#!/usr/bin/python


import re

import cliapp


class AutoDisp(cliapp.Application):

    lid = 'LVDS1'
    externals = ['VGA1', 'HDMI1', 'DVI1', 'DP1']

    def process_args(self, args):
        out = self.runcmd(['xrandr', '-q'])
        outputs = self.parse_outputs(out)
        
        got_internal = self.got_output(self.lid, outputs)
        got_externals = [x 
                         for x in self.externals 
                         if self.got_output(x, outputs)]
                         
        argv = ['xrandr']
        if got_externals:
            res, name = max((outputs[x], x) for x in got_externals)
            argv += ['--output', name, '--mode', '%dx%d' % res]
            if got_internal:
                argv += ['--output', self.lid, '--off']
        elif got_internal:
            argv += ['--output', self.lid, 
                     '--mode', '%dx%d' % outputs[self.lid]]
        else:
            raise cliapp.AppException('Oops, don\'t know what to do')

        self.runcmd(argv)

    def got_output(self, name, outputs):
        return name in outputs
        
    def parse_outputs(self, xrandr):
        output = re.compile(r'^(?P<output>[A-Z0-9]+) connected ')
        mode = re.compile(r'^   (?P<x>\d+)x(?P<y>\d+) ')
    
        result = {}
        current = None

        lines = xrandr.splitlines()
        for line in lines:
            words = line.split()
            output_match = output.match(line)
            mode_match = mode.match(line)
            if output_match:
                current = output_match.group('output')
            elif mode_match:
                assert current is not None
                x = int(mode_match.group('x'))
                y = int(mode_match.group('y'))
                prev = result.get(current, (0,0))
                result[current] = max((x,y), prev)

        return result    
    
AutoDisp().run()