#ifndef INTERNAL_STRING_H                                /*-*-C-*-vi:se ft=c:*/
#define INTERNAL_STRING_H
/**
 * @author     Ruby developers <ruby-core@ruby-lang.org>
 * @copyright  This  file  is   a  part  of  the   programming  language  Ruby.
 *             Permission  is hereby  granted,  to  either redistribute  and/or
 *             modify this file, provided that  the conditions mentioned in the
 *             file COPYING are met.  Consult the file for details.
 * @brief      Internal header for String.
 */
#include "ruby/internal/config.h"
#include <stddef.h>             /* for size_t */
#include "internal/compilers.h" /* for __has_builtin */
#include "ruby/internal/stdbool.h"     /* for bool */
#include "ruby/encoding.h"      /* for rb_encoding */
#include "ruby/ruby.h"          /* for VALUE */
#include "encindex.h"

#define STR_SHARED                  FL_USER0 /* = ELTS_SHARED */
#define STR_NOEMBED                 FL_USER1
#define STR_CHILLED         FL_USER2
#define STR_FAKESTR                 FL_USER19

enum ruby_rstring_private_flags {
    RSTRING_CHILLED = STR_CHILLED,
};

#ifdef rb_fstring_cstr
# undef rb_fstring_cstr
#endif

static inline bool
rb_str_encindex_fastpath(int encindex)
{
    // The overwhelming majority of strings are in one of these 3 encodings,
    // which are all either ASCII or perfect ASCII supersets.
    // Hence you can use fast, single byte algorithms on them, such as `memchr` etc,
    // without all the overhead of fetching the rb_encoding and using functions such as
    // rb_enc_mbminlen etc.
    // Many other encodings could qualify, but they are expected to be rare occurrences,
    // so it's better to keep that list small.
    switch (encindex) {
      case ENCINDEX_ASCII_8BIT:
      case ENCINDEX_UTF_8:
      case ENCINDEX_US_ASCII:
        return true;
      default:
        return false;
    }
}

static inline bool
rb_str_enc_fastpath(VALUE str)
{
    return rb_str_encindex_fastpath(ENCODING_GET_INLINED(str));
}

static inline rb_encoding *
rb_str_enc_get(VALUE str)
{
    RUBY_ASSERT(RB_TYPE_P(str, T_STRING));
    return rb_enc_from_index(ENCODING_GET(str));
}

/* string.c */
VALUE rb_str_dup_m(VALUE str);
VALUE rb_fstring(VALUE);
VALUE rb_fstring_cstr(const char *str);
VALUE rb_fstring_enc_new(const char *ptr, long len, rb_encoding *enc);
int rb_str_buf_cat_escaped_char(VALUE result, unsigned int c, int unicode_p);
int rb_str_symname_p(VALUE);
VALUE rb_str_quote_unprintable(VALUE);
char *rb_str_fill_terminator(VALUE str, const int termlen);
void rb_str_change_terminator_length(VALUE str, const int oldtermlen, const int termlen);
VALUE rb_str_locktmp_ensure(VALUE str, VALUE (*func)(VALUE), VALUE arg);
VALUE rb_str_chomp_string(VALUE str, VALUE chomp);
VALUE rb_external_str_with_enc(VALUE str, rb_encoding *eenc);
VALUE rb_str_cat_conv_enc_opts(VALUE newstr, long ofs, const char *ptr, long len,
                               rb_encoding *from, int ecflags, VALUE ecopts);
VALUE rb_enc_str_scrub(rb_encoding *enc, VALUE str, VALUE repl);
VALUE rb_str_escape(VALUE str);
size_t rb_str_memsize(VALUE);
char *rb_str_to_cstr(VALUE str);
const char *ruby_escaped_char(int c);
void rb_str_make_independent(VALUE str);
int rb_enc_str_coderange_scan(VALUE str, rb_encoding *enc);
int rb_ascii8bit_appendable_encoding_index(rb_encoding *enc, unsigned int code);
VALUE rb_str_include(VALUE str, VALUE arg);
VALUE rb_str_byte_substr(VALUE str, VALUE beg, VALUE len);
VALUE rb_str_substr_two_fixnums(VALUE str, VALUE beg, VALUE len, int empty);
VALUE rb_str_tmp_frozen_no_embed_acquire(VALUE str);
void rb_str_make_embedded(VALUE);
VALUE rb_str_upto_each(VALUE, VALUE, int, int (*each)(VALUE, VALUE), VALUE);
size_t rb_str_size_as_embedded(VALUE);
bool rb_str_reembeddable_p(VALUE);
bool rb_str_embedded_shared_root_p(VALUE);
VALUE rb_str_upto_endless_each(VALUE, int (*each)(VALUE, VALUE), VALUE);
VALUE rb_str_with_debug_created_info(VALUE, VALUE, int);
VALUE rb_str_frozen_bare_string(VALUE);
const char *rb_str_null_check(VALUE);
VALUE rb_str_casecmp(VALUE str1, VALUE str2);

