/*

 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "utilities/utf8.hpp"

// Assume the utf8 string is in legal form and has been

// checked in the class file parser/format checker.

template<typename T> char* UTF8::next(const char* str, T* value) {

  unsigned const char *ptr = (const unsigned char *)str;

  unsigned char ch, ch2, ch3;

  int length = -1;              /* bad length */

  jchar result;

  switch ((ch = ptr[0]) >> 4) {

    default:

    result = ch;

    length = 1;

    break;

  case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:

    /* Shouldn't happen. */

    break;

  case 0xC: case 0xD:

    /* 110xxxxx  10xxxxxx */

    if (((ch2 = ptr[1]) & 0xC0) == 0x80) {

      unsigned char high_five = ch & 0x1F;

      unsigned char low_six = ch2 & 0x3F;

      result = (high_five << 6) + low_six;

      length = 2;

      break;

    }

    break;

  case 0xE:

    /* 1110xxxx 10xxxxxx 10xxxxxx */

    if (((ch2 = ptr[1]) & 0xC0) == 0x80) {

      if (((ch3 = ptr[2]) & 0xC0) == 0x80) {

        unsigned char high_four = ch & 0x0f;

        unsigned char mid_six = ch2 & 0x3f;

        unsigned char low_six = ch3 & 0x3f;

        result = (((high_four << 6) + mid_six) << 6) + low_six;

        length = 3;

      }

    }

    break;

  } /* end of switch */

  if (length <= 0) {

    *value = (T)ptr[0];    /* default bad result; */

    return (char*)(ptr + 1); // make progress somehow

  }

  *value = (T)result;

  // The assert is correct but the .class file is wrong

  // assert(UNICODE::utf8_size(result) == length, "checking reverse computation");

  return (char *)(ptr + length);

}

char* UTF8::next_character(const char* str, jint* value) {

  unsigned const char *ptr = (const unsigned char *)str;

  /* See if it's legal supplementary character:

     11101101 1010xxxx 10xxxxxx 11101101 1011xxxx 10xxxxxx */

  if (is_supplementary_character(ptr)) {

    *value = get_supplementary_character(ptr);

    return (char *)(ptr + 6);

  }

  jchar result;

  char* next_ch = next(str, &result);

  *value = result;

  return next_ch;

}

// Count bytes of the form 10xxxxxx and deduct this count

// from the total byte count.  The utf8 string must be in

// legal form which has been verified in the format checker.

int UTF8::unicode_length(const char* str, int len, bool& is_latin1, bool& has_multibyte) {

  int num_chars = len;

  has_multibyte = false;

  is_latin1 = true;

  unsigned char prev = 0;

  for (int i = 0; i < len; i++) {

    unsigned char c = str[i];

    if ((c & 0xC0) == 0x80) {

      // Multibyte, check if valid latin1 character.

      has_multibyte = true;

      if (prev > 0xC3) {

        is_latin1 = false;

      }

      --num_chars;

    }

    prev = c;

  }

  return num_chars;

}

// Count bytes of the utf8 string except those in form

// 10xxxxxx which only appear in multibyte characters.

// The utf8 string must be in legal form and has been

// verified in the format checker.

int UTF8::unicode_length(const char* str, bool& is_latin1, bool& has_multibyte) {

  int num_chars = 0;

  has_multibyte = false;

  is_latin1 = true;

  unsigned char prev = 0;

  for (const char* p = str; *p; p++) {

    unsigned char c = (*p);

    if ((c & 0xC0) == 0x80) {

      // Multibyte, check if valid latin1 character.

      has_multibyte = true;

      if (prev > 0xC3) {

        is_latin1 = false;

      }

    } else {

      num_chars++;

    }

    prev = c;

  }

  return num_chars;

}

// Writes a jchar as utf8 and returns the end

static u_char* utf8_write(u_char* base, jchar ch) {

  if ((ch != 0) && (ch <=0x7f)) {

    base[0] = (u_char) ch;

    return base + 1;

