;; This file is free software: you can redistribute it and/or modify
;; it under the terms of version 3 of the GNU General Public License
;; as published by the Free Software Foundation.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; TODO: Get :x-if.interpret to make ACTION objects.

;; —————————————————————————————————————
;; PACKAGES

(defpackage :x-if
  (:use :cl)
  (:nicknames :xif))

(defpackage :x-if.misc
  (:use :cl :anaphora)
  (:nicknames :xif.m)
  (:export :line-cdr :line-car :line-length :line-position
           :in-string-p :remove-line
           :position-equal
           :triangulate))

(defpackage :x-if.lexicon
  (:use :cl :earley-parser)
  (:nicknames :xif.l)
  (:export :action-indirect-required-p :action-direct-required-p
           :action-p :action-function :add-action :add-verb :remove-word
           *string-lexicon* *lexicon*
           :add-game-object-words :delete-game-object-words
           :add-adjective :add-noun :add-proper-noun :add-verb
           :reload-lexicon))

(defpackage :x-if.environment
  (:use :cl :bknr.datastore)
  (:nicknames :xif.e)
  (:export :id→game-object :get-player
           :all-game-objects
           :noun→game-objects :proper-noun→game-objects :adjective→game-objects
           :all-entities
           :noun→entities :proper-noun→entities :adjective→entities
           :all-mobs
           :noun→mobs :proper-noun→mobs :adjective→mobs
           :noun→locations :proper-noun→locations :adjective→locations
           :verb→actions
           :all-locations
           :id :description
           :indirect-object-required-p :direct-object-required-p
           :nouns :proper-nouns :adjectives
           :max-children :weight :hp :max-hp
           :children :parent
           :link :unlink))

(defpackage :x-if.parsing
  (:use :cl)
  (:nicknames :xif.p)
  (:export :parse
           :noun-phrases :det :prep :proper-noun :noun-name :det :prep
           :nominal-phrase :noun
           :adjective-phrase :adjective
           :verb-phrase :verb :direct-object :indirect-object
           :the-action :the-subject))

(defpackage :x-if.interpret
  (:use :cl)
  (:nicknames :xif.i)
  (:export :noun-phrase→game-objects))

(defpackage :x-if.client
  (:use :cl :xif.e :bknr.datastore)
  (:nicknames :xif.c)
  (:export :start
           :text :input-sentence :display-options :input-options :play-music
           :show-image :status :prompt))

(defpackage :x-if.client.terminal
  (:use :cl :xif.e)
  (:nicknames :xif.c.t))




;; —————————————————————————————————————
;; X-IF.PARSING
;; SENTENCE PARSING

(in-package :x-if.parsing)

;; —————————————————————————————————————

;; This package will take a sentence (string) and turn it into an
;; easily-parseable tree. It also provides some functions to make parsing this
;; tree easy. It does not, however, actually “process” the sentence for the
;; game engine itself— that's :x-if.interpret's job.

;; It doesn't define the lexicon, either. That's :x-if.environment's job.

;; This uses Earley parse-trees from :cl-earley-parser— so, when a function
;; says "tree", it means a list with a identifying car and several sublists.
;; For example, here's a noun-phrase's tree:

;; ("NP" ("proper-noun" "Princess") (prep "beside"))

;; A "full tree" is the tree of an entire statement— not a sub-tree thereof.
;; The only functions that require the full statement tree is #'the-subject
;; and #'the-action, so don't sweat it.

;; —————————————————————————————————————

;; STRING → LIST_OF_TREES
(defun parse (sentence)
  "Parse a given string into a list of Earley trees."
  (mapcar #'car
  (mapcar #'parse-statement
          (mapcar #'clean-statement (split-statements sentence)))))

;; —————————————————————————————————————

;; STRING → TREE
(defun parse-statement (statement)
  "Parse a given statement into an Earley tree."
  (earley-parser:chart-listing->trees
    (earley-parser:earley-parse statement
      (earley-parser:load-bnf-grammar #p"example/grammar.txt")
      xif.l:*lexicon*)))

(defun split-statements (sentence)
  "Split up a string into different statements, based on punctuation."
  (cl-strings:split sentence ","))

(defun clean-statement (statement) statement)

