core: render web previews for channels (#7029)

* plan: web previews for channels

* types for recipient side to support channel web previews and domain names

* fix

* migrations

* update schema and api types

* update schema

* rename migrations

* core: render channel preview data

* core: render channel preview data in relays

* website: use cpp to inject JS functions

* JSC files

* remove directory.js

* channel preview renderer

* Revert "cli: fix redraw slowness (#6735)"

This reverts commit b801d77c74.

* sample channel page

* default avatar

* rename options

* better layout

* layout

* images

* some fixes

* tails

* markdown colors

* image sizes

* reactions

* fix reactions

* fewer avatars

* forward icon

* command to change group access parameters

* view public group access changes in CLI

* media metadata color

* ios: group web access ui

* update ui

* add init

* kotlin, labels

* update page

* update relay base URL

* fix

* ios update channel web page info

* update kotlin layout

* use cards

* update layout

* use domains for relay data, path is fixed

* update embed code

* fix bots api

* include only history items and senders

* update preview JS/HTML

* show different error if link is different

* remove stale json files

* better layout

* layout fixes

* improve layout

* improve layout

* update embed code

* web cta

* better layout

* buttons

* layout

* paddings

* desktop cta

* desktop cta

* cta layout

* fonts

* paddings

* paddings

* more paddings

* copy link

* read more

* hide avatar and placeholder when all messages are from channel

* color scheme

* fix color

* improve

* layout

* welcome message

* dark mode colors

* padding

* font size

* overscroll

* font

* logo on button

* better join

* buttons

* refactor

* another logo

* text

* desktop button

* button text

* center

* fix svg

* padding

* smaller gap

* render channel on any message changes etc

* fixes

* atomic file updates, escape attributes

* fix tests

* more tests

* more efficient rendering

* improve security

* sanitize links, include mentioned members

* schema

* fixes

* improve rendering

* fix showing correct subscribers count

* fix member names

---------

Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>

src/Simplex/Chat/Controller.hs

@@ -39,6 +39,7 @@ import Data.Char (ord)
 import Data.Int (Int64)
 import Data.List.NonEmpty (NonEmpty)
 import Data.Map.Strict (Map)
+import Data.Set (Set)
 import qualified Data.Map.Strict as M
 import Data.Maybe (fromMaybe)
 import Data.String
@@ -162,6 +163,7 @@ data ChatConfig = ChatConfig
     ciExpirationInterval :: Int64, -- microseconds
     deliveryWorkerDelay :: Int64, -- microseconds
     deliveryBucketSize :: Int,
+    webPreviewConfig :: Maybe WebPreviewConfig,
     channelSubscriberRole :: GroupMemberRole, -- TODO [relays] starting role should be communicated in protocol from owner to relays
     relayChecksInterval :: NominalDiffTime,
     relayInactiveTTL :: NominalDiffTime,
@@ -173,6 +175,43 @@ data ChatConfig = ChatConfig
     chatHooks :: ChatHooks
   }
 
+data WebPreviewConfig = WebPreviewConfig
+  { webDomain :: Text,
+    webJsonDir :: FilePath,
+    webCorsFile :: Maybe FilePath,
+    webUpdateInterval :: Int, -- seconds
+    webPreviewItemCount :: Int
+  }
+
+data PublishableGroup = PublishableGroup
+  { pgFileName :: FilePath,
+    pgCorsEntry :: Maybe (Text, CorsOrigin)
+  }
+
+data CorsOrigin = CorsAny | CorsOrigins [Text]
+  deriving (Show)
+
+data WebPreviewState = WebPreviewState
+  { publishableGroupIds :: TVar (Map Int64 PublishableGroup),
+    priorityRender :: TQueue Int64,
+    filesToRemove :: TQueue FilePath,
+    corsNeeded :: TVar Bool,
+    routinePending :: TVar (Set Int64),
+    wakeSignal :: TMVar (),
+    webPreviewWorkerAsync :: TVar (Maybe (Async ()))
+  }
+
+newWebPreviewState :: IO WebPreviewState
+newWebPreviewState = do
+  publishableGroupIds <- newTVarIO mempty
+  priorityRender <- newTQueueIO
+  filesToRemove <- newTQueueIO
+  corsNeeded <- newTVarIO False
+  routinePending <- newTVarIO mempty
+  wakeSignal <- newEmptyTMVarIO
+  webPreviewWorkerAsync <- newTVarIO Nothing
+  pure WebPreviewState {publishableGroupIds, priorityRender, filesToRemove, corsNeeded, routinePending, wakeSignal, webPreviewWorkerAsync}
+
 -- | Builds the read-only context threaded through store functions from chat config.
 -- The single construction point, so new store-wide config (e.g. server keys) is added in one place.
 mkStoreCxt :: ChatConfig -> StoreCxt
@@ -266,6 +305,7 @@ data ChatController = ChatController
     deliveryJobWorkers :: TMap DeliveryWorkerKey Worker,
     relayRequestWorkers :: TMap Int Worker, -- single global worker with key 1 is used to fit into existing worker management framework
     relayGroupLinkChecksAsync :: TVar (Maybe (Async ())),
+    webPreviewState :: Maybe WebPreviewState,
     chatRelayTests :: TMap ConnId RelayTest,
     expireCIThreads :: TMap UserId (Maybe (Async ())),
     expireCIFlags :: TMap UserId Bool,
@@ -555,6 +595,7 @@ data ChatCommand
   | ShowGroupProfile GroupName
   | UpdateGroupDescription GroupName (Maybe Text)
   | ShowGroupDescription GroupName
+  | SetPublicGroupAccess GroupName PublicGroupAccess
   | CreateGroupLink GroupName GroupMemberRole
   | GroupLinkMemberRole GroupName GroupMemberRole
   | DeleteGroupLink GroupName