// Copyright (c) 2018-present The Bitcoin Core developers

// Distributed under the MIT software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <script/parsing.h>

#include <algorithm>

#include <cstddef>

#include <string>

namespace script {

bool Const(const std::string& str, std::span<const char>& sp, bool skip)

{

    if ((size_t)sp.size() >= str.size() && std::equal(str.begin(), str.end(), sp.begin())) {

        if (skip) sp = sp.subspan(str.size());

        return true;

    }

    return false;

}

bool Func(const std::string& str, std::span<const char>& sp)

{

    if ((size_t)sp.size() >= str.size() + 2 && sp[str.size()] == '(' && sp[sp.size() - 1] == ')' && std::equal(str.begin(), str.end(), sp.begin())) {

        sp = sp.subspan(str.size() + 1, sp.size() - str.size() - 2);

        return true;

    }

    return false;

}

std::span<const char> Expr(std::span<const char>& sp)

{

    int level = 0;

    auto it = sp.begin();

    while (it != sp.end()) {

        if (*it == '(' || *it == '{') {

            ++level;

        } else if (level && (*it == ')' || *it == '}')) {

            --level;

        } else if (level == 0 && (*it == ')' || *it == '}' || *it == ',')) {

            break;

        }

        ++it;

    }

    std::span<const char> ret = sp.first(it - sp.begin());

    sp = sp.subspan(it - sp.begin());

    return ret;

}

} // namespace script