;;; Guix QA Frontpage
;;;
;;; Copyright © 2022 Christopher Baines <mail@cbaines.net>
;;;
;;; This program is free software: you can redistribute it and/or
;;; modify it under the terms of the GNU Affero General Public License
;;; as published by the Free Software Foundation, either version 3 of
;;; the License, or (at your option) any later version.
;;;
;;; This program 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
;;; Affero General Public License for more details.
;;;
;;; You should have received a copy of the GNU Affero General Public
;;; License along with this program.  If not, see
;;; <http://www.gnu.org/licenses/>.

(define-module (guix-qa-frontpage server)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-71)
  #:use-module (ice-9 match)
  #:use-module (web http)
  #:use-module (web request)
  #:use-module (web uri)
  #:use-module (system repl error-handling)
  #:use-module (fibers web server)
  #:use-module (guix store)
  #:use-module (guix-data-service web util)
  #:use-module (guix-qa-frontpage database)
  #:use-module (guix-qa-frontpage patchwork)
  #:use-module (guix-qa-frontpage manage-builds)
  #:use-module (guix-qa-frontpage guix-data-service)
  #:use-module (guix-qa-frontpage view util)
  #:use-module (guix-qa-frontpage view home)
  #:use-module (guix-qa-frontpage view patches)
  #:use-module (guix-qa-frontpage view branches)
  #:use-module (guix-qa-frontpage view branch)
  #:use-module (guix-qa-frontpage view issue)
  #:export (start-guix-qa-frontpage-web-server))

(define (make-controller assets-directory database)

  (define handle-static-assets
    (if (string-prefix? (%store-prefix)
                        assets-directory)
        (static-asset-from-store-renderer assets-directory)
        (static-asset-from-directory-renderer assets-directory)))

  (lambda (request
           method-and-path-components
           mime-types
           body)

    (define path
      (uri-path (request-uri request)))

    (match method-and-path-components
      (('GET)
       (render-html
        #:sxml (home)))
      (('GET "assets" rest ...)
       (or (handle-static-assets (string-join rest "/")
                                 (request-headers request))
           (not-found (request-uri request))))
      (('GET "branches")
       (let ((branches
              (with-sqlite-cache
               database
               'branches
               (lambda ()
                 (list-branches
                  (list-branches-url 2)))
               #:ttl 60)))
         (render-html
          #:sxml
          (branches-view branches))))
      (('GET "branch" branch)
       (let ((derivation-changes
              change-details
              (with-sqlite-cache
               database
               'branch-derivation-changes
               branch-derivation-changes
               #:args
               (list (branch-derivation-changes-url
                      branch
                      #:systems %systems-to-submit-builds-for))
               #:ttl 6000)))
         (render-html
          #:sxml
          (branch-view branch
                       derivation-changes))))
      (('GET "patches")
       (let ((latest-series
              (with-sqlite-cache
               database
               'latest-patchwork-series-by-issue
               latest-patchwork-series-by-issue
               #:ttl 1200)))
         (render-html
          #:sxml
          (patches-view latest-series))))
      (('GET "issue" number)
       (let ((series (assq-ref (with-sqlite-cache
                                database
                                'latest-patchwork-series-by-issue
                                latest-patchwork-series-by-issue
                                #:ttl 1200)
                               (string->number number))))
         (if series
             (let ((derivation-changes
                    change-details
                    (with-sqlite-cache
                     database
                     'derivation-changes
                     patch-series-derivation-changes
                     #:args
                     (list (patch-series-derivation-changes-url
                            series
                            #:systems %systems-to-submit-builds-for))
                     #:ttl 6000))
                   (comparison-details
                    (with-sqlite-cache
                     database
                     'lint-warnings
                     patch-series-comparison
                     #:args
                     (list (patch-series-compare-url series))
                     #:ttl 6000)))
               (render-html
                #:sxml (issue-view number
                                   series
                                   derivation-changes
                                   change-details
                                   comparison-details)))
             (render-html
              #:sxml (general-not-found
                      "Issue not found"
                      "This could mean the issue does not exist, it
has no patches or has been closed.")
              #:code 404))))
      ((method path ...)
       (render-html
        #:sxml (general-not-found
                "Page not found"
                "")
        #:code 404)))))

(define (handler request body controller)
  (display
   (format #f "~a ~a\n"
           (request-method request)
           (uri-path (request-uri request))))

  (call-with-error-handling
   (lambda ()
     (let-values (((request-components mime-types)
                   (request->path-components-and-mime-type request)))
       (controller request
                   (cons (request-method request)
                         request-components)
                   mime-types
                   body)))
   #:on-error 'backtrace
   #:post-error (lambda args
                  (render-html #:sxml (error-page args)
                               #:code 500))))

(define* (start-guix-qa-frontpage-web-server port host assets-directory
                                             database)
  (define controller
    (make-controller assets-directory database))

  (call-with-error-handling
   (lambda ()
     (run-server (lambda (request body)
                   (apply values (handler request body controller)))
                 #:host host
                 #:port port))
   #:on-error 'backtrace
   #:post-error (lambda (key . args)
                  (when (eq? key 'system-error)
                    (match args
                      (("bind" "~A" ("Address already in use") _)
                       (simple-format
                        (current-error-port)
                        "\n
error: guix-data-service could not start, as it could not bind to port ~A

Check if it's already running, or whether another process is using that
port. Also, the port used can be changed by passing the --port option.\n"
                        port)))))))