everywhere: add email notifications

db/20190213033530-email-notifications.sql

@@ -0,0 +1,38 @@
+-- Email notifications
+-- There are two kinds of email notifications: those sent to domain moderators
+-- and those sent to commenters. Domain owners can choose to subscribe their
+-- moderators to all comments, those pending moderation, or no emails. Each
+-- moderator can independently opt out of these emails, of course. Commenters,
+-- on the other, can choose to opt into reply notifications by email.
+
+-- TODO: daily and weekly digests instead of just batched real-time emails?
+
+-- TODO: more granular options to unsubscribe from emails for particular
+-- domains can be provided - add unsubscribedReplyDomains []TEXT and
+-- unsubscribedModeratorDomains []TEXT to emails table?
+
+-- Each address has a cooldown period so that emails aren't sent within 10
+-- minutes of each other. Why is this a separate table instead of another
+-- column on commenters/owners? Because there may be some mods that haven't
+-- logged in to create a row in the commenter table.
+CREATE TABLE IF NOT EXISTS emails (
+  email TEXT NOT NULL UNIQUE PRIMARY KEY,
+  unsubscribeSecretHex TEXT NOT NULL UNIQUE,
+  lastEmailNotificationDate TIMESTAMP NOT NULL,
+  pendingEmails INTEGER NOT NULL DEFAULT 0,
+  sendReplyNotifications BOOLEAN NOT NULL DEFAULT false,
+  sendModeratorNotifications BOOLEAN NOT NULL DEFAULT true
+);
+
+CREATE INDEX IF NOT EXISTS unsubscribeSecretHexIndex ON emails(unsubscribeSecretHex);
+
+-- Which comments should be sent?
+-- Possible values: all, pending-moderation, none
+-- Default to pending-moderation because this is critical. If the user forgets
+-- to moderate, some comments will never see the light of day.
+ALTER TABLE domains
+  ADD COLUMN emailNotificationPolicy TEXT DEFAULT 'pending-moderation';
+
+-- Each page now needs to store the title of the page.
+ALTER TABLE pages
+  ADD COLUMN title TEXT DEFAULT '';