/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2014 Paul Sokolovsky
 * Copyright (c) Quectel Wireless Solution, Co., Ltd.All Rights Reserved.
 *
 * 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 <stdio.h>
#include <assert.h>
#include <string.h>

#include "py/runtime.h"
#include "py/binary.h"
#include "py/objstr.h"
#include "py/stackctrl.h"

#if MICROPY_PY_URE

#define re1_5_stack_chk() MP_STACK_CHECK()

#include "re1.5/re1.5.h"

#define FLAG_DEBUG 0x1000

typedef struct _mp_obj_re_t {
 mp_obj_base_t base;
 ByteProg re;
} mp_obj_re_t;

typedef struct _mp_obj_match_t {
 mp_obj_base_t base;
 int num_matches;
 mp_obj_t str;
 const char *caps[0];
} mp_obj_match_t;

STATIC mp_obj_t mod_re_compile(size_t n_args, const mp_obj_t *args);
#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_obj_type_t re_type;
#endif

STATIC void match_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
 (void)kind;
 mp_obj_match_t *self = MP_OBJ_TO_PTR(self_in);
 mp_printf(print, "<match num=%d>", self->num_matches);
}

STATIC mp_obj_t match_group(mp_obj_t self_in, mp_obj_t no_in) {
 mp_obj_match_t *self = MP_OBJ_TO_PTR(self_in);
 mp_int_t no = mp_obj_get_int(no_in);
 if (no < 0 || no >= self->num_matches) {
 nlr_raise(mp_obj_new_exception_arg1(&mp_type_IndexError, no_in));
 }

 const char *start = self->caps[no * 2];
 if (start == NULL) {
 // no match for this group
 return mp_const_none;
 }
 return mp_obj_new_str_of_type(mp_obj_get_type(self->str),
 (const byte *)start, self->caps[no * 2 + 1] - start);
}
MP_DEFINE_CONST_FUN_OBJ_2(match_group_obj, match_group);

#if MICROPY_PY_URE_MATCH_GROUPS

STATIC mp_obj_t match_groups(mp_obj_t self_in) {
 mp_obj_match_t *self = MP_OBJ_TO_PTR(self_in);
 if (self->num_matches <= 1) {
 return mp_const_empty_tuple;
 }
 mp_obj_tuple_t *groups = MP_OBJ_TO_PTR(mp_obj_new_tuple(self->num_matches - 1, NULL));
 for (int i = 1; i < self->num_matches; ++i) {
 groups->items[i - 1] = match_group(self_in, MP_OBJ_NEW_SMALL_INT(i));
 }
 return MP_OBJ_FROM_PTR(groups);
}
MP_DEFINE_CONST_FUN_OBJ_1(match_groups_obj, match_groups);

#endif

#if MICROPY_PY_URE_MATCH_SPAN_START_END

STATIC void match_span_helper(size_t n_args, const mp_obj_t *args, mp_obj_t span[2]) {
 mp_obj_match_t *self = MP_OBJ_TO_PTR(args[0]);

 mp_int_t no = 0;
 if (n_args == 2) {
 no = mp_obj_get_int(args[1]);
 if (no < 0 || no >= self->num_matches) {
 nlr_raise(mp_obj_new_exception_arg1(&mp_type_IndexError, args[1]));
 }
 }

 mp_int_t s = -1;
 mp_int_t e = -1;
 const char *start = self->caps[no * 2];
 if (start != NULL) {
 // have a match for this group
 const char *begin = mp_obj_str_get_str(self->str);
 s = start - begin;
 e = self->caps[no * 2 + 1] - begin;
 }

 span[0] = mp_obj_new_int(s);
 span[1] = mp_obj_new_int(e);
}

STATIC mp_obj_t match_span(size_t n_args, const mp_obj_t *args) {
 mp_obj_t span[2];
 match_span_helper(n_args, args, span);
 return mp_obj_new_tuple(2, span);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(match_span_obj, 1, 2, match_span);

STATIC mp_obj_t match_start(size_t n_args, const mp_obj_t *args) {
 mp_obj_t span[2];
 match_span_helper(n_args, args, span);
 return span[0];
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(match_start_obj, 1, 2, match_start);