;; —————————————————————————————————————

;; TREE → LIST_OF_TREES_OF_NOUN_PHRASES
(defun noun-phrases (tree)
  "Return the noun-phrases within a given tree."
  (let ((phrase nil))
    (loop :while   (setf phrase (assoc "NP" (cdr tree) :test #'equal))
          :collect phrase
          :do      (setq tree (remove phrase tree)))))

;; TREE → TREE_OF_VERB_PHRASE
(defun verb-phrase (tree)
  "Return a tree's verb-phrase."
  (assoc "VP" (cdr tree) :test #'equal))

;; TREE → TREE_OF_ADJECTIVE_PHRASE
(defun adjective-phrase (tree)
  "Return the adjective-phrase of a given tree."
  (assoc "AP" (cdr tree) :test #'equal))

;; TREE_OF_VERB_PHRASE → TREE_OF_NOUN_PHRASE
(defun direct-object (verb-phrase)
  "Return a verb-phrase's direct object."
  (loop :for n-p :in (noun-phrases verb-phrase)
        :if (not (prep n-p))
        :return n-p))

;; TREE_OF_VERB_PHRASE → TREE_OF_NOUN_PHRASE
(defun indirect-object (verb-phrase)
  "Return a verb-phrase's indirect object."
  (loop :for n-p :in (noun-phrases verb-phrase)
        :if (prep n-p)
        :return n-p))

;; TREE_OF_NOUN_PHRASE → TREE_OF_NOMINAL_PHRASE
(defun nominal (noun-phrase)
  "Return the nominal of a noun— how it's referred to."
  (assoc "nominal" (cdr tree) :test #'equal))

;; —————————————————————————————————————

;; TREE_OF_VERB_PHRASE → CONS
(defun verb (tree)
  (assoc "verb" (cdr tree) :test #'equal))

;; TREE_OF_NOUN_PHRASE → CONS
(defun prep (noun-phrase)
  (assoc "prep" (cdr noun-phrase) :test #'equal))

;; TREE_OF_NOMINAL_PHRASE → STRING
(defun noun (nominal-phrase)
  "Return the name of a noun's nominal phrase."
  (cadr (assoc "noun" (cdr nominal-phrase) :test #'equal)))

;; TREE_OF_NOUN_PHRASE → STRING
(defun det (noun-phrase)
  "Return a noun-phrase's det attr— 'the', 'a', 'this', etc."
  (cadr (assoc "det" (cdr noun-phrase) :test #'equal)))

;; TREE_OF_NOUN_PHRASE → STRING
(defun proper-noun (noun-phrase)
  "Return the proper noun of a noun-phrase."
  (cadr (assoc "proper-noun" (cdr noun-phrase) :test #'equal)))

;; TREE_OF_NOUN_PHRASE → STRING
(defun noun-name (noun-phrase)
  "Return the name of a noun, whether it's a proper noun or not."
  (if (nominal noun-phrase)
    (noun (nominal noun-phrase))
    (proper-noun noun-phrase)))

;; TREE_OF_NOUN_PHRASE → STRING
(defun adjective (noun-phrase)
  "Return the name of a noun's nominal phrase."
  (cadr (assoc "noun" (cdr nominal-phrase) :test #'equal)))

;; —————————————————————————————————————

;; FULL_TREE → TREE_OF_VERB_PHRASE
(defun the-action (full-tree)
  "Return THE main action of a sentence— takes the root of a statement's  tree."
  (verb-phrase full-tree))

;; FULL_TREE → TREE_OF_NOUN_PHRASE
(defun the-subject (full-tree)
  "Return THE subject of a sentence— AKA, the first noun-phrase. Assumes
  subject-verb-etc order."
  (car (noun-phrases full-tree)))




;; —————————————————————————————————————
;; X-IF.LEXICON
;; MANAGEMENT OF EARLEY-PARSER'S LEXICON

(in-package :x-if.lexicon)

;; —————————————————————————————————————

(defvar *string-lexicon*)
(setq *string-lexicon*
"the :class <det>
that :class <det>
this :class <det>
here :class <prep>
there :class <prep>
above :class <prep>
below :class <prep>
beside :class <prep>
across :class <prep>
be :class <aux>
to :class <prep>
with :class <prep>
a :class <det>
an :class <det>
")

