;; #!/usr/bin/sbcl --script
(load "~/quicklisp/setup")

(let ((*standard-output* (make-broadcast-stream)))
  (ql:quickload "cl-readline"))

(defpackage :sbcli
  (:use :common-lisp :trivial-package-local-nicknames)
  (:import-from :magic-ed
                :magic-ed)
  (:export sbcli help what *repl-version* *repl-name* *prompt* *prompt2* *result-indicator* *config-file*
           *hist-file* *special*
           *syntax-highlighting* *pygmentize* *pygmentize-options*))

(in-package :sbcli)

;; repl-utilities: nice to have, but don't clutter the CIEL package by exporting them.
;; For instance, "summary" is too common a word to be exported.
(cl-reexport:reexport-from :repl-utilities
                           :include
                           '(:repl-utilities
                             :readme
                             ;; :doc  ;; conflicts with our little %doc helper.
                             :summary
                             :package-apropos
                             :trace-package
                             :print-hash))

(defvar *repl-version* "0.1.5") ;XXX: print CIEL version.
(defvar *banner* "

       _..._
    .-'_..._''.                         .---.
  .' .'      '.\.--.      __.....__     |   |
 / .'           |__|  .-''         '.   |   |
. '             .--. /     .-''''-.  `. |   |
| |             |  |/     /________\   \|   |
| |             |  ||                  ||   |
. '             |  |\    .-------------'|   |
 \ '.          .|  | \    '-.____...---.|   |
  '. `._____.-'/|__|  `.             .' |   |
    `-.______ /         `''-...... -'   '---'
             `


")
(defvar *repl-name*    "CIEL's REPL")
(defvar *prompt*       (format nil "~a" (cl-ansi-text:green "ciel-user> ")))
(defvar *prompt2*       "....> ")
(defvar *result-indicator*          "=> ")
(defvar *config-file*  "~/.cielrc")
(defvar *hist-file*    "~/.ciel_history")
(defvar *hist*         (list))
(defvar *syntax-highlighting* nil)
(defvar *pygmentize* nil "(optional) Path to a pygments executable. If not set, we try to find it.")
(defvar *pygmentize-options* (list "-s" "-l" "lisp"))
(defparameter *lisp-critic* nil "If non-nil, give feedback on the code you type using lisp-critic.")
(declaim (special *special*))

(defun print-system-info (&optional (stream t))
  ;; see also https://github.com/40ants/cl-info
  (format stream "~&OS: ~a ~a~&" (software-type) (software-version))
  (format stream "~&Lisp: ~a ~a~&" (lisp-implementation-type) (lisp-implementation-version))
  #+asdf
  (format stream "~&ASDF: ~a~&" (asdf:asdf-version))
  #-asdf
  (format stream "NO ASDF!")
  #+quicklisp
  (format stream "~&Quicklisp: ~a~&" (ql-dist:all-dists))
  #-quicklisp
  (format stream "!! Quicklisp is not installed !!"))

(defun read-hist-file ()
  (with-open-file (in *hist-file* :if-does-not-exist :create)
    (loop for line = (read-line in nil nil)
      while line
      ;; hack because cl-readline has no function for this.
      ;; TODO: it has it now.
      do (cffi:foreign-funcall "add_history"
                               :string line
                               :void))))

(defun update-hist-file (str)
  (with-open-file (out *hist-file*
                       :direction :output
                       :if-exists :append
                       :if-does-not-exist :create)
    (write-line str out)))

(defun end ()
  "Ends the session."
  (format t "~%Bye!~&")
  (uiop:quit))

;; (defun reset ()
;;   "Resets the session environment"
;;   (delete-package 'sbcli)
;;   (defpackage :sbcli (:use :common-lisp :ciel))
;;   ;XXX: ?
;;   (in-package :sbcli))

(defun novelty-check (str1 str2)
  (string/= (string-trim " " str1)
            (string-trim " " str2)))

(defun history-add (txt res)
  (setq *hist* (cons (list txt res) *hist*)))

(defun format-output (&rest args)
  (format (car args) "~a ; => ~a" (caadr args) (cadadr args)))

