;; Types

(define make-type
  (lambda (name)
    name))

(define typed-value-packer
  (lambda (type)
    (lambda (value)
      (cons type value))))

(define typed-value-unpacker
  (lambda (type)
    (lambda (value)
      (if (equal? type (car value))
          (cdr value)
          (error "type mismatch")))))

(define movie-type (make-type 'movie))

(define pack-movie (typed-value-packer movie-type))
(define unpack-movie (typed-value-unpacker movie-type))

(define make-movie
  (lambda (title director year actors)
    (pack-movie
     (list title director year actors))))

(define movie-title
  (lambda (movie)
    (car (unpack-movie movie))))

(define movie-director
  (lambda (movie)
    (car (cdr (unpack-movie movie)))))

(define movie-year
  (lambda (movie)
    (car (cdr (cdr (unpack-movie movie))))))

(define movie-actors
  (lambda (movie)
    (cadddr (unpack-movie movie))))

(define director-type (make-type 'director))

(define pack-director (typed-value-packer director-type))
(define unpack-director (typed-value-unpacker director-type))

(define make-director
  (lambda (name)
    (pack-director name)))

(define director-name
  (lambda (director)
    (unpack-director director)))

(define year-type (make-type 'year))

(define pack-year (typed-value-packer year-type))
(define unpack-year (typed-value-unpacker year-type))

(define make-year
  (lambda (number)
    (pack-year number)))

(define year-number
  (lambda (year)
    (unpack-year year)))

(define actor-type (make-type 'actor))

(define pack-actor (typed-value-packer actor-type))
(define unpack-actor (typed-value-unpacker actor-type))

(define make-actor
  (lambda (name)
    (pack-actor name)))

(define actor-name
  (lambda (actor)
    (unpack-actor actor)))

(define title-type (make-type 'title))

(define pack-title (typed-value-packer title-type))
(define unpack-title (typed-value-unpacker title-type))

(define make-title
  (lambda (name)
    (pack-title name)))

(define title-name
  (lambda (title)
    (unpack-title title)))

(define construct-movie
  (lambda (title-name director-name year-number actor-names)
    (make-movie (make-title title-name)
		(make-director director-name)
		(make-year year-number)
		(map make-actor actor-names))))

