#ifndef SASS_PRELEXER_H

#define SASS_PRELEXER_H

#include <cstring>

#include "lexer.hpp"

namespace Sass {

  // using namespace Lexer;

  namespace Prelexer {

    //####################################

    // KEYWORD "REGEX" MATCHERS

    //####################################

    // Match Sass boolean keywords.

    const char* kwd_true(const char* src);

    const char* kwd_false(const char* src);

    const char* kwd_only(const char* src);

    const char* kwd_and(const char* src);

    const char* kwd_or(const char* src);

    const char* kwd_not(const char* src);

    const char* kwd_eq(const char* src);

    const char* kwd_neq(const char* src);

    const char* kwd_gt(const char* src);

    const char* kwd_gte(const char* src);

    const char* kwd_lt(const char* src);

    const char* kwd_lte(const char* src);

    // Match standard control chars

    const char* kwd_at(const char* src);

    const char* kwd_dot(const char* src);

    const char* kwd_comma(const char* src);

    const char* kwd_colon(const char* src);

    const char* kwd_slash(const char* src);

    const char* kwd_star(const char* src);

    const char* kwd_plus(const char* src);

    const char* kwd_minus(const char* src);

    //####################################

    // SPECIAL "REGEX" CONSTRUCTS

    //####################################

    // Match a sequence of characters delimited by the supplied chars.

    template <char beg, char end, bool esc>

    const char* delimited_by(const char* src) {

      src = exactly<beg>(src);

      if (!src) return 0;

      const char* stop;

      while (true) {

        if (!*src) return 0;

        stop = exactly<end>(src);

        if (stop && (!esc || *(src - 1) != '\\')) return stop;

        src = stop ? stop : src + 1;

      }

    }

    // skip to delimiter (mx) inside given range

    // this will savely skip over all quoted strings

    // recursive skip stuff delimited by start/stop

    // first start/opener must be consumed already!

    template<prelexer start, prelexer stop>

    const char* skip_over_scopes(const char* src, const char* end) {

      size_t level = 0;

      bool in_squote = false;

      bool in_dquote = false;

      // bool in_braces = false;

      while (*src) {

        // check for abort condition

        if (end && src >= end) break;

        // has escaped sequence?

        if (*src == '\\') {

          ++ src; // skip this (and next)

        }

        else if (*src == '"') {

          in_dquote = ! in_dquote;

        }

        else if (*src == '\'') {

          in_squote = ! in_squote;

        }

        else if (in_dquote || in_squote) {

          // take everything literally

        }

        // find another opener inside?

        else if (const char* pos = start(src)) {

          ++ level; // increase counter

          src = pos - 1; // advance position

        }

        // look for the closer (maybe final, maybe not)

        else if (const char* final = stop(src)) {

          // only close one level?

          if (level > 0) -- level;

          // return position at end of stop

          // delimiter may be multiple chars

          else return final;

          // advance position

          src = final - 1;

        }

        // next

        ++ src;

      }

      return 0;

    }

    // skip to a skip delimited by parentheses

    // uses smart `skip_over_scopes` internally

    const char* parenthese_scope(const char* src);

    // skip to delimiter (mx) inside given range

    // this will savely skip over all quoted strings

    // recursive skip stuff delimited by start/stop

    // first start/opener must be consumed already!

    template<prelexer start, prelexer stop>

    const char* skip_over_scopes(const char* src) {

      return skip_over_scopes<start, stop>(src, 0);

    }

    // Match a sequence of characters delimited by the supplied chars.

    template <prelexer start, prelexer stop>

    const char* recursive_scopes(const char* src) {

      // parse opener

      src = start(src);

      // abort if not found

      if (!src) return 0;

      // parse the rest until final closer

      return skip_over_scopes<start, stop>(src);

    }

    // Match a sequence of characters delimited by the supplied strings.

    template <const char* beg, const char* end, bool esc>

    const char* delimited_by(const char* src) {

      src = exactly<beg>(src);

      if (!src) return 0;

      const char* stop;

      while (true) {

        if (!*src) return 0;

        stop = exactly<end>(src);

        if (stop && (!esc || *(src - 1) != '\\')) return stop;

        src = stop ? stop : src + 1;

      }

    }

    // Tries to match a certain number of times (between the supplied interval).

    template<prelexer mx, size_t lo, size_t hi>

    const char* between(const char* src) {

      for (size_t i = 0; i < lo; ++i) {

        src = mx(src);

        if (!src) return 0;

      }

      for (size_t i = lo; i <= hi; ++i) {

        const char* new_src = mx(src);

        if (!new_src) return src;

        src = new_src;

      }

      return src;

    }

    // equivalent of STRING_REGULAR_EXPRESSIONS

    const char* re_string_double_open(const char* src);

    const char* re_string_double_close(const char* src);

    const char* re_string_single_open(const char* src);

    const char* re_string_single_close(const char* src);

    const char* re_string_uri_open(const char* src);

    const char* re_string_uri_close(const char* src);

