;;;; ---------------------------------------------------------------------------
;;;; Generic support for configuration files

(uiop/package:define-package :uiop/configuration
  (:recycle :uiop/configuration :asdf/configuration) ;; necessary to upgrade from 2.27.
  (:use :uiop/package :uiop/common-lisp :uiop/utility
   :uiop/os :uiop/pathname :uiop/filesystem :uiop/stream :uiop/image :uiop/lisp-build)
  (:export
   #:user-configuration-directories #:system-configuration-directories ;; implemented in backward-driver
   #:in-first-directory #:in-user-configuration-directory #:in-system-configuration-directory ;; idem
   #:get-folder-path
   #:xdg-data-home #:xdg-config-home #:xdg-data-dirs #:xdg-config-dirs
   #:xdg-cache-home #:xdg-runtime-dir #:system-config-pathnames
   #:filter-pathname-set #:xdg-data-pathnames #:xdg-config-pathnames
   #:find-preferred-file #:xdg-data-pathname #:xdg-config-pathname
   #:validate-configuration-form #:validate-configuration-file #:validate-configuration-directory
   #:configuration-inheritance-directive-p
   #:report-invalid-form #:invalid-configuration #:*ignored-configuration-form* #:*user-cache*
   #:*clear-configuration-hook* #:clear-configuration #:register-clear-configuration-hook
   #:resolve-location #:location-designator-p #:location-function-p #:*here-directory*
   #:resolve-relative-location #:resolve-absolute-location #:upgrade-configuration
   #:uiop-directory))
(in-package :uiop/configuration)

(with-upgradability ()
  (define-condition invalid-configuration ()
    ((form :reader condition-form :initarg :form)
     (location :reader condition-location :initarg :location)
     (format :reader condition-format :initarg :format)
     (arguments :reader condition-arguments :initarg :arguments :initform nil))
    (:report (lambda (c s)
               (format s (compatfmt "~@<~? (will be skipped)~@:>")
                       (condition-format c)
                       (list* (condition-form c) (condition-location c)
                              (condition-arguments c))))))

  (defun configuration-inheritance-directive-p (x)
    "Is X a configuration inheritance directive?"
    (let ((kw '(:inherit-configuration :ignore-inherited-configuration)))
      (or (member x kw)
          (and (length=n-p x 1) (member (car x) kw)))))

  (defun report-invalid-form (reporter &rest args)
    "Report an invalid form according to REPORTER and various ARGS"
    (etypecase reporter
      (null
       (apply 'error 'invalid-configuration args))
      (function
       (apply reporter args))
      ((or symbol string)
       (apply 'error reporter args))
      (cons
       (apply 'apply (append reporter args)))))

  (defvar *ignored-configuration-form* nil
    "Have configuration forms been ignored while parsing the configuration?")

  (defun validate-configuration-form (form tag directive-validator
                                            &key location invalid-form-reporter)
    "Validate a configuration FORM. By default it will raise an error if the
FORM is not valid.  Otherwise it will return the validated form.
     Arguments control the behavior:
     The configuration FORM should be of the form (TAG . <rest>)
     Each element of <rest> will be checked by first seeing if it's a configuration inheritance
directive (see CONFIGURATION-INHERITANCE-DIRECTIVE-P) then invoking DIRECTIVE-VALIDATOR
on it.
     In the event of an invalid form, INVALID-FORM-REPORTER will be used to control
reporting (see REPORT-INVALID-FORM) with LOCATION providing information about where
the configuration form appeared."
    (unless (and (consp form) (eq (car form) tag))
      (setf *ignored-configuration-form* t)
      (report-invalid-form invalid-form-reporter :form form :location location)
      (return-from validate-configuration-form nil))
    (loop :with inherit = 0 :with ignore-invalid-p = nil :with x = (list tag)
          :for directive :in (cdr form)
          :when (cond
                  ((configuration-inheritance-directive-p directive)
                   (incf inherit) t)
                  ((eq directive :ignore-invalid-entries)
                   (setf ignore-invalid-p t) t)
                  ((funcall directive-validator directive)
                   t)
                  (ignore-invalid-p
                   nil)
                  (t
                   (setf *ignored-configuration-form* t)
                   (report-invalid-form invalid-form-reporter :form directive :location location)
                   nil))
            :do (push directive x)
          :finally
             (unless (= inherit 1)
               (report-invalid-form invalid-form-reporter
                                    :form form :location location
                                    ;; we throw away the form and location arguments, hence the ~2*
                                    ;; this is necessary because of the report in INVALID-CONFIGURATION
                                    :format (compatfmt "~@<Invalid source registry ~S~@[ in ~S~]. ~
                                                        One and only one of ~S or ~S is required.~@:>")
                                    :arguments '(:inherit-configuration :ignore-inherited-configuration)))
             (return (nreverse x))))