  }

  if (ch <= 0x7FF) {

    /* 11 bits or less. */

    unsigned char high_five = ch >> 6;

    unsigned char low_six = ch & 0x3F;

    base[0] = high_five | 0xC0; /* 110xxxxx */

    base[1] = low_six | 0x80;   /* 10xxxxxx */

    return base + 2;

  }

  /* possibly full 16 bits. */

  char high_four = ch >> 12;

  char mid_six = (ch >> 6) & 0x3F;

  char low_six = ch & 0x3f;

  base[0] = high_four | 0xE0; /* 1110xxxx */

  base[1] = mid_six | 0x80;   /* 10xxxxxx */

  base[2] = low_six | 0x80;   /* 10xxxxxx */

  return base + 3;

}

template<typename T> void UTF8::convert_to_unicode(const char* utf8_str, T* unicode_str, int unicode_length) {

  unsigned char ch;

  const char *ptr = utf8_str;

  int index = 0;

  /* ASCII case loop optimization */

  for (; index < unicode_length; index++) {

    if((ch = ptr[0]) > 0x7F) { break; }

    unicode_str[index] = (T)ch;

    ptr = (const char *)(ptr + 1);

  }

  for (; index < unicode_length; index++) {

    ptr = UTF8::next(ptr, &unicode_str[index]);

  }

}

// Explicit instantiation for all supported string types.

template char* UTF8::next<jchar>(const char* str, jchar* value);

template char* UTF8::next<jbyte>(const char* str, jbyte* value);

template void UTF8::convert_to_unicode<jchar>(const char* utf8_str, jchar* unicode_str, int unicode_length);

template void UTF8::convert_to_unicode<jbyte>(const char* utf8_str, jbyte* unicode_str, int unicode_length);

// returns the quoted ascii length of a 0-terminated utf8 string

int UTF8::quoted_ascii_length(const char* utf8_str, int utf8_length) {

  const char *ptr = utf8_str;

  const char* end = ptr + utf8_length;

  int result = 0;

  while (ptr < end) {

    jchar c;

    ptr = UTF8::next(ptr, &c);

    if (c >= 32 && c < 127) {

      result++;

    } else {

      result += 6;

    }

  }

  return result;

}

// converts a utf8 string to quoted ascii

void UTF8::as_quoted_ascii(const char* utf8_str, int utf8_length, char* buf, int buflen) {

  const char *ptr = utf8_str;

  const char *utf8_end = ptr + utf8_length;

  char* p = buf;

  char* end = buf + buflen;

  while (ptr < utf8_end) {

    jchar c;

    ptr = UTF8::next(ptr, &c);

    if (c >= 32 && c < 127) {

      if (p + 1 >= end) break;      // string is truncated

      *p++ = (char)c;

    } else {

      if (p + 6 >= end) break;      // string is truncated

      sprintf(p, "\\u%04x", c);

      p += 6;

    }

  }

  assert(p < end, "sanity");

  *p = '\0';

}

const char* UTF8::from_quoted_ascii(const char* quoted_ascii_str) {

  const char *ptr = quoted_ascii_str;

  char* result = NULL;

  while (*ptr != '\0') {

    char c = *ptr;

    if (c < 32 || c >= 127) break;

  }

  if (*ptr == '\0') {

    // nothing to do so return original string

    return quoted_ascii_str;

  }

  // everything up to this point was ok.

  int length = ptr - quoted_ascii_str;

  char* buffer = NULL;

  for (int round = 0; round < 2; round++) {

    while (*ptr != '\0') {

      if (*ptr != '\\') {

        if (buffer != NULL) {

          buffer[length] = *ptr;

        }

        length++;

      } else {

        switch (ptr[1]) {

          case 'u': {

            ptr += 2;

            jchar value=0;

            for (int i=0; i<4; i++) {

              char c = *ptr++;

              switch (c) {

                case '0': case '1': case '2': case '3': case '4':

                case '5': case '6': case '7': case '8': case '9':

                  value = (value << 4) + c - '0';

                  break;

                case 'a': case 'b': case 'c':

                case 'd': case 'e': case 'f':

                  value = (value << 4) + 10 + c - 'a';

                  break;

                case 'A': case 'B': case 'C':

                case 'D': case 'E': case 'F':

                  value = (value << 4) + 10 + c - 'A';

                  break;

                default:

