choc_TextTable.h

//
//    ██████ ██   ██  ██████   ██████
//   ██      ██   ██ ██    ██ ██            ** Classy Header-Only Classes **
//   ██      ███████ ██    ██ ██
//   ██      ██   ██ ██    ██ ██           https://github.com/Tracktion/choc
//    ██████ ██   ██  ██████   ██████
//
//   CHOC is (C)2022 Tracktion Corporation, and is offered under the terms of the ISC license:
//
//   Permission to use, copy, modify, and/or distribute this software for any purpose with or
//   without fee is hereby granted, provided that the above copyright notice and this permission
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#ifndef CHOC_TEXT_TABLE_HEADER_INCLUDED
#define CHOC_TEXT_TABLE_HEADER_INCLUDED

#include "choc_StringUtilities.h"

namespace choc::text
{

/**
    A class to build and format basic text tables with columns that are padded to
    make them vertically-aligned.

    Just create a TextTable object, then
      - add items to the current row with the << operator
      - start a new row with newRow()
      - when done, use the toString and getRows() methods to get the result.

    Rows can have a different number of columns, and the table's size is based on the
    maximum number of columns.
*/
struct TextTable
{
    TextTable() = default;
    ~TextTable() = default;

    /// Appends a column to the current row.
    TextTable& operator<< (std::string_view text);

    /// Clears and resets the table
    void clear();

    /// Ends the current row, so that subsequent new columns will be added to a new row
    void newRow();

    /// Returns the current number of rows
    size_t getNumRows() const;

    /// Finds the number of columns (by looking for the row with the most columns)
    size_t getNumColumns() const;

    /// Returns a vector of strings for each each row, which will have been
    /// padded and formatted to align vertically. Each row will have the prefix
    /// and suffix strings attached, and the columnSeparator string added between
    /// each column.
    std::vector<std::string> getRows (std::string_view rowPrefix,
                                      std::string_view columnSeparator,
                                      std::string_view rowSuffix) const;

    /// Returns a string containing all the rows in the table.
    /// See getRows() for details about the format strings. This method simply
    /// concatenates all the strings for each row.
    std::string toString (std::string_view rowPrefix,
                          std::string_view columnSeparator,
                          std::string_view rowSuffix) const;

private:
    //==============================================================================
    struct Row
    {
        std::vector<std::string> columns;

        void addColumn (std::string_view text);
        std::string toString (std::string_view columnSeparator, const std::vector<size_t> widths) const;
    };

    std::vector<Row> rows;
    bool startNewRow = true;

    std::vector<size_t> getColumnWidths() const;
};


//==============================================================================
//        _        _           _  _
//     __| |  ___ | |_   __ _ (_)| | ___
//    / _` | / _ \| __| / _` || || |/ __|
//   | (_| ||  __/| |_ | (_| || || |\__ \ _  _  _
//    \__,_| \___| \__| \__,_||_||_||___/(_)(_)(_)
//
//   Code beyond this point is implementation detail...
//
//==============================================================================

inline TextTable& TextTable::operator<< (std::string_view text)
{
    if (startNewRow)
    {
        startNewRow = false;
        rows.push_back ({});
    }

    rows.back().addColumn (text);
    return *this;
}

inline void TextTable::newRow()
{
    if (startNewRow)
        rows.push_back ({});
    else
        startNewRow = true;
}

inline void TextTable::clear()
{
    rows.clear();
    startNewRow = true;
}

inline size_t TextTable::getNumRows() const
{
    return rows.size();
}

inline size_t TextTable::getNumColumns() const
{
    size_t maxColummns = 0;

    for (auto& row : rows)
        maxColummns = std::max (maxColummns, row.columns.size());

    return maxColummns;
}

inline std::vector<std::string> TextTable::getRows (std::string_view rowPrefix,
                                                    std::string_view columnSeparator,
                                                    std::string_view rowSuffix) const
{
    std::vector<std::string> result;
    result.reserve (rows.size());
    auto widths = getColumnWidths();

    for (auto& row : rows)
        result.push_back (std::string (rowPrefix)
                            + row.toString (columnSeparator, widths)
                            + std::string (rowSuffix));

    return result;
}

inline std::string TextTable::toString (std::string_view rowPrefix,
                                        std::string_view columnSeparator,
                                        std::string_view rowSuffix) const
{
    std::string result;

    for (auto& row : getRows (rowPrefix, columnSeparator, rowSuffix))
        result += row;

    return result;
}

inline std::vector<size_t> TextTable::getColumnWidths() const
{
    std::vector<size_t> widths;
    widths.resize (getNumColumns());

    for (auto& row : rows)
        for (size_t i = 0; i < row.columns.size(); ++i)
            widths[i] = std::max (widths[i], row.columns[i].length());

    return widths;
}

inline void TextTable::Row::addColumn (std::string_view text)
{
    columns.emplace_back (text);
}

inline std::string TextTable::Row::toString (std::string_view columnSeparator, const std::vector<size_t> widths) const
{
    std::string result;
    size_t index = 0;

    for (auto& width : widths)
    {
        if (index != 0)
            result += columnSeparator;

        std::string padded;

        if (index < columns.size())
            padded = columns[index];

        padded.resize (width, ' ');
        result += padded;
        ++index;
    }

    return result;
}

} // namespace choc::text

#endif