(defun write-to-file (fname)
  "Writes the current session to a file <filename>"
  (with-open-file (file fname
                       :direction :output
                       :if-exists :supersede
                       :if-does-not-exist :create)
    (format file "~{~/sbcli:format-output/~^~%~}" (reverse *hist*))))

(defun what (sym)
  "Gets help on a symbol <sym>: :? str"
  (format t "inspecting ~a.~&~
  To inspect further objects, type their number.~&~
  To quit, type q and Enter." sym)
  (handler-case (inspect (read-from-string sym))
    (error (c) (format *error-output* "Error during inspection: ~a~%" c))))

(defun help ()
  "Prints this general help message"
  (format t "~a version ~a~%" *repl-name* *repl-version*)
  (write-line "Read more on packages with readme or summary. For example: (summary :str)")
  (write-line "Special commands:")
  (maphash
    (lambda (k v) (format t "  %~a => ~a~%" k (documentation (cdr v) t)))
    *special*)
  ;; (write-line "Currently defined:")
  ;; (print-currently-defined)
  (write-line "Press CTRL-D or type :q to exit"))

(defun symbol-documentation (symbol)
  "Print the available documentation for this symbol."
  ;; Normally, the documentation function takes as second argument the
  ;; type designator. We loop over each type and print the available
  ;; documentation.
  (handler-case (loop for doc-type in '(variable function structure type setf)
                   with sym = (if (stringp symbol)
                                  ;; used from the readline REPL
                                  (read-from-string symbol)
                                  ;; used from Slime
                                  symbol)
                   for doc = (unless (consp sym) ;; when a function is quoted: :doc 'defun
                               ;; instead of :doc defun
                               (documentation sym doc-type))
                   when  doc
                   do (format t "~a: ~a~&" doc-type doc)
                   when (and (equal doc-type 'function)
                             (fboundp sym))
                   do (format t "ARGLIST: ~a~&" (format nil "~(~a~)"
                                                        (trivial-arguments:arglist sym))))
    (error (c) (format *error-output* "Error during documentation lookup: ~a~&" c))))

(defun print-currently-defined ()
  (do-all-symbols (s *package*)
    (when (and (or (fboundp s) (boundp s)) (eql (symbol-package s) *package*))
      (let ((what (cond ((fboundp s) 'function) ((constantp s) 'constant) (t 'variable))))
        (format t " ~a: ~a (~a) ~a~%" (string-downcase (string s))
                                      (or (documentation s what)
                                          "No documentation")
                                      what
                                      (if (boundp s)
                                        (format nil "(value ~a)" (eval s))
                                        ""))))))

(defun dump-disasm (sym)
  "Dumps the disassembly of a symbol <sym>"
  (handler-case (disassemble (read-from-string sym))
    (unbound-variable (var) (format t "~a~%" var))
    (type-error (err) (format t "~a~%" err))
    (sb-int:compiled-program-error (err) (format t "~a~%" err))
    (undefined-function (fun) (format t "~a~%" fun))))

(defun dump-type (expr)
  "Prints the type of a expression <expr>"
  (handler-case (format t "~a~%" (type-of (eval (read-from-string expr))))
    (unbound-variable (var) (format t "~a~%" var))
    (type-error (err) (format t "~a~%" err))
    (sb-int:compiled-program-error (err) (format t "~a~%" err))
    (undefined-function (fun) (format t "~a~%" fun))))

(defun edit-and-load-file (file)
  "Edit a file with EDITOR and evaluate it."
  (magic-ed file))

(defun toggle-lisp-critic ()
  "Enable or disable the lisp critic. He critizes the code you type before compiling it."
  (setf *lisp-critic* (not *lisp-critic*))
  (format t "The lisp-critic is ~a.~&" (if *lisp-critic* "enabled" "disabled")))

;; -1 means take the string as one arg
(defvar *special*
  (alexandria:alist-hash-table
   `( ;; ("help" . (0 . ,#'general-help))
     ("help" . (0 . ,#'help))
     ("doc" . (1 . ,#'symbol-documentation))
     ("?" . (1 . ,#'what))
     ;; ("r" . (1 . ,#'readme))
     ;; ("s" . (1 . ,#'summary))
     ("w" . (1 . ,#'write-to-file))
     ("d" . (1 . ,#'dump-disasm))
     ("t" . (-1 . ,#'dump-type))
     ("q" . (0 . ,#'end))
     ;; ("z" . (0 . ,#'reset))
     ("lisp-critic" . (0 . ,#'toggle-lisp-critic))
     ("edit" . (1 . ,#'edit-and-load-file))
     )
   :test 'equal)
  "All special commands starting with :")

