/**
 * collectd - src/utils_format_graphite.c
 * Copyright (C) 2012  Thomas Meson
 * Copyright (C) 2012  Florian octo Forster
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; only version 2 of the License is applicable.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 *
 * Authors:
 *   Thomas Meson <zllak at hycik.org>
 *   Florian octo Forster <octo at collectd.org>
 **/

#include "collectd.h"
#include "plugin.h"
#include "common.h"

#include "utils_format_graphite.h"
#include "utils_cache.h"
#include "utils_parse_option.h"

/* Utils functions to format data sets in graphite format.
 * Largely taken from write_graphite.c as it remains the same formatting */

static int gr_format_values (char *ret, size_t ret_len,
        int ds_num, const data_set_t *ds, const value_list_t *vl,
        gauge_t const *rates)
{
    size_t offset = 0;
    int status;

    assert (0 == strcmp (ds->type, vl->type));

    memset (ret, 0, ret_len);

#define BUFFER_ADD(...) do { \
    status = ssnprintf (ret + offset, ret_len - offset, \
            __VA_ARGS__); \
    if (status < 1) \
    { \
        return (-1); \
    } \
    else if (((size_t) status) >= (ret_len - offset)) \
    { \
        return (-1); \
    } \
    else \
    offset += ((size_t) status); \
} while (0)

    if (ds->ds[ds_num].type == DS_TYPE_GAUGE)
        BUFFER_ADD ("%f", vl->values[ds_num].gauge);
    else if (rates != NULL)
        BUFFER_ADD ("%f", rates[ds_num]);
    else if (ds->ds[ds_num].type == DS_TYPE_COUNTER)
        BUFFER_ADD ("%llu", vl->values[ds_num].counter);
    else if (ds->ds[ds_num].type == DS_TYPE_DERIVE)
        BUFFER_ADD ("%"PRIi64, vl->values[ds_num].derive);
    else if (ds->ds[ds_num].type == DS_TYPE_ABSOLUTE)
        BUFFER_ADD ("%"PRIu64, vl->values[ds_num].absolute);
    else
    {
        ERROR ("gr_format_values plugin: Unknown data source type: %i",
                ds->ds[ds_num].type);
        return (-1);
    }

#undef BUFFER_ADD

    return (0);
}

static void gr_copy_escape_part (char *dst, const char *src, size_t dst_len,
    char escape_char)
{
    size_t i;

    memset (dst, 0, dst_len);

    if (src == NULL)
        return;

    for (i = 0; i < dst_len; i++)
    {
        if (src[i] == 0)
        {
            dst[i] = 0;
            break;
        }

        if ((src[i] == '.')
                || isspace ((int) src[i])
                || iscntrl ((int) src[i]))
            dst[i] = escape_char;
        else
            dst[i] = src[i];
    }
}

static int gr_format_name (char *ret, int ret_len,
        value_list_t const *vl,
        char const *ds_name,
        char const *prefix,
        char const *postfix,
        char const escape_char,
        unsigned int flags)
{
    char n_host[DATA_MAX_NAME_LEN];
    char n_plugin[DATA_MAX_NAME_LEN];
    char n_plugin_instance[DATA_MAX_NAME_LEN];
    char n_type[DATA_MAX_NAME_LEN];
    char n_type_instance[DATA_MAX_NAME_LEN];

    char tmp_plugin[2 * DATA_MAX_NAME_LEN + 1];
    char tmp_type[2 * DATA_MAX_NAME_LEN + 1];

    if (prefix == NULL)
        prefix = "";

    if (postfix == NULL)
        postfix = "";

    gr_copy_escape_part (n_host, vl->host,
            sizeof (n_host), escape_char);
    gr_copy_escape_part (n_plugin, vl->plugin,
            sizeof (n_plugin), escape_char);
    gr_copy_escape_part (n_plugin_instance, vl->plugin_instance,
            sizeof (n_plugin_instance), escape_char);
    gr_copy_escape_part (n_type, vl->type,
            sizeof (n_type), escape_char);
    gr_copy_escape_part (n_type_instance, vl->type_instance,
            sizeof (n_type_instance), escape_char);

