;;;;;;;facts;;;;;;;
;(deffacts categories ;unused, would be used later in the program
;   (category hatchback Alfa_Romeo_Giulietta Volkswagen_Golf Ford_Fiesta)
;   (category coupe Jaguar_XKR Mazda_MX5 Audi_TT)
;   (category supercar Aston_Martin_DB9 Ferrari_458_Italia Audi_R8)
;   (category saloon BMW_3_Series Mercedes_C_Class Jaguar_XF)
;   (category estate Mercedes_E_Class_Estate Subaru_Legacy ;BMW_5_Series_Touring)
;   (category hot_hatch Citroen_DS3 Volkswagen_Golf_GTI Ford_Focus_ST )
;   (category suv Range_Rover BMW_X5 Volvo_XC90)
;)

(deftemplate category
    (slot type)
    (slot value)
)

(deffacts types
    (category (type hatchback)(value 0))
    (category (type coupe)(value 0))
    (category (type supercar)(value 0))
    (category (type saloon)(value 0))
    (category (type estate)(value 0))
    (category (type hot_hatch)(value 0))
    (category (type suv)(value 0))
)


;;;;;;;question fuctions;;;;;;;
(deffunction ask-question (?question $?allowed-values)
   (printout t ?question)
   (bind ?answer (read))
   (if (lexemep ?answer)
       then (bind ?answer (lowcase ?answer)))
   (while (not (member ?answer ?allowed-values)) do
      (printout t ?question)
      (bind ?answer (read))
      (if (lexemep ?answer)
          then (bind ?answer (lowcase ?answer))))
   ?answer
)

(deffunction yes-or-no-p (?question)
   (bind ?response (ask-question ?question yes no y n))
   (if (or (eq ?response yes) (eq ?response y))
       then TRUE
       else FALSE)
)


;;;;;;;probability function;;;;;;;
(deffunction calc(?b ?type)
    ?fact <- (category (type ?type)(value ?a)) ;retrieve the matching fact index
    (bind ?probability (/ (* ?a ?b) (+ (* ?a ?b) (* (- 1 ?a) (- 1 ?b)))))
    (bind ?prob (/ (round (* ?probability 100)) 100)) ;round to 2 decimal places
    (modify ?fact (value (?prob))) ;modify the value of the fact at that index
)


;;;;;;;questions;;;;;;;
;As this is the first question, we don't need to work out the probability,
;just set the facts to their respective values, as they are 0 by default, which will not work in the equation.
(defrule carry_multiple_passengers ""
    (declare (salience 10))
    (not (multiple_passengers ?))
    ?h <- (category (type hatchback)) ;get the fact indices
    ?c <- (category (type coupe))
    ?sc <- (category (type supercar))
    ?s <- (category (type saloon))
    ?e <- (category (type estate))
    ?hh <- (category (type hot_hatch))
    ?suv <- (category (type suv))
   =>
   (if (yes-or-no-p "Do you have to carry multiple passengers (yes/no)?")
       then
    (assert (multiple_passengers yes))
    (modify ?h (value 1)) ;modify the facts
    (modify ?c (value 0.3))
    (modify ?sc (value 0.3))
    (modify ?s (value 0.9))
    (modify ?e (value 1))
    (modify ?hh (value 0.6))
    (modify ?suv (value 0.8))
   else
    (assert (multiple_passengers no))
   )
)

(defrule carry_child_passengers ""
    (declare (salience 9))
    (not (child_passengers ?))
   =>
   (if (yes-or-no-p "Do you have to carry child passengers (yes/no)?")
       then
    (assert (child_passengers yes))
    (calc 1 hatchback) ;call the calc function, with the P(b) probability, and the type
    (calc 0.2 coupe)
    (calc 0.1 supercar)
    (calc 0.7 saloon)
    (calc 1 estate)
    (calc 0.5 hot_hatch)
    (calc 0.6 suv)
   else
    (assert (child_passengers no))
   )
)

(defrule drive_on_circuit ""
    (declare (salience 8))
    (not (circuit_drive ?))
   =>
   (if (yes-or-no-p "Do you want to drive on a circuit? (yes/no)?")
       then
    (calc 0.4 hatchback)
    (calc 1 coupe)
    (calc 1 supercar)
    (calc 0.6 saloon)
    (calc 0.4 estate)
    (calc 0.8 hot_hatch)
    (calc 0.4 suv)
   else
    (assert (circuit_drive no))
   )
)

(defrule drive_off_road ""
    (declare (salience 7))
    (not (offroad_drive ?))
   =>
   (if (yes-or-no-p "Do you want to drive off-road (yes/no)?")
       then
    (calc 0.3 hatchback)
    (calc 0.1 coupe)
    (calc 0.1 supercar)
    (calc 0.3 saloon)
    (calc 0.5 estate)
    (calc 0.3 hot_hatch)
    (calc 1 suv)
   else
    (assert (offroad_drive no))
   )
)

(defrule drive_congested_areas ""
    (declare (salience 6))
    (not (drive_congested ?))
   =>
   (if (yes-or-no-p "Do you drive in congested areas (yes/no)?")
       then
    (calc 1 hatchback)
    (calc 0.5 coupe)
    (calc 0.3 supercar)
    (calc 0.8 saloon)
    (calc 0.8 estate)
    (calc 0.7 hot_hatch)
    (calc 0.6 suv)
   else
    (assert (drive_congested no))
   )
)

(defrule drive_rush_hour ""
    (declare (salience 5))
    (not (rush_hour_drive ?))
   =>
   (if (yes-or-no-p "Do you frequently drive in rush hour traffic (yes/no)?")
       then
    (calc 1 hatchback)
    (calc 0.5 coupe)
    (calc 0.3 supercar)
    (calc 0.9 saloon)
    (calc 0.9 estate)
    (calc 0.7 hot_hatch)
    (calc 0.6 suv)
   else
    (assert (rush_hour_drive no))
   )
)

(defrule park_on_road ""
    (declare (salience 4))
    (not (road_park ?))
   =>
   (if (yes-or-no-p "Can you only park on the road (yes/no)?")
       then
    (calc 1 hatchback)
    (calc 0.5 coupe)
    (calc 0.3 supercar)
    (calc 0.9 saloon)
    (calc 0.9 estate)
    (calc 0.6 hot_hatch)
    (calc 0.7 suv)
   else
    (assert (road_park no))
   )
)