;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 ng0 <ng0@we.make.ritual.n0.is>
;;; Copyright © 2016, 2017, 2018 Julien Lepiller <julien@lepiller.eu>
;;; Copyright © 2017 Christopher Baines <mail@cbaines.net>
;;; Copyright © 2017 nee <nee-git@hidamari.blue>
;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix 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.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu services web)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module (gnu system shadow)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages web)
  #:use-module (gnu packages php)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module ((guix utils) #:select (version-major))
  #:use-module ((guix packages) #:select (package-version))
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (ice-9 match)
  #:export (<httpd-configuration>
            httpd-configuration
            httpd-configuration?
            httpd-configuration-package
            httpd-configuration-pid-file
            httpd-configuration-config

            <httpd-virtualhost>
            httpd-virtualhost
            httpd-virtualhost?
            httpd-virtualhost-addresses-and-ports
            httpd-virtualhost-contents

            <httpd-config-file>
            httpd-config-file
            httpd-config-file?
            httpd-config-file-modules
            httpd-config-file-server-root
            httpd-config-file-server-name
            httpd-config-file-listen
            httpd-config-file-pid-file
            httpd-config-file-error-log
            httpd-config-file-user
            httpd-config-file-group

            httpd-service-type

            <nginx-configuration>
            nginx-configuration
            nginx-configuration?
            nginx-configuartion-nginx
            nginx-configuration-log-directory
            nginx-configuration-run-directory
            nginx-configuration-server-blocks
            nginx-configuration-upstream-blocks
            nginx-configuration-server-names-hash-bucket-size
            nginx-configuration-server-names-hash-bucket-max-size
            nginx-configuration-file

            <nginx-server-configuration>
            nginx-server-configuration
            nginx-server-configuration?
            nginx-server-configuration-listen
            nginx-server-configuration-server-name
            nginx-server-configuration-root
            nginx-server-configuration-locations
            nginx-server-configuration-index
            nginx-server-configuration-ssl-certificate
            nginx-server-configuration-ssl-certificate-key
            nginx-server-configuration-server-tokens?
            nginx-server-configuration-raw-content

            <nginx-upstream-configuration>
            nginx-upstream-configuration
            nginx-upstream-configuration?
            nginx-upstream-configuration-name
            nginx-upstream-configuration-servers

            <nginx-location-configuration>
            nginx-location-configuration
            nginx-location-configuration?
            nginx-location-configuration-uri
            nginx-location-configuration-body

            <nginx-named-location-configuration>
            nginx-named-location-configuration
            nginx-named-location-configuration?
            nginx-named-location-configuration-name
            nginx-named-location-configuration-body

            nginx-service
            nginx-service-type

            fcgiwrap-configuration
            fcgiwrap-configuration?
            fcgiwrap-service-type

            <php-fpm-configuration>
            php-fpm-configuration
            make-php-fpm-configuration
            php-fpm-configuration?
            php-fpm-configuration-php
            php-fpm-configuration-socket
            php-fpm-configuration-user
            php-fpm-configuration-group
            php-fpm-configuration-socket-user
            php-fpm-configuration-socket-group
            php-fpm-configuration-pid-file
            php-fpm-configuration-log-file
            php-fpm-configuration-process-manager
            php-fpm-configuration-display-errors
            php-fpm-configuration-workers-log-file
            php-fpm-configuration-file

            <php-fpm-dynamic-process-manager-configuration>
            php-fpm-dynamic-process-manager-configuration
            make-php-fpm-dynamic-process-manager-configuration
            php-fpm-dynamic-process-manager-configuration?
            php-fpm-dynamic-process-manager-configuration-max-children
            php-fpm-dynamic-process-manager-configuration-start-servers
            php-fpm-dynamic-process-manager-configuration-min-spare-servers
            php-fpm-dynamic-process-manager-configuration-max-spare-servers

