(in-package :panettone)
(declaim (optimize (safety 3)))

;;;
;;; Data model
;;;

(deftype issue-status ()
  '(member :open :closed))

(defclass/std issue-comment ()
  ((body :type string)
   (author-dn :type string)
   (created-at :type local-time:timestamp
               :std (local-time:now))))

(defclass/std issue (cl-prevalence:object-with-id)
  ((subject body :type string :std "")
   (author-dn :type string)
   (comments :std nil :type list :with-prefix)
   (status :std :open :type issue-status)
   (created-at :type local-time:timestamp
               :std (local-time:now))))

(defclass/std user ()
  ((cn dn mail displayname :type string)))

;;;
;;; LDAP integration
;;;

(defvar *ldap* nil
  "The ldap connection")

(defun connect-ldap (&key
                       (host "localhost")
                       (port 389))
  (setq *ldap* (ldap:new-ldap :host host :port port)))

(defun ldap-entry->user (entry)
  (apply
   #'make-instance
   'user
   :dn (ldap:dn entry)
   (alexandria:mappend
    (lambda (field)
      (list field (car (ldap:attr-value entry field))))
    (list :mail
          :cn
          :displayname))))

(defun find-user/ldap (username)
  (check-type username (simple-array character (*)))
  (ldap:search
   *ldap*
   `(and (= objectClass organizationalPerson)
         (or
          (= cn ,username)
          (= dn ,username)))
   ;; TODO(grfn): make this configurable
   :base "ou=users,dc=tvl,dc=fyi")
  (ldap:next-search-result *ldap*))

(defun find-user (username)
  (check-type username (simple-array character (*)))
  (when-let ((ldap-entry (find-user/ldap username)))
    (ldap-entry->user ldap-entry)))

(defun find-user-by-dn (dn)
  (ldap:search *ldap* `(= objectClass organizationalPerson)
               :base dn
               :scope 'ldap:base)
  (when-let ((ldap-entry (ldap:next-search-result *ldap*)))
    (ldap-entry->user ldap-entry)))

(comment
 (user-by-dn "cn=glittershark,ou=users,dc=tvl,dc=fyi")
 )

(defun authenticate-user (user-or-username password)
  "Checks the given USER-OR-USERNAME has the given PASSWORD, by making a bind
request against the ldap server at *ldap*. Returns the user if authentication is
successful, `nil' otherwise"
  (when-let ((user (if (typep user-or-username 'user) user-or-username
                       (find-user user-or-username))))
    (let ((dn (dn user)))
      (multiple-value-bind (_r code-sym _msg)
          (ldap:bind
           (ldap:new-ldap :host (ldap:host *ldap*)
                          :port (ldap:port *ldap*)
                          :user dn
                          :pass password))
        (when (equalp code-sym 'trivial-ldap:success)
          user)))))

(defun author (object)
  (find-user-by-dn (author-dn object)))

;;;
;;; Persistence
;;;

(defvar *p-system* nil
  "The persistence system for this instance of Panettone")

(define-condition issue-not-found (error)
  ((id :type integer
       :initarg :id
       :reader not-found-id
       :documentation "ID of the issue that was not found"))
  (:documentation
   "Error condition for when an issue requested by ID is not
  found"))

(defun get-issue (system id)
  (restart-case
      (or
       (cl-prevalence:find-object-with-id system 'issue id)
       (error 'issue-not-found :id id))
    (different-id (new-id)
      :report "Use a different issue ID"
      :interactive (lambda ()
                     (format t "Enter a new ID: ")
                     (multiple-value-list (eval (read))))
      (get-issue system new-id))))

(defun list-issues (system)
  (cl-prevalence:find-all-objects system 'issue))

(defun issues-with-status (system status)
  (remove-if-not (lambda (issue) (eq (status issue) status))
                 (list-issues system)))

(defun open-issues (system) (issues-with-status system :open))
(defun closed-issues (system) (issues-with-status system :closed))

(defun create-issue (system &rest attrs)
  (cl-prevalence:tx-create-object
   system
   'issue
   (chunk-list 2 attrs)))