(defun special-command-p (text)
  "A *special* command starts with %."
  (str:starts-with-p "%" text))

;; both functions are required to get completion on %
(defun list-special-commands ()
  (loop for k being the hash-key of *special*
     collect (format nil "%~a" k)))
(defun intern-special-commands ()
  (loop for k being the hash-key of *special*
     for symname = (format nil "%~a" k)
     do (intern symname :sbcli)))
(intern-special-commands)

(defun call-special (fundef call args)
  (let ((l (car fundef))
        (fun (cdr fundef))
        (rl (length args)))
    (cond
      ((= -1 l) (funcall fun (str:join " " args)))
      ((< rl l)
        (format *error-output*
                "Expected ~a arguments to ~a, but got ~a!~%"
                l call rl))
      (t (apply fun (subseq args 0 l))))))

(defun handle-special-input (text)
  (let* ((splt (str:words text))
         (k (subseq (car splt) 1 (length (car splt))))
         (v (gethash k *special*)))
    (if v
      (call-special v (car splt) (cdr splt))
      (format *error-output* "Unknown special command: ~a~%" k))))

(defun evaluate-lisp (text parsed)
  "Evaluate (EVAL) the user input.
  In case of evaluation error, print it.
  Then print the result. Print its multiple values.
  Save the input history.
  Handle the special *, + et all REPL history variables."
  (let ((result-list
         (multiple-value-list
          (handler-case (eval parsed)
            (unbound-variable (var)
              (format *error-output* "~a~%" var))
            (undefined-function (fun)
              (format *error-output* "~a~%" fun))
            (sb-int:compiled-program-error ()
              (format *error-output* "~a"
                      (cl-ansi-text:red "Compiler error.~%")))
            (error (condition)
              (format *error-output* "~a~a~%"
                      (cl-ansi-text:red "Evaluation error: ")
                      condition))))))
    (history-add text (car result-list))
    (when result-list
      (setf +++ ++
            /// //
            *** (car ///)
            ++ +
            // /
            ** (car //)
            + parsed
            / result-list
            * (car result-list))
      ;; Print the result, and all multple values. They are printed like so:
      ;; (not the best with =>)
      ;; ciel-user> (values 1 2 3)
      ;; => 1
      ;; 2
      ;; 3
      (format t "~a~{~s~&~}~%" *result-indicator* result-list))))

#+(or nil)
(let* ((input "(values :one :two)")
       (result (with-output-to-string (*standard-output*)
                 (evaluate-lisp "whatever" (read-from-string input)))))
  (assert (and (str:containsp ":one"
                              result
                              :ignore-case t)
               (str:containsp ":two"
                              result
                              :ignore-case t)))
  (assert (equal '(:ONE :TWO)
                 /)))


(defun lisp-critic-applicable (txt)
  "TXT is code that should start with a parenthesis. Don't critique global variables."
  (str:starts-with? "(" (str:trim txt)))

(defun handle-lisp (before text)
  (let* ((new-txt (format nil "~a ~a" before text))
         (parsed (handler-case (read-from-string new-txt)
                   (end-of-file () (sbcli new-txt *prompt2*))
                   (error (condition)
                     (format *error-output* "Parser error: ~a~%" condition))))
         (to-critic (when (and *lisp-critic*
                               (lisp-critic-applicable new-txt)
                               parsed)
                      `(lisp-critic:critique ,parsed))))

    (when to-critic
      ;; The call to lisp-critic doesn't evaluate the lisp code,
      ;; it only scans it and prints feedback.
      (evaluate-lisp text to-critic))
    ;; But even if the lisp-critic is enabled,
    ;; we want the code we type to be eval'ed.
    (when parsed
      (evaluate-lisp text parsed))))

(defun handle-input (before text)
  (if (and (> (length text) 1)
           (special-command-p text))
    (handle-special-input text)
    (handle-lisp before text)))