(define our-movie-database		; longer version than in the text
  (list (construct-movie '(amarcord)
			 '(federico fellini)
			 1974
			 '((magali noel)
			   (bruno zanin)
			   (pupella maggio)
			   (armando drancia)))
        (construct-movie '(the big easy)
			 '(jim mcbride)
			 1987
			 '((dennis quaid)
			   (ellen barkin)
			   (ned beatty)
			   (lisa jane persky)
			   (john goodman)
			   (charles ludlam)))
        (construct-movie '(boyz n the hood)
			 '(john singleton)
			 1991
			 '((cuba gooding jr.)
			   (ice cube)
			   (larry fishburne)
			   (tyra ferrell)
			   (morris chestnut)))
        (construct-movie '(dead again)
			 '(kenneth branagh)
			 1991
			 '((kenneth branagh)
			   (emma thompson)
			   (andy garcia)
			   (derek jacobi)
			   (hanna schygulla)))
        (construct-movie '(the godfather)
			 '(francis ford coppola)
			 1972
			 '((marlon brando)
			   (al pacino)
			   (james caan)
			   (robert duvall)
			   (diane keaton)))
        (construct-movie '(an american in paris)
			 '(vincente minnelli)
			 1952
			 '((gene kelley)
			   (leslie caron)
			   (oscar levant)
			   (nina foch)
			   (george guetary)))
        (construct-movie '(casablanca)
			 '(michael curtiz)
			 1942
			 '((humphrey bogart)
			   (ingrid bergman)
			   (paul henreid)
			   (claude rains)
			   (sydney greenstreet)
			   (peter lorre)
			   (s z sakall)
			   (conrad veidt)
			   (dooley wilson)))
        (construct-movie '(citizen kane)
			 '(orson welles)
			 1941
			 '((orson welles)
			   (joseph cotten)
			   (dorothy comingore)
			   (ray collins)
			   (george coulouris)
			   (agnes moorehead)
			   (ruth warrick)))
        (construct-movie '(gone with the wind)
			 '(victor fleming)
			 1939
			 '((clark gable)
			   (vivien leigh)
			   (leslie howard)
			   (olivia de havilland)
			   (hattie mcdaniel)
			   (butterfly mcqueen)))
        (construct-movie '(lawrence of arabia)
			 '(david lean)
			 1962
			 '((peter otoole)
			   (alec guinness)
			   (anthony quinn)
			   (jack hawkins)
			   (jose ferrer)
			   (omar sharif)
			   (anthony quayle)
			   (claude rains)
			   (arthur kennedy)
			   (donald wolfit)))
        (construct-movie '(the manchurian candidate)
			 '(john frankenheimer)
			 1962
			 '((frank sinatra)
			   (laurence harvey)
			   (janet leigh)
			   (angela lansbury)
			   (henry silva)
			   (james gregory)
			   (leslie parrish)
			   (john mcgiver)
			   (khigh dhiegh)
			   (james edwards)))
        (construct-movie '(metropolis)
			 '(fritz lang)
			 1926
			 '((alfred abel)
			   (gustay frohlich)
			   (brigitte helm)
			   (rudolf kleinrogge)
			   (heinrich george)))
        (construct-movie '(othello)
			 '(orson welles)
			 1952
			 '((orson welles)
			   (michael mac liammoir)
			   (robert coote)
			   (suzanne cloutier)
			   (faye compton)
			   (doris dowling)
			   (michael laurence)))
        (construct-movie '(spartacus)
			 '(stanley kubrick)
			 1960
			 '((kirk douglas)
			   (laurence olivier)
			   (jean simmons)
			   (charles laughton)
			   (peter ustinov)
			   (john gavin)
			   (tony curtis)
			   (woody strode)))
        (construct-movie '(a star is born)
			 '(george cuckor)
			 1954
			 '((judy garland)
			   (james mason)
			   (jack carson)
			   (tommy noonan)
			   (charles bickford)))
        (construct-movie '(after the rehearsal)
			 '(ingmar bergman)
			 1984
			 '((erland josephson)
			   (ingrid thulin)
			   (lena olin)
			   (nadja palmstjerna-weiss)))
        (construct-movie '(amadeus)
			 '(milos forman)
			 1984
			 '((f murray abraham)
			   (tom hulce)
			   (elizabeth berridge)
			   (simon callow)
			   (roy dotrice)
			   (christine ebersole)
			   (jeffrey jones)))
        (construct-movie '(blood simple)
			 '(joel coen)
			 1985
			 '((john getz)
			   (frances mcdormand)
			   (dan hedaya)
			   (m emmet walsh)
			   (samm-art williams)))
        (construct-movie '(chinatown)
			 '(roman polanski)
			 1974
			 '((jack nicholson)
			   (faye dunaway)
			   (john huston)
			   (perry lopez)
			   (john hillerman)
			   (darrell zwerling)
			   (diane ladd)
			   (roman polanski)))
        (construct-movie '(the cotton club)
			 '(francis ford coppola)
			 1984
			 '((richard gere)
			   (gregory hines)
			   (diane lane)
			   (lonette mckee)
			   (bob hoskins)
			   (james remar)
			   (fred gwynne)))
        (construct-movie '(the crying game)
			 '(neil jordan)
			 1992
			 '((stephen rea)
			   (jaye davidson)
			   (forest whitaker)
			   (miranda richardson)
			   (adrian dunbar)
			   (breffini mckenna)
			   (joe savino)))
        (construct-movie '(the day of the jackal)
			 '(fred zinnemann)
			 1973
			 '((edward fox)
			   (terence alexander)
			   (michel auclair)
			   (alan badel)
			   (tony britton)
			   (denis carey)
			   (olga georges-picot)
			   (cyril cusack)))
        (construct-movie '(diva)
			 '(jean-jacques beineix)
			 1981
			 '((wilhelmenia wiggins fernandez)
			   (frederic andrei)
			   (richard bohringer)
			   (thay an luu)
			   (jacques fabbri)
			   (chantal deruaz)))
        (construct-movie '(the dresser)
			 '(peter yates)
			 1984
			 '((albert finney)
			   (tom courtenay)
			   (edward fox)
			   (zena walker)))
        (construct-movie '(el norte)
			 '(gregory nava)
			 1983
			 '((zaide silvia gutierrez)
			   (david villalpando)
			   (ernesto gomez cruz)
			   (alicia del lago)
			   (trinidad silva)))
        (construct-movie '(the exorcist)
			 '(william friedkin)
			 1973
			 '((ellen burstyn)
			   (linda blair)
			   (jason miller)
			   (max von sydow)
			   (kitty winn)
			   (lee j cobb)))
        (construct-movie '(a fish called wanda)
			 '(michael chrichton)
			 1988
			 '((john cleese)
			   (jamie lee curtis)
			   (kevin kline)
			   (michael palin)
			   (maria aitken)
			   (tom georgeson)
			   (patricia hayes)))
        (construct-movie '(flirting)
			 '(john duigan)
			 1992
			 '((noah taylor)
			   (thandie newton)
			   (nicole kidman)
			   (bartholomew rose)
			   (felix nobis)
			   (josh picker)
			   (kiri paramore)))
        (construct-movie '(gates of heaven)
			 '(errol morris)
			 1978
			 '())
        (construct-movie '(house of games)
			 '(david mamet)
			 1987
			 '((lindsay crouse)
			   (joe mantegna)
			   (mike nussman)
			   (lilia skala)
			   (j t walsh)
			   (jack wallace)))
        (construct-movie '(iceman)
			 '(fred schepisi)
			 1984
			 '((timothy hutton)
			   (john lone)
			   (lindsay crouse)))
        (construct-movie '(jaws)
			 '(steven spielberg)
			 1975
			 '((roy scheider)
			   (robert shaw)
			   (richard dreyfuss)
			   (lorraine gary)
			   (murray hamilton)))
        (construct-movie '(johnny got his gun)
			 '(dalton trumbo)
			 1971
			 '((timothy bottoms)
			   (kathy fields)
			   (jason robards)
			   (diane varsi)
			   (donald sutherland)
			   (eduard franz)))
        (construct-movie '(local hero)
			 '(bill forsyth)
			 1983
			 '((burt lancaster)
			   (peter reigert)
			   (peter capaldi)
			   (fulton mckay)
			   (denis lawson)))
        (construct-movie '(malcolm x)
			 '(spike lee)
			 1992
			 '((denzel washington)
			   (angela basset)
			   (albert hall)
			   (al freeman jr)
			   (delroy lindo)
			   (spike lee)))))
; (define display-actor-in-movie?
;  (lambda (firstname lastname movie)
;    (if (actor-in-movie? (list firstname lastname) movie)
;        (display "Yes, indeed.")
;        (display "No, that's not the case"))))
;
;(define actor-in-movie?
;  (lambda (actor movie)
;    (let ((movies (movies-with-title-name movie)))
;      (if (null? movies)
;          #f
;          (member? actor (map actor-name (movie-actors (car movies))))))))

