""" display an ascii barGraph within the boundary of a terminal console. 
    
    This is just an experiment for learning and do to some
    practicing on python3.
    
    code is free for non-commercial personal and educational use.
    
    Author:     Axel Werner [axel.werner.1973@gmail.com]
    Version:    2015-08-10
    
    Personal Comments and ToDos:
    =============================
    - i know this code is not very beautiful yet and is very cluttered. if i would
        reuse it, i should convert it into a class and do more re-factoring to make
        it friendlier to read and easy to maintain. 
    
"""

import shutil
import random
import time

consoleWidth, consoleHeight = shutil.get_terminal_size() # returns a integer tuple

leftDelimiter="["
rightDelimiter="]"
progressBarChar="="
progressBarFillerChar="."

limiterLastRandNum=0.5 # global 
    
def getProgressBar( progressPercentage=0.0, width=50 ):
    """ return progressBar as string ranging from float 0.0 to 1.0 ."""
    
    if progressPercentage > 1:
        print("ERROR: percentage must be between 0.0 and 1.0")
        print("         instead the percentage i received is:", progressPercentage)
        exit(1)
        
    percentageDisplayStr= str(int(progressPercentage*100))+"%"

    LengthOfpercentageDisplayStr=len(percentageDisplayStr)
    maxWidthOfpercentageDisplayStr=4 # '100%'
    numOfFillersNeeded=maxWidthOfpercentageDisplayStr-LengthOfpercentageDisplayStr
    percentageDisplayStr=percentageDisplayStr+numOfFillersNeeded*" "
    
    maxBarWidth=width-1-( len(leftDelimiter)+len(rightDelimiter)+len(percentageDisplayStr) )
    effectiveWidthOfProgressBar=int(maxBarWidth*progressPercentage)
    effectiveWidthOfFillerBar=int(maxBarWidth-effectiveWidthOfProgressBar)
    
    
    progressString=effectiveWidthOfProgressBar*progressBarChar
    fillerString=effectiveWidthOfFillerBar*progressBarFillerChar
    wholeBarStr=percentageDisplayStr+leftDelimiter+progressString+fillerString+rightDelimiter
    return wholeBarStr
    
def limitedRandGen():
    """ return a random Number between 0.0 and 1.0 within limited dynamic range of 3%. """
    global limiterLastRandNum

    newRandNum=random.random()
    delta=abs(limiterLastRandNum-newRandNum) # Betrag bestimmen (Vorzeichen ignorieren)

    while (delta*100) > 3.0 : # set limitation percentage here
        newRandNum=random.random()
        delta=abs(limiterLastRandNum-newRandNum) # Betrag bestimmen (Vorzeichen ignorieren)

    limiterLastRandNum=newRandNum
    return newRandNum

    
print("\n"*3)
print("DEMO1: run bargraph straight from 0 to 100%")
for progress in range(100+1):
    print( getProgressBar(progress/100.0, width=consoleWidth) )


print("\n"*3)
print("DEMO2: displaying 300 random percentages barGraphs on the same line at full width")
numOfFrames=300
for i in range(numOfFrames):
    print( "\r" + getProgressBar( progressPercentage=limitedRandGen(), width=consoleWidth ), end="" )
    time.sleep(50 / 1000) # delays for x seconds

    
print("\n"*3)
print("DEMO3: displaying 300 random percentages barGraphs on the same line at width=50")
numOfFrames=300
for i in range(numOfFrames):
    print( "\r" + getProgressBar( progressPercentage=limitedRandGen(), width=50 ), end="" )
    time.sleep(50 / 1000) # delays for x seconds


print("\n"*3)
print("consoleWidth =", consoleWidth)

input("press ENTER to continue...")