                  ShouldNotReachHere();

              }

            }

            if (buffer == NULL) {

              char utf8_buffer[4];

              char* next = (char*)utf8_write((u_char*)utf8_buffer, value);

              length += next - utf8_buffer;

            } else {

              char* next = (char*)utf8_write((u_char*)&buffer[length], value);

              length += next - &buffer[length];

            }

            break;

          }

          case 't': if (buffer != NULL) buffer[length] = '\t'; ptr += 2; length++; break;

          case 'n': if (buffer != NULL) buffer[length] = '\n'; ptr += 2; length++; break;

          case 'r': if (buffer != NULL) buffer[length] = '\r'; ptr += 2; length++; break;

          case 'f': if (buffer != NULL) buffer[length] = '\f'; ptr += 2; length++; break;

          default:

            ShouldNotReachHere();

        }

      }

    }

    if (round == 0) {

      buffer = NEW_RESOURCE_ARRAY(char, length + 1);

      ptr = quoted_ascii_str;

    } else {

      buffer[length] = '\0';

    }

  }

  return buffer;

}

// Returns NULL if 'c' it not found. This only works as long

// as 'c' is an ASCII character

const jbyte* UTF8::strrchr(const jbyte* base, int length, jbyte c) {

  assert(length >= 0, "sanity check");

  assert(c >= 0, "does not work for non-ASCII characters");

  // Skip backwards in string until 'c' is found or end is reached

  while(--length >= 0 && base[length] != c);

  return (length < 0) ? NULL : &base[length];

}

bool UTF8::equal(const jbyte* base1, int length1, const jbyte* base2, int length2) {

  // Length must be the same

  if (length1 != length2) return false;

  for (int i = 0; i < length1; i++) {

    if (base1[i] != base2[i]) return false;

  }

  return true;

}

bool UTF8::is_supplementary_character(const unsigned char* str) {

  return ((str[0] & 0xFF) == 0xED) && ((str[1] & 0xF0) == 0xA0) && ((str[2] & 0xC0) == 0x80)

      && ((str[3] & 0xFF) == 0xED) && ((str[4] & 0xF0) == 0xB0) && ((str[5] & 0xC0) == 0x80);

}

jint UTF8::get_supplementary_character(const unsigned char* str) {

  return 0x10000 + ((str[1] & 0x0f) << 16) + ((str[2] & 0x3f) << 10)

                 + ((str[4] & 0x0f) << 6)  + (str[5] & 0x3f);

}

bool UTF8::is_legal_utf8(const unsigned char* buffer, int length,

                         bool version_leq_47) {

  int i = 0;

  int count = length >> 2;

  for (int k=0; k<count; k++) {

    unsigned char b0 = buffer[i];

    unsigned char b1 = buffer[i+1];

    unsigned char b2 = buffer[i+2];

    unsigned char b3 = buffer[i+3];

    // For an unsigned char v,

    // (v | v - 1) is < 128 (highest bit 0) for 0 < v < 128;

    // (v | v - 1) is >= 128 (highest bit 1) for v == 0 or v >= 128.

    unsigned char res = b0 | b0 - 1 |

                        b1 | b1 - 1 |

                        b2 | b2 - 1 |

                        b3 | b3 - 1;

    if (res >= 128) break;

    i += 4;

  }

  for(; i < length; i++) {

    unsigned short c;

    // no embedded zeros

    if (buffer[i] == 0) return false;

    if(buffer[i] < 128) {

      continue;

    }

    if ((i + 5) < length) { // see if it's legal supplementary character

      if (UTF8::is_supplementary_character(&buffer[i])) {

        c = UTF8::get_supplementary_character(&buffer[i]);

        i += 5;

        continue;

      }

    }

    switch (buffer[i] >> 4) {

      default: break;

      case 0x8: case 0x9: case 0xA: case 0xB: case 0xF:

        return false;

      case 0xC: case 0xD:  // 110xxxxx  10xxxxxx

        c = (buffer[i] & 0x1F) << 6;

        i++;

        if ((i < length) && ((buffer[i] & 0xC0) == 0x80)) {

          c += buffer[i] & 0x3F;

          if (version_leq_47 || c == 0 || c >= 0x80) {

            break;