(defun get-package-for-search (text)
  "Return a list with:
  - the text after the colon or double colon
  - the package name
  - T if we look for an external symbol, NIL for an internal one."
  (let ((pos))
    (cond
      ((setf pos (search "::" text))
       (list (subseq text  (+ pos 2))
             (subseq text 0 pos)
             nil))
      ((setf pos (position #\: text))
       (if (zerop pos)
           (list text nil t)
           (list (subseq text (1+ pos))
                 (subseq text 0 pos)
                 t)))
      (t (list text nil  t)))))

(defun list-external-symbols (sym-name pkg-name)
  "List external symbols of PKG-NAME (a string).
  (the symbol name is currently ignored)."
  (declare (ignorable sym-name))
  (assert (stringp pkg-name))
  (loop :for sym :being :the :external-symbols :of (find-package pkg-name)
     :collect (format nil "~(~a:~a~)" pkg-name sym)))

(defun list-internal-symbols (sym-name pkg-name)
  "List internal symbols of the package named PKG-NAME (a string)."
  (declare (ignorable sym-name))
  (assert (stringp pkg-name))
  (loop :for sym :being :the :symbols :of (find-package pkg-name)
     :collect (format nil "~(~a::~a~)" pkg-name sym)))

(defun list-local-nicknames (&optional (package *package*))
  "Return a list of local nicknames.
 (downcased strings, with a trailing colon to denote a package)"
  (loop :for pair in (package-local-nicknames package)
     :collect (format nil "~a:" (str:downcase (car pair)))))

(defun list-symbols-and-packages (sym-name)
  "Base case, when the user entered a string with no colon that would delimit a package.
  Return the current packages, symbols of the current package, current keywords.
  They are filtered afterwards, in SELECT-COMPLETIONS."
  (declare (ignorable sym-name))
  (concatenate 'list
               (list-special-commands)
               (loop :for pkg :in (list-all-packages)
                  :append (loop :for name :in (package-nicknames pkg)
                             :collect (format nil "~(~a:~)" name))
                  :collect (format nil "~(~a:~)" (package-name pkg)))
               (list-local-nicknames *package*)
               (loop :for sym :being :the :symbols :of *package*
                  :collect (string-downcase sym))
               (loop :for kw :being :the :symbols :of (find-package "KEYWORD")
                  :collect (format nil ":~(~a~)" kw))))

(defun select-completions (text items)
  "TEXT is the string entered at the prompt, ITEMS is a list of
strings to match candidates against (for example in the form \"package:sym\")."
  (setf items
        (loop :for item :in items
           :when (str:starts-with-p text item)
           :collect item))
  (unless (cdr items)
    (setf rl:*completion-append-character*
          (if (str:ends-with-p ":" (car items))
              #\nul
              #\space))
    (return-from select-completions items))
  (cons
   (subseq (car items) 0
           (loop :for item :in (cdr items)
              :minimize (or (mismatch (car items) item) (length item))))
   items))

#+(or)
(progn
  (assert (member "str:concat"
                  (select-completions "str:con" (list "str:containsp" "str:concat" "str:constant-case"))
                  :test #'string-equal)))

(defun custom-complete (text &optional start end)
  "Custom completer function for readline, triggered when we press TAB.

  START and END are required in the lambda list but are not used. We
  only complete package and function names, they would help to
  complete arguments."
  (declare (ignore start end))
  (when (string-equal text "")
    (return-from custom-complete nil))
  (destructuring-bind (sym-name pkg-name external-p)
      (get-package-for-search (string-upcase text))
    (when (and pkg-name
               (not (find-package pkg-name)))
      (return-from custom-complete nil))
    (select-completions
     (str:downcase text)
     (cond
       ((zerop (length pkg-name))
        (list-symbols-and-packages sym-name))
       (external-p
        (list-external-symbols sym-name pkg-name))
       (t
        (list-internal-symbols sym-name pkg-name))))))

#+(or)
(progn
  (assert (member "str:suffixp"
                  (custom-complete "str:suff")
                  :test #'string-equal))
  (assert (member "uiop:file-exists-p"
                  (custom-complete "uiop:file-")
                  :test #'string-equal)))

