12 files changed, 303 insertions, 1 deletions
diff --git a/lib/pleroma/chat.ex b/lib/pleroma/chat.ex
new file mode 100644
index 000000000..b61bc4c0e
--- /dev/null
+++ b/lib/pleroma/chat.ex
@@ -0,0 +1,46 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Chat do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  alias Pleroma.User
+  alias Pleroma.Repo
+
+  @moduledoc """
+  Chat keeps a reference to ChatMessage conversations between a user and an recipient. The recipient can be a user (for now) or a group (not implemented yet).
+
+  It is a helper only, to make it easy to display a list of chats with other people, ordered by last bump. The actual messages are retrieved by querying the recipients of the ChatMessages.
+  """
+
+  schema "chats" do
+    belongs_to(:user, User, type: FlakeId.Ecto.CompatType)
+    field(:recipient, :string)
+    field(:unread, :integer, default: 0, read_after_writes: true)
+
+    timestamps()
+  end
+
+  def creation_cng(struct, params) do
+    struct
+    |> cast(params, [:user_id, :recipient, :unread])
+    |> validate_required([:user_id, :recipient])
+    |> unique_constraint(:user_id, name: :chats_user_id_recipient_index)
+  end
+
+  def get(user_id, recipient) do
+    __MODULE__
+    |> Repo.get_by(user_id: user_id, recipient: recipient)
+  end
+
+  def bump_or_create(user_id, recipient) do
+    %__MODULE__{}
+    |> creation_cng(%{user_id: user_id, recipient: recipient, unread: 1})
+    |> Repo.insert(
+      on_conflict: [set: [updated_at: NaiveDateTime.utc_now()], inc: [unread: 1]],
+      conflict_target: [:user_id, :recipient]
+    )
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/activity_pub.ex b/lib/pleroma/web/activity_pub/activity_pub.ex
index 19286fd01..0b4892501 100644
--- a/lib/pleroma/web/activity_pub/activity_pub.ex
+++ b/lib/pleroma/web/activity_pub/activity_pub.ex
@@ -397,6 +397,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     end
   end
 
+  # TODO: Is this even used now?
   # TODO: This is weird, maybe we shouldn't check here if we can make the activity.
   @spec like(User.t(), Object.t(), String.t() | nil, boolean()) ::
           {:ok, Activity.t(), Object.t()} | {:error, any()}
diff --git a/lib/pleroma/web/activity_pub/builder.ex b/lib/pleroma/web/activity_pub/builder.ex
index 429a510b8..f0a6c1e1b 100644
--- a/lib/pleroma/web/activity_pub/builder.ex
+++ b/lib/pleroma/web/activity_pub/builder.ex
@@ -10,6 +10,28 @@ defmodule Pleroma.Web.ActivityPub.Builder do
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.ActivityPub.Visibility
 
+  def create(actor, object_id, recipients) do
+    {:ok,
+     %{
+       "id" => Utils.generate_activity_id(),
+       "actor" => actor.ap_id,
+       "to" => recipients,
+       "object" => object_id,
+       "type" => "Create"
+     }, []}
+  end
+
+  def chat_message(actor, recipient, content) do
+    {:ok,
+     %{
+       "id" => Utils.generate_object_id(),
+       "actor" => actor.ap_id,
+       "type" => "ChatMessage",
+       "to" => [recipient],
+       "content" => content
+     }, []}
+  end
+
   @spec like(User.t(), Object.t()) :: {:ok, map(), keyword()}
   def like(actor, object) do
     object_actor = User.get_cached_by_ap_id(object.data["actor"])
diff --git a/lib/pleroma/web/activity_pub/object_validator.ex b/lib/pleroma/web/activity_pub/object_validator.ex
index dc4bce059..49cc72561 100644
--- a/lib/pleroma/web/activity_pub/object_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validator.ex
@@ -12,18 +12,46 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidator do
   alias Pleroma.Object
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator
 
   @spec validate(map(), keyword()) :: {:ok, map(), keyword()} | {:error, any()}
   def validate(object, meta)
 
   def validate(%{"type" => "Like"} = object, meta) do
     with {:ok, object} <-
-           object |> LikeValidator.cast_and_validate() |> Ecto.Changeset.apply_action(:insert) do
+           object
+           |> LikeValidator.cast_and_validate()
+           |> Ecto.Changeset.apply_action(:insert) do
       object = stringify_keys(object |> Map.from_struct())
       {:ok, object, meta}
     end
   end
 