(define filter
  (lambda (predicate list)
    (cond
      ((null? list) '())
      ((predicate (car list))
       (cons (car list)
             (filter predicate (cdr list))))
      (else
       (filter predicate (cdr list))))))

(define query-loop
  (lambda ()
    (let ((question (read)))
      (if (exit? question)
          (display '(see you later))
          (begin (answer-by-pattern question patterns+actions)
                 (newline)
                 (query-loop))))))

(define answer-by-pattern 
  (lambda (question p/as)
    (if (null? p/as)
        (display '(I did not understand your question))
        (if (matches? (pattern (car p/as)) question)
            (let ((subs (substitutions-in-to-match
                         (pattern (car p/as))
                         question)))
              (let ((result ((action (car p/as)) subs)))
                (if (null? result)
                    (display "I don't know")
                     (display result))))
            (answer-by-pattern question (cdr p/as))))))
   
(define exit?
  (lambda (question)
    (member? question
             '((bye)
               (quit)
               (exit)
               (goodbye)
               (au revoir)))))

(define member?
  (lambda (element list)
    (cond
      ((null? list) #f)
      ((equal? element (car list)) #t)
      (else (member? element (cdr list))))))

(define movies-with-title-name
  (lambda (name)
    (filter (lambda (movie)
              (equal? name
                      (title-name (movie-title movie))))
            our-movie-database)))

(define pattern/action-type (make-type 'pattern/action))

(define pack-pattern/action (typed-value-packer pattern/action-type))
(define unpack-pattern/action (typed-value-unpacker pattern/action-type))

(define make-pattern/action
  (lambda (pattern action)
    (pack-pattern/action
     (cons pattern action))))

(define display-directors-of
  (lambda (title)
    (display 
     (director-name (movie-director
                     (car (movies-with-title-name title)))))))
 
(define patterns+actions
  (list (make-pattern/action '(who is the director of ...)
                             display-directors-of)))

(define pattern
  (lambda (p/a)
    (car (unpack-pattern/action p/a))))

(define action
  (lambda (p/a)
    (cdr (unpack-pattern/action p/a))))
(define substitutions-in-to-match
  (lambda (pattern question)
    (cond ((equal? (car pattern) (car question))
           (substitutions-in-to-match (cdr pattern) (cdr question)))
          ((equal? (car pattern) '...)
           question))))
(define matches?
  (lambda (pattern question)
    (cond
      ((null? pattern)
       (if (null? question)
           #t
           #f))
      ((null? question)
       #f)
      ;; pattern and question non-null?
      ((equal? '... (car pattern))
       #t)
      ((equal? (car question) (car pattern))
       (matches? (cdr pattern)
                 (cdr question)))
      (else #f))))