#include <StringStream.h>

#include <Cytoplasm/Memory.h>
#include <Cytoplasm/Stream.h>
#include <Cytoplasm/Str.h>
#include <Cytoplasm/Io.h>

#include <string.h>

static ssize_t
ReadStreamWriter(void *coop, void *to, size_t n)
{
    /* Reading from a stream writer is silly. */
    (void) coop;
    (void) to;
    (void) n;
    return 0;
}
static ssize_t
WriteStreamWriter(void *coop, void *from, size_t n)
{
    char **cook = coop;
    char *tmp = NULL;
    char *str = Malloc(n + 1);

    memcpy(str, from, n);
    str[n] = '\0';

    tmp = *cook;
    *cook = StrConcat(2, *cook, str);
    Free(tmp);
    Free(str);
    return 0;
}
static off_t
SeekStreamWriter(void *coop, off_t mag, int sgn)
{
    /* TODO: Seeking would be useful, though not supported yet. */
    (void) coop;
    (void) mag;
    (void) sgn;
    return 0;
}

static int
CloseStreamWriter(void *coop)
{
    /* Nothing to free as of now. */
    (void) coop;
    return 0;
}

static const IoFunctions Functions = {
    .read   = ReadStreamWriter,
    .seek   = SeekStreamWriter,
    .write  = WriteStreamWriter,
    .close  = CloseStreamWriter,
};

Stream *
StrStreamWriter(char **buffer)
{
    Io *raw_io;
    if (!buffer)
    {
        return NULL;
    }

    raw_io = IoCreate(buffer, Functions);
    return StreamIo(raw_io);
}