// Copyright 2022, The Cozo Project Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

#ifndef COZOROCKS_ITER_H
#define COZOROCKS_ITER_H

#include "common.h"
#include "slice.h"
#include "status.h"

struct IterBridge {
    DB *db;
    Transaction *tx;
    unique_ptr<Iterator> iter;
    string lower_storage;
    string upper_storage;
    Slice lower_bound;
    Slice upper_bound;
    unique_ptr<ReadOptions> r_opts;

    explicit IterBridge(Transaction *tx_) : db(nullptr), tx(tx_), iter(nullptr), lower_bound(),
                                                                     upper_bound(),
                                                                     r_opts(new ReadOptions) {
        r_opts->ignore_range_deletions = true;
        r_opts->auto_prefix_mode = true;
    }

    inline void set_snapshot(const Snapshot *snapshot) {
        r_opts->snapshot = snapshot;
    }

//    inline ReadOptions &get_r_opts() {
//        return *r_opts;
//    }

    inline void verify_checksums(bool val) {
        r_opts->verify_checksums = val;
    }

    inline void fill_cache(bool val) {
        r_opts->fill_cache = val;
    }

    inline void tailing(bool val) {
        r_opts->tailing = val;
    }

    inline void total_order_seek(bool val) {
        r_opts->total_order_seek = val;
    }

    inline void auto_prefix_mode(bool val) {
        r_opts->auto_prefix_mode = val;
    }

    inline void prefix_same_as_start(bool val) {
        r_opts->prefix_same_as_start = val;
    }

    inline void pin_data(bool val) {
        r_opts->pin_data = val;
    }

    inline void clear_bounds() {
        r_opts->iterate_lower_bound = nullptr;
        r_opts->iterate_upper_bound = nullptr;
        lower_bound.clear();
        upper_bound.clear();
    }

    inline void set_lower_bound(RustBytes bound) {
        lower_storage = convert_slice_to_string(bound);
        lower_bound = lower_storage;
        r_opts->iterate_lower_bound = &lower_bound;
    }

    inline void set_upper_bound(RustBytes bound) {
        upper_storage = convert_slice_to_string(bound);
        upper_bound = upper_storage;
        r_opts->iterate_upper_bound = &upper_bound;
    }

    inline void start() {
        if (db == nullptr) {
            iter.reset(tx->GetIterator(*r_opts));
        } else {
            iter.reset(db->NewIterator(*r_opts));
        }
    }

    inline void reset() {
        iter.reset();
        clear_bounds();
    }

    inline void to_start() {
        iter->SeekToFirst();
    }

    inline void to_end() {
        iter->SeekToLast();
    }

    inline void seek(RustBytes key) {
        iter->Seek(convert_slice(key));
    }

    inline void seek_backward(RustBytes key) {
        iter->SeekForPrev(convert_slice(key));
    }

    inline bool is_valid() const {
        return iter->Valid();
    }

    inline void next() {
        iter->Next();
    }

    inline void prev() {
        iter->Prev();
    }

    inline void status(RocksDbStatus &status) const {
        write_status(iter->status(), status);
    }

    [[nodiscard]] inline RustBytes key() const {
        return convert_slice_back(iter->key());
    }

    [[nodiscard]] inline RustBytes val() const {
        return convert_slice_back(iter->value());
    }
};

#endif //COZOROCKS_ITER_H