            <php-fpm-static-process-manager-configuration>
            php-fpm-static-process-manager-configuration
            make-php-fpm-static-process-manager-configuration
            php-fpm-static-process-manager-configuration?
            php-fpm-static-process-manager-configuration-max-children

            <php-fpm-on-demand-process-manager-configuration>
            php-fpm-on-demand-process-manager-configuration
            make-php-fpm-on-demand-process-manager-configuration
            php-fpm-on-demand-process-manager-configuration?
            php-fpm-on-demand-process-manager-configuration-max-children
            php-fpm-on-demand-process-manager-configuration-process-idle-timeout

            php-fpm-service-type
            nginx-php-location

            cat-avatar-generator-service))

;;; Commentary:
;;;
;;; Web services.
;;;
;;; Code:

(define-record-type* <httpd-module>
  httpd-module make-httpd-module
  httpd-module?
  (name httpd-load-module-name)
  (file httpd-load-module-file))

;; Default modules for the httpd-service-type, taken from etc/httpd/httpd.conf
;; file in the httpd package.
(define %default-httpd-modules
  (map (match-lambda
         ((name file)
          (httpd-module
           (name name)
           (file file))))
       '(("authn_file_module" "modules/mod_authn_file.so")
         ("authn_core_module" "modules/mod_authn_core.so")
         ("authz_host_module" "modules/mod_authz_host.so")
         ("authz_groupfile_module" "modules/mod_authz_groupfile.so")
         ("authz_user_module" "modules/mod_authz_user.so")
         ("authz_core_module" "modules/mod_authz_core.so")
         ("access_compat_module" "modules/mod_access_compat.so")
         ("auth_basic_module" "modules/mod_auth_basic.so")
         ("reqtimeout_module" "modules/mod_reqtimeout.so")
         ("filter_module" "modules/mod_filter.so")
         ("mime_module" "modules/mod_mime.so")
         ("log_config_module" "modules/mod_log_config.so")
         ("env_module" "modules/mod_env.so")
         ("headers_module" "modules/mod_headers.so")
         ("setenvif_module" "modules/mod_setenvif.so")
         ("version_module" "modules/mod_version.so")
         ("unixd_module" "modules/mod_unixd.so")
         ("status_module" "modules/mod_status.so")
         ("autoindex_module" "modules/mod_autoindex.so")
         ("dir_module" "modules/mod_dir.so")
         ("alias_module" "modules/mod_alias.so"))))

(define-record-type* <httpd-config-file>
  httpd-config-file make-httpd-config-file
  httpd-config-file?
  (modules        httpd-config-file-modules
                  (default %default-httpd-modules))
  (server-root    httpd-config-file-server-root
                  (default httpd))
  (server-name    httpd-config-file-server-name
                  (default #f))
  (document-root  httpd-config-file-document-root
                  (default "/srv/http"))
  (listen         httpd-config-file-listen
                  (default '("80")))
  (pid-file       httpd-config-file-pid-file
                  (default "/var/run/httpd"))
  (error-log      httpd-config-file-error-log
                  (default "/var/log/httpd/error_log"))
  (user           httpd-config-file-user
                  (default "httpd"))
  (group          httpd-config-file-group
                  (default "httpd"))
  (extra-config   httpd-config-file-extra-config
                  (default
                    (list "TypesConfig etc/httpd/mime.types"))))

(define-gexp-compiler (httpd-config-file-compiler
                       (file <httpd-config-file>) system target)
  (match file
    (($ <httpd-config-file> load-modules server-root server-name
                                   document-root listen pid-file error-log
                                   user group extra-config)
     (gexp->derivation
      "httpd.conf"
      #~(call-with-output-file (ungexp output "out")
          (lambda (port)
            (display
             (string-append
              (ungexp-splicing
               `(,@(append-map
                    (match-lambda
                      (($ <httpd-module> name module)
                       `("LoadModule " ,name " " ,module "\n")))
                    load-modules)
                 ,@`("ServerRoot " ,server-root "\n")
                 ,@(if server-name
                       `("ServerName " ,server-name "\n")
                       '())
                 ,@`("DocumentRoot " ,document-root "\n")
                 ,@(append-map
                    (lambda (listen-value)
                      `("Listen " ,listen-value "\n"))
                    listen)
                 ,@(if pid-file
                       `("Pidfile " ,pid-file "\n")
                       '())
                 ,@(if error-log
                       `("ErrorLog " ,error-log "\n")
                       '())
                 ,@(if user
                       `("User " ,user "\n")
                       '())
                 ,@(if group
                       `("Group " ,group "\n")
                       '())
                 "\n\n"
                 ,@extra-config)))
             port)))
      #:local-build? #t))))

