#include "sass.hpp"

#include "sass.h"

#include "ast.hpp"

#include "util.hpp"

#include "util_string.hpp"

#include "lexer.hpp"

#include "prelexer.hpp"

#include "constants.hpp"

#include "utf8/checked.h"

#include <cmath>

#include <stdint.h>

#if defined(_MSC_VER) && _MSC_VER >= 1800 && _MSC_VER < 1900 && defined(_M_X64)

#include <mutex>

#endif

namespace Sass {

  double round(double val, size_t precision)

  {

    // Disable FMA3-optimized implementation when compiling with VS2013 for x64 targets

    // See https://github.com/sass/node-sass/issues/1854 for details

    // FIXME: Remove this workaround when we switch to VS2015+

    #if defined(_MSC_VER) && _MSC_VER >= 1800 && _MSC_VER < 1900 && defined(_M_X64)

      static std::once_flag flag;

      std::call_once(flag, []() { _set_FMA3_enable(0); });

    #endif

    // https://github.com/sass/sass/commit/4e3e1d5684cc29073a507578fc977434ff488c93

    if (std::fmod(val, 1) - 0.5 > - std::pow(0.1, precision + 1)) return std::ceil(val);

    else if (std::fmod(val, 1) - 0.5 > std::pow(0.1, precision)) return std::floor(val);

    // work around some compiler issue

    // cygwin has it not defined in std

    using namespace std;

    return ::round(val);

  }

  /* Locale unspecific atof function. */

  double sass_strtod(const char *str)

  {

    char separator = *(localeconv()->decimal_point);

    if(separator != '.'){

      // The current locale specifies another

      // separator. convert the separator to the

      // one understood by the locale if needed

      const char *found = strchr(str, '.');

      if(found != NULL){

        // substitution is required. perform the substitution on a copy

        // of the string. This is slower but it is thread safe.

        char *copy = sass_copy_c_string(str);

        *(copy + (found - str)) = separator;

        double res = strtod(copy, NULL);

        free(copy);

        return res;

      }

    }

    return strtod(str, NULL);

  }

  // helper for safe access to c_ctx

  const char* safe_str (const char* str, const char* alt) {

    return str == NULL ? alt : str;

  }

  void free_string_array(char ** arr) {

    if(!arr)

        return;

    char **it = arr;

    while (it && (*it)) {

      free(*it);

      ++it;

    }

    free(arr);

  }

  char **copy_strings(const sass::vector<sass::string>& strings, char*** array, int skip) {

    int num = static_cast<int>(strings.size()) - skip;

    char** arr = (char**) calloc(num + 1, sizeof(char*));

    if (arr == 0)

      return *array = (char **)NULL;

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

      arr[i] = (char*) malloc(sizeof(char) * (strings[i + skip].size() + 1));

      if (arr[i] == 0) {

        free_string_array(arr);

        return *array = (char **)NULL;

      }

      std::copy(strings[i + skip].begin(), strings[i + skip].end(), arr[i]);

      arr[i][strings[i + skip].size()] = '\0';

    }

    arr[num] = 0;

    return *array = arr;

  }

  // read css string (handle multiline DELIM)

  sass::string read_css_string(const sass::string& str, bool css)

  {

    if (!css) return str;

    sass::string out("");

    bool esc = false;

    for (auto i : str) {

      if (i == '\\') {

        esc = ! esc;

      } else if (esc && i == '\r') {

        continue;

      } else if (esc && i == '\n') {

        out.resize (out.size () - 1);

        esc = false;

        continue;

      } else {

        esc = false;

      }

      out.push_back(i);

    }

    // happens when parsing does not correctly skip

    // over escaped sequences for ie. interpolations

    // one example: foo\#{interpolate}

    // if (esc) out += '\\';

    return out;

  }

  // double escape all escape sequences

  // keep unescaped quotes and backslashes

  sass::string evacuate_escapes(const sass::string& str)

  {

    sass::string out("");

    bool esc = false;

    for (auto i : str) {

      if (i == '\\' && !esc) {

        out += '\\';

        out += '\\';

        esc = true;