    if (n_plugin_instance[0] != '\0')
        ssnprintf (tmp_plugin, sizeof (tmp_plugin), "%s%c%s",
            n_plugin,
            (flags & GRAPHITE_SEPARATE_INSTANCES) ? '.' : '-',
            n_plugin_instance);
    else
        sstrncpy (tmp_plugin, n_plugin, sizeof (tmp_plugin));

    if (n_type_instance[0] != '\0')
        ssnprintf (tmp_type, sizeof (tmp_type), "%s%c%s",
            n_type,
            (flags & GRAPHITE_SEPARATE_INSTANCES) ? '.' : '-',
            n_type_instance);
    else
        sstrncpy (tmp_type, n_type, sizeof (tmp_type));

    /* Assert always_append_ds -> ds_name */
    assert (!(flags & GRAPHITE_ALWAYS_APPEND_DS) || (ds_name != NULL));
    if (ds_name != NULL)
        ssnprintf (ret, ret_len, "%s%s%s.%s.%s.%s",
            prefix, n_host, postfix, tmp_plugin, tmp_type, ds_name);
    else
        ssnprintf (ret, ret_len, "%s%s%s.%s.%s",
            prefix, n_host, postfix, tmp_plugin, tmp_type);

    return (0);
}

int format_graphite (char *buffer, size_t buffer_size,
    data_set_t const *ds, value_list_t const *vl,
    char const *prefix, char const *postfix, char const escape_char,
    unsigned int flags)
{
    int status = 0;
    int i;
    int buffer_pos = 0;

    gauge_t *rates = NULL;
    if (flags & GRAPHITE_STORE_RATES)
      rates = uc_get_rate (ds, vl);

    for (i = 0; i < ds->ds_num; i++)
    {
        char const *ds_name = NULL;
        char        key[10*DATA_MAX_NAME_LEN];
        char        values[512];
        size_t      message_len;
        char        message[1024];

        if ((flags & GRAPHITE_ALWAYS_APPEND_DS)
            || (ds->ds_num > 1))
          ds_name = ds->ds[i].name;

        /* Copy the identifier to `key' and escape it. */
        status = gr_format_name (key, sizeof (key), vl, ds_name,
                    prefix, postfix, escape_char, flags);
        if (status != 0)
        {
            ERROR ("format_graphite: error with gr_format_name");
            sfree (rates);
            return (status);
        }

        escape_string (key, sizeof (key));
        /* Convert the values to an ASCII representation and put that into
         * `values'. */
        status = gr_format_values (values, sizeof (values), i, ds, vl, rates);
        if (status != 0)
        {
            ERROR ("format_graphite: error with gr_format_values");
            sfree (rates);
            return (status);
        }

        /* Compute the graphite command */
        message_len = (size_t) ssnprintf (message, sizeof (message),
                "%s %s %u\r\n",
                key,
                values,
                (unsigned int) CDTIME_T_TO_TIME_T (vl->time));
        if (message_len >= sizeof (message)) {
            ERROR ("format_graphite: message buffer too small: "
                    "Need %zu bytes.", message_len + 1);
            sfree (rates);
            return (-ENOMEM);
        }

        /* Append it in case we got multiple data set */
        if ((buffer_pos + message_len) >= buffer_size)
        {
            ERROR ("format_graphite: target buffer too small");
            sfree (rates);
            return (-ENOMEM);
        }
        memcpy((void *) (buffer + buffer_pos), message, message_len);
        buffer_pos += message_len;
    }
    sfree (rates);
    return (status);
} /* int format_graphite */

/* vim: set sw=2 sts=2 et fdm=marker : */
