/*
    ELAPI

    Module implements high level API for logging events

    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 <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/time.h>
#include <dlfcn.h>
#include "elapi_debug.h"
#include "elapi_dispatcher.h"
#include "elapi_collection.h"
#include "elapi_sink.h"

char event_name[] = "event";

/* Pointer to default global dispatcher */
struct dispatcher_handle *global_dispatcher = (struct dispatcher_handle *)(NULL);


/* Function to open audit using default routing functions */
/* If appname is NULL - uses module name */
int open_audit(const char *appname, char **desired_sinks) 
{
    int error;
    
    DEBUG_STRING("open_audit","Entry");

    error = create_audit_dispatcher(&global_dispatcher,appname,desired_sinks,NULL,NULL);

    DEBUG_NUMBER("open_audit Exit:",error);
    return error;
}

/* Function to open audit using custom routing function */
int open_audit_with_router(const char *appname, 
                           char **desired_sinks,
                           event_router_fn desired_router,
                           void *custom_data)
{
    int error;
    
    DEBUG_STRING("open_audit_with_router","Entry");

    error = create_audit_dispatcher(&global_dispatcher,appname,desired_sinks,desired_router,custom_data);

    DEBUG_NUMBER("open_audit_with_router Exit:",error);
    return error;
}


/* Get dispatcher if you want to add sink to a default deispatcher or do some advaced operations */
struct dispatcher_handle *get_dispatcher(void)
{
    DEBUG_STRING("get_dispatcher was called.","Returning default dispatcher.");
    return global_dispatcher;
}

/* Close audit */
void close_audit(void)
{
    DEBUG_STRING("close_audit","Entry");

    destroy_audit_dispatcher(global_dispatcher);

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

/* Creates collection with the timestamp already prepopulated */
int create_event(struct collection_item **event,char *name)
{
    int error;
    char *nm;    

    DEBUG_STRING("create_event","Entry");

    if(name == NULL) nm = event_name;
    else nm = name;

    /* Construct collection and add timestamp */
    if(((error = create_collection(event,nm)) != 0) ||
       ((error = set_timestamp(*event,NULL,NULL)) !=0 )) {
        DEBUG_NUMBER("Failed to create event:",error);
        return error;
    }

    DEBUG_STRING("create_event Exit:","");
    return EOK;

}

/* Internal untility function to tokenize a string */
static char *get_next_property(char *cursor,int *type, char **property, int *has_len) 
{
    int adjust_by;  
    char *start;

    DEBUG_STRING("get_next_property","Entry");

    DEBUG_STRING("Cursor",cursor);

    /* Initialize passed in data */
    *has_len = 0;
    *property = NULL;
    *type = ELAPI_TYPE_STRING;

    while((*cursor != '\0') && (*cursor != '%')) cursor++;

    /* End of string - we are done */
    if(*cursor == '\0') {
        DEBUG_STRING("End of format - returning.","");
        return NULL; 
    }

	/* This is the beginning of the formatted token */
    cursor++;
    if((*cursor == '*') && (*(cursor+1) == 's') && (*(cursor+2) == '(')) {
        *type = ELAPI_TYPE_STRING;
        *has_len = 1;        
        adjust_by = 3;
    } 
    else if((*cursor == 's') && (*(cursor+1) == '(')) {
        *type = ELAPI_TYPE_STRING;
        adjust_by = 2;
    } 
    else if(((*cursor == 'i')||(*cursor == 'd')) && (*(cursor+1) == '(')) {
        *type = ELAPI_TYPE_INTEGER;
        adjust_by = 2;
    } 
    else if((*cursor == 'u') && (*(cursor+1) == '(')) {
        *type = ELAPI_TYPE_INTEGER;
        adjust_by = 2;
    } 
    else if((*cursor == 'l') && ((*(cursor+1) == 'i')||(*(cursor+1) == 'd')) && (*(cursor+2) == '(')) {
        *type = ELAPI_TYPE_LONG;
        adjust_by = 3;
    } 
    else if((*cursor == 'l') && (*(cursor+1) == 'u') && (*(cursor+2) == '(')) {
        *type = ELAPI_TYPE_LONG;
        adjust_by = 3;
    } 
    else if(((*cursor == 'f')||(*cursor == 'e')) && (*(cursor+1) == '(')) {
        *type = ELAPI_TYPE_DOUBLE;
        adjust_by = 2;
    } 
    else if((*cursor == 'b') && (*(cursor+1) == '(')) {
        *type = ELAPI_TYPE_BINARY;
        adjust_by = 2;
    }
    else {
        DEBUG_STRING("Invalid type specifier format:",cursor);
        return cursor; 
    }
 
    cursor += adjust_by;
    start = cursor;