      } else if (esc && i == '"') {

        out += '\\';

        out += i;

        esc = false;

      } else if (esc && i == '\'') {

        out += '\\';

        out += i;

        esc = false;

      } else if (esc && i == '\\') {

        out += '\\';

        out += i;

        esc = false;

      } else {

        esc = false;

        out += i;

      }

    }

    // happens when parsing does not correctly skip

    // over escaped sequences for ie. interpolations

    // one example: foo\#{interpolate}

    // if (esc) out += '\\';

    return out;

  }

  // bell characters are replaced with spaces

  void newline_to_space(sass::string& str)

  {

    std::replace(str.begin(), str.end(), '\n', ' ');

  }

  // 1. Removes whitespace after newlines.

  // 2. Replaces newlines with spaces.

  //

  // This method only considers LF and CRLF as newlines.

  sass::string string_to_output(const sass::string& str)

  {

    sass::string result;

    result.reserve(str.size());

    std::size_t pos = 0;

    while (true) {

      const std::size_t newline = str.find_first_of("\n\r", pos);

      if (newline == sass::string::npos) break;

      result.append(str, pos, newline - pos);

      if (str[newline] == '\r') {

        if (str[newline + 1] == '\n') {

          pos = newline + 2;

        } else {

          // CR without LF: append as-is and continue.

          result += '\r';

          pos = newline + 1;

          continue;

        }

      } else {

        pos = newline + 1;

      }

      result += ' ';

      const std::size_t non_space = str.find_first_not_of(" \f\n\r\t\v", pos);

      if (non_space != sass::string::npos) {

        pos = non_space;

      }

    }

    result.append(str, pos, sass::string::npos);

    return result;

  }

  sass::string escape_string(const sass::string& str)

  {

    sass::string out;

    out.reserve(str.size());

    for (char c : str) {

      switch (c) {

        case '\n':

          out.append("\\n");

          break;

        case '\r':

          out.append("\\r");

          break;

        case '\f':

          out.append("\\f");

          break;

        default:

          out += c;

      }

    }

    return out;

  }

  sass::string comment_to_compact_string(const sass::string& text)

  {

    sass::string str = "";

    size_t has = 0;

    char prev = 0;

    bool clean = false;

    for (auto i : text) {

      if (clean) {

        if (i == '\n') { has = 0; }

        else if (i == '\t') { ++ has; }

        else if (i == ' ') { ++ has; }

        else if (i == '*') {}

        else {

          clean = false;

          str += ' ';

          if (prev == '*' && i == '/') str += "*/";

          else str += i;

        }

      } else if (i == '\n') {

        clean = true;

      } else {

        str += i;

      }

      prev = i;

    }

    if (has) return str;

    else return text;

  }

  // find best quote_mark by detecting if the string contains any single

  // or double quotes. When a single quote is found, we not we want a double

  // quote as quote_mark. Otherwise we check if the string cotains any double

  // quotes, which will trigger the use of single quotes as best quote_mark.

  char detect_best_quotemark(const char* s, char qm)

  {

    // ensure valid fallback quote_mark

    char quote_mark = qm && qm != '*' ? qm : '"';

    while (*s) {

      // force double quotes as soon

      // as one single quote is found

      if (*s == '\'') { return '"'; }

      // a single does not force quote_mark

      // maybe we see a double quote later

      else if (*s == '"') { quote_mark = '\''; }

      ++ s;

    }

    return quote_mark;

  }

  sass::string read_hex_escapes(const sass::string& s)

  {

    sass::string result;

    bool skipped = false;

    for (size_t i = 0, L = s.length(); i < L; ++i) {

      // implement the same strange ruby sass behavior

      // an escape sequence can also mean a unicode char

      if (s[i] == '\\' && !skipped) {

        // remember

        skipped = true;

        // escape length

        size_t len = 1;

