/*
    ELAPI

    Implemenation of the file sink.

    Copyright (C) Dmitri Pal <dpal@redhat.com> 2009

    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; either version 3 of the License, or
    (at your option) any later version.
    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, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <errno.h>
#include <malloc.h>
#include <syslog.h>
#include "elapi_sink.h"
#include "elapi_collection.h"
#include "elapi_debug.h"
#include "elapi_util.h"
#include "elapi_ini.h"

/* FIXME - this should be taken from the config.h generated by autotools */
#define FILE_RETRY    60
/* 
#define FILE_AUDIT_CONFIG  "/etc/elapi/file_defaults.conf"
#define FILE_AUDIT_DIR     "/etc/elapi/file_defaults.d"
*/
#define FILE_AUDIT_CONFIG  "/home/dpal/IPA/Code/elapi/etc/file_defaults.conf"
#define FILE_AUDIT_DIR     "/home/dpal/IPA/Code/elapi/etc/file_defaults.d"


/* FIXME there is currently no code 
 * to make sure we do not call syslog functions from multiple dispatchers.
 * We probably should create a mutex at the load of the library and
 * set a flag when the init function is called the first time
 * and not call the openlog any more times.
 * But I guess syslog can deal with this internally.
 */ 


/* Default conmfiguration for syslog */
struct file_conf {
    int keep_open;    
    char *file_name;
    FILE *file;
};

/* Internal function to intialize configuration */   
static int init_config(struct data_descriptor *dblock) 
{
    struct file_conf *conf_data;
    struct collection_item *config_from_file = (struct collection_item *)(NULL);
    int found = 0;
    int *keep_open_cfg = (int *)(NULL);
    char *file_name_cfg = NULL;
    int error;

    DEBUG_STRING("init_config","Entry");

    /* Allocate configuration data */
    conf_data = (struct file_conf *)(malloc(sizeof(struct file_conf)));
    if(conf_data == (struct file_conf *)(NULL)) return errno;

    /* Read configuration from the configuration file if any */
    (void)config_to_collection(dblock->appname, FILE_AUDIT_CONFIG, FILE_AUDIT_DIR, &config_from_file); 
    
    conf_data->keep_open = 1;
    conf_data->file_name = NULL;

    DEBUG_NUMBER("Keep open:",conf_data->keep_open);
    DEBUG_STRING("File name:",conf_data->file_name);

    /* Update defaults with settings from the file */
    error = get_value_from_config((void *)(&keep_open_cfg),ELAPI_TYPE_INTEGER, INI_DEFAULT_SECTION,"keep_open",config_from_file);
    if(error != EOK) {
        /* There is fundamentally something wrong */
        DEBUG_NUMBER("Attempt to get option returned error",error);        
        free((void *)(conf_data));       
        return error; 
    }

    /* Get the value */
    if(keep_open_cfg != (int *)(NULL)) {
        conf_data->keep_open = *keep_open_cfg;
        free((void *)(keep_open_cfg));
    } 
        
    error = get_value_from_config((void *)(&file_name_cfg),ELAPI_TYPE_STRING, INI_DEFAULT_SECTION,"file_name",config_from_file);
    if(error != EOK) {
        /* There is fundamentally something wrong */
        DEBUG_NUMBER("Attempt to get option returned error",error);        
        free((void *)(conf_data));       
        return error; 
    }

    /* Get the value */
    if(file_name_cfg != (char *)(NULL)) {
        conf_data->file_name = file_name_cfg;
    } 

    DEBUG_NUMBER("Keep open (after conf file):",conf_data->keep_open);
    DEBUG_STRING("File name (after conf file):",conf_data->file_name);

    dblock->config = (void *)(conf_data);

    if((conf_data->file_name != NULL) && (conf_data->keep_open != 0)) {
        conf_data->file = fopen(conf_data->file_name,"w");
    }
    else conf_data->file = stderr;

    DEBUG_STRING("init_config","Entry");
    return EOK;
}

/***** Standard functions each facility has to provide *****/
/* Initialize facility - open files, establish connnectons, etc... */
static int file_sink_init(struct data_descriptor *dblock)
{
    struct serial_data *event_storage;
    int error;

    DEBUG_STRING("file_sink_init","Entry");

    /* Prepare the block where the format function will store its data */
    errno = 0;
    dblock->internal_data = NULL;
    event_storage = (struct serial_data *)(malloc(sizeof(struct serial_data)));
    if(event_storage == (struct serial_data *)(NULL)) return errno;

    event_storage->buffer = NULL;
    event_storage->size = 0;
    event_storage->length = 0;
    event_storage->nest_level = 0;

    dblock->internal_data = (void *)(event_storage);
    
