#|-*- mode:lisp -*-|#
#|
exec ros -Q -- $0 "$@"
|#

;; Woo is a fast non-blocking HTTP server built on top of
;; libev. Although Woo is written in Common Lisp, it aims
;; to be the fastest web server written in any programming
;; language.

;; https://github.com/fukamachi/woo

;; Quicklisp is a library manager for Common Lisp. Use
;; QuickLisp's quickload function to retrieve external
;; packages. These packages are automatically curl'd when
;; the program runs.

;; Woo - https://github.com/fukamachi/woo
;; st-json - https://github.com/marijnh/ST-JSON
;; Serapeum - https://github.com/ruricolist/serapeum
;; Postmodern - https://github.com/marijnh/Postmodern
;; QURI - https://github.com/fukamachi/quri

(sb-ext:restrict-compiler-policy 'speed 3)
(sb-ext:restrict-compiler-policy 'safety 0)
(sb-ext:restrict-compiler-policy 'debug 0)
(sb-ext:restrict-compiler-policy 'compilation-speed 0)


(ql:quickload '(postmodern
                ;; st-json 10-15% faster than jonathan
                ;; according to this benchmark
                ;; https://sabracrolleton.github.io/json-review#write-times
                st-json
                ;; Previously cl-markup was used but Spinneret
                ;; is 30% faster and more convenient. CL-WHO also as fast as
                ;; Spinneret but requires manual string escaping which is error-prone.
                spinneret
                quri
                uiop
                woo
                alexandria
                serapeum
                function-cache
                cl+ssl
                slynk
                slynk/mrepl
                slynk-macrostep
                slynk-named-readtables
                log4cl-extras)
              :silent t)


(load (merge-pathnames "helpers/starts-with.lisp"
                       *load-pathname*))
(load (merge-pathnames "helpers/parse-argv.lisp"
                       *load-pathname*))


(function-cache:defcached db-host ()
  (or (uiop:getenv "DB_HOST")
      "tfb-database"))

(function-cache:defcached db-port ()
  (parse-integer (or (uiop:getenv "DB_PORT")
                     "5432")))


(function-cache:defcached db-use-ssl ()
  (if (uiop:getenv "DB_USE_SSL")
      :full
      :no))

(function-cache:defcached db-name ()
  (or (uiop:getenv "DB_NAME")
      "hello_world"))

(function-cache:defcached db-user ()
  (or (uiop:getenv "DB_USER")
      "benchmarkdbuser"))

(function-cache:defcached db-pass ()
  (or (uiop:getenv "DB_PASS")
      "benchmarkdbpass"))


(defmacro with-binary-connection (() &body body)
  `(postmodern:with-connection (list (db-name)
                                     (db-user)
                                     (db-pass)
                                     (db-host)
                                     :port (db-port)
                                     :use-binary t
                                     :use-ssl (db-use-ssl)
                                     :pooled-p t)
     ,@body))


(declaim (ftype (function () list)
                plaintext)
         (inline plaintext))
(defun plaintext ()
  "Plaintext handler."
  '(200
    (:content-type "text/plain"
     :server "Woo")
    ("Hello, World!")))


(declaim (ftype (function () list)
                json)
         (inline json))
(defun json ()
  "JSON handler using Jonathan to encode JSON"
  `(200
    (:content-type "application/json"
     :server "Woo")
    (,(st-json:write-json-to-string (serapeum:dict "message"
                                                   "Hello, World!")))))


(postmodern:defprepared get-a-random-record-query
    (:select 'randomnumber
      :from 'world
      :where (:= 'id '$1))
    :single)


(declaim (ftype (function (fixnum) (values))
                get-a-random-record)
         (inline get-a-random-record))
(defun get-a-random-record (id)
  (declare (fixnum id))
  
  (let ((id (min id 10000)))
    (let ((number (get-a-random-record-query id)))
      (declare (type fixnum number))
      (serapeum:dict "id" id
                     "randomNumber" number))))


(declaim (ftype (function () list)
                db)
         (inline db))
(defun db ()
  "DB handler using Jonathan to encode JSON and Postmodern to access PostgreSQL"
  (with-binary-connection ()
    (let ((id (+ 1 (random 10000))))
      `(200
        (:content-type "application/json"
         :server "Woo")
        (,(st-json:write-json-to-string (get-a-random-record id)))))))


(declaim (ftype (function (fixnum) fixnum)
                ensure-integer-is-between-one-and-five-hundreds)
         (inline ensure-integer-is-between-one-and-five-hundreds))
(defun ensure-integer-is-between-one-and-five-hundreds (n)
  (max (min n 500)
       1))