(defvar *lexicon* nil)


;; STRING STRING → NIL
(defun add-word (word class)
  "Add a word of the given class to the string-lexicon and parsed lexicon."
  (setq *string-lexicon*
        (concatenate 'string *string-lexicon*
                     (format nil "~A :class \<~A\>~%" word class)))
  (reload-lexicon))


;; STRING → NIL
(defun remove-word (word)
  "Remove a word from the string-lexicon and parsed lexicon."
  (when (is-word-p word)
    (setq *string-lexicon*
          (xif.m:remove-line *string-lexicon* word
                             :test #'cl-strings:starts-with))
    (reload-lexicon)))

;; STRING → BOOLEAN
(defun is-word-p (word)
  "Return whether or not a given word is in the lexicon."
  (xif.m:line-position *string-lexicon* word :test #'cl-strings:starts-with))


;; SYMBOL SYMBOL STRING → (DEFUN … )
(defmacro defun-add-wordclass (function-name class-symbol class-string)
  "Define the add-WORD function of the given word-class. #'add-noun, etc."
  `(defun ,function-name (,class-symbol)
     ,(format nil "Add a word of class ~A to the lexicon." class-string)
     (add-word ,class-symbol ,class-string)))

(defun-add-wordclass add-proper-noun proper-noun "proper-noun")
(defun-add-wordclass add-noun noun "noun")
(defun-add-wordclass add-adjective adjective "adjective")
(defun-add-wordclass add-verb verb "verb")


;; GAME-OBJECT → NIL
(defmethod add-game-object-words ((object xif.e::game-object))
  "Add a game-object's words (nouns, adjectives, proper-nouns) to the lexicon."
  (mapcar #'add-adjective (xif.e:adjectives object))
  (mapcar #'add-proper-noun (xif.e:proper-nouns object))
  (mapcar #'add-noun (xif.e:nouns object)))

;; GAME-OBJECT → NIL
(defmethod remove-game-object-words ((object xif.e::game-object))
  "Remove a game-object's words (nouns, adjectives, proper-nouns) to the lexicon."
  (mapcar #'xif.l:remove-word (xif.e:nouns object))
  (mapcar #'xif.l:remove-word (xif.e:proper-nouns object))
  (mapcar #'xif.l:remove-word (xif.e:adjectives object)))

;; STRING → LEXICON
(defun load-string-lexicon (lex-string)
  "Read all words from a dictionary file into a lexicon and a part of speech.
  Abridged version of #'earley-parser:load-lexicon (which reads from a file)."
  (with-input-from-string (lex-str-stream lex-string)
  (let ((lexicon (make-hash-table :test earley-parser::*string-comparer*))
        (part-of-speech nil))
    (loop :while (listen lex-str-stream)
          :do (let ((w (earley-parser::read-lexicon-line lex-str-stream)))
                (pushnew (earley-parser::terminal-class w)
                         part-of-speech
                         :test earley-parser::*string-comparer*)
                (push w (gethash (earley-parser::terminal-word w) lexicon))))
    (earley-parser::make-lexicon :dictionary lexicon
                                 :part-of-speech part-of-speech))))

;; NIL → NIL
(defun reload-lexicon ()
  "Updates the lexicon by parsing the string-lexicon."
  (setq *lexicon* (load-string-lexicon *string-lexicon*)))




;; —————————————————————————————————————
;; X-IF.INTERPRET
;; SENTENCE INTERPRETATION

(in-package :x-if.interpret)

;; —————————————————————————————————————

;; This package will take a parsed sentence (earley tree) and return proper
;; actions to be taken based on the sentence.

;; #'interpret will return either a list— of a function-name, followed by
;; x-if.environment objects with identifying symbols, or an error string with
;; symbol signifying the error as a second return-value.

;; The actionable list (function-name, followed by arguments to said function)
;; will look like this, for example:
;;  '(#'kill :direct <XIF.E:MAN> :indirect <XIF.E:KNIFE> :subject <XIF.E:PLAYER>)
;; if you give it the sentence
;;   "Kill the man with the knife."
;; … assuming that the knife is a valid object (in inventory or room) and the
;; man is is valid as well (in room or inventory).