(define-record-type <httpd-virtualhost>
  (httpd-virtualhost addresses-and-ports contents)
  httpd-virtualhost?
  (addresses-and-ports httpd-virtualhost-addresses-and-ports)
  (contents            httpd-virtualhost-contents))

(define-record-type* <httpd-configuration>
  httpd-configuration make-httpd-configuration
  httpd-configuration?
  (package  httpd-configuration-package
            (default httpd))
  (pid-file httpd-configuration-pid-file
            (default "/var/run/httpd"))
  (config   httpd-configuration-config
            (default (httpd-config-file))))

(define %httpd-accounts
  (list (user-group (name "httpd") (system? #t))
        (user-account
         (name "httpd")
         (group "httpd")
         (system? #t)
         (comment "Apache HTTPD server user")
         (home-directory "/var/empty")
         (shell (file-append shadow "/sbin/nologin")))))

(define httpd-shepherd-services
  (match-lambda
    (($ <httpd-configuration> package pid-file config)
     (list (shepherd-service
            (provision '(httpd))
            (documentation "The Apache HTTP Server")
            (requirement '(networking))
            (start #~(make-forkexec-constructor
                      `(#$(file-append package "/bin/httpd")
                        #$@(if config
                               (list "-f" config)
                               '()))
                      #:pid-file #$pid-file))
            (stop #~(make-kill-destructor)))))))

(define httpd-activation
  (match-lambda
    (($ <httpd-configuration> package pid-file config)
     (match-record
      config
      <httpd-config-file>
      (error-log document-root)
      #~(begin
          (use-modules (guix build utils))

          (mkdir-p #$(dirname error-log))
          (mkdir-p #$document-root))))))

(define (httpd-process-extensions original-config extension-configs)
  (let ((config (httpd-configuration-config
                 original-config)))
    (if (httpd-config-file? config)
        (httpd-configuration
         (inherit original-config)
         (config
          (httpd-config-file
           (inherit config)
           (extra-config
            (append (httpd-config-file-extra-config config)
                    (append-map
                     (match-lambda
                       (($ <httpd-virtualhost>
                           addresses-and-ports
                           contents)
                        `(,(string-append
                            "<VirtualHost " addresses-and-ports ">\n")
                          ,@contents
                          "\n</VirtualHost>\n"))
                       ((? string? x)
                        `("\n" ,x "\n"))
                       ((? list? x)
                        `("\n" ,@x "\n")))
                     extension-configs)))))))))

(define httpd-service-type
  (service-type (name 'httpd)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          httpd-shepherd-services)
                       (service-extension activation-service-type
                                          httpd-activation)
                       (service-extension account-service-type
                                          (const %httpd-accounts))))
                (compose concatenate)
                (extend httpd-process-extensions)
                (default-value
                  (httpd-configuration))))

(define-record-type* <nginx-server-configuration>
  nginx-server-configuration make-nginx-server-configuration
  nginx-server-configuration?
  (listen              nginx-server-configuration-listen
                       (default '("80" "443 ssl")))
  (server-name         nginx-server-configuration-server-name
                       (default (list 'default)))
  (root                nginx-server-configuration-root
                       (default "/srv/http"))
  (locations           nginx-server-configuration-locations
                       (default '()))
  (index               nginx-server-configuration-index
                       (default (list "index.html")))
  (try-files           nginx-server-configuration-try-files
                       (default '()))
  (ssl-certificate     nginx-server-configuration-ssl-certificate
                       (default #f))
  (ssl-certificate-key nginx-server-configuration-ssl-certificate-key
                       (default #f))
  (server-tokens?      nginx-server-configuration-server-tokens?
                       (default #f))
  (raw-content         nginx-server-configuration-raw-content
                       (default '())))

