/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 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 <string.h>
#include <errno.h> // for declaration of global errno variable
#include <fcntl.h>

#include "py/runtime.h"
#include "py/stream.h"

#if MICROPY_PY_BTREE

#include <db.h>
#include <../../btree/btree.h>

typedef struct _mp_obj_btree_t {
 mp_obj_base_t base;
 mp_obj_t stream; // retain a reference to prevent GC from reclaiming it
 DB *db;
 mp_obj_t start_key;
 mp_obj_t end_key;
 #define FLAG_END_KEY_INCL 1
 #define FLAG_DESC 2
 #define FLAG_ITER_TYPE_MASK 0xc0
 #define FLAG_ITER_KEYS 0x40
 #define FLAG_ITER_VALUES 0x80
 #define FLAG_ITER_ITEMS 0xc0
 byte flags;
 byte next_flags;
} mp_obj_btree_t;

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_obj_type_t btree_type;
#endif

#define CHECK_ERROR(res) \
 if (res == RET_ERROR) { \
 mp_raise_OSError(errno); \
 }

void __dbpanic(DB *db) {
 mp_printf(&mp_plat_print, "__dbpanic(%p)\n", db);
}

STATIC mp_obj_btree_t *btree_new(DB *db, mp_obj_t stream) {
 mp_obj_btree_t *o = m_new_obj(mp_obj_btree_t);
 o->base.type = &btree_type;
 o->stream = stream;
 o->db = db;
 o->start_key = mp_const_none;
 o->end_key = mp_const_none;
 o->next_flags = 0;
 return o;
}

STATIC void btree_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
 (void)kind;
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 mp_printf(print, "<btree %p>", self->db);
}

STATIC mp_obj_t btree_flush(mp_obj_t self_in) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 return MP_OBJ_NEW_SMALL_INT(__bt_sync(self->db, 0));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(btree_flush_obj, btree_flush);

STATIC mp_obj_t btree_close(mp_obj_t self_in) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 return MP_OBJ_NEW_SMALL_INT(__bt_close(self->db));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(btree_close_obj, btree_close);

STATIC mp_obj_t btree_put(size_t n_args, const mp_obj_t *args) {
 (void)n_args;
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(args[0]);
 DBT key, val;
 key.data = (void *)mp_obj_str_get_data(args[1], &key.size);
 val.data = (void *)mp_obj_str_get_data(args[2], &val.size);
 return MP_OBJ_NEW_SMALL_INT(__bt_put(self->db, &key, &val, 0));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_put_obj, 3, 4, btree_put);

STATIC mp_obj_t btree_get(size_t n_args, const mp_obj_t *args) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(args[0]);
 DBT key, val;
 key.data = (void *)mp_obj_str_get_data(args[1], &key.size);
 int res = __bt_get(self->db, &key, &val, 0);
 if (res == RET_SPECIAL) {
 if (n_args > 2) {
 return args[2];
 } else {
 return mp_const_none;
 }
 }
 CHECK_ERROR(res);
 return mp_obj_new_bytes(val.data, val.size);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_get_obj, 2, 3, btree_get);

STATIC mp_obj_t btree_seq(size_t n_args, const mp_obj_t *args) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(args[0]);
 int flags = MP_OBJ_SMALL_INT_VALUE(args[1]);
 DBT key, val;
 if (n_args > 2) {
 key.data = (void *)mp_obj_str_get_data(args[2], &key.size);
 }

 int res = __bt_seq(self->db, &key, &val, flags);
 CHECK_ERROR(res);
 if (res == RET_SPECIAL) {
 return mp_const_none;
 }

 mp_obj_t pair_o = mp_obj_new_tuple(2, NULL);
 mp_obj_tuple_t *pair = MP_OBJ_TO_PTR(pair_o);
 pair->items[0] = mp_obj_new_bytes(key.data, key.size);
 pair->items[1] = mp_obj_new_bytes(val.data, val.size);
 return pair_o;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_seq_obj, 2, 4, btree_seq);

STATIC mp_obj_t btree_init_iter(size_t n_args, const mp_obj_t *args, byte type) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(args[0]);
 self->next_flags = type;
 self->start_key = mp_const_none;
 self->end_key = mp_const_none;
 if (n_args > 1) {
 self->start_key = args[1];
 if (n_args > 2) {
 self->end_key = args[2];
 if (n_args > 3) {
 self->next_flags = type | MP_OBJ_SMALL_INT_VALUE(args[3]);
 }
 }
 }
 return args[0];
}