(declaim (ftype (function (list) fixnum)
                extract-number-of-records-to-fetch)
         (inline extract-number-of-records-to-fetch))
(defun extract-number-of-records-to-fetch (env)
  (let ((n (handler-case
               (parse-integer (cdr (assoc "queries" (quri:url-decode-params (getf env :query-string)) :test #'equal)))
             (error (c) (values 1 c)))))
    (ensure-integer-is-between-one-and-five-hundreds n)))


(declaim (ftype (function (fixnum) list)
                get-some-random-integers-between-one-and-ten-thousand)
         (inline get-some-random-integers-between-one-and-ten-thousand))
(defun get-some-random-integers-between-one-and-ten-thousand (n)
  (declare (fixnum n))
  (loop :repeat n
        :collect (+ 1 (random 10000))))


(declaim (ftype (function (fixnum) list)
                get-some-random-records)
         (inline get-some-random-records))
(defun get-some-random-records (n)
  (loop repeat n
        for id fixnum = (1+ (random 10000))
        collect (get-a-random-record id)))


(declaim (ftype (function (list) list)
                queries)
         (inline queries))
(defun queries (env)
  "QUERIES handler using Jonathan to encode JSON and Postmodern to access PostgreSQL"
  (with-binary-connection ()
    `(200
      (:content-type "application/json"
       :server "Woo")
      (,(st-json:write-json-to-string
         (get-some-random-records
          (extract-number-of-records-to-fetch env)))))))


(postmodern:defprepared get-all-fortunes
    (:select 'id 'message
      :from 'fortune)
    :rows)


(declaim (ftype (function () list)
                get-all-fortunes-plus-one)
         (inline get-all-fortunes-plus-one))
(defun get-all-fortunes-plus-one ()
  (let* ((records (get-all-fortunes))
         (records-p-one
           (append records '((0 "Additional fortune added at request time.")))))
    (sort (copy-list records-p-one) #'string-lessp :key #'second)))


(declaim (ftype (function () list)
                fortunes)
         (inline fortunes))
(defun fortunes ()
  "FORTUNES handler using Spinneret to generate HTML and Postmodern to access PostgreSQL."
  (let ((*print-pretty* nil)
        ;; Without this setting Spinneret does not close tags when it is possible
        ;; and benchmark's validator fails.
        (spinneret:*html-style* :tree))
    (with-binary-connection ()
      `(200
        (:content-type "text/html; charset=UTF-8"
         :server "Woo")
        (,(spinneret:with-html-string
            (:doctype)
            (:html
             ;; Here I have to use :tag,
             ;; because otherwise spinneret inserts
             ;; <meta charset="UTF-8" /> and benchmark's verification fails.
             (:tag :name "head"
                   (:title "Fortunes"))
             (:body
              (:table
               (:tr
                (:th "id")
                (:th "message"))
               (loop for fortune-row in (get-all-fortunes-plus-one)
                     do (:tr
                         (:td (format nil "~d" (first fortune-row)))
                         (:td (second fortune-row)))))))))))))


(defun make-batch-update-query (n)
  (declare (type fixnum n))
  (format nil
          "UPDATE world AS ori SET randomnumber = new.randomnumber::integer FROM (VALUES ~{~A~^, ~}) AS new (id, randomnumber) WHERE ori.id = new.id::integer"
          (loop for i fixnum below n
                for arg1 fixnum = (+ (* i 2)
                                     1)
                for arg2 fixnum = (+ (* i 2)
                                     2)
                collect (format nil "($~A,$~A)" arg1 arg2))))


(defparameter *batch-updaters* (make-hash-table))


(defmacro define-batch-updater (n)
  (let ((name (intern (format nil "UPDATE-BATCH-~A" n)))
        (query (make-batch-update-query n)))
    `(progn
       (postmodern:defprepared ,name
           (:raw ,query)
           :rows)
       (setf (gethash ,n *batch-updaters*)
             #',name))))


(defmacro define-batch-updaters (n)
  (loop for i fixnum from 1 to n
        collect `(define-batch-updater ,i) into forms
        finally (return `(progn ,@forms))))


;; Here we are defining a number of functions
;; which use prepared statements to update
;; a given number of records.
;; 
;; Each function does something like this:
;; 
;; UPDATE world AS ori SET randomnumber = new.randomnumber FROM
;; (VALUES (($1, $2), ($3, $4), ($5, $6), ($7, $8), ($9, $10)) AS new (id, randomnumber) WHERE ori.id = new.id
;;
;; Previous version of the update function formatted SQL query
;; using FORMAT function. In real world application this could lead to SQL injection.
(define-batch-updaters 500)


