
        close(STDOUT_FILENO);
        exit(0);
    }
    
    // parent process
    else if(pid > 0) {
        close(pfd[1]);
        for(i=0;i<offset;++i)
            if(read(pfd[0], offbuf, 1) == 0)
                break;
        do {
            nread = read(pfd[0], outputbuf+totalread, size-totalread);
            totalread += nread;
        }
        while((nread != 0) && (totalread < size));
        close(pfd[0]);
    }
    
    else {
        return -EACCES;
    }

    return totalread;
}
/* ---------------------------------------------------------------------------- */

static struct fuse_operations myfs_oper = {
    .getattr    = myfs_getattr,
    .readdir    = myfs_readdir,
    .open       = myfs_open,
    .read       = myfs_read,
};
/* ---------------------------------------------------------------------------- */

int main(int argc, char *argv[]) {
        
    return fuse_main(argc, argv, &myfs_oper, NULL);
}
/* ---------------------------------------------------------------------------- */