;; If, for example, either the knife or man are invalid, an appropriate string
;; will be returned instead, to be printed as an error.
;; For instance: "you can't do that" or "that object isn't here", in cases
;; where the word is in lexicon but not currently applicable.
;; It will also return an appropriate error symbol, as a second value—
;; I.E., 'INVALID-ACTION, etc.

;; If a word *isn't* in lexicon, or something else crops up, then
;; #'x.if.parsing:parse will return an error symbol instead of a queued-action
;; object— which means that #'interpret will recieve that error symbol from the
;; engine. In this case, #'interpret will return the symbol as if it were its
;; own error-symbol, but with an error-symbol of 'PARSE-DIE.
;; If the error is in the interpretation method, it'll obviously return the
;; second error-symbol as 'INTERPRET-DIE.

;; Anyway, ultimately the engine will actually execute the actionable list
;; generated by #'interpret.

;; —————————————————————————————————————

;; TODO: Obviously, if there are multiple matches it should error TF out
;; and die, and... and... AHHHH good luck ;w;

;; TREE_OF_STATEMENT → LIST || SYMBOL
(defmethod interpret ((statement-tree list))
  "Actually interpret a parsed statement-tree; returns a list with the
  applicable function-name for the action, and the objects for the direct and
  indirect objects, as well as the subject."
  (let* ((subject  (aif (the-subject statement-tree) (name→mobs it) "I")
         (action   (the-action statement-tree))
         (verb     (verb action))
         (indirect (indirect-object action))
         (direct   (direct-object action))))
    (cond ((not (xif.l:action-p verb))
           "That… that's just not a thing people do.")
          ((and (not indirect) (xif.l:action-indirect-required-p verb))
           (values "With what?" 'NO-INDIRECT))
          ((and (not direct)   (xif.l:action-direct-required-p verb))
           (values "To what?" 'NO-INDIRECT))
          (T
           (list (xif.l:action-function verb)
                 :subject subject :indirect indirect :direct direct)))))

;; SYMBOL → SYMBOL SYMBOL
(defmethod interpret ((error symbol))
  "If passed on an error-symbol by #'xif.p:parse, then return that symbol.
  Note: If you need to determine if a returned error is from parsing (xif.p) or
  interpreting (xif.i), check the symbol's package (#'symbol-package)."
  (values error 'PARSE-DIE))

;; LIST → GAME-OBJECT
(defun statement→subject-object (statement-tree)
  "Return the the subject's object of a given statement."
  (aif (xif.p:the-subject statement-tree)
       (car (noun-phrase→game-objects it))
       (xif.e:get-player)))

;; LIST → QUEUED-ACTION
(defun statement→queued-action (statement-tree)
  "Interpret a earley-tree parsed statement into a queued-action for
  later execution."
  (verb-phrase→queued-action
   (xif.p:the-action statement-tree)
   :subject (statement→subject-object statement-tree)))

;; LIST :OBJECT → QUEUED-ACTION
(defun verb-phrase→queued-action (verb-phrase &key (subject-object nil))
  "Interpret a earley-parsed verb-phrase into an queued-action object."
  (awhen (verb-phrase→action verb-phrase)
    (make-instance 'xif.e::queued-action
      :function-name (slot-value 'function-name it)
      :indirect-object
                   (noun-phrase→game-objects (xif.p:indirect-object verb-phrase)
                                               :subject subject-object)
      :direct-object
                   (noun-phrase→game-objects (xif.p:direct-object verb-phrase)
                                               :subject subject-object))))

;; LIST → ACTION
(defun verb-phrase→action (verb-phrase)
  "Return the action congruent with the given verb-phrase— that is, the
  indirect/direct options are compatible, and the verb matches."
  (let ((verb     (verb verb-phrase))
        (indirect (noun-phrase→game-objects (xif.p:indirect-object verb-phrase)))
        (direct   (noun-phrase→game-objects (xif.p:direct-object verb-phrase)))
        (actions  (xif.e:verb→actions verb)))
    (loop :for action :in actions
          :if (congruent-vp-action-p action verb indirect direct)
          :return action)))

