#include "PieceTable.h"

PieceTable::PieceTable(const uint8_t * file_buffer, unsigned long file_buffer_size)
{
    m_file_buffer = file_buffer;
    m_file_buffer_size = file_buffer_size;
    start_piece = &m_pieces[PIECE_INDEX_START];
    end_piece = &m_pieces[PIECE_INDEX_END];
    start_piece->next = end_piece;
    end_piece->prev = start_piece;
    m_piece_index = 2u;
}

void PieceTable::append_initial_line_piece(uint8_t * start, uint32_t length, bool eol)
{
    Piece * piece = add_piece();
    piece->prev = end_piece->prev;
    piece->next = end_piece;
    piece->start = start;
    piece->length = length;
    piece->flags = 0u;
    if (eol)
        piece->flags |= Piece::EOL_FLAG;
    end_piece->prev->next = piece;
    end_piece->prev = piece;
    m_num_lines++;
}

PieceTable::Piece * PieceTable::get_start_of_line(PieceTable::Piece * start) const
{
    Piece * piece = start;

    while (piece->prev != start_piece && !piece->prev->eol())
    {
        piece = piece->prev;
    }

    return piece;
}

std::shared_ptr<PieceTable::Cursor> PieceTable::add_cursor()
{
    auto cursor = std::make_shared<Cursor>();

    cursor->piece = start_piece->next;
    cursor->line_number = 1u;
    cursor->offset = 0u;

    m_cursors.push_back(cursor);

    return cursor;
}