(define-record-type* <nginx-upstream-configuration>
  nginx-upstream-configuration make-nginx-upstream-configuration
  nginx-upstream-configuration?
  (name                nginx-upstream-configuration-name)
  (servers             nginx-upstream-configuration-servers))

(define-record-type* <nginx-location-configuration>
  nginx-location-configuration make-nginx-location-configuration
  nginx-location-configuration?
  (uri                 nginx-location-configuration-uri
                       (default #f))
  (body                nginx-location-configuration-body))

(define-record-type* <nginx-named-location-configuration>
  nginx-named-location-configuration make-nginx-named-location-configuration
  nginx-named-location-configuration?
  (name                nginx-named-location-configuration-name
                       (default #f))
  (body                nginx-named-location-configuration-body))

(define-record-type* <nginx-configuration>
  nginx-configuration make-nginx-configuration
  nginx-configuration?
  (nginx         nginx-configuration-nginx          ;<package>
                 (default nginx))
  (log-directory nginx-configuration-log-directory  ;string
                 (default "/var/log/nginx"))
  (run-directory nginx-configuration-run-directory  ;string
                 (default "/var/run/nginx"))
  (server-blocks nginx-configuration-server-blocks
                 (default '()))          ;list of <nginx-server-configuration>
  (upstream-blocks nginx-configuration-upstream-blocks
                   (default '()))      ;list of <nginx-upstream-configuration>
  (server-names-hash-bucket-size nginx-configuration-server-names-hash-bucket-size
                                 (default #f))
  (server-names-hash-bucket-max-size nginx-configuration-server-names-hash-bucket-max-size
                                     (default #f))
  (file          nginx-configuration-file         ;#f | string | file-like
                 (default #f)))

(define (config-domain-strings names)
 "Return a string denoting the nginx config representation of NAMES, a list
of domain names."
 (map (match-lambda
        ('default "_ ")
        ((? string? str) (list str " ")))
      names))

(define (config-index-strings names)
 "Return a string denoting the nginx config representation of NAMES, a list
of index files."
 (map (match-lambda
        ((? string? str) (list str " ")))
      names))

(define emit-nginx-location-config
  (match-lambda
    (($ <nginx-location-configuration> uri body)
     (list
      "      location " uri " {\n"
      (map (lambda (x) (list "        " x "\n")) body)
      "      }\n"))
    (($ <nginx-named-location-configuration> name body)
     (list
      "      location @" name " {\n"
      (map (lambda (x) (list "        " x "\n")) body)
      "      }\n"))))

(define (emit-nginx-server-config server)
  (let ((listen (nginx-server-configuration-listen server))
        (server-name (nginx-server-configuration-server-name server))
        (ssl-certificate (nginx-server-configuration-ssl-certificate server))
        (ssl-certificate-key
         (nginx-server-configuration-ssl-certificate-key server))
        (root (nginx-server-configuration-root server))
        (index (nginx-server-configuration-index server))
        (try-files (nginx-server-configuration-try-files server))
        (server-tokens? (nginx-server-configuration-server-tokens? server))
        (locations (nginx-server-configuration-locations server))
        (raw-content (nginx-server-configuration-raw-content server)))
    (define-syntax-parameter <> (syntax-rules ()))
    (define-syntax-rule (and/l x tail ...)
      (let ((x* x))
        (if x*
            (syntax-parameterize ((<> (identifier-syntax x*)))
              (list tail ...))
            '())))
    (list
     "    server {\n"
     (map (lambda (directive) (list "      listen " directive ";\n")) listen)
     "      server_name " (config-domain-strings server-name) ";\n"
     (and/l ssl-certificate     "      ssl_certificate " <> ";\n")
     (and/l ssl-certificate-key "      ssl_certificate_key " <> ";\n")
     "      root " root ";\n"
     "      index " (config-index-strings index) ";\n"
     (if (not (nil? try-files))
         (and/l (config-index-strings try-files) "      try_files " <> ";\n")
         "")
     "      server_tokens " (if server-tokens? "on" "off") ";\n"
     "\n"
     (map emit-nginx-location-config locations)
     "\n"
     (map (lambda (x) (list "      " x "\n")) raw-content)
     "    }\n")))

