txtv/src/stringutil.cpp

//  _____         _  _____
// |_   _|____  _| ||_   _|_   __
//   | |/ _ \ \/ / __|| | \ \ / /
//   | |  __/>  <| |_ | |  \ V /
//   |_|\___/_/\_\\__||_|   \_/
// Author: Love Billenius <lovebillenius@disroot.org>
// License: GPL-3

#include "stringutil.hpp"

#include <algorithm>
#include <cctype>
#include <sstream>


namespace string_utils {
    bool isAllWhitespace(const std::string &str) {
        return std::ranges::all_of(str, [](const unsigned char c) -> bool {
            return std::isspace(c);
        });
    }

    void removeTrailingWhitespace(std::string &str) {
        auto shouldRemoveTrailingWhitespace = [&str]() -> bool {
            std::size_t last_newline = str.find_last_of('\n');

            if (last_newline == std::string::npos)
                return isAllWhitespace(str);

            const std::string last_line = str.substr(last_newline + 1);
            return isAllWhitespace(last_line);
        };

        while (shouldRemoveTrailingWhitespace()) {
            const std::size_t last_newline = str.find_last_of('\n');

            if (last_newline == std::string::npos) {
                if (isAllWhitespace(str))
                    str.clear();
                break;
            }

            str.erase(last_newline);
        }
    }

    void removeTabs(std::string &str) {
        std::erase(str, '\t');
    }

    void limitConsecutiveWhitespace(std::string &str, const uint_fast8_t maxWhitespace) {
        std::istringstream stream(str);
        std::string line;
        std::ostringstream processedStream;

        uint_fast8_t whitespaceRow = 0;
        bool hasAddedRealTextJet = false;

        while (std::getline(stream, line)) {
            const bool onlySpace = isAllWhitespace(line);

            if (!hasAddedRealTextJet) {
                if (onlySpace)
                    continue; // Skip leading empty lines
                hasAddedRealTextJet = true;
            } else if (onlySpace) {
                whitespaceRow++;
            } else {
                whitespaceRow = 0;
            }

            if (whitespaceRow > maxWhitespace)
                continue; // Skip lines exceeding maxWhitespace

            processedStream << line << "\n";
        }

        str = processedStream.str();
    }
}