  (defun validate-configuration-file (file validator &key description)
    "Validate a configuration FILE.  The configuration file should have only one s-expression
in it, which will be checked with the VALIDATOR FORM.  DESCRIPTION argument used for error
reporting."
    (let ((forms (read-file-forms file)))
      (unless (length=n-p forms 1)
        (error (compatfmt "~@<One and only one form allowed for ~A. Got: ~3i~_~S~@:>~%")
               description forms))
      (funcall validator (car forms) :location file)))

  (defun validate-configuration-directory (directory tag validator &key invalid-form-reporter)
    "Map the VALIDATOR across the .conf files in DIRECTORY, the TAG will
be applied to the results to yield a configuration form.  Current
values of TAG include :source-registry and :output-translations."
    (let ((files (sort (ignore-errors ;; SORT w/o COPY-LIST is OK: DIRECTORY returns a fresh list
                        (remove-if
                         'hidden-pathname-p
                         (directory* (make-pathname :name *wild* :type "conf" :defaults directory))))
                       #'string< :key #'namestring)))
      `(,tag
        ,@(loop :for file :in files :append
                                    (loop :with ignore-invalid-p = nil
                                          :for form :in (read-file-forms file)
                                          :when (eq form :ignore-invalid-entries)
                                            :do (setf ignore-invalid-p t)
                                          :else
                                            :when (funcall validator form)
                                              :collect form
                                          :else
                                            :when ignore-invalid-p
                                              :do (setf *ignored-configuration-form* t)
                                          :else
                                            :do (report-invalid-form invalid-form-reporter :form form :location file)))
        :inherit-configuration)))

  (defun resolve-relative-location (x &key ensure-directory wilden)
    "Given a designator X for an relative location, resolve it to a pathname."
    (ensure-pathname
     (etypecase x
       (null nil)
       (pathname x)
       (string (parse-unix-namestring
                x :ensure-directory ensure-directory))
       (cons
        (if (null (cdr x))
            (resolve-relative-location
             (car x) :ensure-directory ensure-directory :wilden wilden)
            (let* ((car (resolve-relative-location
                         (car x) :ensure-directory t :wilden nil)))
              (merge-pathnames*
               (resolve-relative-location
                (cdr x) :ensure-directory ensure-directory :wilden wilden)
               car))))
       ((eql :*/) *wild-directory*)
       ((eql :**/) *wild-inferiors*)
       ((eql :*.*.*) *wild-file*)
       ((eql :implementation)
        (parse-unix-namestring
         (implementation-identifier) :ensure-directory t))
       ((eql :implementation-type)
        (parse-unix-namestring
         (string-downcase (implementation-type)) :ensure-directory t))
       ((eql :hostname)
        (parse-unix-namestring (hostname) :ensure-directory t)))
     :wilden (and wilden (not (pathnamep x)) (not (member x '(:*/ :**/ :*.*.*))))
     :want-relative t))

  (defvar *here-directory* nil
    "This special variable is bound to the currect directory during calls to
PROCESS-SOURCE-REGISTRY in order that we be able to interpret the :here
directive.")

