text: /*
   * This software is licensed under the terms of the MIT License.
   * See COPYING for further information.
   * ---
   * Copyright (c) 2011-2019, Lukas Weber <laochailan@web.de>.
   * Copyright (c) 2012-2019, Andrei Alexeyev <akari@taisei-project.org>.
   */
  
  #include "taisei.h"
  
  #include "stringops.h"
  #include "miscmath.h"
  #include "assert.h"
  
  bool strendswith(const char *s, const char *e) {
  	int ls = strlen(s);
  	int le = strlen(e);
  
  	if(le > ls)
  		return false;
  
  	int i; for(i = 0; i < le; ++i)
  	if(s[ls-i-1] != e[le-i-1])
  		return false;
  
  	return true;
  }
  
  bool strstartswith(const char *s, const char *p) {
  	int ls = strlen(s);
  	int lp = strlen(p);
  
  	if(ls < lp)
  		return false;
  
  	return !strncmp(s, p, lp);
  }
  
  bool strendswith_any(const char *s, const char **earray) {
  	for(const char **e = earray; *e; ++e) {
  		if(strendswith(s, *e)) {
  			return true;
  		}
  	}
  
  	return false;
  }
  
  bool strstartswith_any(const char *s, const char **earray) {
  	for(const char **e = earray; *e; ++e) {
  		if(strstartswith(s, *e)) {
  			return true;
  		}
  	}
  
  	return false;
  }
  
  void stralloc(char **dest, const char *src) {
  	free(*dest);
  
  	if(src) {
  		*dest = malloc(strlen(src)+1);
  		strcpy(*dest, src);
  	} else {
  		*dest = NULL;
  	}
  }
  
  char* strjoin(const char *first, ...) {
  	va_list args;
  	size_t size = strlen(first) + 1;
  	char *str = malloc(size);
  
  	strcpy(str, first);
  	va_start(args, first);
  
  	for(;;) {
  		char *next = va_arg(args, char*);
  
  		if(!next) {
  			break;
  		}
  
  		size += strlen(next);
  		str = realloc(str, size);
  		strcat(str, next);
  	}
  
  	va_end(args);
  	return str;
  }
  
  char* vstrfmt(const char *fmt, va_list args) {
  	size_t written = 0;
  	size_t fmtlen = strlen(fmt);
  	size_t asize = 1;
  	char *out = NULL;
  
  	while(asize <= fmtlen)
  		asize *= 2;
  
  	for(;;) {
  		out = realloc(out, asize);
  
  		va_list nargs;
  		va_copy(nargs, args);
  		written = vsnprintf(out, asize, fmt, nargs);
  		va_end(nargs);
  
  		if(written < asize) {
  			break;
  		}
  
  		asize = written + 1;
  	}
  
  	if(asize > strlen(out) + 1) {
  		out = realloc(out, strlen(out) + 1);
  	}
  
  	return out;
  }
  
  char* strfmt(const char *fmt, ...) {
  	va_list args;
  	va_start(args, fmt);
  	char *str = vstrfmt(fmt, args);
  	va_end(args);
  	return str;
  }
  
  char* strftimealloc(const char *fmt, const struct tm *timeinfo) {
  	size_t sz_allocated = 64;
  
  	while(true) {
  		char str[sz_allocated];
  
  		if(strftime(str, sz_allocated, fmt, timeinfo)) {
  			return strdup(str);
  		}
  
  		sz_allocated *= 2;
  	};
  }
  
  void strip_trailing_slashes(char *buf) {
  	for(char *c = buf + strlen(buf) - 1; c >= buf && (*c == '/' || *c == '\\'); c--)
  		*c = 0;
  }
  
  char* strappend(char **dst, char *src) {
  	if(!*dst) {
  		return *dst = strdup(src);
  	}
  
  	*dst = realloc(*dst, strlen(*dst) + strlen(src) + 1);
  	strcat(*dst, src);
  	return *dst;
  }
  
