;;; Guix Data Service -- Information about Guix over time
;;; Copyright © 2019 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-data-service web jobs controller)
  #:use-module (ice-9 match)
  #:use-module (guix-data-service utils)
  #:use-module (guix-data-service database)
  #:use-module (guix-data-service web render)
  #:use-module (guix-data-service web controller)
  #:use-module (guix-data-service web query-parameters)
  #:use-module (guix-data-service web util)
  #:use-module (guix-data-service jobs)
  #:use-module (guix-data-service jobs load-new-guix-revision)
  #:use-module (guix-data-service web jobs html)
  #:export (jobs-controller))

(define (jobs-controller request
                         method-and-path-components
                         mime-types
                         body)
  (match method-and-path-components
    (('GET "jobs")
     (let ((parsed-query-parameters
            (guard-against-mutually-exclusive-query-parameters
             (parse-query-parameters
              request
              `((before_id  ,parse-number)
                (limit_results  ,parse-result-limit
                                #:no-default-when (all_results)
                                #:default 20)
                (all_results    ,parse-checkbox-value)))
             '((limit_results all_results)))))
       (render-jobs mime-types
                    parsed-query-parameters)))
    (('GET "jobs" "events")
     (let ((parsed-query-parameters
            (guard-against-mutually-exclusive-query-parameters
             (parse-query-parameters
              request
              `((limit_results  ,parse-result-limit
                                #:no-default-when (all_results)
                                #:default 50)
                (all_results    ,parse-checkbox-value)))
             '((limit_results all_results)))))
       (render-job-events mime-types
                          parsed-query-parameters)))
    (('GET "jobs" "queue")
     (render-job-queue mime-types))
    (('GET "job" job-id)
     (let ((parsed-query-parameters
            (parse-query-parameters
             request
             `((start_character ,parse-number)
               (characters ,parse-number #:default 10000000)))))
       (render-job mime-types
                   job-id
                   parsed-query-parameters)))
    (_ #f)))

(define (render-jobs mime-types query-parameters)
  (define limit-results (assq-ref query-parameters 'limit_results))

  (letpar& ((jobs
             (with-resource-from-pool (connection-pool) conn
               (select-jobs-and-events
                conn
                (assq-ref query-parameters 'before_id)
                limit-results)))
            (recent-events
             (call-with-resource-from-pool
              (connection-pool)
              select-recent-job-events)))
    (case (most-appropriate-mime-type
           '(application/json text/html)
           mime-types)
      ((application/json)
       (render-json
        `((recent-events
           . ,(list->vector
               (map (match-lambda
                      ((_ commit _ _ event occurred_at)
                       `((commit . ,commit)
                         (event . ,event)
                         (occurred_at . ,occurred_at))))
                    recent-events)))
          (jobs
           . ,(list->vector
               (map (match-lambda
                      ((_ commit source _ created-at _ events log)
                       `((commit . ,commit)
                         (source . ,source)
                         (created-at . ,created-at)
                         (events . ,events)
                         (log . ,log))))
                    jobs))))))
      (else
       (render-html
        #:sxml (view-jobs
                query-parameters
                jobs
                recent-events
                (and limit-results
                     (>= (length jobs)
                         limit-results))))))))

(define (render-job-events mime-types query-parameters)
  (let ((recent-events
         (with-resource-from-pool (connection-pool) conn
           (select-recent-job-events
            conn
            ;; TODO Ideally there wouldn't be a limit
            #:limit (or (assq-ref query-parameters 'limit_results)
                        1000000)))))
    (render-html
     #:sxml (view-job-events
             query-parameters
             recent-events))))

(define (render-job-queue mime-types)
  (render-html
   #:sxml (view-job-queue
           (call-with-resource-from-pool
            (connection-pool)
            select-unprocessed-jobs-and-events))))

(define (render-job mime-types job-id query-parameters)
  (let ((log-text
         (with-resource-from-pool (connection-pool) conn
           (log-for-job conn job-id
                        #:character-limit
                        (assq-ref query-parameters 'characters)
                        #:start-character
                        (assq-ref query-parameters 'start_character)))))
    (case (most-appropriate-mime-type
           '(text/plain text/html)
           mime-types)
      ((text/plain)
       (render-text log-text))
      (else
       (render-html
        #:sxml (view-job
                job-id
                query-parameters
                log-text))))))