/**
 * journald-native ruby gem - a simple systemd-journal wrapper
 * Copyright (C) 2014 Anton Smirnov
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <ruby.h>
#include "journald_native.h"

void Init_journald_native();

/* initializers */
static void jdl_init_modules();
static void jdl_init_constants();
static void jdl_init_methods();

/* methods */
static VALUE jdl_native_print(VALUE self, VALUE priority, VALUE message);
static VALUE jdl_native_send(int argc, VALUE* argv, VALUE self);
static VALUE jdl_native_perror(VALUE self, VALUE message);
static VALUE jdl_native_is_dummy();

/* globals */
static VALUE mJournald;
static VALUE mNative;

void Init_journald_native()
{
    jdl_init_modules();
    jdl_init_constants();
    jdl_init_methods();
}

static void jdl_init_modules()
{
    mJournald = rb_define_module("Journald");
    mNative   = rb_define_module_under(mJournald, "Native");
}

static void jdl_init_constants()
{
    rb_define_const(mJournald, "LOG_EMERG",   INT2NUM(LOG_EMERG));    /* system is unusable */
    rb_define_const(mJournald, "LOG_ALERT",   INT2NUM(LOG_ALERT));    /* action must be taken immediately */
    rb_define_const(mJournald, "LOG_CRIT",    INT2NUM(LOG_CRIT));     /* critical conditions */
    rb_define_const(mJournald, "LOG_ERR",     INT2NUM(LOG_ERR));      /* error conditions */
    rb_define_const(mJournald, "LOG_WARNING", INT2NUM(LOG_WARNING));  /* warning conditions */
    rb_define_const(mJournald, "LOG_NOTICE",  INT2NUM(LOG_NOTICE));   /* normal but significant condition */
    rb_define_const(mJournald, "LOG_INFO",    INT2NUM(LOG_INFO));     /* informational */
    rb_define_const(mJournald, "LOG_DEBUG",   INT2NUM(LOG_DEBUG));    /* debug-level messages */

    // dummy detection const
    rb_define_const(mNative,   "IS_DUMMY",    jdl_native_is_dummy());
}

static void jdl_init_methods()
{
    rb_define_singleton_method(mNative, "sd_journal_print",  jdl_native_print,  2);
    rb_define_singleton_method(mNative, "sd_journal_send",   jdl_native_send,  -1); /* -1 to pass as C array */
    rb_define_singleton_method(mNative, "sd_journal_perror", jdl_native_perror, 1);

    // dummy detection method
    rb_define_singleton_method(mNative, "dummy?", jdl_native_is_dummy, 0);
}

static VALUE jdl_native_print(VALUE v_self, VALUE v_priority, VALUE v_message)
{
    int   priority = NUM2INT(v_priority);
    char* message  = StringValueCStr(v_message);
    int   result   = sd_journal_print(priority, "%s", message);

    return INT2NUM(result);
}

static VALUE jdl_native_send(int argc, VALUE* argv, VALUE self)
{
    /* first check everything is a string / convertable to string */
    for (int i = 0; i < argc; i++) {
        StringValue(argv[i]); /* you may get a ruby exception here */
    }

    /* allocate memory after all checks to avoid possible memory leak */
    iovec_t* msgs = xcalloc(argc, sizeof(iovec_t));

    for (int i = 0; i < argc; i++) {
        VALUE v = argv[i];
        msgs[i].iov_base = RSTRING_PTR(v);
        msgs[i].iov_len  = RSTRING_LEN(v);
    }

    int result = sd_journal_sendv(msgs, argc);

    xfree(msgs);

    return INT2NUM(result);
}

static VALUE jdl_native_perror(VALUE v_self, VALUE v_message)
{
    char* message = StringValueCStr(v_message);
    int   result = sd_journal_perror(message);

    return INT2NUM(result);
}

static VALUE jdl_native_is_dummy()
{
    return JOURNALD_NATIVE_SD_JOURNAL_DUMMY ? Qtrue : Qfalse;
}