#ifndef CURSOR_H
#define CURSOR_H

#include <stdint.h>
#include <stdlib.h>
#include "Encoding.h"
#include "GapBuffer.h"

class Iterator
{
public:
    Iterator(GapBuffer * gap_buffer, Encoding::Type encoding)
    {
        m_gap_buffer = gap_buffer;
        m_offset = 0u;
        m_encoding = encoding;
    }
    bool valid() const
    {
        return m_offset < m_gap_buffer->size();
    }
    void go_forward();
    bool check_go_forward();
    void go_back();
    bool check_go_back();
    uint8_t * address() const
    {
        return m_gap_buffer->address(m_offset);
    }
    uint32_t operator*() const
    {
        if (valid())
        {
            return Encoding::decode(m_encoding, address());
        }
        else
        {
            return 0xFFFFFFFFu;
        }
    }
    GapBuffer * gap_buffer() const { return m_gap_buffer; }
    bool operator<(const Iterator & other) const
    {
        return m_offset < other.m_offset;
    }
    size_t offset() { return m_offset; }
    void set_offset(size_t new_offset) { m_offset = new_offset; }

protected:
    GapBuffer * m_gap_buffer;
    size_t m_offset;
    Encoding::Type m_encoding;
};

class Cursor
{
public:
    Cursor(GapBuffer * gap_buffer, Encoding::Type encoding)
        : m_iterator(gap_buffer, encoding)
    {
        m_line = 0u;
        init_column();
    }
    bool is_start_of_line();
    bool is_end_of_line(bool allow_eol);
    bool go_start_of_line();
    bool go_end_of_line(bool allow_eol);
    bool go_left();
    bool go_right(bool allow_eol);
    bool go_up(size_t target_column);
    bool go_down(size_t target_column);
    bool operator<(const Cursor & other) const
    {
        return m_iterator < other.m_iterator;
    }
    uint32_t operator*() const { return *m_iterator; }
    uint8_t * address() const { return m_iterator.address(); }
    bool valid() const { return m_iterator.valid(); }
    size_t line() const { return m_line; }
    size_t column() const { return m_column; }
    Iterator & iterator() { return m_iterator; }
    void set_line(size_t line) { m_line = line; }
    void calculate_column();

protected:
    Iterator m_iterator;
    size_t m_line;
    size_t m_column;

    void init_column();
    void forward_to_column(size_t target_column);
};

#endif