#include<stdio.h>
#include<stdlib.h>
#include<general.h>
#include<string.h>
#include<zlib.h>
#include<inttypes.h>
#include<b64zlib_compression.h>


/* zlib compression base64 encoded */
/* compressed must not be pre-malloced */
/* taken from https://gist.github.com/arq5x/5315739 */
/* This function is not to be used in compressing paraview data. See below. */
ts_uint ts_compress_data(char *data, ts_uint data_len, char **compressed){
	z_stream defstream;
	defstream.zalloc = Z_NULL;
	defstream.zfree = Z_NULL;
	defstream.opaque = Z_NULL;
	defstream.avail_in = data_len+1;
	defstream.next_in = (unsigned char *)data;	
	char *compr=(char *)malloc(data_len*sizeof(char));
	defstream.avail_out = data_len+1;
	defstream.next_out = (unsigned char *)compr;
	deflateInit(&defstream, 6);
//	deflateInit(&defstream, Z_BEST_COMPRESSION);
    	deflate(&defstream, Z_FINISH);
    	deflateEnd(&defstream);
	*compressed=compr;
	return defstream.total_out;
}

ts_uint ts_compress_string64(char *data, ts_uint data_len, char **encoded_compressed){
	size_t nbase;
	char *compr;
	size_t number_of_compressed_bytes=ts_compress_data(data, data_len, &compr);
	*encoded_compressed=base64_encode((unsigned char *)compr,number_of_compressed_bytes,&nbase);
	free(compr);
	return nbase;
}

char *ts_compress(char *data, ts_uint data_len){
	size_t nbase1, nbase2;
	unsigned char *compr=(unsigned char *)malloc(data_len);
	size_t number_of_compressed_bytes=data_len;

	compress(compr,&number_of_compressed_bytes, (unsigned char *)data, data_len);
//	printf("Compressdion error code=%d, Z_OK=%d, Z_BUF_ERROR=%d", errcode, Z_OK, Z_BUF_ERROR);

	char *encoded_compressed=base64_encode((unsigned char *)compr,number_of_compressed_bytes,&nbase1);

	free(compr);

	ts_uint header[4]={1, data_len, data_len, number_of_compressed_bytes};

	char *encoded_header=(char *)base64_encode((unsigned char *)header, 4*sizeof(ts_uint), &nbase2);
	char *return_value=malloc((nbase1+nbase2+1)*sizeof(char));
	strncpy(return_value,encoded_header,nbase2);
	strncpy(return_value+nbase2,encoded_compressed,nbase1);
	*(return_value+nbase1+nbase2)=0;

//	printf("Compressed size in bytes= %ld, size of encoded header= %ld, size of encoded compressed= %ld.\n",number_of_compressed_bytes, nbase2, nbase1);
	free(encoded_compressed);
	free(encoded_header);
	return return_value;
}

ts_uint ts_decompress_string64(char *b64, ts_uint data_len, char **decompressed){
return TS_SUCCESS;

}

/* base64 encoding, taken from http://stackoverflow.com/questions/342409/how-do-i-base64-encode-decode-in-c */
static char encoding_table[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
                                'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
                                'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
                                'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
                                'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
                                'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
                                'w', 'x', 'y', 'z', '0', '1', '2', '3',
                                '4', '5', '6', '7', '8', '9', '+', '/'};
static char *decoding_table = NULL;
static int mod_table[] = {0, 2, 1};


char *base64_encode(const unsigned char *data, size_t input_length, size_t *output_length) {
	*output_length = 4 * ((input_length + 2) / 3);
	int i,j;
	char *encoded_data = malloc(*output_length);
	if (encoded_data == NULL) return NULL;
	
	for (i = 0, j = 0; i < input_length;) {

       	uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
       	uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;

       	encoded_data[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
       	encoded_data[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
       	encoded_data[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
       	encoded_data[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
	}

	for (i = 0; i < mod_table[input_length % 3]; i++)
       	encoded_data[*output_length - 1 - i] = '=';

	return encoded_data;
}


unsigned char *base64_decode(const char *data, size_t input_length, size_t *output_length) {
	int i,j;
	if (decoding_table == NULL) build_decoding_table();

	if (input_length % 4 != 0) return NULL;

	*output_length = input_length / 4 * 3;
	if (data[input_length - 1] == '=') (*output_length)--;
	if (data[input_length - 2] == '=') (*output_length)--;

	unsigned char *decoded_data = malloc(*output_length);
	if (decoded_data == NULL) return NULL;

	for (i = 0, j = 0; i < input_length;) {
       	uint32_t sextet_a = data[i] == '=' ? 0 & i++ : decoding_table[(int)data[i++]];
       	uint32_t sextet_b = data[i] == '=' ? 0 & i++ : decoding_table[(int)data[i++]];
   		uint32_t sextet_c = data[i] == '=' ? 0 & i++ : decoding_table[(int)data[i++]];
       	uint32_t sextet_d = data[i] == '=' ? 0 & i++ : decoding_table[(int)data[i++]];

       	uint32_t triple = (sextet_a << 3 * 6)
        	+ (sextet_b << 2 * 6)
        	+ (sextet_c << 1 * 6)
        	+ (sextet_d << 0 * 6);

       	if (j < *output_length) decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
       	if (j < *output_length) decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
       	if (j < *output_length) decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
    }
	if(decoding_table !=NULL) free(decoding_table);
    return decoded_data;
}


void build_decoding_table() {

    decoding_table = malloc(256);
	int i;
    for (i = 0; i < 64; i++)
		decoding_table[(unsigned char) encoding_table[i]] = i;
}


void base64_cleanup() {
    free(decoding_table);
}