#include <assert.h>

#include "terminalframebuffer.hpp"

using namespace Terminal;

Cell::Cell()
  : contents(),
    fallback( false ),
    width( 1 ),
    renditions()
{}

Cell::Cell( const Cell &x )
  : contents( x.contents ),
    fallback( x.fallback ),
    width( x.width ),
    renditions( x.renditions )
{}

Cell & Cell::operator=( const Cell &x )
{
  contents = x.contents;
  fallback = x.fallback;
  width = x.width;
  renditions = x.renditions;

  return *this;
}

Row::Row( size_t s_width )
  : cells( s_width )
{}

void Cell::reset( void )
{
  contents.clear();
  fallback = false;
  width = 1;
  renditions.clear();
}

DrawState::DrawState( int s_width, int s_height )
  : width( s_width ), height( s_height ),
    cursor_col( 0 ), cursor_row( 0 ),
    combining_char_col( 0 ), combining_char_row( 0 ), tabs( s_width ),
    scrolling_region_top_row( 0 ), scrolling_region_bottom_row( height - 1 ),
    renditions(), save(),
    next_print_will_wrap( false ), origin_mode( false ), auto_wrap_mode( true ),
    insert_mode( false )
{
  for ( int i = 0; i < width; i++ ) {
    tabs[ i ] = ( (i % 8) == 0 );
  }
}

Framebuffer::Framebuffer( int s_width, int s_height )
  : rows( s_height, Row( s_width ) ), ds( s_width, s_height )
{}

void Framebuffer::scroll( int N )
{
  if ( N >= 0 ) {
    for ( int i = 0; i < N; i++ ) {
      delete_line( ds.get_scrolling_region_top_row() );
      ds.move_row( -1, true );
    }
  } else {
    N = -N;

    for ( int i = 0; i < N; i++ ) {
      rows.erase( rows.begin() + ds.get_scrolling_region_bottom_row() );
      rows.insert( rows.begin() + ds.get_scrolling_region_top_row(), Row( ds.get_width() ) );
      ds.move_row( 1, true );
    }
  }
}

void DrawState::new_grapheme( void )
{
  combining_char_col = cursor_col;
  combining_char_row = cursor_row;  
}

void DrawState::snap_cursor_to_border( void )
{
  if ( cursor_row < limit_top() ) cursor_row = limit_top();
  if ( cursor_row > limit_bottom() ) cursor_row = limit_bottom();
  if ( cursor_col < 0 ) cursor_col = 0;
  if ( cursor_col >= width ) cursor_col = width - 1;
}

void DrawState::move_row( int N, bool relative )
{
  if ( relative ) {
    cursor_row += N;
  } else {
    cursor_row = N + limit_top();
  }

  snap_cursor_to_border();
  new_grapheme();
  next_print_will_wrap = false;
}

void DrawState::move_col( int N, bool relative, bool implicit )
{
  if ( implicit ) {
    new_grapheme();
  }

  if ( relative ) {
    cursor_col += N;
  } else {
    cursor_col = N;
  }

  if ( implicit && (cursor_col >= width) ) {
    next_print_will_wrap = true;
  }

  snap_cursor_to_border();
  if ( !implicit ) {
    new_grapheme();
    next_print_will_wrap = false;
  }
}

void Framebuffer::move_rows_autoscroll( int rows )
{
  /* don't scroll if outside the scrolling region */
  if ( (ds.get_cursor_row() < ds.get_scrolling_region_top_row())
       || (ds.get_cursor_row() > ds.get_scrolling_region_bottom_row()) ) {
    ds.move_row( rows, true );
    return;
  }

  if ( ds.get_cursor_row() + rows > ds.get_scrolling_region_bottom_row() ) {
    scroll( ds.get_cursor_row() + rows - ds.get_scrolling_region_bottom_row() );
  } else if ( ds.get_cursor_row() + rows < ds.get_scrolling_region_top_row() ) {
    scroll( ds.get_cursor_row() + rows - ds.get_scrolling_region_top_row() );
  }

  ds.move_row( rows, true );
}

Cell *Framebuffer::get_cell( void )
{
  assert( ds.get_width() );
  assert( ds.get_height() );