STATIC mp_obj_t btree_keys(size_t n_args, const mp_obj_t *args) {
 return btree_init_iter(n_args, args, FLAG_ITER_KEYS);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_keys_obj, 1, 4, btree_keys);

STATIC mp_obj_t btree_values(size_t n_args, const mp_obj_t *args) {
 return btree_init_iter(n_args, args, FLAG_ITER_VALUES);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_values_obj, 1, 4, btree_values);

STATIC mp_obj_t btree_items(size_t n_args, const mp_obj_t *args) {
 return btree_init_iter(n_args, args, FLAG_ITER_ITEMS);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_items_obj, 1, 4, btree_items);

STATIC mp_obj_t btree_getiter(mp_obj_t self_in, mp_obj_iter_buf_t *iter_buf) {
 (void)iter_buf;
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 if (self->next_flags != 0) {
 // If we're called immediately after keys(), values(), or items(),
 // use their setup for iteration.
 self->flags = self->next_flags;
 self->next_flags = 0;
 } else {
 // Otherwise, iterate over all keys.
 self->flags = FLAG_ITER_KEYS;
 self->start_key = mp_const_none;
 self->end_key = mp_const_none;
 }

 return self_in;
}

STATIC mp_obj_t btree_iternext(mp_obj_t self_in) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 DBT key, val;
 int res;
 bool desc = self->flags & FLAG_DESC;
 if (self->start_key != MP_OBJ_NULL) {
 int flags = R_FIRST;
 if (self->start_key != mp_const_none) {
 key.data = (void *)mp_obj_str_get_data(self->start_key, &key.size);
 flags = R_CURSOR;
 } else if (desc) {
 flags = R_LAST;
 }
 res = __bt_seq(self->db, &key, &val, flags);
 self->start_key = MP_OBJ_NULL;
 } else {
 res = __bt_seq(self->db, &key, &val, desc ? R_PREV : R_NEXT);
 }

 if (res == RET_SPECIAL) {
 return MP_OBJ_STOP_ITERATION;
 }
 CHECK_ERROR(res);

 if (self->end_key != mp_const_none) {
 DBT end_key;
 end_key.data = (void *)mp_obj_str_get_data(self->end_key, &end_key.size);
 BTREE *t = self->db->internal;
 int cmp = t->bt_cmp(&key, &end_key);
 if (desc) {
 cmp = -cmp;
 }
 if (self->flags & FLAG_END_KEY_INCL) {
 cmp--;
 }
 if (cmp >= 0) {
 self->end_key = MP_OBJ_NULL;
 return MP_OBJ_STOP_ITERATION;
 }
 }

 switch (self->flags & FLAG_ITER_TYPE_MASK) {
 case FLAG_ITER_KEYS:
 return mp_obj_new_bytes(key.data, key.size);
 case FLAG_ITER_VALUES:
 return mp_obj_new_bytes(val.data, val.size);
 default: {
 mp_obj_t pair_o = mp_obj_new_tuple(2, NULL);
 mp_obj_tuple_t *pair = MP_OBJ_TO_PTR(pair_o);
 pair->items[0] = mp_obj_new_bytes(key.data, key.size);
 pair->items[1] = mp_obj_new_bytes(val.data, val.size);
 return pair_o;
 }
 }
}

STATIC mp_obj_t btree_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(self_in);
 if (value == MP_OBJ_NULL) {
 // delete
 DBT key;
 key.data = (void *)mp_obj_str_get_data(index, &key.size);
 int res = __bt_delete(self->db, &key, 0);
 if (res == RET_SPECIAL) {
 mp_raise_type(&mp_type_KeyError);
 }
 CHECK_ERROR(res);
 return mp_const_none;
 } else if (value == MP_OBJ_SENTINEL) {
 // load
 DBT key, val;
 key.data = (void *)mp_obj_str_get_data(index, &key.size);
 int res = __bt_get(self->db, &key, &val, 0);
 if (res == RET_SPECIAL) {
 mp_raise_type(&mp_type_KeyError);
 }
 CHECK_ERROR(res);
 return mp_obj_new_bytes(val.data, val.size);
 } else {
 // store
 DBT key, val;
 key.data = (void *)mp_obj_str_get_data(index, &key.size);
 val.data = (void *)mp_obj_str_get_data(value, &val.size);
 int res = __bt_put(self->db, &key, &val, 0);
 CHECK_ERROR(res);
 return mp_const_none;
 }
}