    /* Prepare the configuration data block */
    if((error = init_config(dblock))) {
        DEBUG_NUMBER("Failed to init config",error);
        free(dblock->internal_data);
        dblock->internal_data = NULL;        
        return error;
    }

    DEBUG_NUMBER("DBLOCK in init",dblock);
    DEBUG_NUMBER("internal data in init",dblock->internal_data);

    DEBUG_STRING("file_sink_init","Exit");
    return EOK;
}


/* Formatting calback */ 
static int file_sink_format(struct data_descriptor *dblock,
                              char *format_str,
                              struct collection_item *event)
{
    struct serial_data *serialized_data;
    int error = EOK;

    DEBUG_STRING("file_sink_format","Entry");
    DEBUG_NUMBER("DBLOCK in format",dblock);
    DEBUG_NUMBER("internal data in format",dblock->internal_data);

    serialized_data = (struct serial_data *)(dblock->internal_data);

    if(format_str != NULL) {
        /* Use format string */
        DEBUG_STRING("Using format:",format_str);
        error = serialize_with_format(event,format_str,serialized_data);
    }
    else {
        /* Traverse collection */
        DEBUG_STRING("Using default serialization callback","");
        error = traverse_collection(event,ELAPI_TRAVERSE_DEFAULT | ELAPI_TRAVERSE_END ,serialize,(void *)(serialized_data));
    }
    if(error) {
        DEBUG_NUMBER("Serialization returned error",error);
        return error;
    }

    DEBUG_STRING("stderr_sink_format","Exit");
    return EOK;
}


/* Cleanup per event internal data after a failure */
static void file_sink_cleanup(struct data_descriptor *dblock)
{
    struct serial_data *event_storage;

    DEBUG_STRING("file_sink_cleanup","Entry");

    event_storage = (struct serial_data *)(dblock->internal_data);

    if(event_storage->buffer != NULL) {
        free(event_storage->buffer);
        event_storage->buffer = NULL;
        event_storage->size = 0;
        event_storage->length = 0;
        event_storage->nest_level = 0;
    }

    DEBUG_STRING("file_sink_cleanup","Exit");
}

/* Close facility */ 
static void file_sink_close(struct data_descriptor *dblock)
{
    struct file_conf *conf_data;

    DEBUG_STRING("file_sink_close","Entry");

    if(dblock->internal_data != NULL) {
        file_sink_cleanup(dblock);
        free(dblock->internal_data);
        dblock->internal_data=NULL;
    }

    if(dblock->config != NULL) {
        conf_data = (struct file_conf *)(dblock->config);

        if((conf_data->file_name != NULL) && (conf_data->keep_open != 0)) {
            close(conf_data->file);
        }

        if(conf_data->file_name != NULL) free(conf_data->file_name);
        free(dblock->config);
        dblock->config=NULL;
    }

    DEBUG_STRING("file_sink_close","Exit");
}


/* Logging calback */ 
static int file_sink_submit(struct data_descriptor *dblock)
{
    struct serial_data *event_storage;
    struct file_conf *conf_data;

    DEBUG_STRING("file_sink_submit","Entry");
    DEBUG_NUMBER("DBLOCK in submit",dblock);
    DEBUG_NUMBER("internal data in submit",dblock->internal_data);

    event_storage = (struct file_event *)(dblock->internal_data);
    conf_data = (struct file_conf *)(dblock->config);
   
    DEBUG_STRING("OUTPUT:",event_storage->buffer);

    if((conf_data->file_name != NULL) && (conf_data->keep_open == 0)) {
        conf_data->file = fopen(conf_data->file_name,"w");
    }

    fprintf(conf_data->file, "%s\n", event_storage->buffer);

    if((conf_data->file_name != NULL) && (conf_data->keep_open == 0)) {
        close(conf_data->file);
    }

    file_sink_cleanup(dblock);

    DEBUG_STRING("file_sink_submit","Exit");
    return EOK;
}

/* Return a filled in structure */
void get_sink_info(struct sink_capability *sink_cpb_block)
{
    DEBUG_STRING("get_sink_info","Entry");

    sink_cpb_block->retry_interval = FILE_RETRY;
    sink_cpb_block->flags = SINK_FLAG_NO_LIMIT;
    sink_cpb_block->instance = 0;
    sink_cpb_block->init_cb = file_sink_init;
    sink_cpb_block->cleanup_cb = file_sink_cleanup;
    sink_cpb_block->format_cb = file_sink_format;
    sink_cpb_block->submit_cb = file_sink_submit;
    sink_cpb_block->close_cb = file_sink_close;

    DEBUG_STRING("get_sink_info","Exit");    
}