;; ACTION STRING VARYING VARYING → BOOLEAN
(defun congruent-vp-action-p (action verb indirect direct)
  "Return whether or not the given indirect and direct object values are
  congruent with a given 'action' object. That is, if there is a NIL indirect
  object (or direct) where there ought not to be, the action and given
  verb-phrase are incompatible. (This allows multiple actions with the same
  to exist, so long as the indirect and direct arguments are compatible)."
  (flet ((congruent-indirect-p (action indirect)
           (or (and (not indirect) (not (xif.e:indirect-object-required-p action)))
               (and indirect       (xif.e:indirect-object-required-p action))))
         (congruent-direct-p (action direct)
           (or (and (not direct) (not (xif.e:direct-object-required-p action)))
               (and direct       (xif.e:direct-object-required-p action)))))
    (and (congurent-indirect-p action indirect)
         (congruent-direct-p action direct))))


;; LIST :GAME-OBJECT → LIST_OF_GAME-OBJECT(S)
(defun noun-phrase→game-objects (noun-phrase &key (subject nil))
  "Returns game-object(s) that correspond to the given noun-phrase, using
  the proper-noun/noun and adjective in the phrase. If passed the statement's
  subject (likely player character), it will also narrow down the results by
  matching results' parents to the subject's parent. (Presumably the parent
  would ultimately be the same room as the player.)"
  (let ((adjective (xif.p:adjective noun-phrase))
        (noun (xif.p:noun noun-phrase))
        (proper-noun (xif.p:proper-noun noun-phrase)))
    (alet
      (xif.m:triangulate (xif.e:adjective→game-objects adjective)
                   (xif.e:noun→game-objects noun)
                   (xif.e:proper-noun→game-objects proper-noun))
      (if (and subject (< 1 (length it)))
        (xif.m:triangulate it (parent→game-objects (xif.e:parent subject)))
        it))))
                     



;; —————————————————————————————————————
;; X-IF.ENVIRONMENT
;; OBJECTS, GAME-STATE, ETC.

(in-package :x-if.environment)

;; —————————————————————————————————————

;; This package contains all aspect of the actual game 'environment'—
;; all objects (rooms, entities, etc), means of accessing and modifying them,
;; etc.

;; There is a main overarching class (game-object), of which everything else is
;; derived. From there, there are two divering subclasses— the 'location'

;; —————————————————————————————————————
;; CLASSES

;; The overarching class
(define-persistent-class game-object ()
  ((id :read
      :initarg :id :reader id
      :index-type bknr.datastore::unique-index
      :index-initargs (:test #'equal)
      :index-reader id→game-object
      :index-values all-game-objects)
   (nouns :update
      :initarg :nouns :reader nouns)
   (proper-nouns :update
      :initarg :proper-name :reader proper-nouns
      :initform nil)
   (adjectives :update
      :initarg :adjectives :reader adjectives
      :initform nil)
   (description :update
      :initarg :desc :reader description
      :initform nil)
   (parent :update
      :initarg :parent :reader parent
      :initform nil)
   (children :update
      :initarg :children :reader children
      :initform nil)
   (max-children :update
      :initarg :max-children :reader max-children
      :initform nil)))

;; For any object that can interacted with
(define-persistent-class entity (game-object)
  ((hp :update
      :initarg :hp :reader hp
      :initform nil)
   (max-hp :update
       :initarg :max-hp :reader max-hp
       :initform nil)
   (weight :update
       :initarg :weight :reader weight
       :initform 0)))

;; These classes only exist for indexing and semantic purposes;
;; they are identical to their super-classes

;; For NPCs, animals, etc.
(define-persistent-class mob (entity) ())

;; For the PLAYER.
(define-persistent-class player (mob) ())

;; For LOCATIONS (rooms and such).
(define-persistent-class location (game-object) ())


;; For hypothetical ACTIONS;
;; that is, commands the player can enter which will execute a given function.
(define-persistent-class action ()
  ((function-name :read
      :initarg :function :reader function-name)
      ; :index-type bknr.datastore::hash-index
      ; :index-reader function→action
   (verbs :read
       :initarg :verbs :reader verbs)
       ; :index-type bknr.datastore::hash-index
       ; :index-reader verb→action
   (direct-object-p :read
       :initarg :direct-object-p :initform nil
                    :reader direct-object-required-p)
   (indirect-object-p :read
       :initarg :indirect-object-p :initform nil
                      :reader indirect-object-required-p)))


