/* 
 *  libpinyin
 *  Library to deal with pinyin.
 *  
 *  Copyright (C) 2006-2007, 2011 Peng Wu
 *  
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <glib.h>
#include "pinyin.h"

static PhraseLargeTable * g_phrases = NULL;

void print_help(){
    printf("Usage: gen_ngram [--skip-pi-gram-training]\n");
    printf("                 [--bigram-file <FILENAME>]\n");
}

int main(int argc, char * argv[]){
    int i = 1;
    bool train_pi_gram = true;
    const char * bigram_filename = "../../data/bigram.db";

    setlocale(LC_ALL, "");
    while ( i < argc ){
	if ( strcmp("--help", argv[i]) == 0){
	    print_help();
            exit(0);
	}else if ( strcmp("--skip-pi-gram-training", argv[i]) == 0 ){
	    train_pi_gram = false;
	}else if ( strcmp("--bigram-file", argv[i]) == 0){
            if ( ++i >= argc ) {
                print_help();
                exit(EINVAL);
            }
            bigram_filename = argv[i];
	}else{
            print_help();
            exit(EINVAL);
        }
	++i;
    }
    
    g_phrases = new PhraseLargeTable;
    //init phrase lookup
    MemoryChunk * chunk = new MemoryChunk;
    chunk->load("../../data/phrase_index.bin");
    g_phrases->load(chunk);

    FacadePhraseIndex phrase_index;
    
    //gb_char binary file
    chunk = new MemoryChunk;
    chunk->load("../../data/gb_char.bin");
    phrase_index.load(1, chunk);
    
    //gbk_char binary file
    chunk = new MemoryChunk;
    chunk->load("../../data/gbk_char.bin");
    phrase_index.load(2, chunk);
    
    Bigram bigram;
    bigram.attach(bigram_filename, ATTACH_CREATE|ATTACH_READWRITE);
    
    
    char* linebuf = NULL;
    size_t size = 0;
    phrase_token_t last_token, cur_token = last_token = 0;
    while( getline(&linebuf, &size, stdin) ){
	if ( feof(stdin) )
	    break;
        linebuf[strlen(linebuf)-1] = '\0';

        glong phrase_len = 0;
        utf16_t * phrase = g_utf8_to_utf16(linebuf, -1, NULL, &phrase_len, NULL);

        if ( phrase_len == 0 )
            continue;

	phrase_token_t token = 0;
        int result = g_phrases->search( phrase_len, phrase, token);
	if ( ! (result & SEARCH_OK) )
	    token = 0;

	last_token = cur_token;
	cur_token = token;
	if ( cur_token ){
	    //training uni-gram
            phrase_index.add_unigram_frequency(cur_token, 1);
	}
	if ( cur_token ){
	    SingleGram * single_gram = NULL;
	    if ( 0 == last_token ){
		if (train_pi_gram)
		    bigram.load(sentence_start, single_gram);
	    } else
		bigram.load(last_token, single_gram);

	    if ( NULL == single_gram ){
		single_gram = new SingleGram;
	    }
	    guint32 freq, total_freq;
	    //increase freq
	    if (single_gram->get_freq(cur_token, freq))
                assert(single_gram->set_freq(cur_token, freq + 1));
            else
                assert(single_gram->insert_freq(cur_token, 1));
	    //increase total freq
	    single_gram->get_total_freq(total_freq);
	    single_gram->set_total_freq(total_freq + 1);
	    if ( 0 == last_token ){
		if ( train_pi_gram )
		    bigram.store(sentence_start, single_gram);
	    }else
		bigram.store(last_token, single_gram);
	    delete single_gram;
	}
    }

    free(linebuf);
    
    MemoryChunk * new_chunk = new MemoryChunk;
    phrase_index.store(1, new_chunk);
    new_chunk->save("../../data/gb_char.bin");
    phrase_index.load(1, new_chunk);

    new_chunk = new MemoryChunk;
    phrase_index.store(2, new_chunk);
    new_chunk->save("../../data/gbk_char.bin");
    phrase_index.load(2, new_chunk);

    return 0;
}