#include <apr.h>
#include <apr_strings.h>
#include <apr_file_io.h>
#include <apr_poll.h>
#include <apr_buckets.h>

#include <stdlib.h>

#ifndef NL
#define NL APR_EOL_STR
#endif

#define IO_BUF_LEN (8092)
#define MIN_LEN (81)

typedef struct ctxt_t
{
    apr_pool_t *p;
    apr_bucket_alloc_t *buckets;
    apr_bucket_brigade *bbin;
    apr_bucket_brigade *bbtmp;
    apr_file_t *outfile;
} ctxt_t;

static apr_status_t read_line(ctxt_t *ctxt)
{
    char buf[IO_BUF_LEN];
    apr_status_t rv;
    apr_size_t len = sizeof(buf);
    apr_size_t nbytes = 0;
    
    rv = apr_brigade_split_line(ctxt->bbtmp, ctxt->bbin, APR_NONBLOCK_READ, len);
    
    if (rv != APR_SUCCESS) {
        return rv;
    }
    
    rv = apr_brigade_flatten(ctxt->bbtmp, buf, &len);
    if (rv != APR_SUCCESS) {
        return rv;
    }
    
    if (len == 0) {
        return APR_EOF;
    }

    if (len < MIN_LEN) {
        return rv;
    }
    
    rv = apr_file_write_full(ctxt->outfile, buf, len, &nbytes);
    
    return rv;
}


int main(int argc, const char * const argv[])
{
    apr_status_t rv;
    apr_pool_t *p;
    apr_file_t *infile;
    ctxt_t ctxt;

    rv = apr_initialize();
    if (rv != APR_SUCCESS) {
        fprintf(stderr, "Unable to Initialize APR!"NL);
        return EXIT_FAILURE;
    }

    atexit(apr_terminate);
    
    rv = apr_pool_create(&p, NULL);
    if (rv != APR_SUCCESS) {
        fprintf(stderr, "Unable to create Root Pool!"NL);
        return EXIT_FAILURE;
    }
    
    rv = apr_file_open_stdout(&ctxt.outfile, p);
    if (rv != APR_SUCCESS) {
        fprintf(stderr, "Unable to open stdout!"NL);
        return EXIT_FAILURE;
    }
    

    rv = apr_file_open_stdin(&infile, p);
    if (rv != APR_SUCCESS) {
        fprintf(stderr, "Unable to open stdin!"NL);
        return EXIT_FAILURE;
    }
    
    {
        apr_bucket *e;
        apr_pollset_t *pollset;
        apr_pollfd_t pollfd;

        ctxt.p = p;
        ctxt.buckets = apr_bucket_alloc_create(p);
        ctxt.bbin = apr_brigade_create(p, ctxt.buckets);
        ctxt.bbtmp = apr_brigade_create(p, ctxt.buckets);
        
        e = apr_bucket_pipe_create(infile, ctxt.buckets);
        APR_BRIGADE_INSERT_TAIL(ctxt.bbin, e);
        
        rv = apr_pollset_create(&pollset, 1, ctxt.p, 0);

        if (rv != APR_SUCCESS) {
            fprintf(stderr, "Unable to create pollset!"NL);
            return EXIT_FAILURE;
        }
        
        pollfd.desc_type = APR_POLL_FILE;
        pollfd.reqevents = APR_POLLIN;
        pollfd.desc.f = infile;
        pollfd.client_data = NULL;

        rv = apr_pollset_add(pollset, &pollfd);

        if (rv != APR_SUCCESS) {
            fprintf(stderr, "Unable to add input to pollset!"NL);
            return EXIT_FAILURE;
        }
        
        do {
            int lrv;
            const apr_pollfd_t *descs = NULL;
            
            rv = apr_pollset_poll(pollset, -1, &lrv, &descs);
            
            if (APR_STATUS_IS_EINTR(rv)) {
                continue;
            }
            else if (rv) {
                fprintf(stderr, "pollset failed!"NL);
                return EXIT_FAILURE;
            }
            
            if (!lrv) {
                continue;
            }
            
            do {
                rv = read_line(&ctxt);
                apr_brigade_cleanup(ctxt.bbtmp);
            } while(rv == APR_SUCCESS);
            
            if (rv && !APR_STATUS_IS_EAGAIN(rv)) {
                break;
            }
            rv = APR_SUCCESS;
            
        } while (1);

        apr_pollset_destroy(pollset);
    }

    return EXIT_SUCCESS;
}