;; For tu┼Łeblaj ACTIONS; generated by :x-if.interpret from interpreting a user
;; statement. This is what will actually be executed by :x-if.interpret.
(defclass queued-action ()
  ((function-name
       :initarg :function :accessor function-name)
   (direct-object
       :initarg :direct-object :initform nil :accessor direct-object)
   (indirect-object
       :initarg :indirect-object :initform nil :accessor indirect-object)
   (subject
       :initarg :subject :initform (get-player) :accessor subject)))


;; —————————————————
;; OBJECT ADD/DEL

;; These are here to appropriately modify the LEXICON (xif.l:*lexicon*)
;; according to objects in the game. Words used to describe objects
;; and actions will be added when an object is initialized; deleted
;; when destroyed.

(defmethod initialize-instance :after ((game-object game-object) &key)
  (xif.l:add-game-object-words game-object))

(defmethod destroy-object :after ((game-object game-object) &key)
  (xif.l:delete-game-object-words game-object))



(defmethod initialize-instance :after ((action action) &key)
  (mapcar #'xif.l:add-verb (verbs action)))

;; TODO: write #'xif.l:remove-action
(defmethod destroy-object :after ((action action) &key))


;; —————————————————
;; PARENT/CHILD

;; GAME-OBJECT GAME-OBJECT → NIL
(deftransaction link (child parent)
  "Link two objects together, as child and parent."
  (setf (slot-value parent 'children)
        (nconc (slot-value parent 'children) (list child)))
  ;; --
  (if (child-p child) (unlink child))
  (setf (slot-value child 'parent) parent))

;; GAME-OBJECT → NIL
(deftransaction unlink (child)
  "Seperate a child from it's parent (and vice-versa)."
  (let ((parent (slot-value child 'parent)))
    (setf (slot-value parent 'children)
          (delete child (slot-value parent 'children)))
    ;; --
    (setf (slot-value child 'parent) nil)))


;; GAME-OBJECT → BOOLEAN
(defmethod parent-p ((object game-object))
  "Return whether or not an object is a parent (has 1+ children)."
  (slot-value object 'children))

;; GAME-OBJECT → BOOLEAN
(defmethod child-p ((object game-object))
  "Return whether or not an object is a child (has a parent)."
  (slot-value object 'parent))


;; —————————————————
;; INDEXING

;; NIL → PLAYER
(defun get-player ()
  "Return the player object."
  (car (store-objects-with-class 'player)))

;; NIL → LIST_OF_LOCATIONS
(defun all-locations ()
  "Get all location objects."
  (store-objects-with-class 'location))

;; NIL → LIST_OF_MOBS
(defun all-mobs ()
  "Get all mob objects."
  (store-objects-with-class 'mob))

;; NIL → LIST_OF_ENTITIES
(defun all-entities ()
  "Get all entity objects."
  (store-objects-with-class 'entity))

;; NIL → LIST_OF_ENTITIES
(defun all-actions ()
  "Get all entity objects."
  (store-objects-with-class 'action))


;; LIST_OF_OBJECTS STRING → LIST_OF_OBJECTS
(defun noun→objects (objects noun)
  "Return objects within the current list of objects of the given noun."
  (index-by-slot-list objects 'nouns noun))

;; LIST_OF_OBJECTS STRING → LIST_OF_OBJECTS
(defun adjective→objects (objects adjective)
  "Return objects within the current list of objects of the given adjective."
  (index-by-slot-list objects 'adjectives adjective))

;; LIST_OF_OBJECTS STRING → LIST_OF_OBJECTS
(defun proper-noun→objects (objects proper-noun)
  "Return objects within the current list of objects of the given proper-noun"
  (index-by-slot-list objects 'proper-nouns proper-noun))

;; STRING → LIST_OF_ACTIONS
(defun verb→actions (verb)
  "Return all actions matching the given verb."
  (index-by-slot-list (all-actions) 'verbs verb))