    /* Now we need to extruct the name of the property */
    /* We will not be nice here - the add_property will validate if the name is ok */
    while((*cursor != '\0') && (*cursor != ')')) cursor++;

    /* End of string - we are done */
    if((*cursor == '\0') || (cursor==start)) {
        DEBUG_STRING("Bad property","");
        return cursor; 
    }

    *cursor ='\0';
    *property = start;
    *cursor++;

    DEBUG_STRING("Returning Property:",*property);
    DEBUG_NUMBER("Returning Type:",*type);
    DEBUG_NUMBER("Returning Has length:",*has_len);


    DEBUG_STRING("get_next_property","Exit");

    return cursor;
} 

/* Creates collection - event based on the specified format */
int construct_event(struct collection_item **event,char *name, char *format, ...)
{
    int error;
    char *dup_fmt;
    char *cursor;
    int type;
    char *property;
    int has_len;
    va_list args;
    char *data_str;
    int data_int;
    unsigned int data_uint;
    long data_long;
    unsigned long data_ulong;
    void *data_bin;
    double data_dbl;
    int length;
    void *data;
 
    DEBUG_STRING("constuct_event","Entry");

    /* Create event with timestamp */
    error = create_event(event,name);
    if(error) {
        DEBUG_NUMBER("create_event returned error:",error);
        return error;
    }

    /* Format is omitted just return */
    if(format == NULL) {
        DEBUG_STRING("constuct_event","NULL format exit");
        return EOK;
    }

    /* Process the format */
    /* Duplicate it */
    errno = 0;
    dup_fmt = strdup(format);
    if(dup_fmt == NULL) {
        error = errno;
        DEBUG_NUMBER("Failed to dup format:",error);
        destroy_collection(*event);
        return ENOMEM;
    }
        
    va_start(args,format);

    cursor = dup_fmt;
    while((cursor = get_next_property(cursor,&type,&property,&has_len)) != NULL) {

        /* Handle the case when the parsing failed */
        if(property == NULL) {
            DEBUG_STRING("Error parsing:",dup_fmt);
            free(dup_fmt);
            destroy_collection(*event);
            va_end(args);
            return error;
        }

        /* Get data */
        switch(type) {

            case ELAPI_TYPE_STRING:     data_str = va_arg(args,char *);
                                        data = (void *)data_str;
                                        if(has_len) length = va_arg(args,int);
                                        else length = strlen(data_str)+1; 
                                        DEBUG_STRING("Adding string:",data_str);
                                        DEBUG_NUMBER("Length:",length);
                                        break;
            case ELAPI_TYPE_BINARY:     data_bin = va_arg(args,void *);
                                        data = (void *)data_bin;
                                        length = va_arg(args,int);
                                        break;
            case ELAPI_TYPE_INTEGER:    data_int = va_arg(args,int);
                                        data = (void *)(&data_int);
                                        length = sizeof(int);
                                        break;
            case ELAPI_TYPE_UNSIGNED:   data_uint = va_arg(args,unsigned int);
                                        data = (void *)(&data_uint);
                                        length = sizeof(unsigned int);
                                        break;
            case ELAPI_TYPE_LONG:       data_long = va_arg(args,long);
                                        data = (void *)(&data_long);
                                        length = sizeof(long);
                                        break;
            case ELAPI_TYPE_ULONG:      data_ulong = va_arg(args,unsigned long);
                                        data = (void *)(&data_ulong);
                                        length = sizeof(unsigned long);
                                        break;
            case ELAPI_TYPE_DOUBLE:     data_dbl = va_arg(args,double);
                                        data = (void *)(&data_dbl);
                                        length = sizeof(double);
                                        break;

            default:
                                        DEBUG_NUMBER("Unknown type",type);
                                        continue;
        }
         
