/*
 *
 * Copyright 2023 Oleg Borodin  <borodin@unix7.org>
 *
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>

#include <bstream.h>


#define STREAM_INITCAPA 128

bstream_t* bstream_init(bstream_t* stream) {
    stream->data = malloc(STREAM_INITCAPA);
    stream->wpos = 0;
    stream->rpos = 0;
    stream->capa = STREAM_INITCAPA;
    return stream;
}

bstream_t* new_bstream() {
    bstream_t* stream = malloc(sizeof(bstream_t));
    if (stream == NULL) return NULL;
    stream->data = malloc(STREAM_INITCAPA);
    stream->wpos = 0;
    stream->rpos = 0;
    stream->capa = STREAM_INITCAPA;
    return stream;
}

size_t bstream_dump(bstream_t * stream) {
    for (size_t i = 0; i < stream->wpos; i++) {
        printf("%c", stream->data[i]);
    }
    return stream->wpos;
}


ssize_t bstream_write(bstream_t * stream, void* buf, size_t size) {
    if ((stream->wpos + size) > stream->capa) {
        size_t newcapa = stream->capa * 2;
        stream->data = realloc(stream->data, (size_t)newcapa);
        stream->capa = newcapa;
    }
    if (buf != NULL) {
        memcpy(&(stream->data[stream->wpos]), buf, (size_t)size);
    }
    stream->wpos += size;
    return (ssize_t)size;
}

ssize_t bstream_read(bstream_t * stream, void* buf, size_t size) {
    size_t unread = stream->wpos - stream->rpos;
    if (size > unread) {
        size = unread;
    }
    if (buf != NULL) {
        memcpy(buf, &(stream->data[stream->rpos]), size);
    }
    stream->rpos += size;
    return (ssize_t)size;
}

#define RBUF_SIZE 64

ssize_t bstream_fread(bstream_t * stream, char* filename) {

    int fd = open(filename, O_RDONLY);
    if (fd < 0) return (ssize_t)-1;

    char buf[RBUF_SIZE];
    size_t size = 0;
    size_t rsize = 0;
    while ((size = (size_t)read(fd, buf, RBUF_SIZE)) > 0) {
        if ((stream->wpos + size) > stream->capa) {
            size_t newcapa = stream->capa * 2;
            stream->data = realloc(stream->data, (size_t)newcapa);
            stream->capa = newcapa;
        }
        memcpy(&(stream->data[stream->wpos]), buf, (size_t)size);
        stream->wpos += size;
        rsize += size;
    }
    close(fd);
    return (ssize_t)rsize;
}

char bstream_getc(bstream_t * stream) {
    size_t unread = stream->wpos - stream->rpos;

    if (unread == 0)
        return EOF;
    return (char)stream->data[stream->rpos++];
}


size_t bstream_wpos(bstream_t * stream) {
    return stream->wpos;
}

size_t bstream_rpos(bstream_t * stream) {
    return stream->rpos;
}


void bstream_destroy(bstream_t * stream) {
    if (stream != NULL)
        free(stream->data);
}

void bstream_free(bstream_t * stream) {
    if (stream != NULL)
        free(stream->data);
    free(stream);
}