+  def validate(%{"type" => "ChatMessage"} = object, meta) do
+    with {:ok, object} <-
+           object
+           |> ChatMessageValidator.cast_and_apply() do
+      object = stringify_keys(object)
+      {:ok, object, meta}
+    end
+  end
+
+  def validate(%{"type" => "Create"} = object, meta) do
+    with {:ok, object} <-
+           object
+           |> CreateChatMessageValidator.cast_and_apply() do
+      object = stringify_keys(object)
+      {:ok, object, meta}
+    end
+  end
+
+  def stringify_keys(%{__struct__: _} = object) do
+    object
+    |> Map.from_struct()
+    |> stringify_keys
+  end
+
   def stringify_keys(object) do
     object
     |> Map.new(fn {key, val} -> {to_string(key), val} end)
diff --git a/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex b/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex
new file mode 100644
index 000000000..ab5be3596
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/chat_message_validator.ex
@@ -0,0 +1,58 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator do
+  use Ecto.Schema
+
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+
+  import Ecto.Changeset
+
+  @primary_key false
+  @derive Jason.Encoder
+
+  embedded_schema do
+    field(:id, Types.ObjectID, primary_key: true)
+    field(:to, Types.Recipients, default: [])
+    field(:type, :string)
+    field(:content, :string)
+    field(:actor, Types.ObjectID)
+    field(:published, Types.DateTime)
+  end
+
+  def cast_and_apply(data) do
+    data
+    |> cast_data
+    |> apply_action(:insert)
+  end
+
+  def cast_and_validate(data) do
+    data
+    |> cast_data()
+    |> validate_data()
+  end
+
+  def cast_data(data) do
+    %__MODULE__{}
+    |> changeset(data)
+  end
+
+  def fix(data) do
+    data
+    |> Map.put_new("actor", data["attributedTo"])
+  end
+
+  def changeset(struct, data) do
+    data = fix(data)
+
+    struct
+    |> cast(data, __schema__(:fields))
+  end
+
+  def validate_data(data_cng) do
+    data_cng
+    |> validate_inclusion(:type, ["ChatMessage"])
+    |> validate_required([:id, :actor, :to, :type, :content])
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex b/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex
new file mode 100644
index 000000000..659311480
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/create_chat_message_validator.ex
@@ -0,0 +1,35 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+# NOTES
+# - Can probably be a generic create validator
+# - doesn't embed, will only get the object id
+# - object has to be validated first, maybe with some meta info from the surrounding create
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator do
+  use Ecto.Schema
+
+  alias Pleroma.Web.ActivityPub.ObjectValidators.Types
+
+  import Ecto.Changeset
+
+  @primary_key false
+
+  embedded_schema do
+    field(:id, Types.ObjectID, primary_key: true)
+    field(:actor, Types.ObjectID)
+    field(:type, :string)
+    field(:to, Types.Recipients, default: [])
+    field(:object, Types.ObjectID)
+  end
+
+  def cast_and_apply(data) do
+    data
+    |> cast_data
+    |> apply_action(:insert)
+  end
+
+  def cast_data(data) do
+    cast(%__MODULE__{}, data, __schema__(:fields))
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/object_validators/create_validator.ex b/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex
index 926804ce7..926804ce7 100644
--- a/lib/pleroma/web/activity_pub/object_validators/create_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex
diff --git a/lib/pleroma/web/activity_pub/object_validators/types/recipients.ex b/lib/pleroma/web/activity_pub/object_validators/types/recipients.ex
new file mode 100644
index 000000000..5a3040842
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/object_validators/types/recipients.ex
@@ -0,0 +1,23 @@
+defmodule Pleroma.Web.ActivityPub.ObjectValidators.Types.Recipients do
+  use Ecto.Type
+
+  def type, do: {:array, :string}
+
+  def cast(object) when is_binary(object) do
+    cast([object])
+  end
+
+  def cast([_ | _] = data), do: {:ok, data}
+
+  def cast(_) do
+    :error
+  end
+
+  def dump(data) do
+    {:ok, data}
+  end
+
+  def load(data) do
+    {:ok, data}
+  end
+end
diff --git a/lib/pleroma/web/activity_pub/side_effects.ex b/lib/pleroma/web/activity_pub/side_effects.ex
index 666a4e310..594f32700 100644
--- a/lib/pleroma/web/activity_pub/side_effects.ex
+++ b/lib/pleroma/web/activity_pub/side_effects.ex
@@ -5,8 +5,10 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
   liked object, a `Follow` activity will add the user to the follower
   collection, and so on.
   """
+  alias Pleroma.Chat
   alias Pleroma.Notification
   alias Pleroma.Object
+  alias Pleroma.User
   alias Pleroma.Web.ActivityPub.Utils
 
   def handle(object, meta \\ [])
@@ -21,8 +23,35 @@ defmodule Pleroma.Web.ActivityPub.SideEffects do
     {:ok, object, meta}
   end
 
