#!/usr/bin/env python

import os
import sys
import subprocess
import termios
import tty
import readline
import math

readline.parse_and_bind('tab: complete')
readline.parse_and_bind('set editing-mode vi')

def termsize():
    rows, columns = os.popen('stty size', 'r').read().split()
    return (int(rows),int(columns))

class bc:
    MAG = '\033[95m'
    BLU = '\033[94m'
    GRE = '\033[92m'
    YEL = '\033[93m'
    RED = '\033[91m'
    CYA = '\033[96m'
    WHI = '\033[1m'
    END = '\033[0m'
    CLR = '\033[2J'

    def disable(self):
        self.MAG = ''
        self.BLU = ''
        self.GRE = ''
        self.YEL = ''
        self.RED = ''
        self.END = ''
        self.CLR = ''
        self.CYA = ''
        self.WHI = ''
        
    def pos(self,y,x):
        return "\033["+str(y)+";"+str(x)+"H"

class getch:
    def __init__(self):
        import sys, tty, termios
        
    def get(self):
        
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


def ichr(i):
    ''' convert integer to 1-9, a-z, A-Z, omitting x '''  

    if i < 10:
        return str(i)
    i=i + 87
    if i>119:
        i=i+1
    if i>122:
        i=i-122+64
    return chr(i)

def drawmenu(entries):
    maxrows,maxcolumns = termsize()
    maxrows-=5
    maxcolumns-=10
    twocol=False
    co=bc()
    helptext=""
    
    print(co.END+co.CLR+co.pos(1,3)+co.YEL+'XRandrMenu  x:exit  '+helptext+co.END)
    if len(entries)>20:
        twocol=True
        maxrows=int(math.ceil(min(maxrows/2.0, len(entries)/2.0)))
        maxcolumns=int(math.ceil(maxcolumns/2.0))
    r=1
    for e in range(len(entries)):
        if r>maxrows:
            break
        printline=entries[e][2]
        if len(printline)>maxcolumns:
            printline=printline[:maxcolumns]+"..."
        print(co.WHI+entries[e][0]+co.END+' '+entries[e][3]+printline+co.END)
        r=1+r
    if twocol:
        r=1
        for e in range(e,len(entries)):
            if r>maxrows:
                break
            printline=entries[e][2]
            if len(printline)>maxcolumns:
                printline=printline[:maxcolumns]+"..."
            print(co.pos(r+1,maxcolumns)+'| '+co.WHI+entries[e][0]+co.END+' '+entries[e][3]+printline+co.END)
            r=1+r
        print(co.pos(maxrows+2,0))

def read_displays():
    proc = subprocess.Popen('xrandr', stdout=subprocess.PIPE)
    output = proc.stdout.read()
    entries=[]
    connected=False
    for line in output.split('\n'):
        try:
            idx=int(line[1:2])
            entries.append([line[1:3], line[4:]])
        except:
            pass
    return entries

        
def append_index(entries,offset=0,color=None):
    e=1+offset
    for el in range(len(entries)):
        entries[el]=[ichr(e), entries[el][0], entries[el][1], color]
        e=e+1
    return entries

def launch(key,entries,args=""):
    ''' launch the given resolution '''
    idx=[i for i in range(len(entries)) if entries[i][0]==key][0]
    command_str=['xrandr','--size',entries[idx][1]]
    try:
        subprocess.call(command_str)
    except:
        print('Unable to run:')
        print(command_str)


def initialize():
    entries=read_displays()
    entries=append_index(entries,offset=0,color=bc.CYA)
    return entries
    
def main():
    arg_input=None
    if (len(sys.argv)>1):
        if (sys.argv[1]=="-h"):
            print("Start within a VNC session to select different screen resolutions")
            sys.exit(0)
        arg_input=sys.argv[1]
    entries=initialize()
    print(entries)
    ch=getch()
    drawmenu(entries)
    while True:
        if arg_input:
            inkey=ord(arg_input)
        else:
            inkey=ord(ch.get())
        #print('-'+str((inkey))+'-')
        if inkey in [120,27,3,24,4]:
            sys.exit(0)
        if inkey==46: # .
            entries=initialize()
        if chr(inkey) in [x[0] for x in entries]:
            launch(chr(inkey),entries)
            entries=initialize()
        if arg_input:
            sys.exit(0)
        drawmenu(entries)

main()