Merge develop

lib/pleroma/web/pleroma_api/controllers/emoji_api_controller.ex

@@ -0,0 +1,617 @@
+defmodule Pleroma.Web.PleromaAPI.EmojiAPIController do
+  use Pleroma.Web, :controller
+
+  require Logger
+
+  def emoji_dir_path do
+    Path.join(
+      Pleroma.Config.get!([:instance, :static_dir]),
+      "emoji"
+    )
+  end
+
+  @doc """
+  Lists packs from the remote instance.
+
+  Since JS cannot ask remote instances for their packs due to CPS, it has to
+  be done by the server
+  """
+  def list_from(conn, %{"instance_address" => address}) do
+    address = String.trim(address)
+
+    if shareable_packs_available(address) do
+      list_resp =
+        "#{address}/api/pleroma/emoji/packs" |> Tesla.get!() |> Map.get(:body) |> Jason.decode!()
+
+      json(conn, list_resp)
+    else
+      conn
+      |> put_status(:internal_server_error)
+      |> json(%{error: "The requested instance does not support sharing emoji packs"})
+    end
+  end
+
+  @doc """
+  Lists the packs available on the instance as JSON.
+
+  The information is public and does not require authentification. The format is
+  a map of "pack directory name" to pack.json contents.
+  """
+  def list_packs(conn, _params) do
+    # Create the directory first if it does not exist. This is probably the first request made
+    # with the API so it should be sufficient
+    with {:create_dir, :ok} <- {:create_dir, File.mkdir_p(emoji_dir_path())},
+         {:ls, {:ok, results}} <- {:ls, File.ls(emoji_dir_path())} do
+      pack_infos =
+        results
+        |> Enum.filter(&has_pack_json?/1)
+        |> Enum.map(&load_pack/1)
+        # Check if all the files are in place and can be sent
+        |> Enum.map(&validate_pack/1)
+        # Transform into a map of pack-name => pack-data
+        |> Enum.into(%{})
+
+      json(conn, pack_infos)
+    else
+      {:create_dir, {:error, e}} ->
+        conn
+        |> put_status(:internal_server_error)
+        |> json(%{error: "Failed to create the emoji pack directory at #{emoji_dir_path()}: #{e}"})
+
+      {:ls, {:error, e}} ->
+        conn
+        |> put_status(:internal_server_error)
+        |> json(%{
+          error:
+            "Failed to get the contents of the emoji pack directory at #{emoji_dir_path()}: #{e}"
+        })
+    end
+  end
+
+  defp has_pack_json?(file) do
+    dir_path = Path.join(emoji_dir_path(), file)
+    # Filter to only use the pack.json packs
+    File.dir?(dir_path) and File.exists?(Path.join(dir_path, "pack.json"))
+  end
+
+  defp load_pack(pack_name) do
+    pack_path = Path.join(emoji_dir_path(), pack_name)
+    pack_file = Path.join(pack_path, "pack.json")
+
+    {pack_name, Jason.decode!(File.read!(pack_file))}
+  end
+
+  defp validate_pack({name, pack}) do
+    pack_path = Path.join(emoji_dir_path(), name)
+
+    if can_download?(pack, pack_path) do
+      archive_for_sha = make_archive(name, pack, pack_path)
+      archive_sha = :crypto.hash(:sha256, archive_for_sha) |> Base.encode16()
+
+      pack =
+        pack
+        |> put_in(["pack", "can-download"], true)
+        |> put_in(["pack", "download-sha256"], archive_sha)
+
+      {name, pack}
+    else
+      {name, put_in(pack, ["pack", "can-download"], false)}
+    end
+  end
+
+  defp can_download?(pack, pack_path) do
+    # If the pack is set as shared, check if it can be downloaded
+    # That means that when asked, the pack can be packed and sent to the remote
+    # Otherwise, they'd have to download it from external-src
+    pack["pack"]["share-files"] &&
+      Enum.all?(pack["files"], fn {_, path} ->
+        File.exists?(Path.join(pack_path, path))
+      end)
+  end
+
+  defp create_archive_and_cache(name, pack, pack_dir, md5) do
+    files =
+      ['pack.json'] ++
+        (pack["files"] |> Enum.map(fn {_, path} -> to_charlist(path) end))
+
+    {:ok, {_, zip_result}} = :zip.zip('#{name}.zip', files, [:memory, cwd: to_charlist(pack_dir)])
+
+    cache_seconds_per_file = Pleroma.Config.get!([:emoji, :shared_pack_cache_seconds_per_file])
+    cache_ms = :timer.seconds(cache_seconds_per_file * Enum.count(files))
+
+    Cachex.put!(
+      :emoji_packs_cache,
+      name,
+      # if pack.json MD5 changes, the cache is not valid anymore
+      %{pack_json_md5: md5, pack_data: zip_result},
+      # Add a minute to cache time for every file in the pack
+      ttl: cache_ms
+    )
+
+    Logger.debug("Created an archive for the '#{name}' emoji pack, \
+keeping it in cache for #{div(cache_ms, 1000)}s")
+
+    zip_result
+  end
+
+  defp make_archive(name, pack, pack_dir) do
+    # Having a different pack.json md5 invalidates cache
+    pack_file_md5 = :crypto.hash(:md5, File.read!(Path.join(pack_dir, "pack.json")))
+
+    case Cachex.get!(:emoji_packs_cache, name) do
+      %{pack_file_md5: ^pack_file_md5, pack_data: zip_result} ->
+        Logger.debug("Using cache for the '#{name}' shared emoji pack")
+        zip_result
+
+      _ ->
+        create_archive_and_cache(name, pack, pack_dir, pack_file_md5)
+    end
+  end
+
+  @doc """
+  An endpoint for other instances (via admin UI) or users (via browser)
+  to download packs that the instance shares.