  (defvar *user-cache* nil
    "A specification as per RESOLVE-LOCATION of where the user keeps his FASL cache")

  (defun resolve-absolute-location (x &key ensure-directory wilden)
    "Given a designator X for an absolute location, resolve it to a pathname"
    (ensure-pathname
     (etypecase x
       (null nil)
       (pathname x)
       (string
        (let ((p #-mcl (parse-namestring x)
                 #+mcl (probe-posix x)))
          #+mcl (unless p (error "POSIX pathname ~S does not exist" x))
          (if ensure-directory (ensure-directory-pathname p) p)))
       (cons
        (return-from resolve-absolute-location
          (if (null (cdr x))
              (resolve-absolute-location
               (car x) :ensure-directory ensure-directory :wilden wilden)
              (merge-pathnames*
               (resolve-relative-location
                (cdr x) :ensure-directory ensure-directory :wilden wilden)
               (resolve-absolute-location
                (car x) :ensure-directory t :wilden nil)))))
       ((eql :root)
        ;; special magic! we return a relative pathname,
        ;; but what it means to the output-translations is
        ;; "relative to the root of the source pathname's host and device".
        (return-from resolve-absolute-location
          (let ((p (make-pathname :directory '(:relative))))
            (if wilden (wilden p) p))))
       ((eql :home) (user-homedir-pathname))
       ((eql :here) (resolve-absolute-location
                     (or *here-directory* (pathname-directory-pathname (truename (load-pathname))))
                     :ensure-directory t :wilden nil))
       ((eql :user-cache) (resolve-absolute-location
                           *user-cache* :ensure-directory t :wilden nil)))
     :wilden (and wilden (not (pathnamep x)))
     :resolve-symlinks *resolve-symlinks*
     :want-absolute t))

  ;; Try to override declaration in previous versions of ASDF.
  (declaim (ftype (function (t &key (:directory boolean) (:wilden boolean)
                               (:ensure-directory boolean)) t) resolve-location))

  (defun resolve-location (x &key ensure-directory wilden directory)
    "Resolve location designator X into a PATHNAME"
    ;; :directory backward compatibility, until 2014-01-16: accept directory as well as ensure-directory
    (loop :with dirp = (or directory ensure-directory)
          :with (first . rest) = (if (atom x) (list x) x)
          :with path = (or (resolve-absolute-location
                            first :ensure-directory (and (or dirp rest) t)
                            :wilden (and wilden (null rest)))
                           (return nil))
          :for (element . morep) :on rest
          :for dir = (and (or morep dirp) t)
          :for wild = (and wilden (not morep))
          :for sub = (merge-pathnames*
                      (resolve-relative-location
                       element :ensure-directory dir :wilden wild)
                      path)
          :do (setf path (if (absolute-pathname-p sub) (resolve-symlinks* sub) sub))
          :finally (return path)))

  (defun location-designator-p (x)
    "Is X a designator for a location?"
    ;; NIL means "skip this entry", or as an output translation, same as translation input.
    ;; T means "any input" for a translation, or as output, same as translation input.
    (flet ((absolute-component-p (c)
             (typep c '(or string pathname
                        (member :root :home :here :user-cache))))
           (relative-component-p (c)
             (typep c '(or string pathname
                        (member :*/ :**/ :*.*.* :implementation :implementation-type)))))
      (or (typep x 'boolean)
          (absolute-component-p x)
          (and (consp x) (absolute-component-p (first x)) (every #'relative-component-p (rest x))))))

  (defun location-function-p (x)
    "Is X the specification of a location function?"
    ;; Location functions are allowed in output translations, and notably used by ABCL for JAR file support.
    (and (length=n-p x 2) (eq (car x) :function)))

  (defvar *clear-configuration-hook* '())

  (defun register-clear-configuration-hook (hook-function &optional call-now-p)
    "Register a function to be called when clearing configuration"
    (register-hook-function '*clear-configuration-hook* hook-function call-now-p))

  (defun clear-configuration ()
    "Call the functions in *CLEAR-CONFIGURATION-HOOK*"
    (call-functions *clear-configuration-hook*))

  (register-image-dump-hook 'clear-configuration)

  (defun upgrade-configuration ()
    "If a previous version of ASDF failed to read some configuration, try again now."
    (when *ignored-configuration-form*
      (clear-configuration)
      (setf *ignored-configuration-form* nil)))