        // parse as many sequence chars as possible

        // ToDo: Check if ruby aborts after possible max

        while (i + len < L && s[i + len] && Util::ascii_isxdigit(static_cast<unsigned char>(s[i + len]))) ++ len;

        if (len > 1) {

          // convert the extracted hex string to code point value

          // ToDo: Maybe we could do this without creating a substring

          uint32_t cp = strtol(s.substr (i + 1, len - 1).c_str(), NULL, 16);

          if (s[i + len] == ' ') ++ len;

          // assert invalid code points

          if (cp == 0) cp = 0xFFFD;

          // replace bell character

          // if (cp == '\n') cp = 32;

          // use a very simple approach to convert via utf8 lib

          // maybe there is a more elegant way; maybe we should

          // convert the whole output from string to a stream!?

          // allocate memory for utf8 char and convert to utf8

          unsigned char u[5] = {0,0,0,0,0}; utf8::append(cp, u);

          for(size_t m = 0; m < 5 && u[m]; m++) result.push_back(u[m]);

          // skip some more chars?

          i += len - 1; skipped = false;

        }

        else {

          skipped = false;

          result.push_back(s[i]);

        }

      }

      else {

        result.push_back(s[i]);

      }

    }

    return result;

  }

  sass::string unquote(const sass::string& s, char* qd, bool keep_utf8_sequences, bool strict)

  {

    // not enough room for quotes

    // no possibility to unquote

    if (s.length() < 2) return s;

    char q;

    bool skipped = false;

    // this is no guarantee that the unquoting will work

    // what about whitespace before/after the quote_mark?

    if      (*s.begin() == '"'  && *s.rbegin() == '"')  q = '"';

    else if (*s.begin() == '\'' && *s.rbegin() == '\'') q = '\'';

    else                                                return s;

    sass::string unq;

    unq.reserve(s.length()-2);

    for (size_t i = 1, L = s.length() - 1; i < L; ++i) {

      // implement the same strange ruby sass behavior

      // an escape sequence can also mean a unicode char

      if (s[i] == '\\' && !skipped) {

        // remember

        skipped = true;

        // skip it

        // ++ i;

        // if (i == L) break;

        // escape length

        size_t len = 1;

        // parse as many sequence chars as possible

        // ToDo: Check if ruby aborts after possible max

        while (i + len < L && s[i + len] && Util::ascii_isxdigit(static_cast<unsigned char>(s[i + len]))) ++ len;

        // hex string?

        if (keep_utf8_sequences) {

          unq.push_back(s[i]);

        } else if (len > 1) {

          // convert the extracted hex string to code point value

          // ToDo: Maybe we could do this without creating a substring

          uint32_t cp = strtol(s.substr (i + 1, len - 1).c_str(), NULL, 16);

          if (s[i + len] == ' ') ++ len;

          // assert invalid code points

          if (cp == 0) cp = 0xFFFD;

          // replace bell character

          // if (cp == '\n') cp = 32;

          // use a very simple approach to convert via utf8 lib

          // maybe there is a more elegant way; maybe we should

          // convert the whole output from string to a stream!?

          // allocate memory for utf8 char and convert to utf8

          unsigned char u[5] = {0,0,0,0,0}; utf8::append(cp, u);

          for(size_t m = 0; m < 5 && u[m]; m++) unq.push_back(u[m]);

          // skip some more chars?

          i += len - 1; skipped = false;

        }

      }

      // check for unexpected delimiter

      // be strict and throw error back

      // else if (!skipped && q == s[i]) {

      //   // don't be that strict

      //   return s;

      //   // this basically always means an internal error and not users fault

      //   error("Unescaped delimiter in string to unquote found. [" + s + "]", SourceSpan("[UNQUOTE]"));

      // }

      else {

        if (strict && !skipped) {

          if (s[i] == q) return s;

        }

        skipped = false;

        unq.push_back(s[i]);

      }

    }

    if (skipped) { return s; }

    if (qd) *qd = q;

    return unq;

  }

  sass::string quote(const sass::string& s, char q)