+  """
+  def download_shared(conn, %{"name" => name}) do
+    pack_dir = Path.join(emoji_dir_path(), name)
+    pack_file = Path.join(pack_dir, "pack.json")
+
+    with {_, true} <- {:exists?, File.exists?(pack_file)},
+         pack = Jason.decode!(File.read!(pack_file)),
+         {_, true} <- {:can_download?, can_download?(pack, pack_dir)} do
+      zip_result = make_archive(name, pack, pack_dir)
+      send_download(conn, {:binary, zip_result}, filename: "#{name}.zip")
+    else
+      {:can_download?, _} ->
+        conn
+        |> put_status(:forbidden)
+        |> json(%{
+          error: "Pack #{name} cannot be downloaded from this instance, either pack sharing\
+           was disabled for this pack or some files are missing"
+        })
+
+      {:exists?, _} ->
+        conn
+        |> put_status(:not_found)
+        |> json(%{error: "Pack #{name} does not exist"})
+    end
+  end
+
+  defp shareable_packs_available(address) do
+    "#{address}/.well-known/nodeinfo"
+    |> Tesla.get!()
+    |> Map.get(:body)
+    |> Jason.decode!()
+    |> Map.get("links")
+    |> List.last()
+    |> Map.get("href")
+    # Get the actual nodeinfo address and fetch it
+    |> Tesla.get!()
+    |> Map.get(:body)
+    |> Jason.decode!()
+    |> get_in(["metadata", "features"])
+    |> Enum.member?("shareable_emoji_packs")
+  end
+
+  @doc """
+  An admin endpoint to request downloading a pack named `pack_name` from the instance
+  `instance_address`.
+
+  If the requested instance's admin chose to share the pack, it will be downloaded
+  from that instance, otherwise it will be downloaded from the fallback source, if there is one.
+  """
+  def download_from(conn, %{"instance_address" => address, "pack_name" => name} = data) do
+    address = String.trim(address)
+
+    if shareable_packs_available(address) do
+      full_pack =
+        "#{address}/api/pleroma/emoji/packs/list"
+        |> Tesla.get!()
+        |> Map.get(:body)
+        |> Jason.decode!()
+        |> Map.get(name)
+
+      pack_info_res =
+        case full_pack["pack"] do
+          %{"share-files" => true, "can-download" => true, "download-sha256" => sha} ->
+            {:ok,
+             %{
+               sha: sha,
+               uri: "#{address}/api/pleroma/emoji/packs/download_shared/#{name}"
+             }}
+
+          %{"fallback-src" => src, "fallback-src-sha256" => sha} when is_binary(src) ->
+            {:ok,
+             %{
+               sha: sha,
+               uri: src,
+               fallback: true
+             }}
+
+          _ ->
+            {:error,
+             "The pack was not set as shared and there is no fallback src to download from"}
+        end
+
+      with {:ok, %{sha: sha, uri: uri} = pinfo} <- pack_info_res,
+           %{body: emoji_archive} <- Tesla.get!(uri),
+           {_, true} <- {:checksum, Base.decode16!(sha) == :crypto.hash(:sha256, emoji_archive)} do
+        local_name = data["as"] || name
+        pack_dir = Path.join(emoji_dir_path(), local_name)
+        File.mkdir_p!(pack_dir)
+
+        files = Enum.map(full_pack["files"], fn {_, path} -> to_charlist(path) end)
+        # Fallback cannot contain a pack.json file
+        files = if pinfo[:fallback], do: files, else: ['pack.json'] ++ files
+
+        {:ok, _} = :zip.unzip(emoji_archive, cwd: to_charlist(pack_dir), file_list: files)
+
+        # Fallback can't contain a pack.json file, since that would cause the fallback-src-sha256
+        # in it to depend on itself
+        if pinfo[:fallback] do
+          pack_file_path = Path.join(pack_dir, "pack.json")
+
+          File.write!(pack_file_path, Jason.encode!(full_pack, pretty: true))
+        end
+
+        json(conn, "ok")
+      else
+        {:error, e} ->
+          conn |> put_status(:internal_server_error) |> json(%{error: e})
+
+        {:checksum, _} ->
+          conn
+          |> put_status(:internal_server_error)
+          |> json(%{error: "SHA256 for the pack doesn't match the one sent by the server"})
+      end
+    else
+      conn
+      |> put_status(:internal_server_error)
+      |> json(%{error: "The requested instance does not support sharing emoji packs"})
+    end
+  end
+
+  @doc """
+  Creates an empty pack named `name` which then can be updated via the admin UI.
