Big John's Beef Jerky Calculator

bjbj.hs

import System.Environment(getArgs)
import Graphics.Rendering.Chart
import Data.Colour
import Data.Colour.Names
import Data.Default.Class
import Graphics.Rendering.Chart.Backend.Diagrams
import Graphics.Rendering.Chart.Axis.Floating
import Control.Lens

lifetime_discount = 0.05
loyalty_discount = [0.00, 0.03, 0.05, 0.07]

bjbj_trunc :: Rational -> Rational
bjbj_trunc x = fromIntegral(floor (x * 10)) / 10

bjbj_other_discount :: Rational -> Rational -> Rational
bjbj_other_discount x d = bjbj_trunc (x * d)

bjbj_discount :: Rational -> Rational -> Rational
bjbj_discount x d = x - (x * d)

bjbj_discount_amount :: Rational -> Rational
bjbj_discount_amount x
	| x < 50.00		= 0
	| x < 129.00		= 0.25
	| x < 275.00		= 0.30
	| x < 718.00		= 0.35
	| x < 1724.00	= 0.37
	| x < 3000.00	= 0.40
	| x >= 3000.00	= 0.44

bjbj :: Rational -> Rational -> Double
bjbj x loyalty = fromRational(discounted_price - ((bjbj_other_discount discounted_price lifetime_discount) + (bjbj_other_discount discounted_price loyalty)))
	where
		discounted_price = bjbj_discount x (bjbj_discount_amount x)
		
chart = toRenderable layout
	where
		loyalty :: [PlotLines Double Double]
		loyalty = [(plot_lines_values .~ [[ (fromRational x, bjbj x (loyalty_discount !! 0)) | x <- [0.0, 1.0..3100.0] ]]
			$ plot_lines_style  . line_color .~ opaque blue
			$ plot_lines_title .~ "0% Loyalty Rewards"
			$ def), (plot_lines_values .~ [[ (fromRational x, bjbj x (loyalty_discount !! 1)) | x <- [0.0, 1.0..3100.0] ]]
			$ plot_lines_style  . line_color .~ opaque red
			$ plot_lines_title .~ "0.03% Loyalty Rewards"
			$ def), (plot_lines_values .~ [[ (fromRational x, bjbj x (loyalty_discount !! 2)) | x <- [0.0, 1.0..3100.0] ]]
			$ plot_lines_style  . line_color .~ opaque green
			$ plot_lines_title .~ "0.05% Loyalty Rewards"
			$ def), (plot_lines_values .~ [[ (fromRational x, bjbj x (loyalty_discount !! 3)) | x <- [0.0, 1.0..3100.0] ]]
			$ plot_lines_style  . line_color .~ opaque purple
			$ plot_lines_title .~ "0.07% Loyalty Rewards"
			$ def)]
			
		layout = layout_title .~ "Big John's Beef Jerky Bulk Pricing (with Lifetime Loyalty Discount (5%))"
			$ layout_plots .~ fmap toPlot loyalty
			$ def

main = renderableToSVGFile chart 800.0 600.0 "bigjohnsbeefjerky_optimal.svg"