/*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdint.h>
  
  #include "py/unicode.h"
  
  // attribute flags
  #define FL_PRINT (0x01)
  #define FL_SPACE (0x02)
  #define FL_DIGIT (0x04)
  #define FL_ALPHA (0x08)
  #define FL_UPPER (0x10)
  #define FL_LOWER (0x20)
  #define FL_XDIGIT (0x40)
  
  // shorthand character attributes
  #define AT_PR (FL_PRINT)
  #define AT_SP (FL_SPACE | FL_PRINT)
  #define AT_DI (FL_DIGIT | FL_PRINT | FL_XDIGIT)
  #define AT_AL (FL_ALPHA | FL_PRINT)
  #define AT_UP (FL_UPPER | FL_ALPHA | FL_PRINT)
  #define AT_LO (FL_LOWER | FL_ALPHA | FL_PRINT)
  #define AT_UX (FL_UPPER | FL_ALPHA | FL_PRINT | FL_XDIGIT)
  #define AT_LX (FL_LOWER | FL_ALPHA | FL_PRINT | FL_XDIGIT)
  
  // table of attributes for ascii characters
  STATIC const uint8_t attr[] = {
      0, 0, 0, 0, 0, 0, 0, 0,
      0, AT_SP, AT_SP, AT_SP, AT_SP, AT_SP, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0,
      0, 0, 0, 0, 0, 0, 0, 0,
      AT_SP, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR,
      AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR,
      AT_DI, AT_DI, AT_DI, AT_DI, AT_DI, AT_DI, AT_DI, AT_DI,
      AT_DI, AT_DI, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR,
      AT_PR, AT_UX, AT_UX, AT_UX, AT_UX, AT_UX, AT_UX, AT_UP,
      AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP,
      AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP, AT_UP,
      AT_UP, AT_UP, AT_UP, AT_PR, AT_PR, AT_PR, AT_PR, AT_PR,
      AT_PR, AT_LX, AT_LX, AT_LX, AT_LX, AT_LX, AT_LX, AT_LO,
      AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO,
      AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO, AT_LO,
      AT_LO, AT_LO, AT_LO, AT_PR, AT_PR, AT_PR, AT_PR, 0
  };
  
  #if MICROPY_PY_BUILTINS_STR_UNICODE
  
  unichar utf8_get_char(const byte *s) {
      unichar ord = *s++;
      if (!UTF8_IS_NONASCII(ord)) return ord;
      ord &= 0x7F;
      for (unichar mask = 0x40; ord & mask; mask >>= 1) {
          ord &= ~mask;
      }
      while (UTF8_IS_CONT(*s)) {
          ord = (ord << 6) | (*s++ & 0x3F);
      }
      return ord;
  }
  
  const byte *utf8_next_char(const byte *s) {
      ++s;
      while (UTF8_IS_CONT(*s)) {
          ++s;
      }
      return s;
  }
  
  mp_uint_t utf8_ptr_to_index(const byte *s, const byte *ptr) {
      mp_uint_t i = 0;
      while (ptr > s) {
          if (!UTF8_IS_CONT(*--ptr)) {
              i++;
          }
      }
  
      return i;
  }
  
  size_t utf8_charlen(const byte *str, size_t len) {
      size_t charlen = 0;
      for (const byte *top = str + len; str < top; ++str) {
          if (!UTF8_IS_CONT(*str)) {
              ++charlen;
          }
      }
      return charlen;
  }
  
  #endif
  
  // Be aware: These unichar_is* functions are actually ASCII-only!
  bool unichar_isspace(unichar c) {
      return c < 128 && (attr[c] & FL_SPACE) != 0;
  }
  
  bool unichar_isalpha(unichar c) {
      return c < 128 && (attr[c] & FL_ALPHA) != 0;
  }
  
  /* unused
  bool unichar_isprint(unichar c) {
      return c < 128 && (attr[c] & FL_PRINT) != 0;
  }
  */
  
  bool unichar_isdigit(unichar c) {
      return c < 128 && (attr[c] & FL_DIGIT) != 0;
  }
  
  bool unichar_isxdigit(unichar c) {
      return c < 128 && (attr[c] & FL_XDIGIT) != 0;
  }
  
  bool unichar_isident(unichar c) {
      return c < 128 && ((attr[c] & (FL_ALPHA | FL_DIGIT)) != 0 || c == '_');
  }
  
  bool unichar_isupper(unichar c) {
      return c < 128 && (attr[c] & FL_UPPER) != 0;
  }
  
  bool unichar_islower(unichar c) {
      return c < 128 && (attr[c] & FL_LOWER) != 0;
  }
  
  unichar unichar_tolower(unichar c) {
      if (unichar_isupper(c)) {
          return c + 0x20;
      }
      return c;
  }
  
  unichar unichar_toupper(unichar c) {
      if (unichar_islower(c)) {
          return c - 0x20;
      }
      return c;
  }
  
  mp_uint_t unichar_xdigit_value(unichar c) {
      // c is assumed to be hex digit
      mp_uint_t n = c - '0';
      if (n > 9) {
          n &= ~('a' - 'A');
          n -= ('A' - ('9' + 1));
      }
      return n;
  }
  
  #if MICROPY_PY_BUILTINS_STR_UNICODE
  
  bool utf8_check(const byte *p, size_t len) {
      uint8_t need = 0;
      const byte *end = p + len;
      for (; p < end; p++) {
          byte c = *p;
          if (need) {
              if (c >= 0x80) {
                  need--;
              } else {
                  // mismatch
                  return 0;
              }
          } else {
              if (c >= 0xc0) {
                  if (c >= 0xf8) {
                      // mismatch
                      return 0;
                  }
                  need = (0xe5 >> ((c >> 3) & 0x6)) & 3;
              } else if (c >= 0x80) {
                  // mismatch
                  return 0;
              }
          }
      }
      return need == 0; // no pending fragments allowed
  }
  
  #endif