(define (emit-nginx-upstream-config upstream)
  (list
   "    upstream " (nginx-upstream-configuration-name upstream) " {\n"
   (map (lambda (server)
          (simple-format #f "      server ~A;\n" server))
        (nginx-upstream-configuration-servers upstream))
   "    }\n"))

(define (flatten . lst)
  "Return a list that recursively concatenates all sub-lists of LST."
  (define (flatten1 head out)
    (if (list? head)
        (fold-right flatten1 out head)
        (cons head out)))
  (fold-right flatten1 '() lst))

(define (default-nginx-config config)
  (match-record config
                <nginx-configuration>
                (nginx log-directory run-directory
                 server-blocks upstream-blocks
                 server-names-hash-bucket-size
                 server-names-hash-bucket-max-size)
   (apply mixed-text-file "nginx.conf"
          (flatten
           "user nginx nginx;\n"
           "pid " run-directory "/pid;\n"
           "error_log " log-directory "/error.log info;\n"
           "http {\n"
           "    client_body_temp_path " run-directory "/client_body_temp;\n"
           "    proxy_temp_path " run-directory "/proxy_temp;\n"
           "    fastcgi_temp_path " run-directory "/fastcgi_temp;\n"
           "    uwsgi_temp_path " run-directory "/uwsgi_temp;\n"
           "    scgi_temp_path " run-directory "/scgi_temp;\n"
           "    access_log " log-directory "/access.log;\n"
           "    include " nginx "/share/nginx/conf/mime.types;\n"
           (if server-names-hash-bucket-size
               (string-append
                "    server_names_hash_bucket_size "
                (number->string server-names-hash-bucket-size)
                ";\n")
               "")
           (if server-names-hash-bucket-max-size
               (string-append
                "    server_names_hash_bucket_max_size "
                (number->string server-names-hash-bucket-max-size)
                ";\n")
               "")
           "\n"
           (map emit-nginx-upstream-config upstream-blocks)
           (map emit-nginx-server-config server-blocks)
           "}\n"
           "events {}\n"))))

(define %nginx-accounts
  (list (user-group (name "nginx") (system? #t))
        (user-account
         (name "nginx")
         (group "nginx")
         (system? #t)
         (comment "nginx server user")
         (home-directory "/var/empty")
         (shell (file-append shadow "/sbin/nologin")))))

(define (nginx-activation config)
  (match-record config
                <nginx-configuration>
                (nginx log-directory run-directory file)
   #~(begin
       (use-modules (guix build utils))

       (format #t "creating nginx log directory '~a'~%" #$log-directory)
       (mkdir-p #$log-directory)
       (format #t "creating nginx run directory '~a'~%" #$run-directory)
       (mkdir-p #$run-directory)
       (format #t "creating nginx temp directories '~a/{client_body,proxy,fastcgi,uwsgi,scgi}_temp'~%" #$run-directory)
       (mkdir-p (string-append #$run-directory "/client_body_temp"))
       (mkdir-p (string-append #$run-directory "/proxy_temp"))
       (mkdir-p (string-append #$run-directory "/fastcgi_temp"))
       (mkdir-p (string-append #$run-directory "/uwsgi_temp"))
       (mkdir-p (string-append #$run-directory "/scgi_temp"))
       ;; Start-up logs. Once configuration is loaded, nginx switches to
       ;; log-directory.
       (mkdir-p (string-append #$run-directory "/logs"))
       ;; Check configuration file syntax.
       (system* (string-append #$nginx "/sbin/nginx")
                "-c" #$(or file
                           (default-nginx-config config))
                  "-t"))))