  (defun get-folder-path (folder)
    "Semi-portable implementation of a subset of LispWorks' sys:get-folder-path,
this function tries to locate the Windows FOLDER for one of
:LOCAL-APPDATA, :APPDATA or :COMMON-APPDATA.
     Returns NIL when the folder is not defined (e.g., not on Windows)."
    (or #+(and lispworks os-windows) (sys:get-folder-path folder)
        ;; read-windows-registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders\AppData
        (ecase folder
          (:local-appdata (or (getenv-absolute-directory "LOCALAPPDATA")
                              (subpathname* (get-folder-path :appdata) "Local")))
          (:appdata (getenv-absolute-directory "APPDATA"))
          (:common-appdata (or (getenv-absolute-directory "ALLUSERSAPPDATA")
                               (subpathname* (getenv-absolute-directory "ALLUSERSPROFILE") "Application Data/"))))))


  ;; Support for the XDG Base Directory Specification
  (defun xdg-data-home (&rest more)
    "Returns an absolute pathname for the directory containing user-specific data files.
MORE may contain specifications for a subpath relative to this directory: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (resolve-absolute-location
     `(,(or (getenv-absolute-directory "XDG_DATA_HOME")
            (os-cond
             ((os-windows-p) (get-folder-path :local-appdata))
             (t (subpathname (user-homedir-pathname) ".local/share/"))))
       ,more)))

  (defun xdg-config-home (&rest more)
    "Returns a pathname for the directory containing user-specific configuration files.
MORE may contain specifications for a subpath relative to this directory: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (resolve-absolute-location
     `(,(or (getenv-absolute-directory "XDG_CONFIG_HOME")
            (os-cond
             ((os-windows-p) (xdg-data-home "config/"))
             (t (subpathname (user-homedir-pathname) ".config/"))))
       ,more)))

  (defun xdg-data-dirs (&rest more)
    "The preference-ordered set of additional paths to search for data files.
Returns a list of absolute directory pathnames.
MORE may contain specifications for a subpath relative to these directories: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (mapcar #'(lambda (d) (resolve-location `(,d ,more)))
            (or (remove nil (getenv-absolute-directories "XDG_DATA_DIRS"))
                (os-cond
                 ((os-windows-p) (mapcar 'get-folder-path '(:appdata :common-appdata)))
                 ;; macOS' separate read-only system volume means that the contents
                 ;; of /usr/share are frozen by Apple. Unlike when running natively
                 ;; on macOS, Genera must access the filesystem through NFS. Attempting
                 ;; to export either the root (/) or /usr/share simply doesn't work.
                 ;; (Genera will go into an infinite loop trying to access those mounts.)
                 ;; So, when running Genera on macOS, only search /usr/local/share.
                 ((os-genera-p)
                  #+Genera (sys:system-case
                            (darwin-vlm (mapcar 'parse-unix-namestring '("/usr/local/share/")))
                            (otherwise (mapcar 'parse-unix-namestring '("/usr/local/share/" "/usr/share/")))))
                 (t (mapcar 'parse-unix-namestring '("/usr/local/share/" "/usr/share/")))))))

  (defun xdg-config-dirs (&rest more)
    "The preference-ordered set of additional base paths to search for configuration files.
Returns a list of absolute directory pathnames.
MORE may contain specifications for a subpath relative to these directories:
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (mapcar #'(lambda (d) (resolve-location `(,d ,more)))
            (or (remove nil (getenv-absolute-directories "XDG_CONFIG_DIRS"))
                (os-cond
                 ((os-windows-p) (xdg-data-dirs "config/"))
                 (t (mapcar 'parse-unix-namestring '("/etc/xdg/")))))))

  (defun xdg-cache-home (&rest more)
    "The base directory relative to which user specific non-essential data files should be stored.
Returns an absolute directory pathname.
MORE may contain specifications for a subpath relative to this directory: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (resolve-absolute-location
     `(,(or (getenv-absolute-directory "XDG_CACHE_HOME")
            (os-cond
             ((os-windows-p) (xdg-data-home "cache/"))
             (t (subpathname* (user-homedir-pathname) ".cache/"))))
       ,more)))