        /* Add property to the event */
        error = add_any_property(*event, NULL, property, type, data,length);
        if(error) {
            DEBUG_STRING("Error adding property:",property);
            DEBUG_NUMBER("Type :",type);
            DEBUG_NUMBER("Length :",length);
            free(dup_fmt);
            destroy_collection(*event);
            va_end(args);
            return error;
        }
    }

    va_end(args);
    free(dup_fmt);
    DEBUG_STRING("constuct_event","NULL format exit");
    return EOK;
}

/* Add/Updates the event properties based on the format */ 
int modify_event(struct collection_item *event, int update, char *format, ...)
{
    int error;
    char *dup_fmt;
    char *cursor;
    int type;
    char *property;
    int has_len;
    va_list args;
    char *data_str;
    int data_int;
    unsigned int data_uint;
    long data_long;
    unsigned long data_ulong;
    void *data_bin;
    double data_dbl;
    int length;
    void *data;
 
    DEBUG_STRING("modify_event","Entry");


    /* Format is omitted just return */
    if(format == NULL) {
        DEBUG_STRING("modify_event","NULL format exit");
        return EOK;
    }

    /* Process the format */
    /* Duplicate it */
    errno = 0;
    dup_fmt = strdup(format);
    if(dup_fmt == NULL) {
        error = errno;
        DEBUG_NUMBER("Failed to dup format:",error);
        return ENOMEM;
    }
        
    va_start(args,format);

    cursor = dup_fmt;
    while((cursor = get_next_property(cursor,&type,&property,&has_len)) != NULL) {

        /* Handle the case when the parsing failed */
        if(property == NULL) {
            DEBUG_STRING("Error parsing:",dup_fmt);
            free(dup_fmt);
            va_end(args);
            return error;
        }

        /* Get data */
        switch(type) {

            case ELAPI_TYPE_STRING:     data_str = va_arg(args,char *);
                                        data = (void *)data_str;
                                        if(has_len) length = va_arg(args,int);
                                        else length = strlen(data_str)+1; 
                                        DEBUG_STRING("Modifying string:",data_str);
                                        DEBUG_NUMBER("Length:",length);
                                        break;
            case ELAPI_TYPE_BINARY:     data_bin = va_arg(args,void *);
                                        data = (void *)data_bin;
                                        length = va_arg(args,int);
                                        break;
            case ELAPI_TYPE_INTEGER:    data_int = va_arg(args,int);
                                        data = (void *)(&data_int);
                                        length = sizeof(int);
                                        break;
            case ELAPI_TYPE_UNSIGNED:   data_uint = va_arg(args,unsigned int);
                                        data = (void *)(&data_uint);
                                        length = sizeof(unsigned int);
                                        break;
            case ELAPI_TYPE_LONG:       data_long = va_arg(args,long);
                                        data = (void *)(&data_long);
                                        length = sizeof(long);
                                        break;
            case ELAPI_TYPE_ULONG:      data_ulong = va_arg(args,unsigned long);
                                        data = (void *)(&data_ulong);
                                        length = sizeof(unsigned long);
                                        break;
            case ELAPI_TYPE_DOUBLE:     data_dbl = va_arg(args,double);
                                        data = (void *)(&data_dbl);
                                        length = sizeof(double);
                                        break;

            default:
                                        DEBUG_NUMBER("Unknown type",type);
                                        continue;
        }

        /* Try to update property first but only on the high level */
        if(update) {
            error = update_property(event, property, type, data, length, ELAPI_TRAVERSE_IGNORE);
            if(error == ENOENT) error = add_any_property(event, NULL, property, type, data,length);
        }
        else error = add_any_property(event, NULL, property, type, data,length);
        if(error) {
            DEBUG_STRING("Error adding/updating property:",property);
            DEBUG_NUMBER("Type :",type);
            DEBUG_NUMBER("Length :",length);
            free(dup_fmt);
            va_end(args);
            return error;
        }
    }

    va_end(args);
    DEBUG_STRING("modify_event","NULL format exit");
    return EOK;
} 

/* Log event  */
void log_event(char *format_string,struct collection_item *event)
{
    DEBUG_STRING("log_event","Entry");
    log_audit_event(global_dispatcher, format_string, event);
    DEBUG_STRING("log_event","Entry");
}