  {

    // autodetect with fallback to given quote

    q = detect_best_quotemark(s.c_str(), q);

    // return an empty quoted string

    if (s.empty()) return sass::string(2, q ? q : '"');

    sass::string quoted;

    quoted.reserve(s.length()+2);

    quoted.push_back(q);

    const char* it = s.c_str();

    const char* end = it + strlen(it) + 1;

    while (*it && it < end) {

      const char* now = it;

      if (*it == q) {

        quoted.push_back('\\');

      } else if (*it == '\\') {

        quoted.push_back('\\');

      }

      int cp = utf8::next(it, end);

      // in case of \r, check if the next in sequence

      // is \n and then advance the iterator and skip \r

      if (cp == '\r' && it < end && utf8::peek_next(it, end) == '\n') {

        cp = utf8::next(it, end);

      }

      if (cp == '\n') {

        quoted.push_back('\\');

        quoted.push_back('a');

        // we hope we can remove this flag once we figure out

        // why ruby sass has these different output behaviors

        // gsub(/\n(?![a-fA-F0-9\s])/, "\\a").gsub("\n", "\\a ")

        using namespace Prelexer;

        if (alternatives <

          Prelexer::char_range<'a', 'f'>,

          Prelexer::char_range<'A', 'F'>,

          Prelexer::char_range<'0', '9'>,

          space

        >(it) != NULL) {

          quoted.push_back(' ');

        }

      } else if (cp < 127) {

        quoted.push_back((char) cp);

      } else {

        while (now < it) {

          quoted.push_back(*now);

          ++ now;

        }

      }

    }

    quoted.push_back(q);

    return quoted;

  }

  bool is_hex_doublet(double n)

  {

    return n == 0x00 || n == 0x11 || n == 0x22 || n == 0x33 ||

           n == 0x44 || n == 0x55 || n == 0x66 || n == 0x77 ||

           n == 0x88 || n == 0x99 || n == 0xAA || n == 0xBB ||

           n == 0xCC || n == 0xDD || n == 0xEE || n == 0xFF ;

  }

  bool is_color_doublet(double r, double g, double b)

  {

    return is_hex_doublet(r) && is_hex_doublet(g) && is_hex_doublet(b);

  }

  bool peek_linefeed(const char* start)

  {

    using namespace Prelexer;

    using namespace Constants;

    return sequence <

             zero_plus <

               alternatives <

                 exactly <' '>,

                 exactly <'\t'>,

                 line_comment,

                 block_comment,

                 delimited_by <

                   slash_star,

                   star_slash,

                   false

                 >

               >

             >,

             re_linebreak

           >(start) != 0;

  }

  namespace Util {

    bool isPrintable(StyleRule* r, Sass_Output_Style style) {

      if (r == NULL) {

        return false;

      }

      Block_Obj b = r->block();

      SelectorList* sl = r->selector();

      bool hasSelectors = sl ? sl->length() > 0 : false;

      if (!hasSelectors) {

        return false;

      }

      bool hasDeclarations = false;

      bool hasPrintableChildBlocks = false;

      for (size_t i = 0, L = b->length(); i < L; ++i) {

        Statement_Obj stm = b->at(i);

        if (Cast<AtRule>(stm)) {

          return true;

        } else if (Declaration* d = Cast<Declaration>(stm)) {

          return isPrintable(d, style);

        } else if (ParentStatement* p = Cast<ParentStatement>(stm)) {

          Block_Obj pChildBlock = p->block();

          if (isPrintable(pChildBlock, style)) {

            hasPrintableChildBlocks = true;

          }

        } else if (Comment* c = Cast<Comment>(stm)) {

          // keep for uncompressed

          if (style != COMPRESSED) {

            hasDeclarations = true;

          }

          // output style compressed

          if (c->is_important()) {

            hasDeclarations = c->is_important();

          }

        } else {

          hasDeclarations = true;

        }

        if (hasDeclarations || hasPrintableChildBlocks) {

          return true;

        }

      }

      return false;

    }

    bool isPrintable(String_Constant* s, Sass_Output_Style style)