    // Match a line comment.

    const char* line_comment(const char* src);

    // Match a block comment.

    const char* block_comment(const char* src);

    // Match either.

    const char* comment(const char* src);

    // Match double- and single-quoted strings.

    const char* double_quoted_string(const char* src);

    const char* single_quoted_string(const char* src);

    const char* quoted_string(const char* src);

    // Match interpolants.

    const char* interpolant(const char* src);

    // Match number prefix ([\+\-]+)

    const char* number_prefix(const char* src);

    // Match zero plus white-space or line_comments

    const char* optional_css_whitespace(const char* src);

    const char* css_whitespace(const char* src);

    // Match optional_css_whitepace plus block_comments

    const char* optional_css_comments(const char* src);

    const char* css_comments(const char* src);

    // Match one backslash escaped char

    const char* escape_seq(const char* src);

    // Match CSS css variables.

    const char* custom_property_name(const char* src);

    // Match a CSS identifier.

    const char* identifier(const char* src);

    const char* identifier_alpha(const char* src);

    const char* identifier_alnum(const char* src);

    const char* strict_identifier(const char* src);

    const char* strict_identifier_alpha(const char* src);

    const char* strict_identifier_alnum(const char* src);

    // Match a CSS unit identifier.

    const char* one_unit(const char* src);

    const char* multiple_units(const char* src);

    const char* unit_identifier(const char* src);

    // const char* strict_identifier_alnums(const char* src);

    // Match reference selector.

    const char* re_reference_combinator(const char* src);

    const char* static_reference_combinator(const char* src);

    const char* schema_reference_combinator(const char* src);

    // Match interpolant schemas

    const char* identifier_schema(const char* src);

    const char* value_schema(const char* src);

    const char* sass_value(const char* src);

    // const char* filename(const char* src);

    // const char* filename_schema(const char* src);

    // const char* url_schema(const char* src);

    // const char* url_value(const char* src);

    const char* vendor_prefix(const char* src);

    const char* re_special_directive(const char* src);

    const char* re_prefixed_directive(const char* src);

    const char* re_almost_any_value_token(const char* src);

    // Match CSS '@' keywords.

    const char* at_keyword(const char* src);

    const char* kwd_import(const char* src);

    const char* kwd_at_root(const char* src);

    const char* kwd_with_directive(const char* src);

    const char* kwd_without_directive(const char* src);

    const char* kwd_media(const char* src);

    const char* kwd_supports_directive(const char* src);

    // const char* keyframes(const char* src);

    // const char* keyf(const char* src);

    const char* kwd_mixin(const char* src);

    const char* kwd_function(const char* src);

    const char* kwd_return_directive(const char* src);

    const char* kwd_include_directive(const char* src);

    const char* kwd_content_directive(const char* src);

    const char* kwd_charset_directive(const char* src);

    const char* kwd_extend(const char* src);

    const char* unicode_seq(const char* src);

    const char* kwd_if_directive(const char* src);

    const char* kwd_else_directive(const char* src);

    const char* elseif_directive(const char* src);

    const char* kwd_for_directive(const char* src);

    const char* kwd_from(const char* src);

    const char* kwd_to(const char* src);

    const char* kwd_through(const char* src);

    const char* kwd_each_directive(const char* src);

    const char* kwd_in(const char* src);

    const char* kwd_while_directive(const char* src);

    const char* re_nothing(const char* src);

    const char* re_type_selector2(const char* src);

    const char* re_special_fun(const char* src);

    const char* kwd_warn(const char* src);

    const char* kwd_err(const char* src);

    const char* kwd_dbg(const char* src);

    const char* kwd_null(const char* src);

    const char* re_selector_list(const char* src);

    const char* re_type_selector(const char* src);

    const char* re_static_expression(const char* src);

    // identifier that can start with hyphens

    const char* css_identifier(const char* src);

    const char* css_ip_identifier(const char* src);

    // Match CSS type selectors

    const char* namespace_schema(const char* src);

    const char* namespace_prefix(const char* src);

    const char* type_selector(const char* src);

    const char* hyphens_and_identifier(const char* src);

    const char* hyphens_and_name(const char* src);

    const char* universal(const char* src);

    // Match CSS id names.

    const char* id_name(const char* src);

    // Match CSS class names.

    const char* class_name(const char* src);

    // Attribute name in an attribute selector

    const char* attribute_name(const char* src);

    // Match placeholder selectors.

    const char* placeholder(const char* src);

    // Match CSS numeric constants.

    const char* op(const char* src);

    const char* sign(const char* src);

    const char* unsigned_number(const char* src);

    const char* number(const char* src);

    const char* coefficient(const char* src);

    const char* binomial(const char* src);

    const char* percentage(const char* src);

    const char* ampersand(const char* src);

    const char* dimension(const char* src);

    const char* hex(const char* src);

    const char* hexa(const char* src);

    const char* hex0(const char* src);