(defun format-prompt (text &key (colored t))
  (let ((prompt (str:concat text "> ")))
    (format nil "~a" (if colored
                         (cl-ansi-text:green prompt)
                         prompt))))

(defun sbcli (txt prompt)
  "Read user input and evaluate it.
  This function must be called from inside the CIEL-USER package."
  (let* ((prompt-text (if (functionp prompt)
                          (funcall prompt)
                          prompt))
         (cur-pkg-name (package-name *package*))
         (text
          (handler-case
              (rl:readline :prompt (if (string-equal "CIEL-USER" cur-pkg-name)
                                       prompt-text
                                       (sbcli::format-prompt cur-pkg-name))
                           :add-history t
                           :novelty-check #'sbcli::novelty-check)
            ;; Catch a C-c.
            (#+sbcl sb-sys:interactive-interrupt
              #+ccl  ccl:interrupt-signal-condition
              #+clisp system::simple-interrupt-condition
              #+ecl ext:interactive-interrupt
              #+allegro excl:interrupt-signal
              ()
              (write-char #\linefeed)
              ""))))

    (unless text (sbcli::end))
    (if (string= text "")
        (sbcli::sbcli "" *prompt*))
    (when *hist-file* (sbcli::update-hist-file text))
    (cond
      ;; Handle documentation lookup.
      ((str:ends-with-p " ?" text)
       (sbcli::symbol-documentation (last-nested-expr text)))

      ;; Handle visual commands: run in their own terminal window.
      ((visual-command-p text)
       (run-visual-command text))

      ;; Handle shell commands: everything that doesn't start with a lisp special
      ;; symbol is considered a shell command
      ((and (not (str:starts-with-p "!" text)) ;; that's clesh syntax.
            (not (special-command-p text))     ;; starts with %
            (not (lisp-command-p text)))
       (run-shell-command text))

      ;; Default: run the lisp command (with the lisp-critic, the shell passthrough
      ;; and other add-ons).
      (t
       (sbcli::handle-input txt text)))
    (finish-output nil)
    (format t "~&")
    (sbcli::sbcli "" *prompt*)))

(defun repl ()

  (let ((argv (uiop:command-line-arguments)))
    (when (or (member "-h" argv :test #'string-equal)
              (member "--help" argv :test #'string-equal))
      (format t "~a version ~a~%" *repl-name* *repl-version*)
      (format t "Contribute on: https://github.com/ciel-lang/CIEL~&")
      (print-system-info)
      (format t "CIEL Is an Extended Lisp. It's Common Lisp, batteries included.~&~
        It comes in the form of a Quicklisp library that you can use as any other one in your favourite editor, ~
        as an SBCL core image and as a readline REPL, with developer goodies.~&")
      (uiop:quit)))

  (rl:register-function :complete #'custom-complete)
  (rl:register-function :redisplay #'syntax-hl)

  (if (probe-file *config-file*)
      (load *config-file*))

  (princ *banner*)
  (write-line (str:repeat 80 "-"))
  (print-system-info)
  (write-line (str:repeat 80 "-"))
  (help)
  (write-char #\linefeed)
  (finish-output nil)

  (when *hist-file* (read-hist-file))

  (in-package :ciel-user)

  ;; Enable Clesh, only for the readline REPL,
  ;; part because we don't want to clutter the ciel-user package,
  ;; part because Clesh is buggy for us on Slime (!! and [...]).
  ;; We get the ! pass-through shell:
  ;; !ls
  ;; as well as [ ... ] on multilines.
  ;; Beware: the double bang !! doesn't work. See issues.
  (named-readtables:in-readtable clesh:syntax)

  (handler-case (sbcli::sbcli "" sbcli::*prompt*)
    (error (c)
      ;; Normally lisp code is evaled and protected from errors in evaluate-lisp.
      ;; We need this for magic-ed.
      ;; As a special command it doesn't use evaluate-lisp.
      (format *error-output* "~&Error: ~a~&" c)
      (sbcli::sbcli "" sbcli::*prompt*))
    (sb-sys:interactive-interrupt ()
      (sbcli::end))))

;; When trying it out with --script:
;; (repl)