(defun add-comment (system issue-id &rest attrs)
  "Add a comment with the given ATTRS to the issue ISSUE-ID, and return the
updated issue"
  (let* ((comment (apply #'make-instance 'issue-comment attrs))
         (issue (get-issue system issue-id))
         (comments (append (issue-comments issue)
                           (list comment))))
    (cl-prevalence:tx-change-object-slots
     system
     'issue
     issue-id
     `((comments ,comments)))
    (setf (slot-value issue 'comments) comments)
    comments))

(defun initialize-persistence (data-dir)
  "Initialize the Panettone persistence system, storing data in DATA-DIR"
  (ensure-directories-exist data-dir)
  (setq *p-system*
        (cl-prevalence:make-prevalence-system
         (concatenate 'string
                      data-dir
                      "/snapshot.xml")))


  (when (null (list-issues *p-system*))
    (cl-prevalence:tx-create-id-counter *p-system*)))

;;;
;;; Views
;;;

(defvar *title* "Panettone")

(defvar *user* nil)

(setf (who:html-mode) :html5)

(defun render/footer-nav (&rest extra)
  (who:with-html-output (*standard-output*)
    (:footer
     (:nav
      (if (find (hunchentoot:request-uri*)
                (list "/" "/issues/closed")
                :test #'string=)
          (who:htm (:span :class "placeholder"))
          (who:htm (:a :href "/" "All Issues")))
      (if *user*
          (who:htm
           (:form :class "form-link log-out"
                  :method "post"
                  :action "/logout"
                  (:input :type "submit" :value "Log Out")))
          (who:htm
           (:a :href "/login" "Log In")))))))

(defmacro render ((&key (footer t)) &body body)
  `(who:with-html-output-to-string (*standard-output* nil :prologue t)
     (:html
      :lang "en"
      (:head
       (:title (who:esc *title*))
       (:link :rel "stylesheet" :type "text/css" :href "/main.css"))
      (:body
       (:div
        :class "content"
        ,@body
        (when ,footer
          (render/footer-nav)))))))

(defun render/alert (message)
  "Render an alert box for MESSAGE, if non-null"
  (check-type message (or null string))
  (who:with-html-output (*standard-output*)
    (when message
      (who:htm (:div :class "alert" (who:esc message))))))

(defun render/login (&key message (original-uri "/"))
  (render (:footer nil)
    (:div
     :class "login-form"
     (:header
      (:h1 "Login"))
     (:main
      :class "login-form"
      (render/alert message)
      (:form
       :method :post :action "/login"
       (:input :type "hidden" :name "original-uri"
               :value original-uri)
       (:div
        (:label :for "username"
                "Username")
        (:input :type "text"
                :name "username"
                :id "username"
                :placeholder "username"))
       (:div
        (:label :for "password"
                "Password")
        (:input :type "password"
                :name "password"
                :id "password"
                :placeholder "password"))
       (:input :type "submit"
               :value "Submit"))))))

(defun created-by-at (issue)
  (who:with-html-output (*standard-output*)
    (:span :class "created-by-at"
           "Opened by "
           (:span :class "username"
                  (who:esc
                   (or
                    (when-let ((author (author issue)))
                      (displayname author))
                    "someone")))
           " at "
           (:span :class "timestamp"
                  (who:esc
                   (format-dottime (created-at issue)))))))

(defun render/issue-list (&key issues)
  (who:with-html-output (*standard-output*)
    (:ol
     :class "issue-list"
     (dolist (issue issues)
       (let ((issue-id (get-id issue)))
         (who:htm
          (:li
           (:a :href (format nil "/issues/~A" issue-id)
               (:p
                (:span :class "issue-subject"
                       (who:esc (subject issue))))
               (:span :class "issue-number"
                      (who:esc (format nil "#~A" issue-id)))
               " - "
               (created-by-at issue)
               (let ((num-comments (length (issue-comments issue))))
                 (unless (zerop num-comments)
                   (who:htm
                    (:span :class "comment-count"
                           " - "
                           (who:esc
                            (format nil "~A comment~:p" num-comments))))))))))))))

