init

3 files changed, 252 insertions, 0 deletions

diff --git a/client.js b/client.js
new file mode 100644
index 0000000..c2d041c
--- /dev/null
+++ b/client.js
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+/* Config */
+const baseUrl = 'https://comments.dotemgo.com/comments';
+const pageId = '{{site-url}}{{uri}}';
+const commentsUrl = `${baseUrl}?page_url=${pageId}`;
+
+
+/* State */
+let comments = [];
+
+/* GUI components */
+
+const deleteButton = x =>
+  `<button style='float:right;' onclick='handleDelete("${x.id}", "${x.deletion_key}")'>`+
+    `delete</button>`;
+
+const commentFmt = x =>
+  `<div class='comment' id='comment${x.id}'>${x.content}<br/>${x.created_at}`+
+    `${x.deletion_key  ? deleteButton(x) :''}</div>`;
+
+function commentsRender() {
+  commentsthread.innerHTML =
+    `<div id='commentsthreadinner'>
+                    ${comments.map(commentFmt).join('')}
+                </div>`;
+}
+
+
+/* API calls */
+
+// GET comments
+function fetchComments() {
+  fetch(commentsUrl)
+    .then(r => r.ok && r.json())
+    .then(xs => {
+      comments = xs;
+      if (comments.length) {
+        commentsRender();
+      }
+    })
+}
+
+// POST new comment
+function createComment(comment) {
+  const xs = new BigUint64Array(1);
+  crypto.getRandomValues(xs);
+  comment.deletion_key = xs[0].toString();
+  fetch(baseUrl, {
+    method: 'POST',
+    body: JSON.stringify(comment),
+    headers: {'content-type': 'application/json'}
+  }).then(r => r.ok && r.text())
+    .then(id => {
+      const newComment = {id, created_at: 'just now', ...comment}
+      comments = [newComment, ...comments];
+      commentsRender();
+    })
+}
+
+/* Action Handlers */
+
+function handleCommentFormSubmit() {
+  if (commentcontent.value !== "") {
+    createComment({page_url: pageId, content: commentcontent.value});
+    commentcontent.value = '';
+  }
+}
+
+// DELETE comment
+function handleDelete(commentId, deletionKey) {
+  console.log('deleting:',{commentId,deletionKey});
+  fetch(
+    `${baseUrl}?comment=${commentId}&deletion_key=${deletionKey}`,
+    {method: 'DELETE'}
+  ).then(r => {
+    if (r.ok) {
+      comments = comments.filter(x => x.id !== commentId);
+      commentsRender();
+    }
+  });
+}
+
+
+/* init */
+fetchComments();
diff --git a/main.scm b/main.scm
new file mode 100644
index 0000000..9d65032
--- /dev/null
+++ b/main.scm
@@ -0,0 +1,156 @@
+(import
+  scheme (chicken base)
+  (chicken port) (chicken random) (chicken time)
+  (chicken process-context)
+  spiffy intarweb uri-common
+  sqlite3
+  medea
+  srfi-1 ;list functions
+)
+
+;; db open and create
+(define db (open-database (or (get-environment-variable "DB_FILE") "/tmp/comments.db")))
+
+; Creates table automatically on initial run
+(execute db "CREATE TABLE IF NOT EXISTS comments (
+                id TEXT PRIMARY KEY,
+                page_url TEXT,
+                content TEXT,
+                deletion_key TEXT,
+                created_at DATETIME default current_timestamp
+            )")
+
+; creates a new almost-certainly-unique & chronologically ordered id
+(define (gen-id)
+  (+ (pseudo-random-integer 65536)
+     (* (current-seconds) 100000)))
+
+; inserts comment into db
+(define (create-comment page-url content deletion-key)
+  (let ([id (gen-id)]
+        [content-or-empty (if (or (not content) (eof-object? content))
+                            ""
+                            content)])
+    (execute db "INSERT INTO comments
+             (id, page_url, content, deletion_key)
+             VALUES (?, ?, ?, ?)"
