Support creating and showing review requests

Closes #82.

lisp/forge-commands.el

@@ -454,6 +454,20 @@ point is currently on."
           'confirm)
         (mapconcat #'car value ","))))))
 
+(defun forge-edit-topic-review-requests (topic)
+  "Edit the review-requests of TOPIC."
+  (interactive (list (forge-read-pullreq "Request review for")))
+  (let* ((repo (forge-get-repository topic))
+         (value (closql--iref topic 'review-requests))
+         (choices (mapcar #'cadr (oref repo assignees)))
+         (crm-separator ","))
+    (forge--set-topic-review-requests
+     repo topic
+     (magit-completing-read-multiple*
+      "Request review from: " choices nil
+      'confirm
+      (mapconcat #'car value ",")))))
+
 ;;; Delete
 
 (defun forge-delete-comment (comment)

lisp/forge-db.el

@@ -25,6 +25,8 @@
 (require 'emacsql)
 (require 'emacsql-sqlite)
 
+(defvar forge--db-table-schemata)
+
 (declare-function forge-reset-database "forge")
 
 ;;; Options
@@ -41,7 +43,7 @@
 (defclass forge-database (closql-database)
   ((object-class :initform forge-repository)))
 
-(defconst forge--db-version 2)
+(defconst forge--db-version 3)
 
 (defvar forge--db-connection nil
   "The EmacSQL database connection.")
@@ -54,6 +56,14 @@
     (let* ((db forge--db-connection)
            (version (caar (emacsql db "PRAGMA user_version"))))
       (cond
+       ((and (= version 2) (= forge--db-version 3))
+        (message "Upgrading Forge database from version 2 to 3...")
+        (let ((db forge--db-connection))
+          (emacsql-with-transaction db
+            (emacsql db [:create-table pullreq-review-request $S1]
+                     (cdr (assq 'pullreq-review-request forge--db-table-schemata)))
+            (emacsql db (format "PRAGMA user_version = %s" 3))))
+        (message "Upgrading Forge database from version 2 to 3...done"))
        ((> version forge--db-version)
         (emacsql-close db)
         (user-error "BUG: forge-db-version is too low"))
@@ -283,6 +293,13 @@
       [pullreq] :references pullreq [id]
       :on-delete :cascade))
 
+    (pullreq-review-request
+     [(pullreq :not-null)
+      (id :not-null)]
+     (:foreign-key
+      [pullreq] :references pullreq [id]
+      :on-delete :cascade))
+
     (revnote
      [(class :not-null)
       (id :not-null :primary-key)

lisp/forge-github.el

@@ -228,6 +228,9 @@ repositories.
              t)))
         (when bump
           (forge--set-id-slot repo pullreq 'assignees .assignees)
+          (forge--set-id-slot repo pullreq 'review-requests
+                              (--map (cdr (cadr it))
+                                     (car .reviewRequests)))
           (forge--set-id-slot repo pullreq 'labels .labels))
         pullreq))))
 
@@ -504,6 +507,19 @@ repositories.
        `((assignees . ,remove)))))
   (forge-pull))
 
+(cl-defmethod forge--set-topic-review-requests
+  ((_repo forge-github-repository) topic reviewers)
+  (let ((value (mapcar #'car (closql--iref topic 'review-requests))))
+    (when-let ((add (cl-set-difference reviewers value :test #'equal)))
+      (forge--ghub-post
+       topic "/repos/:owner/:repo/pulls/:number/requested_reviewers"
+       `((reviewers . ,add))))
+    (when-let ((remove (cl-set-difference value reviewers :test #'equal)))
+      (forge--ghub-delete
+       topic "/repos/:owner/:repo/pulls/:number/requested_reviewers"
+       `((reviewers . ,remove)))))
+  (forge-pull))
+
 (cl-defmethod forge--topic-templates ((repo forge-github-repository)
                                       (_ (subclass forge-issue)))
   (when-let ((files (magit-revision-files (oref repo default-branch))))

lisp/forge-pullreq.el

@@ -62,7 +62,7 @@
    (participants)
    (posts                :closql-class forge-pullreq-post)
    (reactions)
-   (review-requests)
+   (review-requests      :closql-table (pullreq-review-request assignee))
    (reviews)
    (timeline)
    ;; We don't use these fields:

lisp/forge-topic.el

@@ -313,7 +313,8 @@ identifier."
   '(forge-insert-topic-title
     forge-insert-topic-state
     forge-insert-topic-labels
-    forge-insert-topic-assignees))
+    forge-insert-topic-assignees
+    forge-insert-topic-review-requests))
 
 (defvar forge-post-section-map
   (let ((map (make-sparse-keymap)))
@@ -471,6 +472,24 @@ identifier."
       (insert (propertize "none" 'face 'magit-dimmed)))
     (insert ?\n)))
 
+(defvar forge-topic-review-requests-section-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map [remap magit-edit-thing] 'forge-edit-topic-review-requests)
+    map))
+
+(cl-defun forge-insert-topic-review-requests
+    (&optional (topic forge-buffer-topic))
+  (when (and (forge-github-repository-p (forge-get-repository topic))
+             (forge-pullreq-p topic))
+    (magit-insert-section (topic-review-requests)
+      (insert (format "%-11s" "Review-Requests: "))
+      (if-let ((review-requests (closql--iref topic 'review-requests)))
+          (insert (mapconcat (pcase-lambda (`(,login ,name))
+                               (format "%s (@%s)" name login))
+                             review-requests ", "))
+        (insert (propertize "none" 'face 'magit-dimmed)))
+      (insert ?\n))))
+
 (defun forge--fontify-markdown (text)
   (with-temp-buffer
     (delay-mode-hooks