(defun auto-batch-update (data)
  (declare (type list data))
  (let* ((batch-length (/ (length data)
                          2))
         (func (gethash batch-length
                        *batch-updaters*)))
    (declare (type (or null function) func))
    (cond
      (func
       (apply func data))
      (t
       (error "No prepared function for batch of length ~A"
              batch-length)))))


(declaim (ftype (function (fixnum) list)
                get-and-update-some-random-records-batch)
         (inline get-and-update-some-random-records-batch))
(defun get-and-update-some-random-records-batch (n)
  "Flexible batch updater. This function will be called with n from 0 upto 500."
  (let* ((random-records (get-some-random-records n))
         (random-numbers (get-some-random-integers-between-one-and-ten-thousand n)))
    (loop with batch-size fixnum = 0
          with args = nil
          for iteration fixnum upfrom 0
          for row in random-records
          for new-random-number in random-numbers
          for record-id = (gethash "id" row)
          
          do (setf args (list*
                         record-id
                         new-random-number
                         args))
             (setf batch-size
                   (1+ batch-size))
             ;; Here we keep old hash but update it with a new
             ;; value to make lisp consing less:
             (setf (gethash "randomNumber" row)
                   new-random-number)
          collect row into results
          when (= batch-size
                  500)
            ;; Sending update to the database.
            ;; This branch works if n > 500
            do (apply #'update-batch-500 args)
               (setf args nil
                     batch-size 0)
          finally (when args
                    ;; If we have some more data to update
                    ;; then will send them to the database too.
                    (auto-batch-update args))
                  (return results))))

(declaim (ftype (function (list) list)
                updates)
         (inline updates))
(defun updates (env)
  "UPDATES handler using Jonathan to encode JSON and Postmodern to access PostgreSQL"
  (with-binary-connection ()
    `(200
      (:content-type "application/json"
       :server "Woo")
      (,(st-json:write-json-to-string (get-and-update-some-random-records-batch
                                       (extract-number-of-records-to-fetch env)))))))


(defparameter *args* nil)

(declaim (ftype (function () list)
                server-info)
         (inline server-info))
(defun server-info ()
  "Shows information about lisp implementation and version"
  `(200
    (:content-type "text/plain"
     :server "Woo")
    (,(format nil "Running on ~A ~A~%Started with: ~A~%"
              (lisp-implementation-type)
              (lisp-implementation-version)
              *args*))))


(declaim (ftype (function (list) list)
                handler)
         (inline handler))
(defun handler (env)
  "Router"
  (log4cl-extras/error:with-log-unhandled ()
    (let ((path (getf env :path-info)))
      (cond ((starts-with path "/plaintext") (plaintext))
            ((starts-with path "/json"     ) (json))
            ((starts-with path "/db"       ) (db))
            ((starts-with path "/queries"  ) (queries env))
            ((starts-with path "/fortunes" ) (fortunes))
            ((starts-with path "/updates"  ) (updates env))
            (t
             (server-info))))))


(defvar slynk:*use-dedicated-output-stream*)


(defun main (&rest argv)
  "Create and start the server, applying argv to the env"
  (let ((args (parse-argv argv))
        (debug-mode (uiop:getenv "DEBUG")))
    ;; Initialize the global random state by "some means" (e.g. current time)
    (setf *random-state* (make-random-state t))
    
    (setf *args* args)
    
    (setf (getf args :worker-num)
          ;; empirically I found that performance is the best when
          ;; we have 4 workers per core.
          (* (getf args :cpu 1)
             4))
    (alexandria:remove-from-plistf args :cpu)
    
    (format t "Starting with args: ~S~%"
            args)
    
    (when debug-mode
      (setf slynk:*use-dedicated-output-stream* nil)
      (slynk:create-server :port 4005
                           :interface "0.0.0.0"
                           :dont-close t))
    
    (when (db-use-ssl)
      (let ((postgres-certs-file
              (probe-file "~/.postgresql/root.crt")))
        (when postgres-certs-file
          (cl+ssl:ssl-load-global-verify-locations postgres-certs-file))))

    (log4cl-extras/config:setup
     (list :level (if debug-mode
                      :debug
                      :error)
           :appenders '((this-console :layout :plain))))
    
    (apply #'woo:run
           #'handler
           :debug nil
           args)))