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/Options.hs

@@ -28,7 +28,7 @@ import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
 import Numeric.Natural (Natural)
 import Options.Applicative
-import Simplex.Chat.Controller (ChatLogLevel (..), SimpleNetCfg (..), updateStr, versionNumber, versionString)
+import Simplex.Chat.Controller (ChatLogLevel (..), SimpleNetCfg (..), WebPreviewConfig (..), updateStr, versionNumber, versionString)
 import Simplex.FileTransfer.Description (mb)
 import Simplex.Messaging.Client (HostMode (..), SMPWebPortServers (..), SocksMode (..), textToHostMode)
 import Simplex.Messaging.Encoding.String
@@ -66,6 +66,7 @@ data CoreChatOpts = CoreChatOpts
     tbqSize :: Natural,
     deviceName :: Maybe Text,
     chatRelay :: Bool,
+    webPreviewConfig :: Maybe WebPreviewConfig,
     highlyAvailable :: Bool,
     yesToUpMigrations :: Bool,
     migrationBackupPath :: Maybe FilePath,
@@ -240,6 +241,46 @@ coreChatOptsP appDir defaultDbName = do
       ( long "relay"
           <> help "Run as a chat relay client"
       )
+  webPreviewConfig <- do
+    webDomain_ <-
+      optional $
+        strOption
+          ( long "relay-web-domain"
+              <> metavar "DOMAIN"
+              <> help "Domain for channel web previews (relay only)"
+          )
+    webJsonDir_ <-
+      optional $
+        strOption
+          ( long "relay-web-dir"
+              <> metavar "DIR"
+              <> help "Directory for channel web preview JSON files (relay only)"
+          )
+    webCorsFile <-
+      optional $
+        strOption
+          ( long "relay-web-cors-file"
+              <> metavar "FILE"
+              <> help "Path to generated Caddy CORS config file (relay only)"
+          )
+    webUpdateInterval <-
+      option auto
+        ( long "relay-web-interval"
+            <> metavar "SECONDS"
+            <> help "Interval between web preview regeneration in seconds (relay only)"
+            <> value 300
+        )
+    webPreviewItemCount <-
+      option auto
+        ( long "relay-web-item-count"
+            <> metavar "COUNT"
+            <> help "Number of recent messages in channel web preview (relay only)"
+            <> value 50
+        )
+    pure $ case (webDomain_, webJsonDir_) of
+      (Just webDomain, Just webJsonDir) -> Just WebPreviewConfig {webDomain, webJsonDir, webCorsFile, webUpdateInterval, webPreviewItemCount}
+      (Nothing, Nothing) -> Nothing
+      _ -> errorWithoutStackTrace "--relay-web-domain and --relay-web-dir must both be provided"
   highlyAvailable <-
     switch
       ( long "ha"
@@ -283,6 +324,7 @@ coreChatOptsP appDir defaultDbName = do
         tbqSize,
         deviceName,
         chatRelay,
+        webPreviewConfig,
         highlyAvailable,
         yesToUpMigrations,
         migrationBackupPath,