  
  #if SDL_BYTEORDER == SDL_BIG_ENDIAN
  	#define UCS4_ID "UCS-4BE"
  #else
  	#define UCS4_ID "UCS-4LE"
  #endif
  
  uint32_t* ucs4chr(const uint32_t *ucs4, uint32_t chr) {
  	for(; *ucs4 != chr; ++ucs4) {
  		if(!*ucs4) {
  			return NULL;
  		}
  	}
  
  	return (uint32_t*)ucs4;
  }
  
  size_t ucs4len(const uint32_t *ucs4) {
  	size_t len;
  	for(len = 0; *ucs4; ++len, ++ucs4);
  	return len;
  }
  
  void utf8_to_ucs4(const char *utf8, size_t bufsize, uint32_t buf[bufsize]) {
  	uint32_t *bufptr = buf;
  	assert(bufsize > 0);
  
  	while(*utf8) {
  		*bufptr++ = utf8_getch(&utf8);
  		assert(bufptr < buf + bufsize);
  	}
  
  	*bufptr++ = 0;
  }
  
  uint32_t* utf8_to_ucs4_alloc(const char *utf8) {
  	uint32_t *ucs4 = (uint32_t*)(void*)SDL_iconv_string(UCS4_ID, "UTF-8", utf8, strlen(utf8) + 1);
  	assert(ucs4 != NULL);
  	return ucs4;
  }
  
  void ucs4_to_utf8(const uint32_t *ucs4, size_t bufsize, char buf[bufsize]) {
  	assert(bufsize > ucs4len(ucs4));
  	char *temp = ucs4_to_utf8_alloc(ucs4);
  	memcpy(buf, temp, bufsize);
  	free(temp);
  }
  
  char* ucs4_to_utf8_alloc(const uint32_t *ucs4) {
  	char *utf8 = SDL_iconv_string("UTF-8", UCS4_ID, (const char*)ucs4, sizeof(uint32_t) * (ucs4len(ucs4) + 1));
  	assert(utf8 != NULL);
  	return utf8;
  }
  
  /*
   * public domain strtok_r() by Charlie Gordon
   *
   *   from comp.lang.c  9/14/2007
   *
   *      http://groups.google.com/group/comp.lang.c/msg/2ab1ecbb86646684
   *
   *     (Declaration that it's public domain):
   *      http://groups.google.com/group/comp.lang.c/msg/7c7b39328fefab9c
   */
  char* strtok_r(char *str, const char *delim, char **nextp) {
  	char *ret;
  
  	if(str == NULL) {
  		str = *nextp;
  	}
  
  	str += strspn(str, delim);
  
  	if(*str == '\0') {
  		return NULL;
  	}
  
  	ret = str;
  	str += strcspn(str, delim);
  
  	if(*str) {
  		*str++ = '\0';
  	}
  
  	*nextp = str;
  	return ret;
  }
  
  static uint32_t crc32_tab[] = {
  	0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
  	0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
  	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
  	0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
  	0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
  	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
  	0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
  	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
  	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
  	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
  	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
  	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
  	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
  	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
  	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
  	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
  	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
  	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
  	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
  	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
  	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
  	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
  	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
  	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
  	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
  	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
  	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
  	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
  	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
  	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
  	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
  	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
  	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
  	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
  	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
  	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
  	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
  	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
  	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
  	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
  };
  
  uint32_t crc32str(uint32_t crc, const char *str) {
  	const uint8_t *p = (uint8_t*)str;
  	crc = crc ^ ~0U;
  
  	while(*p) {
  		crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
  	}
  
  	return crc ^ ~0U;
  }
  
  size_t filename_timestamp(char *buf, size_t buf_size, SystemTime systime) {
  	assert(buf_size >= FILENAME_TIMESTAMP_MIN_BUF_SIZE);
  
  	char buf_msecs[4];
  	char buf_datetime[FILENAME_TIMESTAMP_MIN_BUF_SIZE - sizeof(buf_msecs)];
  	attr_unused size_t written;
  
  	written = snprintf(buf_msecs, sizeof(buf_msecs), "%03u", (uint)(systime.tv_nsec / 1000000));
  	assert(written == sizeof(buf_msecs) - 1);
  	written = strftime(buf_datetime, sizeof(buf_datetime), "%Y%m%d_%H-%M-%S", localtime(&systime.tv_sec));
  	assert(written != 0);
  
  	return snprintf(buf, buf_size, "%s-%s", buf_datetime, buf_msecs);
  }
  
  uint32_t utf8_getch(const char **src) {
  	// Ported from SDL_ttf and slightly modified
  
  	assert(*src != NULL);
  
  	const uint8_t *p = *(const uint8_t**)src;
  	size_t left = 0;
  	bool overlong = false;
  	uint32_t ch = UNICODE_UNKNOWN;
  
