import array
import traceback
import png
import os
import logConfig
import status_mod

# Fake globals for syntax check
import syslog

if False:
  response = None
  request = None
  session = None
  db = None

status_mod.sessionUserMgr.setLastVisit(session, request)
if logConfig.ctrlSessFrgt:
  session.forget(response)


def fb2png(f_in, f_out, width, height):
  array_uint16 = array.array('H')  # unsigned short
  array_uint16.fromfile(f_in, width * height)
  image = []
  for row in range(height):
    line = []
    for col in range(width):
      uint16 = array_uint16[row * width + col]
      line.append((uint16 >> 11) << 3)  # R 0 .. 255
      line.append(((uint16 >> 5) & 0x3F) << 2)  # G 0 .. 255
      line.append((uint16 & 0x1F) << 3)  # B 0 .. 255
    image.append(line)
  writer = png.Writer(width, height)  # RGB, no alpha, no background, no compression
  writer.write(f_out, image)


@auth.requires(request.ajax==True, requires_login=True)
def screenshot():
    try:
        os.mkdir('applications/BS350/static/tmp')
    except OSError:
        syslog.syslog(syslog.LOG_ERR, traceback.format_exc())

    try:
        with open('/dev/fb0', 'rb') as f_in:
            with open('applications/BS350/static/tmp/screenshot.png', 'wb') as f_out:
                fb2png(f_in, f_out, 240, 320)
    except:
        syslog.syslog(syslog.LOG_ERR, traceback.format_exc())