+  """
+  def create(conn, %{"name" => name}) do
+    pack_dir = Path.join(emoji_dir_path(), name)
+
+    if not File.exists?(pack_dir) do
+      File.mkdir_p!(pack_dir)
+
+      pack_file_p = Path.join(pack_dir, "pack.json")
+
+      File.write!(
+        pack_file_p,
+        Jason.encode!(%{pack: %{}, files: %{}}, pretty: true)
+      )
+
+      conn |> json("ok")
+    else
+      conn
+      |> put_status(:conflict)
+      |> json(%{error: "A pack named \"#{name}\" already exists"})
+    end
+  end
+
+  @doc """
+  Deletes the pack `name` and all it's files.
+  """
+  def delete(conn, %{"name" => name}) do
+    pack_dir = Path.join(emoji_dir_path(), name)
+
+    case File.rm_rf(pack_dir) do
+      {:ok, _} ->
+        conn |> json("ok")
+
+      {:error, _} ->
+        conn
+        |> put_status(:internal_server_error)
+        |> json(%{error: "Couldn't delete the pack #{name}"})
+    end
+  end
+
+  @doc """
+  An endpoint to update `pack_names`'s metadata.
+
+  `new_data` is the new metadata for the pack, that will replace the old metadata.
+  """
+  def update_metadata(conn, %{"pack_name" => name, "new_data" => new_data}) do
+    pack_file_p = Path.join([emoji_dir_path(), name, "pack.json"])
+
+    full_pack = Jason.decode!(File.read!(pack_file_p))
+
+    # The new fallback-src is in the new data and it's not the same as it was in the old data
+    should_update_fb_sha =
+      not is_nil(new_data["fallback-src"]) and
+        new_data["fallback-src"] != full_pack["pack"]["fallback-src"]
+
+    with {_, true} <- {:should_update?, should_update_fb_sha},
+         %{body: pack_arch} <- Tesla.get!(new_data["fallback-src"]),
+         {:ok, flist} <- :zip.unzip(pack_arch, [:memory]),
+         {_, true} <- {:has_all_files?, has_all_files?(full_pack, flist)} do
+      fallback_sha = :crypto.hash(:sha256, pack_arch) |> Base.encode16()
+
+      new_data = Map.put(new_data, "fallback-src-sha256", fallback_sha)
+      update_metadata_and_send(conn, full_pack, new_data, pack_file_p)
+    else
+      {:should_update?, _} ->
+        update_metadata_and_send(conn, full_pack, new_data, pack_file_p)
+
+      {:has_all_files?, _} ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "The fallback archive does not have all files specified in pack.json"})
+    end
+  end
+
+  # Check if all files from the pack.json are in the archive
+  defp has_all_files?(%{"files" => files}, flist) do
+    Enum.all?(files, fn {_, from_manifest} ->
+      Enum.find(flist, fn {from_archive, _} ->
+        to_string(from_archive) == from_manifest
+      end)
+    end)
+  end
+
+  defp update_metadata_and_send(conn, full_pack, new_data, pack_file_p) do
+    full_pack = Map.put(full_pack, "pack", new_data)
+    File.write!(pack_file_p, Jason.encode!(full_pack, pretty: true))
+
+    # Send new data back with fallback sha filled
+    json(conn, new_data)
+  end
+
+  defp get_filename(%{"filename" => filename}), do: filename
+
+  defp get_filename(%{"file" => file}) do
+    case file do
+      %Plug.Upload{filename: filename} -> filename
+      url when is_binary(url) -> Path.basename(url)
+    end
+  end
+
+  defp empty?(str), do: String.trim(str) == ""
+
+  defp update_file_and_send(conn, updated_full_pack, pack_file_p) do
+    # Write the emoji pack file
+    File.write!(pack_file_p, Jason.encode!(updated_full_pack, pretty: true))
+
+    # Return the modified file list
+    json(conn, updated_full_pack["files"])
+  end
+
+  @doc """
+  Updates a file in a pack.
