#Sameer Kumar
#Skumar77@gatech.edu
#I worked on this assignment alon, using only this semester's course materials.

#Function One: Border

def border (pic, color, thickness):
  left = 0 + thickness
  right = getWidth(pic) - thickness
  top = 0 + thickness
  bottom = getHeight(pic) - thickness
  for pixel in getPixels(pic):
   if getX(pixel) >= right:
      setColor(pixel, color)
   if getX(pixel) <= left:
      setColor(pixel, color)
   if getY(pixel) <= top:
      setColor(pixel, color)
   if getY(pixel) >= bottom:
      setColor(pixel, color)

#Function Two: Background
def background(pic, color1, color2, threshold):
  half = getWidth(pic) /2
  for pixel in getPixels(pic):
    if getX(pixel) < half:
      if distance(getColor(pixel), green) < threshold:
        setColor(pixel, color1)
    if getX(pixel) >= half:
      if distance(getColor(pixel), green) < threshold:
        setColor(pixel, color2)

#Function Three: selectivePosterize
def selectivePosterize(pic, color1, color2, color3, color4, threshold):
  for pixel in getPixels(pic):
    luminance = (getRed(pixel) + getGreen(pixel) + getBlue(pixel))/3
    x = luminance
    if distance(getColor(pixel), green) > threshold:
        if x < 20:
          setColor(pixel, color1)
        if 20 <= x < 80:
          setColor(pixel, color2)
        if 80 <= x < 160:
          setColor(pixel, color3)
        if x >= 160:
          setColor(pixel, color4)

#Function 4: generatePoster
def generatePoster(pic):
  color1 = makeColor(255,0,0)
  color2 = makeColor(50,50,50)
  color3 = makeColor(224,238,224)
  color4 = makeColor(0,0,0)
  leftColor = makeColor(25,25,112)
  rightColor = makeColor(150,0,0)
  selectivePosterize(pic,color4,color3,color2,color1,195)
  background(pic,leftColor,rightColor,130)
  border(pic, black, 20)