STATIC mp_obj_t btree_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
 mp_obj_btree_t *self = MP_OBJ_TO_PTR(lhs_in);
 switch (op) {
 case MP_BINARY_OP_CONTAINS: {
 DBT key, val;
 key.data = (void *)mp_obj_str_get_data(rhs_in, &key.size);
 int res = __bt_get(self->db, &key, &val, 0);
 CHECK_ERROR(res);
 return mp_obj_new_bool(res != RET_SPECIAL);
 }
 default:
 // op not supported
 return MP_OBJ_NULL;
 }
}

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC const mp_rom_map_elem_t btree_locals_dict_table[] = {
 { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&btree_close_obj) },
 { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&btree_flush_obj) },
 { MP_ROM_QSTR(MP_QSTR_get), MP_ROM_PTR(&btree_get_obj) },
 { MP_ROM_QSTR(MP_QSTR_put), MP_ROM_PTR(&btree_put_obj) },
 { MP_ROM_QSTR(MP_QSTR_seq), MP_ROM_PTR(&btree_seq_obj) },
 { MP_ROM_QSTR(MP_QSTR_keys), MP_ROM_PTR(&btree_keys_obj) },
 { MP_ROM_QSTR(MP_QSTR_values), MP_ROM_PTR(&btree_values_obj) },
 { MP_ROM_QSTR(MP_QSTR_items), MP_ROM_PTR(&btree_items_obj) },
};

STATIC MP_DEFINE_CONST_DICT(btree_locals_dict, btree_locals_dict_table);

STATIC const mp_obj_type_t btree_type = {
 { &mp_type_type },
 // Save on qstr's, reuse same as for module
 .name = MP_QSTR_btree,
 .print = btree_print,
 .getiter = btree_getiter,
 .iternext = btree_iternext,
 .binary_op = btree_binary_op,
 .subscr = btree_subscr,
 .locals_dict = (void *)&btree_locals_dict,
};
#endif

STATIC const FILEVTABLE btree_stream_fvtable = {
 mp_stream_posix_read,
 mp_stream_posix_write,
 mp_stream_posix_lseek,
 mp_stream_posix_fsync
};

#if !MICROPY_ENABLE_DYNRUNTIME
STATIC mp_obj_t mod_btree_open(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
 static const mp_arg_t allowed_args[] = {
 { MP_QSTR_flags, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
 { MP_QSTR_cachesize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
 { MP_QSTR_pagesize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
 { MP_QSTR_minkeypage, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
 };

 // Make sure we got a stream object
 mp_get_stream_raise(pos_args[0], MP_STREAM_OP_READ | MP_STREAM_OP_WRITE | MP_STREAM_OP_IOCTL);

 struct {
 mp_arg_val_t flags;
 mp_arg_val_t cachesize;
 mp_arg_val_t pagesize;
 mp_arg_val_t minkeypage;
 } args;
 mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
 MP_ARRAY_SIZE(allowed_args), allowed_args, (mp_arg_val_t *)&args);
 BTREEINFO openinfo = {0};
 openinfo.flags = args.flags.u_int;
 openinfo.cachesize = args.cachesize.u_int;
 openinfo.psize = args.pagesize.u_int;
 openinfo.minkeypage = args.minkeypage.u_int;

 DB *db = __bt_open(MP_OBJ_TO_PTR(pos_args[0]), &btree_stream_fvtable, &openinfo, /*dflags*/ 0);
 if (db == NULL) {
 mp_raise_OSError(errno);
 }
 return MP_OBJ_FROM_PTR(btree_new(db, pos_args[0]));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(mod_btree_open_obj, 1, mod_btree_open);

STATIC const mp_rom_map_elem_t mp_module_btree_globals_table[] = {
 { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_btree) },
 { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mod_btree_open_obj) },
 { MP_ROM_QSTR(MP_QSTR_INCL), MP_ROM_INT(FLAG_END_KEY_INCL) },
 { MP_ROM_QSTR(MP_QSTR_DESC), MP_ROM_INT(FLAG_DESC) },
};

STATIC MP_DEFINE_CONST_DICT(mp_module_btree_globals, mp_module_btree_globals_table);

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

#endif // MICROPY_PY_BTREE