STATIC mp_obj_t match_end(size_t n_args, const mp_obj_t *args) {
 mp_obj_t span[2];
 match_span_helper(n_args, args, span);
 return span[1];
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(match_end_obj, 1, 2, match_end);

#endif

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_rom_map_elem_t match_locals_dict_table[] = {
 { MP_ROM_QSTR(MP_QSTR_group), MP_ROM_PTR(&match_group_obj) },
 #if MICROPY_PY_URE_MATCH_GROUPS
 { MP_ROM_QSTR(MP_QSTR_groups), MP_ROM_PTR(&match_groups_obj) },
 #endif
 #if MICROPY_PY_URE_MATCH_SPAN_START_END
 { MP_ROM_QSTR(MP_QSTR_span), MP_ROM_PTR(&match_span_obj) },
 { MP_ROM_QSTR(MP_QSTR_start), MP_ROM_PTR(&match_start_obj) },
 { MP_ROM_QSTR(MP_QSTR_end), MP_ROM_PTR(&match_end_obj) },
 #endif
};

STATIC MP_DEFINE_CONST_DICT(match_locals_dict, match_locals_dict_table);

STATIC const mp_obj_type_t match_type = {
 { &mp_type_type },
 .name = MP_QSTR_match,
 .print = match_print,
 .locals_dict = (void *)&match_locals_dict,
};
#endif

STATIC void re_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
 (void)kind;
 mp_obj_re_t *self = MP_OBJ_TO_PTR(self_in);
 mp_printf(print, "<re %p>", self);
}

STATIC mp_obj_t ure_exec(bool is_anchored, uint n_args, const mp_obj_t *args) {
 (void)n_args;
 mp_obj_re_t *self;
 if (mp_obj_is_type(args[0], &re_type)) {
 self = MP_OBJ_TO_PTR(args[0]);
 } else {
 self = MP_OBJ_TO_PTR(mod_re_compile(1, args));
 }
 Subject subj;
 size_t len;
 subj.begin = mp_obj_str_get_data(args[1], &len);
 subj.end = subj.begin + len;
 int caps_num = (self->re.sub + 1) * 2;
 mp_obj_match_t *match = m_new_obj_var(mp_obj_match_t, char *, caps_num);
 // cast is a workaround for a bug in msvc: it treats const char** as a const pointer instead of a pointer to pointer to const char
 memset((char *)match->caps, 0, caps_num * sizeof(char *));
 int res = re1_5_recursiveloopprog(&self->re, &subj, match->caps, caps_num, is_anchored);
 if (res == 0) {
 m_del_var(mp_obj_match_t, char *, caps_num, match);
 return mp_const_none;
 }

 match->base.type = &match_type;
 match->num_matches = caps_num / 2; // caps_num counts start and end pointers
 match->str = args[1];
 return MP_OBJ_FROM_PTR(match);
}

STATIC mp_obj_t re_match(size_t n_args, const mp_obj_t *args) {
 return ure_exec(true, n_args, args);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(re_match_obj, 2, 4, re_match);

STATIC mp_obj_t re_search(size_t n_args, const mp_obj_t *args) {
 return ure_exec(false, n_args, args);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(re_search_obj, 2, 4, re_search);

STATIC mp_obj_t re_split(size_t n_args, const mp_obj_t *args) {
 mp_obj_re_t *self = MP_OBJ_TO_PTR(args[0]);
 Subject subj;
 size_t len;
 const mp_obj_type_t *str_type = mp_obj_get_type(args[1]);
 subj.begin = mp_obj_str_get_data(args[1], &len);
 subj.end = subj.begin + len;
 int caps_num = (self->re.sub + 1) * 2;

 int maxsplit = 0;
 if (n_args > 2) {
 maxsplit = mp_obj_get_int(args[2]);
 }

 mp_obj_t retval = mp_obj_new_list(0, NULL);
 const char **caps = mp_local_alloc(caps_num * sizeof(char *));
 while (true) {
 // cast is a workaround for a bug in msvc: it treats const char** as a const pointer instead of a pointer to pointer to const char
 memset((char **)caps, 0, caps_num * sizeof(char *));
 int res = re1_5_recursiveloopprog(&self->re, &subj, caps, caps_num, false);

