#include <stdlib.h>

#include "../readstat.h"

#include "test_buffer.h"

#include "test_buffer_io.h"

int rt_open_handler(const char *path, void *io_ctx) {

    return 0;

}

int rt_close_handler(void *io_ctx) {

    return 0;

}

readstat_off_t rt_seek_handler(readstat_off_t offset,

        readstat_io_flags_t whence, void *io_ctx) {

    rt_buffer_ctx_t *buffer_ctx = (rt_buffer_ctx_t *)io_ctx;

    readstat_off_t newpos = -1;

    if (whence == READSTAT_SEEK_SET) {

        newpos = offset;

    } else if (whence == READSTAT_SEEK_CUR) {

        newpos = buffer_ctx->pos + offset;

    } else if (whence == READSTAT_SEEK_END) {

        newpos = buffer_ctx->buffer->used + offset;

    }

    if (newpos < 0)

        return -1;

    if (newpos > buffer_ctx->buffer->used)

        return -1;

    buffer_ctx->pos = newpos;

    return newpos;

}

ssize_t rt_read_handler(void *buf, size_t nbytes, void *io_ctx) {

    rt_buffer_ctx_t *buffer_ctx = (rt_buffer_ctx_t *)io_ctx;

    ssize_t bytes_copied = 0;

    ssize_t bytes_left = buffer_ctx->buffer->used - buffer_ctx->pos;

    if (nbytes <= bytes_left) {

        memcpy(buf, buffer_ctx->buffer->bytes + buffer_ctx->pos, nbytes);

        bytes_copied = nbytes;

    } else if (bytes_left > 0) {

        memcpy(buf, buffer_ctx->buffer->bytes + buffer_ctx->pos, bytes_left);

        bytes_copied = bytes_left;

    }

    buffer_ctx->pos += bytes_copied;

    return bytes_copied;

}

readstat_error_t rt_update_handler(long file_size, readstat_progress_handler progress_handler,

        void *user_ctx, void *io_ctx) {

    if (!progress_handler)

        return READSTAT_OK;

    rt_buffer_ctx_t *buffer_ctx = (rt_buffer_ctx_t *)io_ctx;

    if (progress_handler(1.0 * buffer_ctx->pos / buffer_ctx->buffer->used, user_ctx))

        return READSTAT_ERROR_USER_ABORT;

    return READSTAT_OK;

}