const FONT_WIDTH = 8   # glyph width in pixels
const FONT_HEIGHT = 16 # glyph height in pixels (8x16 vga bitmap font)
const FG_COLOR = 0xd0d0d0
const BG_COLOR = 0x101018
const CURSOR_COLOR = 0x50fa7b

global console = {
  column = 0, row = 0, scale = 1, shown = :false, cursor_x = 0, cursor_y = 0, blink = 0,

  # cell size in pixels at the current zoom
  cell_width = fn(self) FONT_WIDTH * self.scale,
  cell_height = fn(self) FONT_HEIGHT * self.scale,
  columns = fn(self) fb_width() / self:cell_width(),
  rows = fn(self) fb_height() / self:cell_height(),

  draw_glyph = fn(self, column, row, character) do
    const origin_x = column * self:cell_width()
    const origin_y = row * self:cell_height()
    fill_rect(origin_x, origin_y, self:cell_width(), self:cell_height(), BG_COLOR) # clear the cell
    const code = character:ascii()
    if code < 32 return :nil
    if code > 127 return :nil
    const glyph = FONT[code - 32]
    for glyph_row in 0..FONT_HEIGHT do
      const bits = glyph[glyph_row]
      for glyph_col in 0..FONT_WIDTH do
        if (bits shr glyph_col) band 1 == 1 fill_rect(origin_x + glyph_col * self.scale, origin_y + glyph_row * self.scale, self.scale, self.scale, FG_COLOR)
      end
    end
  end,

  newline = fn(self) do
    self.column = 0
    self.row += 1
    if self.row >= self:rows() do
      fb_scroll(self:cell_height(), BG_COLOR)
      self.row = self:rows() - 1
    end
  end,

  # we dont do shift/cntrl, thats a job for future me lmao
  # NOTE: future me kinda delt with it, i was mad drunk
  putc = fn(self, character) do
    const code = character:ascii()
    if code == 10 do self:newline() return :nil end # \n
    if code == 13 do self.column = 0 return :nil end # \r
    if code == 8 do                                  # backspace: move left
      if self.column > 0 self.column -= 1
      return :nil
    end
    if code < 32 return :nil
    self:draw_glyph(self.column, self.row, character)
    self.column += 1
    if self.column >= self:columns() self:newline()
  end,

  clear = fn(self) do
    fill_rect(0, 0, fb_width(), fb_height(), BG_COLOR)
    self.column = 0
    self.row = 0
  end,

  cursor_clear = fn(self) do
    if self.shown do
      fill_rect(self.cursor_x * self:cell_width(), self.cursor_y * self:cell_height(), self:cell_width(), self:cell_height(), BG_COLOR)
      self.shown = :false
    end
  end,

  cursor_show = fn(self) do
    self.cursor_x = self.column
    self.cursor_y = self.row
    fill_rect(self.cursor_x * self:cell_width(), self.cursor_y * self:cell_height(), self:cell_width(), self:cell_height(), CURSOR_COLOR)
    self.shown = :true
  end,

  # render every byte the serial mirror has buffered
  drain = fn(self) do
    let byte = serial_next()
    while byte >= 0 do self:putc(string.of_ascii(byte)) byte = serial_next() end
  end,
}

global puts = fn(text) serial_puts(text)

global flush_console = fn() do
  console:cursor_clear()
  console:drain()
  console.blink = 0
  console:cursor_show()
end

global on_tick = fn(ticks) do
  let byte = serial_next()
  if byte >= 0 do
    console:cursor_clear()
    console:putc(string.of_ascii(byte))
    console:drain()
    console.blink = 0
    console:cursor_show()
    return :nil
  end
  if proc_exited() do
    console:cursor_clear()
    puts("% ")
    console:drain()
    console.blink = 0
    console:cursor_show()
    return :nil
  end
  console.blink += 1
  if console.blink >= 50 do
    console.blink = 0
    if console.shown console:cursor_clear() else console:cursor_show()
  end
end