/*
 * uhub - A tiny ADC p2p connection hub
 * Copyright (C) 2007-2009, Jan Vidar Krey
 *
 * 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 "uhub.h"

int is_space(char c)
{
	if (c == ' ') return 1;
	return 0;
}

int is_white_space(char c)
{
	if (c == ' ' || c == '\t' || c == '\r') return 1;
	return 0;
}

static int is_printable(unsigned char c)
{
	if (c >= 32)
		return 1;
		
	if (c == '\t' || c == '\r' || c == '\n')
		return 1;
	return 0;
}


char* strip_white_space(char* string)
{
	char* pos;
	
	while (string[0] && is_white_space(string[0])) string++;
	
	if (!*string)
		return 0;
	
	/* Strip appending whitespace */
	pos = &string[strlen(string)-1];
	while (&string[0] < &pos[0] && is_white_space(pos[0])) { pos[0] = 0; pos--; }
	
	return string;
}

static int is_valid_utf8_str(const char* string, size_t length)
{
	int expect = 0;
	char div = 0;
	size_t pos = 0;
	
	if (length == 0) return 1;
	
	for (pos = 0; pos < length; pos++)
	{
		if (expect)
		{
			if ((string[pos] & 0xC0) == 0x80) expect--;
			else return 0;
		}
		else
		{
			if (string[pos] & 0x80)
			{
				for (div = 0x40; div > 0x10; div /= 2)
				{
					if (string[pos] & div) expect++;
					else break;
				}
				if ((string[pos] & div) || (pos+expect >= length)) return 0;
			}
		}
	}
	return 1;
}

int is_valid_utf8(const char* string)
{
	return is_valid_utf8_str(string, strlen(string));
}

int is_printable_utf8(const char* string, size_t length)
{
	size_t pos = 0;
	for (pos = 0; pos < length; pos++)
	{
		if (!is_printable(string[pos]))
			return 0;
	}
	return is_valid_utf8_str(string, length);
}

int is_valid_base32_char(char c)
{
	if ((c >= 'A' && c <= 'Z') || (c >= '2' && c <= '7')) return 1;
	return 0;
}


int is_num(char c)
{
	if (c >= '0' && c <= '9') return 1;
	return 0;
}


void base32_encode(const unsigned char* buffer, size_t len, char* result) {
	unsigned char word = 0;
	size_t n = 0;
	size_t i = 0;
	size_t index = 0;
	for (; i < len;) {
		if (index > 3) {
			word = (buffer[i] & (0xFF >> index));
			index = (index + 5) % 8;
			word <<= index;
			if (i < len - 1)
				word |= buffer[i + 1] >> (8 - index);
			i++;
		} else {
			word = (buffer[i] >> (8 - (index + 5))) & 0x1F;
			index = (index + 5) % 8;
			if (index == 0) i++;
		}
		result[n++] = BASE32_ALPHABET[word];
	}
	result[n] = '\0';
}

void base32_decode(const char* src, unsigned char* dst, size_t len) {
	size_t index = 0;
	size_t offset = 0;
	size_t i = 0;
	memset(dst, 0, len);
	for (i = 0; src[i]; i++) {
		unsigned char n = 0;
		for (; n < 32; n++) if (src[i] == BASE32_ALPHABET[n]) break;
		if (n == 32) continue;
		if (index <= 3) {
			index = (index + 5) % 8;
			if (index == 0) {
				dst[offset++] |= n;
				if (offset == len) break;
			} else {
				dst[offset] |= n << (8 - index);
			}
		} else {
			index = (index + 5) % 8;
			dst[offset++] |= (n >> index);
			if (offset == len) break;
			dst[offset] |= n << (8 - index);
		}
	}
}


int file_read_lines(const char* file, void* data, file_line_handler_t handler)
{
	int fd;
	ssize_t ret;
	char buf[MAX_RECV_BUF];
	char *pos, *start;
	size_t line_count = 0;

	memset(buf, 0, MAX_RECV_BUF);

	hub_log(log_trace, "Opening file %s for line reading.", file);

	fd = open(file, 0);
	if (fd == -1)
	{
		hub_log(log_error, "Unable to open file %s: %s", file, strerror(errno));
		return -2;
	}
	
	ret = read(fd, buf, MAX_RECV_BUF);
	if (ret < 0)
	{
		hub_log(log_error, "Unable to read from file %s: %s", file, strerror(errno));
		close(fd);
		return -1;
	}
	else  if (ret == 0)
	{
		close(fd);
		hub_log(log_warning, "File is empty.");
		return 0;
	}
	else
	{
		close(fd);
		
		/* Parse configuaration */
		start = buf;
		while ((pos = strchr(start, '\n')))
		{
			pos[0] = '\0';
			if (*start)
			{
				hub_log(log_dump, "Line: %s", start);
				if (handler(start, line_count+1, data) < 0)
					return -1;
			}
			start = &pos[1];
			line_count++;
		}
		
		if (*start)
		{
			buf[strlen(start)] = 0;
			hub_log(log_dump, "Line: %s", start);
			if (handler(start, line_count+1, data) < 0)
				return -1;
		}
	}
	return line_count+1;
}


int uhub_atoi(const char* value) {
	int len = strlen(value);
	int offset = 0;
	int val = 0;
	int i = 0;
	for (; i < len; i++)
		if (value[i] > '9' || value[i] < '0') 
			offset++;
			
	for (i = offset; i< len; i++) 
		val = val*10 + (value[i] - '0');
		
	return value[0] == '-' ? -val : val;
}


/*
 * FIXME: -INTMIN is wrong!
 */
const char* uhub_itoa(int val)
{
	size_t i;
	int value;
	static char buf[22];
	memset(buf, 0, sizeof(buf));
	if (!val)
	{
		strcat(buf, "0");
		return buf;
	}
	i = sizeof(buf) - 1;
	for (value = abs(val); value && i > 0; value /= 10)
		buf[--i] = "0123456789"[value % 10];

	if (val < 0 && i > 0)
		buf[--i] = '-';
	return buf+i;
}


const char* uhub_ulltoa(uint64_t val)
{
	size_t i;
	static char buf[22] = { 0, };
	memset(buf, 0, sizeof(buf));
	
	if (!val)
	{
		strcat(buf, "0");
		return buf;
	}
	i = sizeof(buf) - 1;
	for (; val && i > 0; val /= 10)
		buf[--i] = "0123456789"[val % 10];
	return buf+i;
}



#ifndef HAVE_STRNDUP
char* strndup(const char* string, size_t n)
{
	size_t max = MIN(strlen(string), n);
	char* tmp = hub_malloc(max+1);
	memcpy(tmp, string, max);
	tmp[max] = 0;
	return tmp;
}
#endif

#ifndef HAVE_MEMMEM
void* memmem(const void *haystack, size_t haystacklen, const void *needle, size_t needlelen)
{
	char* c_buf = (char*) haystack;
	char* c_pat = (char*) needle;
	char* ptr = memchr(c_buf, c_pat[0], haystacklen);
	
	while (ptr && (&ptr[0] - &c_buf[0] < haystacklen))
	{
		if (!memcmp(ptr, c_pat, needlelen))
			return ptr;
		ptr = memchr(&ptr[1], c_pat[0], &c_buf[haystacklen] - &ptr[0]);
	}
	return 0;
}
#endif