  (defun xdg-runtime-dir (&rest more)
    "Pathname for user-specific non-essential runtime files and other file objects,
such as sockets, named pipes, etc.
Returns an absolute directory pathname.
MORE may contain specifications for a subpath relative to this directory: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    ;; The XDG spec says that if not provided by the login system, the application should
    ;; issue a warning and provide a replacement. UIOP is not equipped to do that and returns NIL.
    (resolve-absolute-location `(,(getenv-absolute-directory "XDG_RUNTIME_DIR") ,more)))

  ;;; NOTE: modified the docstring because "system user configuration
  ;;; directories" seems self-contradictory. I'm not sure my wording is right.
  (defun system-config-pathnames (&rest more)
    "Return a list of directories where are stored the system's default user configuration information.
MORE may contain specifications for a subpath relative to these directories: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (declare (ignorable more))
    (os-cond
     ((os-unix-p) (list (resolve-absolute-location `(,(parse-unix-namestring "/etc/") ,more))))))

  (defun filter-pathname-set (dirs)
    "Parse strings as unix namestrings and remove duplicates and non absolute-pathnames in a list."
    (remove-duplicates (remove-if-not #'absolute-pathname-p dirs) :from-end t :test 'equal))

  (defun xdg-data-pathnames (&rest more)
    "Return a list of absolute pathnames for application data directories.  With APP,
returns directory for data for that application, without APP, returns the set of directories
for storing all application configurations.
MORE may contain specifications for a subpath relative to these directories: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (filter-pathname-set
     `(,(xdg-data-home more)
       ,@(xdg-data-dirs more))))

  (defun xdg-config-pathnames (&rest more)
    "Return a list of pathnames for application configuration.
MORE may contain specifications for a subpath relative to these directories: a
subpathname specification and keyword arguments as per RESOLVE-LOCATION \(see
also \"Configuration DSL\"\) in the ASDF manual."
    (filter-pathname-set
     `(,(xdg-config-home more)
       ,@(xdg-config-dirs more))))

  (defun find-preferred-file (files &key (direction :input))
    "Find first file in the list of FILES that exists (for direction :input or :probe)
or just the first one (for direction :output or :io).
    Note that when we say \"file\" here, the files in question may be directories."
    (find-if (ecase direction ((:probe :input) 'probe-file*) ((:output :io) 'identity)) files))

  (defun xdg-data-pathname (&optional more (direction :input))
    (find-preferred-file (xdg-data-pathnames more) :direction direction))

  (defun xdg-config-pathname (&optional more (direction :input))
    (find-preferred-file (xdg-config-pathnames more) :direction direction))

  (defun compute-user-cache ()
    "Compute (and return) the location of the default user-cache for translate-output
objects. Side-effects for cached file location computation."
    (setf *user-cache* (xdg-cache-home "common-lisp" :implementation)))
  (register-image-restore-hook 'compute-user-cache)

  (defun uiop-directory ()
    "Try to locate the UIOP source directory at runtime"
    (labels ((pf (x) (ignore-errors (probe-file* x)))
             (sub (x y) (pf (subpathname x y)))
             (ssd (x) (ignore-errors (symbol-call :asdf :system-source-directory x))))
      ;; NB: conspicuously *not* including searches based on #.(current-lisp-pathname)
      (or
       ;; Look under uiop if available as source override, under asdf if avaiable as source
       (ssd "uiop")
       (sub (ssd "asdf") "uiop/")
       ;; Look in recommended path for user-visible source installation
       (sub (user-homedir-pathname) "common-lisp/asdf/uiop/")
       ;; Look in XDG paths under known package names for user-invisible source installation
       (xdg-data-pathname "common-lisp/source/asdf/uiop/")
       (xdg-data-pathname "common-lisp/source/cl-asdf/uiop/") ; traditional Debian location
       ;; The last one below is useful for Fare, primary (sole?) known user
       (sub (user-homedir-pathname) "cl/asdf/uiop/")
       (cerror "Configure source registry to include UIOP source directory and retry."
               "Unable to find UIOP directory")
       (uiop-directory)))))