    // const char* rgb_prefix(const char* src);

    // Match CSS uri specifiers.

    const char* uri_prefix(const char* src);

    // Match CSS "!important" keyword.

    const char* kwd_important(const char* src);

    // Match CSS "!optional" keyword.

    const char* kwd_optional(const char* src);

    // Match Sass "!default" keyword.

    const char* default_flag(const char* src);

    const char* global_flag(const char* src);

    // Match CSS pseudo-class/element prefixes

    const char* pseudo_prefix(const char* src);

    // Match CSS function call openers.

    const char* re_functional(const char* src);

    const char* re_pseudo_selector(const char* src);

    const char* functional_schema(const char* src);

    const char* pseudo_not(const char* src);

    // Match CSS 'odd' and 'even' keywords for functional pseudo-classes.

    const char* even(const char* src);

    const char* odd(const char* src);

    // Match CSS attribute-matching operators.

    const char* exact_match(const char* src);

    const char* class_match(const char* src);

    const char* dash_match(const char* src);

    const char* prefix_match(const char* src);

    const char* suffix_match(const char* src);

    const char* substring_match(const char* src);

    // Match CSS combinators.

    // const char* adjacent_to(const char* src);

    // const char* precedes(const char* src);

    // const char* parent_of(const char* src);

    // const char* ancestor_of(const char* src);

    // Match SCSS variable names.

    const char* variable(const char* src);

    const char* calc_fn_call(const char* src);

    // IE stuff

    const char* ie_progid(const char* src);

    const char* ie_expression(const char* src);

    const char* ie_property(const char* src);

    const char* ie_keyword_arg(const char* src);

    const char* ie_keyword_arg_value(const char* src);

    const char* ie_keyword_arg_property(const char* src);

    // match url()

    const char* H(const char* src);

    const char* W(const char* src);

    // `UNICODE` makes VS sad

    const char* UUNICODE(const char* src);

    const char* NONASCII(const char* src);

    const char* ESCAPE(const char* src);

    const char* real_uri_suffix(const char* src);

    // const char* real_uri_prefix(const char* src);

    const char* real_uri_value(const char* src);

    // Path matching functions.

    // const char* folder(const char* src);

    // const char* folders(const char* src);

    const char* static_string(const char* src);

    const char* static_component(const char* src);

    const char* static_property(const char* src);

    const char* static_value(const char* src);

    // Utility functions for finding and counting characters in a string.

    template<char c>

    const char* find_first(const char* src) {

      while (*src && *src != c) ++src;

      return *src ? src : 0;

    }

    template<prelexer mx>

    const char* find_first(const char* src) {

      while (*src && !mx(src)) ++src;

      return *src ? src : 0;

    }

    template<prelexer mx>

    const char* find_first_in_interval(const char* beg, const char* end) {

      bool esc = false;

      while ((beg < end) && *beg) {

        if (esc) esc = false;

        else if (*beg == '\\') esc = true;

        else if (mx(beg)) return beg;

        ++beg;

      }

      return 0;

    }

    template<prelexer mx, prelexer skip>

    const char* find_first_in_interval(const char* beg, const char* end) {

      bool esc = false;

      while ((beg < end) && *beg) {

        if (esc) esc = false;

        else if (*beg == '\\') esc = true;

        else if (const char* pos = skip(beg)) beg = pos;

        else if (mx(beg)) return beg;

        ++beg;

      }

      return 0;

    }

    template <prelexer mx>

    unsigned int count_interval(const char* beg, const char* end) {

      unsigned int counter = 0;

      bool esc = false;

      while (beg < end && *beg) {

        const char* p;

        if (esc) {

          esc = false;

          ++beg;

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

          esc = true;

          ++beg;

        } else if ((p = mx(beg))) {

          ++counter;

          beg = p;

        }

        else {

          ++beg;

        }

      }

      return counter;

    }

    template <size_t size, prelexer mx, prelexer pad>

    const char* padded_token(const char* src)

    {

      size_t got = 0;

      const char* pos = src;

      while (got < size) {

        if (!mx(pos)) break;

        ++ pos; ++ got;

      }

      while (got < size) {

        if (!pad(pos)) break;

        ++ pos; ++ got;

      }

      return got ? pos : 0;

    }

    template <size_t min, size_t max, prelexer mx>

    const char* minmax_range(const char* src)

    {

      size_t got = 0;

      const char* pos = src;

      while (got < max) {

        if (!mx(pos)) break;

        ++ pos; ++ got;

      }

      if (got < min) return 0;

      if (got > max) return 0;

      return pos;

    }

    template <char min, char max>

    const char* char_range(const char* src)

    {

      if (*src < min) return 0;

      if (*src > max) return 0;

      return src + 1;

    }

  }

}

#endif