    {

      return ! s->value().empty();

    }

    bool isPrintable(String_Quoted* s, Sass_Output_Style style)

    {

      return true;

    }

    bool isPrintable(Declaration* d, Sass_Output_Style style)

    {

      ExpressionObj val = d->value();

      if (String_Quoted_Obj sq = Cast<String_Quoted>(val)) return isPrintable(sq.ptr(), style);

      if (String_Constant_Obj sc = Cast<String_Constant>(val)) return isPrintable(sc.ptr(), style);

      return true;

    }

    bool isPrintable(SupportsRule* f, Sass_Output_Style style) {

      if (f == NULL) {

        return false;

      }

      Block_Obj b = f->block();

      bool hasDeclarations = false;

      bool hasPrintableChildBlocks = false;

      for (size_t i = 0, L = b->length(); i < L; ++i) {

        Statement_Obj stm = b->at(i);

        if (Cast<Declaration>(stm) || Cast<AtRule>(stm)) {

          hasDeclarations = true;

        }

        else if (ParentStatement* b = Cast<ParentStatement>(stm)) {

          Block_Obj pChildBlock = b->block();

          if (!b->is_invisible()) {

            if (isPrintable(pChildBlock, style)) {

              hasPrintableChildBlocks = true;

            }

          }

        }

        if (hasDeclarations || hasPrintableChildBlocks) {

          return true;

        }

      }

      return false;

    }

    bool isPrintable(CssMediaRule* m, Sass_Output_Style style)

    {

      if (m == nullptr) return false;

      Block_Obj b = m->block();

      if (b == nullptr) return false;

      if (m->empty()) return false;

      for (size_t i = 0, L = b->length(); i < L; ++i) {

        Statement_Obj stm = b->at(i);

        if (Cast<AtRule>(stm)) return true;

        else if (Cast<Declaration>(stm)) return true;

        else if (Comment* c = Cast<Comment>(stm)) {

          if (isPrintable(c, style)) {

            return true;

          }

        }

        else if (StyleRule* r = Cast<StyleRule>(stm)) {

          if (isPrintable(r, style)) {

            return true;

          }

        }

        else if (SupportsRule* f = Cast<SupportsRule>(stm)) {

          if (isPrintable(f, style)) {

            return true;

          }

        }

        else if (CssMediaRule* mb = Cast<CssMediaRule>(stm)) {

          if (isPrintable(mb, style)) {

            return true;

          }

        }

        else if (ParentStatement* b = Cast<ParentStatement>(stm)) {

          if (isPrintable(b->block(), style)) {

            return true;

          }

        }

      }

      return false;

    }

    bool isPrintable(Comment* c, Sass_Output_Style style)

    {

      // keep for uncompressed

      if (style != COMPRESSED) {

        return true;

      }

      // output style compressed

      if (c->is_important()) {

        return true;

      }

      // not printable

      return false;

    };

    bool isPrintable(Block_Obj b, Sass_Output_Style style) {

      if (!b) {

        return false;

      }

      for (size_t i = 0, L = b->length(); i < L; ++i) {

        Statement_Obj stm = b->at(i);

        if (Cast<Declaration>(stm) || Cast<AtRule>(stm)) {

          return true;

        }

        else if (Comment* c = Cast<Comment>(stm)) {

          if (isPrintable(c, style)) {

            return true;

          }

        }

        else if (StyleRule* r = Cast<StyleRule>(stm)) {

          if (isPrintable(r, style)) {

            return true;

          }

        }

        else if (SupportsRule* f = Cast<SupportsRule>(stm)) {

          if (isPrintable(f, style)) {

            return true;

          }

        }

        else if (CssMediaRule * m = Cast<CssMediaRule>(stm)) {

          if (isPrintable(m, style)) {

            return true;

          }

        }

        else if (ParentStatement* b = Cast<ParentStatement>(stm)) {

          if (isPrintable(b->block(), style)) {

            return true;

          }

        }

      }

      return false;

    }

  }

}