+             id page-url content-or-empty deletion-key)
+    id))
+
+; turns db row into list of key-value pairs
+(define (comment-row->alist id page-url content created-at)
+  `((id . ,id)
+    (page_url . ,page-url)
+    (created_at . ,created-at)
+    (content . ,content)))
+
+; selects all comments with the given page-url
+(define (get-comments page-url)
+  (map-row comment-row->alist db
+           "SELECT c.id, c.page_url, c.content, c.created_at
+           FROM comments c
+           WHERE c.page_url = ?
+           ORDER BY c.created_at DESC"
+           page-url
+           ))
+
+; deletes any comment with the comment-id and deletion-key given, if any exist
+(define (delete-comment comment-id deletion-key)
+  (execute db "DELETE FROM comments
+           WHERE id = ?
+           AND deletion_key = ?"
+           comment-id deletion-key))
+
+; get query string parameter
+(define (get-req-var k)
+  (alist-ref k (uri-query (request-uri (current-request)))))
+
+; get page_url query string parameter
+(define (get-page-url)
+  (get-req-var 'page_url))
+
+; read current-request body as json. Arrays represented as lists, objects as alists
+(define (read-json-body)
+  (read-json (request-port (current-request)) consume-trailing-whitespace: #f))
+
+; get alist value with key of k
+(define (json-value-ref json-alist k)
+  (and (list? json-alist) (alist-ref k json-alist equal? #f)))
+
+; headers to always add to responses
+(define base-headers
+  '((access-control-allow-origin *)
+    (access-control-allow-credentials true)
+    (access-control-allow-methods GET POST OPTIONS DELETE)
+    (access-control-allow-headers content-type)))
+
+; list of allowed routes, first item is method, second is uri, third is handler function
+(define routes
+  `(
+    (OPTIONS (/ "comments") ,(lambda () 
+                               (send-response
+                                 status: 'ok
+                                 headers:  base-headers)))
+
+    (POST (/ "comments") ,(lambda ()
+                            (let* ([json-body (read-json-body)]
+                                   [page-url (json-value-ref json-body 'page_url)]
+                                   [content (json-value-ref json-body 'content)]
+                                   [deletion-key (json-value-ref json-body 'deletion_key)]
+                                   [bot? (not (equal? "no" (json-value-ref json-body 'bot)))])
+                              (if bot?
+                                (send-status 'bad-request)
+                                (send-response
+                                  status: 'ok
+                                  body: (number->string
+                                          (create-comment page-url content deletion-key))
+                                  headers: base-headers)))))
+
+    (GET (/ "comments") ,(lambda ()
+                           (let* ([page-url (get-page-url)]
+                                  [comments (list->vector (get-comments page-url))])
+                             (send-response
+                               headers:  (cons
+                                           '(content-type application/json)
+                                           base-headers)
+                               status: 'ok
+                               body: (with-output-to-string
+                                       (lambda () (write-json comments))))
+                             )))
+    (DELETE (/ "comments") ,(lambda ()
+                              (let (
+                                    [comment-id (get-req-var 'comment)]
+                                    [deletion-key (get-req-var 'deletion_key)])
+                                (delete-comment comment-id deletion-key)
+                                (send-response
+                                  status: 'no-content
+                                  headers: base-headers)
+                                )))
+    ))
+
+; find route with matching uri and method, or return #f
+(define (find-route uri method)
+  (find
+    (lambda (r)
+      (and
+        (equal?
+          method
+          (first r))
+        (equal?
+          (uri-path uri)
+          (second r))))
+    routes))
+
+; handle a new HTTP request
+(define (handle continue)
+  (let* ([req (current-request)]
+         [uri (request-uri req)]
+         [method (request-method req)]
+         [route (find-route uri method)])
+    (if route
+      ((third route))
+      (begin (display uri) (display method) (send-status 'not-found "Page Not Found")))))
+
+(root-path ".")
+(vhost-map `((".*" . ,handle)))
+(start-server port: 7060)
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..a42daab
--- /dev/null
+++ b/makefile
@@ -0,0 +1,12 @@
+build: ./main.scm
+	mkdir -p ./build
+	chicken-csc -static ./main.scm \
+		-L -lsqlite3
+	mv ./main ./build/main
+run: build
+	./build/main
+
+clean:
+	rm -r build/
+
+