+  def handle(%{data: %{"type" => "Create", "object" => object_id}} = activity, meta) do
+    object = Object.get_by_ap_id(object_id)
+
+    {:ok, _object} = handle_object_creation(object)
+
+    {:ok, activity, meta}
+  end
+
   # Nothing to do
   def handle(object, meta) do
     {:ok, object, meta}
   end
+
+  def handle_object_creation(%{data: %{"type" => "ChatMessage"}} = object) do
+    actor = User.get_cached_by_ap_id(object.data["actor"])
+    recipient = User.get_cached_by_ap_id(hd(object.data["to"]))
+
+    [[actor, recipient], [recipient, actor]]
+    |> Enum.each(fn [user, other_user] ->
+      if user.local do
+        Chat.bump_or_create(user.id, other_user.ap_id)
+      end
+    end)
+
+    {:ok, object}
+  end
+
+  # Nothing to do
+  def handle_object_creation(object) do
+    {:ok, object}
+  end
 end
diff --git a/lib/pleroma/web/activity_pub/transmogrifier.ex b/lib/pleroma/web/activity_pub/transmogrifier.ex
index 0a8ad62ad..becc35ea3 100644
--- a/lib/pleroma/web/activity_pub/transmogrifier.ex
+++ b/lib/pleroma/web/activity_pub/transmogrifier.ex
@@ -16,6 +16,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
   alias Pleroma.Web.ActivityPub.ObjectValidator
   alias Pleroma.Web.ActivityPub.ObjectValidators.LikeValidator
   alias Pleroma.Web.ActivityPub.Pipeline
+  alias Pleroma.Web.ActivityPub.Transmogrifier.ChatMessageHandling
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.ActivityPub.Visibility
   alias Pleroma.Web.Federator
@@ -612,6 +613,12 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
     |> handle_incoming(options)
   end
 
+  def handle_incoming(
+        %{"type" => "Create", "object" => %{"type" => "ChatMessage"}} = data,
+        options
+      ),
+      do: ChatMessageHandling.handle_incoming(data, options)
+
   def handle_incoming(%{"type" => "Like"} = data, _options) do
     with {_, {:ok, cast_data_sym}} <-
            {:casting_data,
diff --git a/lib/pleroma/web/activity_pub/transmogrifier/chat_message_handling.ex b/lib/pleroma/web/activity_pub/transmogrifier/chat_message_handling.ex
new file mode 100644
index 000000000..b5843736f
--- /dev/null
+++ b/lib/pleroma/web/activity_pub/transmogrifier/chat_message_handling.ex
@@ -0,0 +1,30 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.ActivityPub.Transmogrifier.ChatMessageHandling do
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.ObjectValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.ChatMessageValidator
+  alias Pleroma.Web.ActivityPub.ObjectValidators.CreateChatMessageValidator
+  alias Pleroma.Web.ActivityPub.Pipeline
+
+  def handle_incoming(
+        %{"type" => "Create", "object" => %{"type" => "ChatMessage"} = object_data} = data,
+        _options
+      ) do
+    with {_, {:ok, cast_data_sym}} <-
+           {:casting_data, data |> CreateChatMessageValidator.cast_and_apply()},
+         cast_data = ObjectValidator.stringify_keys(cast_data_sym),
+         {_, {:ok, object_cast_data_sym}} <-
+           {:casting_object_data, object_data |> ChatMessageValidator.cast_and_apply()},
+         object_cast_data = ObjectValidator.stringify_keys(object_cast_data_sym),
+         {_, {:ok, validated_object, _meta}} <-
+           {:validate_object, ObjectValidator.validate(object_cast_data, %{})},
+         {_, {:ok, _created_object}} <- {:persist_object, Object.create(validated_object)},
+         {_, {:ok, activity, _meta}} <-
+           {:common_pipeline, Pipeline.common_pipeline(cast_data, local: false)} do
+      {:ok, activity}
+    end
+  end
+end
diff --git a/lib/pleroma/web/common_api/common_api.ex b/lib/pleroma/web/common_api/common_api.ex
index 636cf3301..39e15adbf 100644
--- a/lib/pleroma/web/common_api/common_api.ex
+++ b/lib/pleroma/web/common_api/common_api.ex
@@ -8,6 +8,7 @@ defmodule Pleroma.Web.CommonAPI do
   alias Pleroma.Conversation.Participation
   alias Pleroma.FollowingRelationship
   alias Pleroma.Object
+  alias Pleroma.Repo
   alias Pleroma.ThreadMute
   alias Pleroma.User
   alias Pleroma.UserRelationship
@@ -23,6 +24,28 @@ defmodule Pleroma.Web.CommonAPI do
   require Pleroma.Constants
   require Logger
 
+  def post_chat_message(user, recipient, content) do
+    transaction =
+      Repo.transaction(fn ->
+        with {_, {:ok, chat_message_data, _meta}} <-
+               {:build_object, Builder.chat_message(user, recipient.ap_id, content)},
+             {_, {:ok, chat_message_object}} <-
+               {:create_object, Object.create(chat_message_data)},
+             {_, {:ok, create_activity_data, _meta}} <-
+               {:build_create_activity,
+                Builder.create(user, chat_message_object.data["id"], [recipient.ap_id])},
+             {_, {:ok, %Activity{} = activity, _meta}} <-
+               {:common_pipeline, Pipeline.common_pipeline(create_activity_data, local: true)} do
+          {:ok, activity}
+        end
+      end)
+
+    case transaction do
+      {:ok, value} -> value
+      error -> error
+    end
+  end
+
   def follow(follower, followed) do
     timeout = Pleroma.Config.get([:activitypub, :follow_handshake_timeout])