          }

        }

        return false;

      case 0xE:  // 1110xxxx 10xxxxxx 10xxxxxx

        c = (buffer[i] & 0xF) << 12;

        i += 2;

        if ((i < length) && ((buffer[i-1] & 0xC0) == 0x80) && ((buffer[i] & 0xC0) == 0x80)) {

          c += ((buffer[i-1] & 0x3F) << 6) + (buffer[i] & 0x3F);

          if (version_leq_47 || c >= 0x800) {

            break;

          }

        }

        return false;

    }  // end of switch

  } // end of for

  return true;

}

//-------------------------------------------------------------------------------------

bool UNICODE::is_latin1(jchar c) {

  return (c <= 0x00FF);

}

bool UNICODE::is_latin1(jchar* base, int length) {

  for (int index = 0; index < length; index++) {

    if (base[index] > 0x00FF) {

      return false;

    }

  }

  return true;

}

int UNICODE::utf8_size(jchar c) {

  if ((0x0001 <= c) && (c <= 0x007F)) {

    // ASCII character

    return 1;

  } else  if (c <= 0x07FF) {

    return 2;

  } else {

    return 3;

  }

}

int UNICODE::utf8_size(jbyte c) {

  if (c >= 0x01) {

    // ASCII character. Check is equivalent to

    // (0x01 <= c) && (c <= 0x7F) because c is signed.

    return 1;

  } else {

    // Non-ASCII character or 0x00 which needs to be

    // two-byte encoded as 0xC080 in modified UTF-8.

    return 2;

  }

}

template<typename T>

int UNICODE::utf8_length(T* base, int length) {

  int result = 0;

  for (int index = 0; index < length; index++) {

    T c = base[index];

    result += utf8_size(c);

  }

  return result;

}

template<typename T>

char* UNICODE::as_utf8(T* base, int& length) {

  int utf8_len = utf8_length(base, length);

  u_char* buf = NEW_RESOURCE_ARRAY(u_char, utf8_len + 1);

  char* result = as_utf8(base, length, (char*) buf, utf8_len + 1);

  assert((int) strlen(result) == utf8_len, "length prediction must be correct");

  // Set string length to uft8 length

  length = utf8_len;

  return (char*) result;

}

char* UNICODE::as_utf8(jchar* base, int length, char* buf, int buflen) {

  u_char* p = (u_char*)buf;

  for (int index = 0; index < length; index++) {

    jchar c = base[index];

    buflen -= utf8_size(c);

    if (buflen <= 0) break; // string is truncated

    p = utf8_write(p, c);

  }

  *p = '\0';

  return buf;

}

char* UNICODE::as_utf8(jbyte* base, int length, char* buf, int buflen) {

  u_char* p = (u_char*)buf;

  u_char* end = (u_char*)buf + buflen;

  for (int index = 0; index < length; index++) {

    jbyte c = base[index];

    int sz = utf8_size(c);

    buflen -= sz;

    if (buflen <= 0) break; // string is truncated

    if (sz == 1) {

      // Copy ASCII characters (UTF-8 is ASCII compatible)

      *p++ = c;

    } else {

      // Non-ASCII character or 0x00 which should

      // be encoded as 0xC080 in "modified" UTF8.

      p = utf8_write(p, ((jchar) c) & 0xff);

    }

  }

  *p = '\0';

  return buf;

}

void UNICODE::convert_to_utf8(const jchar* base, int length, char* utf8_buffer) {

  for(int index = 0; index < length; index++) {

    utf8_buffer = (char*)utf8_write((u_char*)utf8_buffer, base[index]);

  }

  *utf8_buffer = '\0';

}

// returns the quoted ascii length of a unicode string

template<typename T>

int UNICODE::quoted_ascii_length(T* base, int length) {

  int result = 0;

  for (int i = 0; i < length; i++) {

    T c = base[i];

    if (c >= 32 && c < 127) {