(defun render/index (&key issues)
  (render ()
    (:header
     (:h1 "Issues")
     (when *user*
       (who:htm
        (:a
         :class "new-issue"
         :href "/issues/new" "New Issue"))))
    (:main
     (:div
      :class "issue-links"
      (:a :href "/issues/closed" "View closed issues"))
     (render/issue-list :issues issues))))

(defun render/closed-issues (&key issues)
  (render ()
    (:header
     (:h1 "Closed issues"))
    (:main
     (:div
      :class "issue-links"
      (:a :href "/" "View open isues"))
     (render/issue-list :issues issues))))

(defun render/new-issue (&optional message)
  (render ()
    (:header
     (:h1 "New Issue"))
    (:main
     (render/alert message)
     (:form :method "post"
            :action "/issues"
            :class "issue-form"
            (:div
             (:input :type "text"
                     :id "subject"
                     :name "subject"
                     :placeholder "Subject"))

            (:div
             (:textarea :name "body"
                        :placeholder "Description"
                        :rows 10))

            (:input :type "submit"
                    :value "Create Issue")))))

(defun render/new-comment (issue-id)
  (who:with-html-output (*standard-output*)
    (:form
     :class "new-comment"
     :method "post"
     :action (format nil "/issues/~A/comments" issue-id)
     (:div
      (:textarea :name "body"
                 :placeholder "Leave a comment"
                 :rows 5))
     (:input :type "submit"
             :value "Comment"))))

(defun render/issue (issue)
  (check-type issue issue)
  (let ((issue-id (get-id issue))
        (issue-status (status issue)))
    (render ()
      (:header
       (:h1 (who:esc (subject issue)))
       (:div :class "issue-number"
             (who:esc (format nil "#~A" issue-id))))
      (:main
       (:div
        :class "issue-info"
        (created-by-at issue)

        (when *user*
          (who:htm
           (:form :class "set-issue-status"
                  :method "post"
                  :action (format nil "/issues/~A/~A"
                                  issue-id
                                  (case issue-status
                                    (:open "close")
                                    (:closed "open")))
                  (:input :type "submit"
                          :class (case issue-status
                                   (:open "close-issue")
                                   (:closed "open-issue"))
                          :value (case issue-status
                                   (:open "Close")
                                   (:closed "Reopen")))))))
       (:p (who:esc (body issue)))
       (let ((comments (issue-comments issue)))
         (who:htm
          (:div
           :class "issue-comments"
           (dolist (comment comments)
             (let ((author (author comment)))
               (who:htm
                (:div
                 :class "comment"
                 (:p (who:esc (body comment)))
                 (:p
                  :class "comment-info"
                  (:span :class "username"
                         (who:esc (displayname author))
                         " at "
                         (who:esc (format-dottime (created-at comment)))))))))
           (when *user*
             (render/new-comment (get-id issue))))))))))

(defun render/not-found (entity-type)
  (render ()
    (:h1 (who:esc entity-type) "Not Found")))

;;;
;;; HTTP handlers
;;;

(defun @auth-optional (next)
  (let ((*user* (hunchentoot:session-value 'user)))
    (funcall next)))

(defun @auth (next)
  (if-let ((*user* (hunchentoot:session-value 'user)))
    (funcall next)
    (hunchentoot:redirect
     (format nil "/login?original-uri=~A"
             (drakma:url-encode
              (hunchentoot:request-uri*)
              :utf-8)))))

(defroute login-form ("/login" :method :get)
    (original-uri)
  (if (hunchentoot:session-value 'user)
      (hunchentoot:redirect (or original-uri "/"))
      (render/login :original-uri original-uri)))

(defroute submit-login ("/login" :method :post)
    (&post original-uri username password)
  (if-let ((user (authenticate-user username password)))
    (progn
      (setf (hunchentoot:session-value 'user) user)
      (hunchentoot:redirect (or original-uri "/")))
    (render/login :message "Invalid credentials")))

(defroute logout ("/logout" :method :post) ()
  (hunchentoot:delete-session-value 'user)
  (hunchentoot:redirect "/"))

(defroute index ("/" :decorators (@auth-optional)) ()
  (let ((issues (open-issues *p-system*)))
    (render/index :issues issues)))