  return &rows[ ds.get_cursor_row() ].cells[ ds.get_cursor_col() ];
}

Cell *Framebuffer::get_cell( int row, int col )
{
  if ( row == -1 ) row = ds.get_cursor_row();
  if ( col == -1 ) col = ds.get_cursor_col();

  return &rows[ row ].cells[ col ];
}

Cell *Framebuffer::get_combining_cell( void )
{
  return &rows[ ds.get_combining_char_row() ].cells[ ds.get_combining_char_col() ];
}

void DrawState::set_tab( void )
{
  tabs[ cursor_col ] = true;
}

void DrawState::clear_tab( int col )
{
  tabs[ col ] = false;
}

int DrawState::get_next_tab( void )
{
  for ( int i = cursor_col + 1; i < width; i++ ) {
    if ( tabs[ i ] ) {
      return i;
    }
  }
  return -1;
}

void DrawState::set_scrolling_region( int top, int bottom )
{
  if ( height < 1 ) {
    return;
  }

  scrolling_region_top_row = top;
  scrolling_region_bottom_row = bottom;

  if ( scrolling_region_top_row < 0 ) scrolling_region_top_row = 0;
  if ( scrolling_region_bottom_row >= height ) scrolling_region_bottom_row = height - 1;

  if ( scrolling_region_bottom_row < scrolling_region_top_row )
    scrolling_region_bottom_row = scrolling_region_top_row;
  /* real rule requires TWO-line scrolling region */

  if ( origin_mode ) {
    snap_cursor_to_border();
    new_grapheme();
  }
}

int DrawState::limit_top( void )
{
  return origin_mode ? scrolling_region_top_row : 0;
}

int DrawState::limit_bottom( void )
{
  return origin_mode ? scrolling_region_bottom_row : height - 1;
}

std::vector<int> DrawState::get_tabs( void )
{
  std::vector<int> ret;

  for ( int i = 0; i < width; i++ ) {
    if ( tabs[ i ] ) {
      ret.push_back( i );
    }
  }

  return ret;
}

void Framebuffer::apply_renditions_to_current_cell( void )
{
  get_cell()->renditions = ds.get_renditions();
}

SavedCursor::SavedCursor()
  : cursor_col( 0 ), cursor_row( 0 ),
    renditions(),
    auto_wrap_mode( true ),
    origin_mode( false )
{}

void DrawState::save_cursor( void )
{
  save.cursor_col = cursor_col;
  save.cursor_row = cursor_row;
  save.renditions = renditions;
  save.auto_wrap_mode = auto_wrap_mode;
  save.origin_mode = origin_mode;
}

void DrawState::restore_cursor( void )
{
  cursor_col = save.cursor_col;
  cursor_row = save.cursor_row;
  renditions = save.renditions;
  auto_wrap_mode = save.auto_wrap_mode;
  origin_mode = save.origin_mode;

  snap_cursor_to_border();
  new_grapheme();
}

void Framebuffer::insert_line( int before_row )
{
  if ( (before_row < ds.get_scrolling_region_top_row())
       || (before_row > ds.get_scrolling_region_bottom_row() + 1) ) {
    return;
  }

  rows.insert( rows.begin() + before_row, Row( ds.get_width() ) );
  rows.erase( rows.begin() + ds.get_scrolling_region_bottom_row() + 1 );
}

void Framebuffer::delete_line( int row )
{
  if ( (row < ds.get_scrolling_region_top_row())
       || (row > ds.get_scrolling_region_bottom_row()) ) {
    return;
  }

  rows.erase( rows.begin() + row );
  rows.insert( rows.begin() + ds.get_scrolling_region_bottom_row(), Row( ds.get_width() ) );
}

void Row::insert_cell( int col )
{
  cells.insert( cells.begin() + col, Cell() );
  cells.erase( cells.end() - 1 );
}

void Row::delete_cell( int col )
{
  cells.erase( cells.begin() + col );
  cells.push_back( Cell() );
}

void Framebuffer::insert_cell( int row, int col )
{
  rows[ row ].insert_cell( col );
}

void Framebuffer::delete_cell( int row, int col )
{
  rows[ row ].delete_cell( col );
}

void Framebuffer::reset( void )
{
  int width = ds.get_width(), height = ds.get_height();
  rows = std::deque<Row>( height, Row( width ) );
  ds = DrawState( width, height );
}