 // if we didn't have a match, or had an empty match, it's time to stop
 if (!res || caps[0] == caps[1]) {
 break;
 }

 mp_obj_t s = mp_obj_new_str_of_type(str_type, (const byte *)subj.begin, caps[0] - subj.begin);
 mp_obj_list_append(retval, s);
 if (self->re.sub > 0) {
 mp_raise_NotImplementedError(MP_ERROR_TEXT("splitting with sub-captures"));
 }
 subj.begin = caps[1];
 if (maxsplit > 0 && --maxsplit == 0) {
 break;
 }
 }
 // cast is a workaround for a bug in msvc (see above)
 mp_local_free((char **)caps);

 mp_obj_t s = mp_obj_new_str_of_type(str_type, (const byte *)subj.begin, subj.end - subj.begin);
 mp_obj_list_append(retval, s);
 return retval;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(re_split_obj, 2, 3, re_split);

#if MICROPY_PY_URE_SUB

STATIC mp_obj_t re_sub_helper(size_t n_args, const mp_obj_t *args) {
 mp_obj_re_t *self;
 if (mp_obj_is_type(args[0], &re_type)) {
 self = MP_OBJ_TO_PTR(args[0]);
 } else {
 self = MP_OBJ_TO_PTR(mod_re_compile(1, args));
 }
 mp_obj_t replace = args[1];
 mp_obj_t where = args[2];
 mp_int_t count = 0;
 if (n_args > 3) {
 count = mp_obj_get_int(args[3]);
 // Note: flags are currently ignored
 }

 size_t where_len;
 const char *where_str = mp_obj_str_get_data(where, &where_len);
 Subject subj;
 subj.begin = where_str;
 subj.end = subj.begin + where_len;
 int caps_num = (self->re.sub + 1) * 2;

 vstr_t vstr_return;
 vstr_return.buf = NULL; // We'll init the vstr after the first match
 mp_obj_match_t *match = mp_local_alloc(sizeof(mp_obj_match_t) + caps_num * sizeof(char *));
 match->base.type = &match_type;
 match->num_matches = caps_num / 2; // caps_num counts start and end pointers
 match->str = where;

 for (;;) {
 // cast is a workaround for a bug in msvc: it treats const char** as a const pointer instead of a pointer to pointer to const char
 memset((char *)match->caps, 0, caps_num * sizeof(char *));
 int res = re1_5_recursiveloopprog(&self->re, &subj, match->caps, caps_num, false);

 // If we didn't have a match, or had an empty match, it's time to stop
 if (!res || match->caps[0] == match->caps[1]) {
 break;
 }

 // Initialise the vstr if it's not already
 if (vstr_return.buf == NULL) {
 vstr_init(&vstr_return, match->caps[0] - subj.begin);
 }

 // Add pre-match string
 vstr_add_strn(&vstr_return, subj.begin, match->caps[0] - subj.begin);

 // Get replacement string
 const char *repl = mp_obj_str_get_str((mp_obj_is_callable(replace) ? mp_call_function_1(replace, MP_OBJ_FROM_PTR(match)) : replace));

 // Append replacement string to result, substituting any regex groups
 while (*repl != '0円') {
 if (*repl == '\\') {
 ++repl;
 bool is_g_format = false;
 if (*repl == 'g' && repl[1] == '<') {
 // Group specified with syntax "\g<number>"
 repl += 2;
 is_g_format = true;
 }

 if ('0' <= *repl && *repl <= '9') {
 // Group specified with syntax "\g<number>" or "\number"
 unsigned int match_no = 0;
 do {
 match_no = match_no * 10 + (*repl++ - '0');
 } while ('0' <= *repl && *repl <= '9');
 if (is_g_format && *repl == '>') {
 ++repl;
 }

 if (match_no >= (unsigned int)match->num_matches) {
 nlr_raise(mp_obj_new_exception_arg1(&mp_type_IndexError, MP_OBJ_NEW_SMALL_INT(match_no)));
 }

 const char *start_match = match->caps[match_no * 2];
 if (start_match != NULL) {
 // Add the substring matched by group
 const char *end_match = match->caps[match_no * 2 + 1];
 vstr_add_strn(&vstr_return, start_match, end_match - start_match);
 }
 } else if (*repl == '\\') {
 // Add the \ character
 vstr_add_byte(&vstr_return, *repl++);
 }
 } else {
 // Just add the current byte from the replacement string
 vstr_add_byte(&vstr_return, *repl++);
 }
 }