(define (nginx-shepherd-service config)
  (match-record config
                <nginx-configuration>
                (nginx file run-directory)
   (let* ((nginx-binary (file-append nginx "/sbin/nginx"))
          (nginx-action
           (lambda args
             #~(lambda _
                 (zero?
                  (system* #$nginx-binary "-c"
                           #$(or file
                                 (default-nginx-config config))
                           #$@args))))))

     ;; TODO: Add 'reload' action.
     (list (shepherd-service
            (provision '(nginx))
            (documentation "Run the nginx daemon.")
            (requirement '(user-processes loopback))
            (start (nginx-action "-p" run-directory))
            (stop (nginx-action "-s" "stop")))))))

(define nginx-service-type
  (service-type (name 'nginx)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          nginx-shepherd-service)
                       (service-extension activation-service-type
                                          nginx-activation)
                       (service-extension account-service-type
                                          (const %nginx-accounts))))
                (compose concatenate)
                (extend (lambda (config servers)
                          (nginx-configuration
                            (inherit config)
                            (server-blocks
                              (append (nginx-configuration-server-blocks config)
                              servers)))))
                (default-value
                  (nginx-configuration))))

(define-record-type* <fcgiwrap-configuration> fcgiwrap-configuration
  make-fcgiwrap-configuration
  fcgiwrap-configuration?
  (package       fcgiwrap-configuration-package ;<package>
                 (default fcgiwrap))
  (socket        fcgiwrap-configuration-socket
                 (default "tcp:127.0.0.1:9000"))
  (user          fcgiwrap-configuration-user
                 (default "fcgiwrap"))
  (group         fcgiwrap-configuration-group
                 (default "fcgiwrap")))

(define fcgiwrap-accounts
  (match-lambda
    (($ <fcgiwrap-configuration> package socket user group)
     (filter identity
             (list
              (and (equal? group "fcgiwrap")
                   (user-group
                    (name "fcgiwrap")
                    (system? #t)))
              (and (equal? user "fcgiwrap")
                   (user-account
                    (name "fcgiwrap")
                    (group group)
                    (system? #t)
                    (comment "Fcgiwrap Daemon")
                    (home-directory "/var/empty")
                    (shell (file-append shadow "/sbin/nologin")))))))))

(define fcgiwrap-shepherd-service
  (match-lambda
    (($ <fcgiwrap-configuration> package socket user group)
     (list (shepherd-service
            (provision '(fcgiwrap))
            (documentation "Run the fcgiwrap daemon.")
            (requirement '(networking))
            (start #~(make-forkexec-constructor
                      '(#$(file-append package "/sbin/fcgiwrap")
			  "-s" #$socket)
		      #:user #$user #:group #$group))
            (stop #~(make-kill-destructor)))))))

(define fcgiwrap-service-type
  (service-type (name 'fcgiwrap)
                (extensions
                 (list (service-extension shepherd-root-service-type
                                          fcgiwrap-shepherd-service)
		       (service-extension account-service-type
                                          fcgiwrap-accounts)))
                (default-value (fcgiwrap-configuration))))