;; SYMBOL SYMBOL FUNCTION SYMBOL FUNCTION → (DEFUN …)
(defmacro defun-obj-word-index (name obj-type all-obj-type word-type word-fun)
  "Makes an index function for the given object type and word-type.
  I.E., will generate #'adjective→mobs for object-type 'mobs' and word-type of
  'adjective'"
  `(defun ,name (,word-type)
     ,(format nil "Return the ~A corresponding with the given ~A."
              obj-type word-type)
     (funcall ,word-fun (funcall ,all-obj-type) ,word-type)))

;; SYMBOL FUNCTION SYMBOL SYMBOL SYMBOL → ( (DEFUN …) (DEFUN …) (DEFUN …))
(defmacro defuns-obj-word-indices (obj-type all-obj adj→obj noun→obj pnoun→obj)
  "Makes the index functions for a given object type for every word type.
  I.E., when given 'mobs', it'll make #'noun→mobs, #'adjective→mobs, etc."
  `(progn
    (defun-obj-word-index ,adj→obj ,obj-type ,all-obj adjective
      #'adjective→objects)
    (defun-obj-word-index ,noun→obj ,obj-type ,all-obj noun #'noun→objects)
    (defun-obj-word-index ,pnoun→obj ,obj-type ,all-obj proper-noun
      #'proper-noun→objects)))


(defuns-obj-word-indices game-object #'all-game-objects
  adjective→game-objects noun→game-objects proper-noun→game-objects)
(defuns-obj-word-indices entity #'all-entities
  adjective→entities noun→entities proper-noun→entities)
(defuns-obj-word-indices mob #'all-mobs
  adjective→mobs noun→mobs proper-noun→mobs)
(defuns-obj-word-indices locations #'all-locations
  adjective→locations noun→locations proper-noun→locations)


;; LIST_OF_OBJECTS SYMBOL VARYING → LIST_OF_OBJECTS
(defun index-by-slot-list (objects slot-name target)
  "Return objects from the given list that contain a target item in the list
  of the given slot."
  (index-by-slot objects slot-name target :test #'xif.m:position-equal))

;; LIST_OF_OBJECTS SYMBOL VARYING :FUNCTION → LIST_OF_OBJECTS
(defun index-by-slot (objects slot-name target &key (test #'equal))
  "Return objects from the given list that pass the given test between
  slot-value and target."
  (loop :for object :in objects
        :if (funcall test target (slot-value object slot-name))
        :collect object))




;; —————————————————————————————————————
;; X-IF.CLIENT
;; ACTUALLY PLAY THE GAME

(in-package :x-if.client)

;; —————————————————————————————————————

;; This is the general client package— everything else uses it.

;; —————————————————————————————————————

(defun status ()
  (format nil "~A~%" (slot-value (get-player) 'xif.e::parent)))

(defun prompt () ">> ")

(defun game-loop ()
  (let ((m 1))
    (display-status)
    (setq m (input-sentence))
    (text "You said: ~A~%" m)
    (text "~A~%" (xif.e:all-game-objects))
    (text "I LOVE YOU~%")
    (sleep 2)
    (game-loop)))

(defun start (game)
  (make-instance 'mp-store :directory #p"~/.local/share/x-if/"
                 :subsystems (list (make-instance 'store-object-subsystem)))
  (if (not (all-game-objects))
    (populate-world))
  (game-loop))

(defun examine (object)
  (text (xif.e:description object)))

(defun populate-world ()
  (make-instance 'xif.e::location :id 0  :proper-nouns '("Lobby")
                 :nouns '("room")
                 :adjectives '("ugly")
                 :description "It's rather ugly, really.")

  (make-instance 'xif.e::mob :id 101  :proper-nouns '("Barry")
                 :nouns '("human" "person" "man" "gentleman" "sir" "dude")
                 :adjectives '("suspicious")
                 :description "He looks suspicious, no?")

  (make-instance 'xif.e::player :id 100
                 :proper-nouns '("Maria" "I" "myself" "me")
                 :nouns '("human" "person" "woman" "lady" "lass" "dudette")
                 :adjectives '("hideous")
                 :description "A rather hideous lass.")