 // Move start pointer to end of last match
 subj.begin = match->caps[1];

 // Stop substitutions if count was given and gets to 0
 if (count > 0 && --count == 0) {
 break;
 }
 }

 mp_local_free(match);

 if (vstr_return.buf == NULL) {
 // Optimisation for case of no substitutions
 return where;
 }

 // Add post-match string
 vstr_add_strn(&vstr_return, subj.begin, subj.end - subj.begin);

 return mp_obj_new_str_from_vstr(mp_obj_get_type(where), &vstr_return);
}

MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(re_sub_obj, 3, 5, re_sub_helper);

#endif

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_rom_map_elem_t re_locals_dict_table[] = {
 { MP_ROM_QSTR(MP_QSTR_match), MP_ROM_PTR(&re_match_obj) },
 { MP_ROM_QSTR(MP_QSTR_search), MP_ROM_PTR(&re_search_obj) },
 { MP_ROM_QSTR(MP_QSTR_split), MP_ROM_PTR(&re_split_obj) },
 #if MICROPY_PY_URE_SUB
 { MP_ROM_QSTR(MP_QSTR_sub), MP_ROM_PTR(&re_sub_obj) },
 #endif
};

STATIC MP_DEFINE_CONST_DICT(re_locals_dict, re_locals_dict_table);

STATIC const mp_obj_type_t re_type = {
 { &mp_type_type },
 .name = MP_QSTR_ure,
 .print = re_print,
 .locals_dict = (void *)&re_locals_dict,
};
#endif

STATIC mp_obj_t mod_re_compile(size_t n_args, const mp_obj_t *args) {
 (void)n_args;
 const char *re_str = mp_obj_str_get_str(args[0]);
 int size = re1_5_sizecode(re_str);
 if (size == -1) {
 goto error;
 }
 mp_obj_re_t *o = m_new_obj_var(mp_obj_re_t, char, size);
 o->base.type = &re_type;
 #if MICROPY_PY_URE_DEBUG
 int flags = 0;
 if (n_args > 1) {
 flags = mp_obj_get_int(args[1]);
 }
 #endif
 int error = re1_5_compilecode(&o->re, re_str);
 if (error != 0) {
 error:
 mp_raise_ValueError(MP_ERROR_TEXT("error in regex"));
 }
 #if MICROPY_PY_URE_DEBUG
 if (flags & FLAG_DEBUG) {
 re1_5_dumpcode(&o->re);
 }
 #endif
 return MP_OBJ_FROM_PTR(o);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_re_compile_obj, 1, 2, mod_re_compile);

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_rom_map_elem_t mp_module_re_globals_table[] = {
 { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ure) },
 { MP_ROM_QSTR(MP_QSTR_compile), MP_ROM_PTR(&mod_re_compile_obj) },
 { MP_ROM_QSTR(MP_QSTR_match), MP_ROM_PTR(&re_match_obj) },
 { MP_ROM_QSTR(MP_QSTR_search), MP_ROM_PTR(&re_search_obj) },
 #if MICROPY_PY_URE_SUB
 { MP_ROM_QSTR(MP_QSTR_sub), MP_ROM_PTR(&re_sub_obj) },
 #endif
 #if MICROPY_PY_URE_DEBUG
 { MP_ROM_QSTR(MP_QSTR_DEBUG), MP_ROM_INT(FLAG_DEBUG) },
 #endif
};

STATIC MP_DEFINE_CONST_DICT(mp_module_re_globals, mp_module_re_globals_table);

const mp_obj_module_t mp_module_ure = {
 .base = { &mp_type_module },
 .globals = (mp_obj_dict_t *)&mp_module_re_globals,
};
#endif

// Source files #include'd here to make sure they're compiled in
// only if module is enabled by config setting.

#define re1_5_fatal(x) assert(!x)
#include "re1.5/compilecode.c"
#if MICROPY_PY_URE_DEBUG
#include "re1.5/dumpcode.c"
#endif
#include "re1.5/recursiveloop.c"
#include "re1.5/charclass.c"

#endif // MICROPY_PY_URE