+
+  Updating can mean three things:
+
+  - `add` adds an emoji named `shortcode` to the pack `pack_name`,
+    that means that the emoji file needs to be uploaded with the request
+    (thus requiring it to be a multipart request) and be named `file`.
+    There can also be an optional `filename` that will be the new emoji file name
+    (if it's not there, the name will be taken from the uploaded file).
+  - `update` changes emoji shortcode (from `shortcode` to `new_shortcode` or moves the file
+    (from the current filename to `new_filename`)
+  - `remove` removes the emoji named `shortcode` and it's associated file
+  """
+
+  # Add
+  def update_file(
+        conn,
+        %{"pack_name" => pack_name, "action" => "add", "shortcode" => shortcode} = params
+      ) do
+    pack_dir = Path.join(emoji_dir_path(), pack_name)
+    pack_file_p = Path.join(pack_dir, "pack.json")
+
+    full_pack = Jason.decode!(File.read!(pack_file_p))
+
+    with {_, false} <- {:has_shortcode, Map.has_key?(full_pack["files"], shortcode)},
+         filename <- get_filename(params),
+         false <- empty?(shortcode),
+         false <- empty?(filename) do
+      file_path = Path.join(pack_dir, filename)
+
+      # If the name contains directories, create them
+      if String.contains?(file_path, "/") do
+        File.mkdir_p!(Path.dirname(file_path))
+      end
+
+      case params["file"] do
+        %Plug.Upload{path: upload_path} ->
+          # Copy the uploaded file from the temporary directory
+          File.copy!(upload_path, file_path)
+
+        url when is_binary(url) ->
+          # Download and write the file
+          file_contents = Tesla.get!(url).body
+          File.write!(file_path, file_contents)
+      end
+
+      updated_full_pack = put_in(full_pack, ["files", shortcode], filename)
+      update_file_and_send(conn, updated_full_pack, pack_file_p)
+    else
+      {:has_shortcode, _} ->
+        conn
+        |> put_status(:conflict)
+        |> json(%{error: "An emoji with the \"#{shortcode}\" shortcode already exists"})
+
+      true ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "shortcode or filename cannot be empty"})
+    end
+  end
+
+  # Remove
+  def update_file(conn, %{
+        "pack_name" => pack_name,
+        "action" => "remove",
+        "shortcode" => shortcode
+      }) do
+    pack_dir = Path.join(emoji_dir_path(), pack_name)
+    pack_file_p = Path.join(pack_dir, "pack.json")
+
+    full_pack = Jason.decode!(File.read!(pack_file_p))
+
+    if Map.has_key?(full_pack["files"], shortcode) do
+      {emoji_file_path, updated_full_pack} = pop_in(full_pack, ["files", shortcode])
+
+      emoji_file_path = Path.join(pack_dir, emoji_file_path)
+
+      # Delete the emoji file
+      File.rm!(emoji_file_path)
+
+      # If the old directory has no more files, remove it
+      if String.contains?(emoji_file_path, "/") do
+        dir = Path.dirname(emoji_file_path)
+
+        if Enum.empty?(File.ls!(dir)) do
+          File.rmdir!(dir)
+        end
+      end
+
+      update_file_and_send(conn, updated_full_pack, pack_file_p)
+    else
+      conn
+      |> put_status(:bad_request)
+      |> json(%{error: "Emoji \"#{shortcode}\" does not exist"})
+    end
+  end
+
+  # Update
+  def update_file(
+        conn,
+        %{"pack_name" => pack_name, "action" => "update", "shortcode" => shortcode} = params
+      ) do
+    pack_dir = Path.join(emoji_dir_path(), pack_name)
+    pack_file_p = Path.join(pack_dir, "pack.json")
+
+    full_pack = Jason.decode!(File.read!(pack_file_p))
+
+    with {_, true} <- {:has_shortcode, Map.has_key?(full_pack["files"], shortcode)},
+         %{"new_shortcode" => new_shortcode, "new_filename" => new_filename} <- params,
+         false <- empty?(new_shortcode),
+         false <- empty?(new_filename) do
+      # First, remove the old shortcode, saving the old path
+      {old_emoji_file_path, updated_full_pack} = pop_in(full_pack, ["files", shortcode])
+      old_emoji_file_path = Path.join(pack_dir, old_emoji_file_path)
+      new_emoji_file_path = Path.join(pack_dir, new_filename)