(define-record-type* <php-fpm-configuration> php-fpm-configuration
  make-php-fpm-configuration
  php-fpm-configuration?
  (php              php-fpm-configuration-php ;<package>
                    (default php))
  (socket           php-fpm-configuration-socket
                    (default (string-append "/var/run/php"
                                            (version-major (package-version php))
                                            "-fpm.sock")))
  (user             php-fpm-configuration-user
                    (default "php-fpm"))
  (group            php-fpm-configuration-group
                    (default "php-fpm"))
  (socket-user      php-fpm-configuration-socket-user
                    (default "php-fpm"))
  (socket-group     php-fpm-configuration-socket-group
                    (default "nginx"))
  (pid-file         php-fpm-configuration-pid-file
                    (default (string-append "/var/run/php"
                                            (version-major (package-version php))
                                            "-fpm.pid")))
  (log-file         php-fpm-configuration-log-file
                    (default (string-append "/var/log/php"
                                            (version-major (package-version php))
                                            "-fpm.log")))
  (process-manager  php-fpm-configuration-process-manager
                    (default (php-fpm-dynamic-process-manager-configuration)))
  (display-errors   php-fpm-configuration-display-errors
                    (default #f))
  (workers-log-file php-fpm-configuration-workers-log-file
                    (default (string-append "/var/log/php"
                                            (version-major (package-version php))
                                            "-fpm.www.log")))
  (file             php-fpm-configuration-file ;#f | file-like
                    (default #f)))

(define-record-type* <php-fpm-dynamic-process-manager-configuration>
  php-fpm-dynamic-process-manager-configuration
  make-php-fpm-dynamic-process-manager-configuration
  php-fpm-dynamic-process-manager-configuration?
  (max-children         php-fpm-dynamic-process-manager-configuration-max-children
                        (default 5))
  (start-servers        php-fpm-dynamic-process-manager-configuration-start-servers
                        (default 2))
  (min-spare-servers    php-fpm-dynamic-process-manager-configuration-min-spare-servers
                        (default 1))
  (max-spare-servers    php-fpm-dynamic-process-manager-configuration-max-spare-servers
                        (default 3)))

(define-record-type* <php-fpm-static-process-manager-configuration>
  php-fpm-static-process-manager-configuration
  make-php-fpm-static-process-manager-configuration
  php-fpm-static-process-manager-configuration?
  (max-children         php-fpm-static-process-manager-configuration-max-children
                        (default 5)))

(define-record-type* <php-fpm-on-demand-process-manager-configuration>
  php-fpm-on-demand-process-manager-configuration
  make-php-fpm-on-demand-process-manager-configuration
  php-fpm-on-demand-process-manager-configuration?
  (max-children         php-fpm-on-demand-process-manager-configuration-max-children
                        (default 5))
  (process-idle-timeout php-fpm-on-demand-process-manager-configuration-process-idle-timeout
                        (default 10)))

(define php-fpm-accounts
  (match-lambda
    (($ <php-fpm-configuration> php socket user group socket-user socket-group _ _ _ _ _ _)
     (list
      (user-group (name "php-fpm") (system? #t))
      (user-group
       (name group)
       (system? #t))
      (user-account
       (name user)
       (group group)
       (supplementary-groups '("php-fpm"))
       (system? #t)
       (comment "php-fpm daemon user")
       (home-directory "/var/empty")
       (shell (file-append shadow "/sbin/nologin")))))))

(define (default-php-fpm-config socket user group socket-user socket-group
          pid-file log-file pm display-errors workers-log-file)
  (apply mixed-text-file "php-fpm.conf"
         (flatten
          "[global]\n"
          "pid =" pid-file "\n"
          "error_log =" log-file "\n"
          "[www]\n"
          "user =" user "\n"
          "group =" group "\n"
          "listen =" socket "\n"
          "listen.owner =" socket-user "\n"
          "listen.group =" socket-group "\n"

          (match pm
            (($ <php-fpm-dynamic-process-manager-configuration>
                pm.max-children
                pm.start-servers
                pm.min-spare-servers
                pm.max-spare-servers)
             (list
              "pm = dynamic\n"
              "pm.max_children =" (number->string pm.max-children) "\n"
              "pm.start_servers =" (number->string pm.start-servers) "\n"
              "pm.min_spare_servers =" (number->string pm.min-spare-servers) "\n"
              "pm.max_spare_servers =" (number->string pm.max-spare-servers) "\n"))