(defroute handle-closed-issues
    ("/issues/closed" :decorators (@auth-optional)) ()
  (let ((issues (closed-issues *p-system*)))
    (render/closed-issues :issues issues)))

(defroute new-issue ("/issues/new" :decorators (@auth)) ()
  (render/new-issue))

(defroute handle-create-issue
    ("/issues" :method :post :decorators (@auth))
    (&post subject body)
  (if (string= subject "")
      (render/new-issue "Subject is required")
      (progn
        (cl-prevalence:execute-transaction
         (create-issue *p-system*
                       'subject subject
                       'body body
                       'author-dn (dn *user*)))
        (cl-prevalence:snapshot *p-system*)
        (hunchentoot:redirect "/"))))

(defroute show-issue ("/issues/:id" :decorators (@auth-optional))
    (&path (id 'integer))
  (handler-case
      (let* ((issue (get-issue *p-system* id))
             (*title* (format nil "~A | Panettone"
                              (subject issue))))
        (render/issue issue))
    (issue-not-found (_)
      (render/not-found "Issue"))))

(defroute handle-create-comment
    ("/issues/:id/comments" :decorators (@auth)
                            :method :post)
    (&path (id 'integer) &post body)
  (flet ((redirect-to-issue ()
           (hunchentoot:redirect (format nil "/issues/~A" id))))
    (if (string= body "")
        (redirect-to-issue)
        (handler-case
            (progn
              (cl-prevalence:execute-transaction
               (add-comment *p-system* id
                            :body body
                            :author-dn (dn *user*)))
              (cl-prevalence:snapshot *p-system*)
              (redirect-to-issue))
          (issue-not-found (_)
            (render/not-found "Issue"))))))

(defroute close-issue
    ("/issues/:id/close" :decorators (@auth)
                         :method :post)
    (&path (id 'integer))
  (cl-prevalence:execute-transaction
   (cl-prevalence:tx-change-object-slots
    *p-system*
    'issue
    id
    '((status :closed))))
  (cl-prevalence:snapshot *p-system*)
  (hunchentoot:redirect (format nil "/issues/~A" id)))

(defroute open-issue
    ("/issues/:id/open" :decorators (@auth)
                         :method :put)
    (&path (id 'integer))
  (cl-prevalence:execute-transaction
   (cl-prevalence:tx-change-object-slots
    *p-system*
    'issue
    id
    '((status open))))
  (cl-prevalence:snapshot *p-system*)
  (hunchentoot:redirect (format nil "/issues/~A" id)))

(defroute styles ("/main.css") ()
  (setf (hunchentoot:content-type*) "text/css")
  (apply #'lass:compile-and-write panettone.css:styles))

(defvar *acceptor* nil
  "Hunchentoot acceptor for Panettone's web server.")

(defun start-panettone (&key port data-dir
                          (ldap-host "localhost")
                          (ldap-port 389))
  (connect-ldap :host ldap-host
                :port ldap-port)
  (initialize-persistence data-dir)

  (setq *acceptor*
        (make-instance 'easy-routes:routes-acceptor :port port))
  (hunchentoot:start *acceptor*))

(defun integer-env (var &key default)
  (or
   (when-let ((str (uiop:getenvp var)))
     (try-parse-integer str))
   default))

(defun main ()
  (let ((port (integer-env "PANETTONE_PORT" :default 6161))
        (ldap-port (integer-env "LDAP_PORT" :default 389))
        (data-dir (or (uiop:getenvp "PANETTONE_DATA_DIR") "/var/lib/panettone")))
    (start-panettone :port port
                     :data-dir data-dir
                     :ldap-port ldap-port)
    (sb-thread:join-thread
     (find-if (lambda (th)
                (string= (sb-thread:thread-name th)
                         (format nil "hunchentoot-listener-*:~A" port)))
              (sb-thread:list-all-threads)))))

(comment
 (setq hunchentoot:*catch-errors-p* nil)
 (start-panettone :port 6161
                  :data-dir "/tmp/panettone"
                  :ldap-port 3899)
 )