+
+      # If the name contains directories, create them
+      if String.contains?(new_emoji_file_path, "/") do
+        File.mkdir_p!(Path.dirname(new_emoji_file_path))
+      end
+
+      # Move/Rename the old filename to a new filename
+      # These are probably on the same filesystem, so just rename should work
+      :ok = File.rename(old_emoji_file_path, new_emoji_file_path)
+
+      # If the old directory has no more files, remove it
+      if String.contains?(old_emoji_file_path, "/") do
+        dir = Path.dirname(old_emoji_file_path)
+
+        if Enum.empty?(File.ls!(dir)) do
+          File.rmdir!(dir)
+        end
+      end
+
+      # Then, put in the new shortcode with the new path
+      updated_full_pack = put_in(updated_full_pack, ["files", new_shortcode], new_filename)
+      update_file_and_send(conn, updated_full_pack, pack_file_p)
+    else
+      {:has_shortcode, _} ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "Emoji \"#{shortcode}\" does not exist"})
+
+      true ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "new_shortcode or new_filename cannot be empty"})
+
+      _ ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: "new_shortcode or new_file were not specified"})
+    end
+  end
+
+  def update_file(conn, %{"action" => action}) do
+    conn
+    |> put_status(:bad_request)
+    |> json(%{error: "Unknown action: #{action}"})
+  end
+
+  @doc """
+  Imports emoji from the filesystem.
+
+  Importing means checking all the directories in the
+  `$instance_static/emoji/` for directories which do not have
+  `pack.json`. If one has an emoji.txt file, that file will be used
+  to create a `pack.json` file with it's contents. If the directory has
+  neither, all the files with specific configured extenstions will be
+  assumed to be emojis and stored in the new `pack.json` file.
+  """
+  def import_from_fs(conn, _params) do
+    with {:ok, results} <- File.ls(emoji_dir_path()) do
+      imported_pack_names =
+        results
+        |> Enum.filter(fn file ->
+          dir_path = Path.join(emoji_dir_path(), file)
+          # Find the directories that do NOT have pack.json
+          File.dir?(dir_path) and not File.exists?(Path.join(dir_path, "pack.json"))
+        end)
+        |> Enum.map(&write_pack_json_contents/1)
+
+      json(conn, imported_pack_names)
+    else
+      {:error, _} ->
+        conn
+        |> put_status(:internal_server_error)
+        |> json(%{error: "Error accessing emoji pack directory"})
+    end
+  end
+
+  defp write_pack_json_contents(dir) do
+    dir_path = Path.join(emoji_dir_path(), dir)
+    emoji_txt_path = Path.join(dir_path, "emoji.txt")
+
+    files_for_pack = files_for_pack(emoji_txt_path, dir_path)
+    pack_json_contents = Jason.encode!(%{pack: %{}, files: files_for_pack})
+
+    File.write!(Path.join(dir_path, "pack.json"), pack_json_contents)
+
+    dir
+  end
+
+  defp files_for_pack(emoji_txt_path, dir_path) do
+    if File.exists?(emoji_txt_path) do
+      # There's an emoji.txt file, it's likely from a pack installed by the pack manager.
+      # Make a pack.json file from the contents of that emoji.txt fileh
+
+      # FIXME: Copy-pasted from Pleroma.Emoji/load_from_file_stream/2
+
+      # Create a map of shortcodes to filenames from emoji.txt
+      File.read!(emoji_txt_path)
+      |> String.split("\n")
+      |> Enum.map(&String.trim/1)
+      |> Enum.map(fn line ->
+        case String.split(line, ~r/,\s*/) do
+          # This matches both strings with and without tags
+          # and we don't care about tags here
+          [name, file | _] -> {name, file}
+          _ -> nil
+        end
+      end)
+      |> Enum.filter(fn x -> not is_nil(x) end)
+      |> Enum.into(%{})
+    else
+      # If there's no emoji.txt, assume all files
+      # that are of certain extensions from the config are emojis and import them all
+      pack_extensions = Pleroma.Config.get!([:emoji, :pack_extensions])
+      Pleroma.Emoji.Loader.make_shortcode_to_file_map(dir_path, pack_extensions)
+    end
+  end
+end