            (($ <php-fpm-static-process-manager-configuration>
                pm.max-children)
             (list
              "pm = static\n"
              "pm.max_children =" (number->string pm.max-children) "\n"))

            (($ <php-fpm-on-demand-process-manager-configuration>
                pm.max-children
                pm.process-idle-timeout)
             (list
              "pm = ondemand\n"
              "pm.max_children =" (number->string pm.max-children) "\n"
              "pm.process_idle_timeout =" (number->string pm.process-idle-timeout) "s\n")))


          "php_flag[display_errors] = " (if display-errors "on" "off") "\n"

          (if workers-log-file
              (list "catch_workers_output = yes\n"
                    "php_admin_value[error_log] =" workers-log-file "\n"
                    "php_admin_flag[log_errors] = on\n")
              (list "catch_workers_output = no\n")))))

(define php-fpm-shepherd-service
  (match-lambda
    (($ <php-fpm-configuration> php socket user group socket-user socket-group
                                pid-file log-file pm display-errors workers-log-file file)
     (list (shepherd-service
            (provision '(php-fpm))
            (documentation "Run the php-fpm daemon.")
            (requirement '(networking))
            (start #~(make-forkexec-constructor
                      '(#$(file-append php "/sbin/php-fpm")
                        "--fpm-config"
                        #$(or file
                              (default-php-fpm-config socket user group
                                socket-user socket-group pid-file log-file
                                pm display-errors workers-log-file)))
                      #:pid-file #$pid-file))
            (stop #~(make-kill-destructor)))))))

(define php-fpm-activation
  (match-lambda
    (($ <php-fpm-configuration> _ _ user _ _ _ _ log-file _ _ workers-log-file _)
     #~(begin
         (use-modules (guix build utils))
         (let* ((user (getpwnam #$user))
                (touch (lambda (file-name)
                         (call-with-output-file file-name (const #t))))
                (init-log-file
                 (lambda (file-name)
                   (when #$workers-log-file
                     (when (not (file-exists? file-name))
                       (touch file-name))
                     (chown file-name (passwd:uid user) (passwd:gid user))
                     (chmod file-name #o660)))))
           (init-log-file #$log-file)
           (init-log-file #$workers-log-file))))))


(define php-fpm-service-type
  (service-type
   (name 'php-fpm)
   (description
    "Run @command{php-fpm} to provide a fastcgi socket for calling php through
a webserver.")
   (extensions
    (list (service-extension shepherd-root-service-type
                             php-fpm-shepherd-service)
          (service-extension activation-service-type
                             php-fpm-activation)
          (service-extension account-service-type
                             php-fpm-accounts)))
   (default-value (php-fpm-configuration))))

(define* (nginx-php-location
          #:key
          (nginx-package nginx)
          (socket (string-append "/var/run/php"
                                 (version-major (package-version php))
                                 "-fpm.sock")))
  "Return a nginx-location-configuration that makes nginx run .php files."
  (nginx-location-configuration
   (uri "~ \\.php$")
   (body (list
          "fastcgi_split_path_info ^(.+\\.php)(/.+)$;"
          (string-append "fastcgi_pass unix:" socket ";")
          "fastcgi_index index.php;"
          (list "include " nginx-package "/share/nginx/conf/fastcgi.conf;")))))

(define* (cat-avatar-generator-service
          #:key
          (cache-dir "/var/cache/cat-avatar-generator")
          (package cat-avatar-generator)
          (configuration (nginx-server-configuration)))
  (simple-service
    'cat-http-server nginx-service-type
    (list (nginx-server-configuration
            (inherit configuration)
            (locations
              (cons
                (let ((base (nginx-php-location)))
                  (nginx-location-configuration
                    (inherit base)
                    (body (list (string-append "fastcgi_param CACHE_DIR \""
                                               cache-dir "\";")
                                (nginx-location-configuration-body base)))))
                (nginx-server-configuration-locations configuration)))
            (root #~(string-append #$package
                                   "/share/web/cat-avatar-generator"))))))