#ifndef _GENERATOR_H_
#define _GENERATOR_H_

#include <string.h>
#include <assert.h>
#include <math.h>

#include "ruby.h"

#if HAVE_RUBY_RE_H
#include "ruby/re.h"
#endif

#if HAVE_RE_H
#include "re.h"
#endif

#ifdef HAVE_RUBY_ENCODING_H
#include "ruby/encoding.h"
#define FORCE_UTF8(obj) rb_enc_associate((obj), rb_utf8_encoding())
#else
#define FORCE_UTF8(obj)
#endif

#define option_given_p(opts, key) RTEST(rb_funcall(opts, i_key_p, 1, key))

#ifndef RHASH_SIZE
#define RHASH_SIZE(hsh) (RHASH(hsh)->tbl->num_entries)
#endif

#ifndef RFLOAT_VALUE
#define RFLOAT_VALUE(val) (RFLOAT(val)->value)
#endif

#ifndef RARRAY_PTR
#define RARRAY_PTR(ARRAY) RARRAY(ARRAY)->ptr
#endif
#ifndef RARRAY_LEN
#define RARRAY_LEN(ARRAY) RARRAY(ARRAY)->len
#endif
#ifndef RSTRING_PTR
#define RSTRING_PTR(string) RSTRING(string)->ptr
#endif
#ifndef RSTRING_LEN
#define RSTRING_LEN(string) RSTRING(string)->len
#endif

#define RSTRING_PAIR(string) RSTRING_PTR(string), RSTRING_LEN(string)

/* fbuffer implementation */

typedef struct FBufferStruct {
    unsigned long initial_length;
    char *ptr;
    unsigned long len;
    unsigned long capa;
} FBuffer;

#define FBUFFER_INITIAL_LENGTH 4096

#define FBUFFER_PTR(fb) (fb->ptr)
#define FBUFFER_LEN(fb) (fb->len)
#define FBUFFER_CAPA(fb) (fb->capa)
#define FBUFFER_PAIR(fb) FBUFFER_PTR(fb), FBUFFER_LEN(fb)

static char *fstrndup(const char *ptr, unsigned long len);
static FBuffer *fbuffer_alloc();
static FBuffer *fbuffer_alloc_with_length(unsigned long initial_length);
static void fbuffer_free(FBuffer *fb);
static void fbuffer_free_only_buffer(FBuffer *fb);
static void fbuffer_clear(FBuffer *fb);
static void fbuffer_append(FBuffer *fb, const char *newstr, unsigned long len);
static void fbuffer_append_long(FBuffer *fb, long number);
static void fbuffer_append_char(FBuffer *fb, char newchr);
static FBuffer *fbuffer_dup(FBuffer *fb);
static VALUE fbuffer_to_s(FBuffer *fb);

/* unicode defintions */

#define UNI_STRICT_CONVERSION 1

typedef unsigned long  UTF32; /* at least 32 bits */
typedef unsigned short UTF16; /* at least 16 bits */
typedef unsigned char  UTF8;  /* typically 8 bits */

#define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD
#define UNI_MAX_BMP (UTF32)0x0000FFFF
#define UNI_MAX_UTF16 (UTF32)0x0010FFFF
#define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF
#define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF

#define UNI_SUR_HIGH_START  (UTF32)0xD800
#define UNI_SUR_HIGH_END    (UTF32)0xDBFF
#define UNI_SUR_LOW_START   (UTF32)0xDC00
#define UNI_SUR_LOW_END     (UTF32)0xDFFF

static const int halfShift  = 10; /* used for shifting by 10 bits */

static const UTF32 halfBase = 0x0010000UL;
static const UTF32 halfMask = 0x3FFUL;

static unsigned char isLegalUTF8(const UTF8 *source, unsigned long length);
static void unicode_escape(char *buf, UTF16 character);
static void unicode_escape_to_buffer(FBuffer *buffer, char buf[6], UTF16 character);
static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string);
static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string);

/* ruby api and some helpers */

typedef struct JSON_Generator_StateStruct {
    char *indent;
    long indent_len;
    char *space;
    long space_len;
    char *space_before;
    long space_before_len;
    char *object_nl;
    long object_nl_len;
    char *array_nl;
    long array_nl_len;
    FBuffer *array_delim;
    FBuffer *object_delim;
    FBuffer *object_delim2;
    long max_nesting;
    char allow_nan;
    char ascii_only;
    long depth;
} JSON_Generator_State;

#define GET_STATE(self)                       \
    JSON_Generator_State *state;              \
    Data_Get_Struct(self, JSON_Generator_State, state)

#define GENERATE_JSON(type)                                                                     \
    FBuffer *buffer;                                                                            \
    VALUE Vstate;                                                                               \
    JSON_Generator_State *state;                                                                \
                                                                                                \
    rb_scan_args(argc, argv, "01", &Vstate);                                                    \
    Vstate = cState_from_state_s(cState, Vstate);                                               \
    Data_Get_Struct(Vstate, JSON_Generator_State, state);                                       \
    buffer = cState_prepare_buffer(Vstate);                                                     \
    generate_json_##type(buffer, Vstate, state, self);                                          \
    return fbuffer_to_s(buffer)

static VALUE mHash_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mArray_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mFixnum_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mBignum_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mFloat_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mString_included_s(VALUE self, VALUE modul);
static VALUE mString_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mString_to_json_raw_object(VALUE self);
static VALUE mString_to_json_raw(int argc, VALUE *argv, VALUE self);
static VALUE mString_Extend_json_create(VALUE self, VALUE o);
static VALUE mTrueClass_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mFalseClass_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mNilClass_to_json(int argc, VALUE *argv, VALUE self);
static VALUE mObject_to_json(int argc, VALUE *argv, VALUE self);
static void State_free(JSON_Generator_State *state);
static JSON_Generator_State *State_allocate();
static VALUE cState_s_allocate(VALUE klass);
static VALUE cState_configure(VALUE self, VALUE opts);
static VALUE cState_to_h(VALUE self);
static void generate_json(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_object(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_array(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_string(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_null(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_false(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_true(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_fixnum(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_bignum(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static void generate_json_float(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj);
static VALUE cState_partial_generate(VALUE self, VALUE obj);
static VALUE cState_generate(VALUE self, VALUE obj);
static VALUE cState_initialize(int argc, VALUE *argv, VALUE self);
static VALUE cState_from_state_s(VALUE self, VALUE opts);
static VALUE cState_indent(VALUE self);
static VALUE cState_indent_set(VALUE self, VALUE indent);
static VALUE cState_space(VALUE self);
static VALUE cState_space_set(VALUE self, VALUE space);
static VALUE cState_space_before(VALUE self);
static VALUE cState_space_before_set(VALUE self, VALUE space_before);
static VALUE cState_object_nl(VALUE self);
static VALUE cState_object_nl_set(VALUE self, VALUE object_nl);
static VALUE cState_array_nl(VALUE self);
static VALUE cState_array_nl_set(VALUE self, VALUE array_nl);
static VALUE cState_max_nesting(VALUE self);
static VALUE cState_max_nesting_set(VALUE self, VALUE depth);
static VALUE cState_allow_nan_p(VALUE self);
static VALUE cState_ascii_only_p(VALUE self);
static VALUE cState_depth(VALUE self);
static VALUE cState_depth_set(VALUE self, VALUE depth);
static FBuffer *cState_prepare_buffer(VALUE self);

#endif