  (make-instance 'xif.e::action :function-name 'xif.c::examine :direct-object-p T
                 :verbs '("examine" "look" "view"))
  
  (xif.e:link (xif.e:get-player) (xif.e:id→game-object 0))
  (xif.e:link (xif.e:id→game-object 101) (xif.e:id→game-object 0)))




;; —————————————————————————————————————
;; X-IF.CLIENT.TERMINAL
;; A SIMPLE CLIENT

(in-package :x-if.client.terminal)

;; —————————————————————————————————————

;; This package is a client package— it uses only basic terminal input/output,
;; so ought to be the most portable possible. No image or music support.

;; —————————————————————————————————————

(defun xif.c::text (string &rest format-args)
  (apply #'format (nconc (list t string) format-args)))

(defun xif.c::input-sentence ()
  (read-line))




;; —————————————————————————————————————
;; X-IF.MISC
;; MISC HELPER FUNCTIONS

(in-package :x-if.misc)

;; —————————————————————————————————————

;; This package just contains random, useful functions that're used throughout
;; x-if. Mainly they're for string manipulations, etc.

;; STRING → LIST_OF_STRINGS
(defun string-lines (string)
  "Turn a multi-line string into a list of lines."
  (cl-strings:split string #\newline))

;; LIST_OF_STRINGS → STRING
(defun lines-string (lines)
  "Turn a list of strings into a multi-lined string, with each string being
  a seperate line."
  (cl-strings:join lines :separator "
"))


;; STRING → STRING
(defmethod line-cdr ((string string))
  "Get the 'cdr' of a multi-lined string (pop off the first line)."
  (line-cdr (string-lines string)))

;; LIST_OF_STRINGS → STRING
(defmethod line-cdr ((lines list))
  "Get the 'cdr' of a list of lines, then turn back into a string."
  (lines-string (cdr lines)))

;; STRING → STRING
(defmethod line-car ((string string))
  "Get a multi-lined string's 'car' (the first line)."
  (line-car (string-lines string)))

;; LIST_OF_STRINGS → STRING
(defmethod line-car ((lines list))
  "Get the 'car' of a list of lines."
  (car lines))


;; STRING → NUMBER
(defun line-length (string)
  "Return the amount of lines in a given string."
  (length (string-lines string)))

;; STRING STRING FUNCTION → NUMBER
(defmethod line-position ((string string) target &key (test #'in-string-p))
  "Return the number of the line in which a given target-string can be found,
  within a multi-lined string."
  (line-position (string-lines string) target :test test))

;; LIST_OF_STRINGS STRING FUNCTION → NUMBER
(defmethod line-position ((lines list) target &key (test #'in-string-p))
  "Return which number string the given target-string can be found in."
  (position T (mapcar (lambda (line) (funcall test line target)) lines)))

;; STRING STRING → BOOLEAN
(defun in-string-p (string target)
  "Return whether or not a target-string is within another string."
  (< 1 (length (cl-strings:split string target))))

;; STRING STRING FUNCTION → STRING
(defmethod remove-line ((string string) target &key (test #'in-string-p))
  "Remove a line matching the given test, given a target string."
  (remove-line (string-lines string) target :test test))

;; LIST_OF_STRINGS STRING FUNCTION → STRING
(defmethod remove-line ((lines list) target &key (test #'in-string-p))
  "Remove a line matching the test, return a multi-lined string based on
  given list, but sans that removed line, ofc."
  (aif (ignore-errors (line-position lines target :test test))
       (lines-string
        (remove (nth it lines) lines :test #'equal :count 1))
       (lines-string list)))

;; VARYING LIST → NUMBER
(defun position-equal (item list)
  "Literally just #'cl:position but with the test equal."
  (position item list :test #'equal))


;; VARYING LIST :FUNCTION → BOOLEAN
(defun lacking (item list &key (test #'equal))
  "Return whether or not the given item is not in a list."
  (not (position item list :test test)))

;; LIST … LIST → LIST
(defun triangulate (&rest victims)
  "Return a list of values that are within each passed list."
  (loop :for car-item :in (car victims)
        :if (lacking nil
              (mapcar (lambda (victim) (position car-item victim)) victims))
        :collect car-item))