/* error.c */
void rb_warn_unchilled_literal(VALUE str);

static inline bool STR_EMBED_P(VALUE str);
static inline bool STR_SHARED_P(VALUE str);
static inline VALUE QUOTE(VALUE v);
static inline VALUE QUOTE_ID(ID v);
static inline bool is_ascii_string(VALUE str);
static inline bool is_broken_string(VALUE str);
static inline VALUE rb_str_eql_internal(const VALUE str1, const VALUE str2);

RUBY_SYMBOL_EXPORT_BEGIN
/* string.c (export) */
VALUE rb_str_tmp_frozen_acquire(VALUE str);
void rb_str_tmp_frozen_release(VALUE str, VALUE tmp);
VALUE rb_setup_fake_str(struct RString *fake_str, const char *name, long len, rb_encoding *enc);
RUBY_SYMBOL_EXPORT_END

VALUE rb_fstring_new(const char *ptr, long len);
void rb_gc_free_fstring(VALUE obj);
bool rb_obj_is_fstring_table(VALUE obj);
void Init_fstring_table();
VALUE rb_obj_as_string_result(VALUE str, VALUE obj);
VALUE rb_str_opt_plus(VALUE x, VALUE y);
VALUE rb_str_concat_literals(size_t num, const VALUE *strary);
VALUE rb_str_eql(VALUE str1, VALUE str2);
VALUE rb_id_quote_unprintable(ID);
VALUE rb_sym_proc_call(ID mid, int argc, const VALUE *argv, int kw_splat, VALUE passed_proc);
VALUE rb_enc_literal_str(const char *ptr, long len, rb_encoding *enc);

struct rb_execution_context_struct;
VALUE rb_ec_str_resurrect(struct rb_execution_context_struct *ec, VALUE str, bool chilled);

#define rb_fstring_lit(str) rb_fstring_new((str), rb_strlen_lit(str))
#define rb_fstring_literal(str) rb_fstring_lit(str)
#define rb_fstring_enc_lit(str, enc) rb_fstring_enc_new((str), rb_strlen_lit(str), (enc))
#define rb_fstring_enc_literal(str, enc) rb_fstring_enc_lit(str, enc)

static inline VALUE
QUOTE(VALUE v)
{
    return rb_str_quote_unprintable(v);
}

static inline VALUE
QUOTE_ID(ID i)
{
    return rb_id_quote_unprintable(i);
}

static inline bool
STR_EMBED_P(VALUE str)
{
    return ! FL_TEST_RAW(str, STR_NOEMBED);
}

static inline bool
STR_SHARED_P(VALUE str)
{
    return FL_ALL_RAW(str, STR_NOEMBED | STR_SHARED);
}

static inline bool
CHILLED_STRING_P(VALUE obj)
{
    return RB_TYPE_P(obj, T_STRING) && FL_TEST_RAW(obj, STR_CHILLED);
}

static inline void
CHILLED_STRING_MUTATED(VALUE str)
{
    if (RB_FL_TEST_RAW(str, STR_CHILLED)) {
        FL_UNSET_RAW(str, STR_CHILLED);
        rb_warn_unchilled_literal(str);
    }
}

static inline bool
is_ascii_string(VALUE str)
{
    return rb_enc_str_coderange(str) == ENC_CODERANGE_7BIT;
}

static inline bool
is_broken_string(VALUE str)
{
    return rb_enc_str_coderange(str) == ENC_CODERANGE_BROKEN;
}

static inline bool
at_char_boundary(const char *s, const char *p, const char *e, rb_encoding *enc)
{
    return rb_enc_left_char_head(s, p, e, enc) == p;
}

static inline bool
at_char_right_boundary(const char *s, const char *p, const char *e, rb_encoding *enc)
{
    RUBY_ASSERT(s <= p);
    RUBY_ASSERT(p <= e);

    return rb_enc_right_char_head(s, p, e, enc) == p;
}

/* expect tail call optimization */
// YJIT needs this function to never allocate and never raise
static inline VALUE
rb_str_eql_internal(const VALUE str1, const VALUE str2)
{
    const long len = RSTRING_LEN(str1);
    const char *ptr1, *ptr2;

    if (len != RSTRING_LEN(str2)) return Qfalse;
    if (!rb_str_comparable(str1, str2)) return Qfalse;
    if ((ptr1 = RSTRING_PTR(str1)) == (ptr2 = RSTRING_PTR(str2)))
        return Qtrue;
    if (memcmp(ptr1, ptr2, len) == 0)
        return Qtrue;
    return Qfalse;
}

static inline bool
rb_streql_cstr(VALUE str, const char *lit, size_t len)
{
    if ((size_t)RSTRING_LEN(str) != len) return false;
    return memcmp(RSTRING_PTR(str), lit, len) == 0;
}
#define rb_streql_lit(str, lit) rb_streql_cstr(str, lit, rb_strlen_lit(lit))

#if __has_builtin(__builtin_constant_p)
# define rb_fstring_cstr(str) \
    (__builtin_constant_p(str) ? \
        rb_fstring_new((str), (long)strlen(str)) : \
        (rb_fstring_cstr)(str))
#endif
#endif /* INTERNAL_STRING_H */