  	if(**src == 0) {
  		return UNICODE_UNKNOWN;
  	}
  
  	if(p[0] >= 0xFC) {
  		if((p[0] & 0xFE) == 0xFC) {
  			if(p[0] == 0xFC && (p[1] & 0xFC) == 0x80) {
  				overlong = true;
  			}
  			ch = p[0] & 0x01;
  			left = 5;
  		}
  	} else if(p[0] >= 0xF8) {
  		if((p[0] & 0xFC) == 0xF8) {
  			if(p[0] == 0xF8 && (p[1] & 0xF8) == 0x80) {
  				overlong = true;
  			}
  			ch = p[0] & 0x03;
  			left = 4;
  		}
  	} else if(p[0] >= 0xF0) {
  		if((p[0] & 0xF8) == 0xF0) {
  			if(p[0] == 0xF0 && (p[1] & 0xF0) == 0x80) {
  				overlong = true;
  			}
  			ch = p[0] & 0x07;
  			left = 3;
  		}
  	} else if(p[0] >= 0xE0) {
  		if((p[0] & 0xF0) == 0xE0) {
  			if(p[0] == 0xE0 && (p[1] & 0xE0) == 0x80) {
  				overlong = true;
  			}
  			ch = p[0] & 0x0F;
  			left = 2;
  		}
  	} else if(p[0] >= 0xC0) {
  		if((p[0] & 0xE0) == 0xC0) {
  			if((p[0] & 0xDE) == 0xC0) {
  				overlong = true;
  			}
  			ch = p[0] & 0x1F;
  			left = 1;
  		}
  	} else {
  		if((p[0] & 0x80) == 0x00) {
  			ch = p[0];
  		}
  	}
  
  	++*src;
  
  	while(left > 0 && **src != 0) {
  		++p;
  
  		if((p[0] & 0xC0) != 0x80) {
  			ch = UNICODE_UNKNOWN;
  			break;
  		}
  
  		ch <<= 6;
  		ch |= (p[0] & 0x3F);
  
  		++*src;
  		--left;
  	}
  
  	if(
  		overlong ||
  		left > 0 ||
  		(ch >= 0xD800 && ch <= 0xDFFF) ||
  		(ch == 0xFFFE || ch == 0xFFFF) ||
  		ch > 0x10FFFF
  	) {
  		ch = UNICODE_UNKNOWN;
  	}
  
  	return ch;
  }
  
  void format_huge_num(uint digits, uint64_t num, size_t bufsize, char *buf) {
  	if(digits == 0) {
  		digits = digitcnt(num);
  	}
  
  	num = umin(upow10(digits) - 1, num);
  
  	div_t separators = div(digits, 3);
  	attr_unused uint len = digits + (separators.quot + !!separators.rem);
  	assert(bufsize >= len);
  
  	char *p = buf;
  
  	// WARNING: i must be signed here
  	for(int i = 0; i < digits; ++i) {
  		if(i && !((i - separators.rem) % 3)) {
  			*p++ = ',';
  		}
  
  		uint64_t divisor = upow10(digits - i - 1);
  		*p++ = '0' + num / divisor;
  		num %= divisor;
  	}
  
  	*p = 0;
  	assert(p == buf + len - 1);
  }
  
  void hexdigest(uint8_t *input, size_t input_size, char *output, size_t output_size) {
  	assert(output_size > input_size * 2);
  
  	static char charmap[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
  	uint8_t *end = input + input_size;
  
  	while(input < end) {
  		uint8_t byte = *input++;
  		*output++ = charmap[byte >> 4];
  		*output++ = charmap[byte & 0xf];
  	}
  
  	*output = 0;
  }
  
  void expand_escape_sequences(char *str) {
  	bool in_escape = false;
  	char *p = str;
  
  	for(p = str; *p; ++p) {
  		if(in_escape) {
  			switch(*p) {
  				case 'n': p[-1] = '\n'; break;
  				case 't': p[-1] = '\t'; break;
  				case 'r': p[-1] = '\r'; break;
  				default:  p[-1] =   *p; break;
  			}
  
  			memmove(p, p + 1, strlen(p + 1) + 1);
  			--p;
  			in_escape = false;
  		} else if(*p == '\\') {
  			in_escape = true;
  		}
  	}
  
  	if(in_escape) {
  		p[-1] = 0;
  	}
  }
  