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diff --git a/lib/pleroma/emoji/pack.ex b/lib/pleroma/emoji/pack.ex
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+++ b/lib/pleroma/emoji/pack.ex
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+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Emoji.Pack do
+  @derive {Jason.Encoder, only: [:files, :pack, :files_count]}
+  defstruct files: %{},
+            files_count: 0,
+            pack_file: nil,
+            path: nil,
+            pack: %{},
+            name: nil
+
+  @type t() :: %__MODULE__{
+          files: %{String.t() => Path.t()},
+          files_count: non_neg_integer(),
+          pack_file: Path.t(),
+          path: Path.t(),
+          pack: map(),
+          name: String.t()
+        }
+
+  @cachex Pleroma.Config.get([:cachex, :provider], Cachex)
+
+  alias Pleroma.Emoji
+  alias Pleroma.Emoji.Pack
+  alias Pleroma.Utils
+
+  @spec create(String.t()) :: {:ok, t()} | {:error, File.posix()} | {:error, :empty_values}
+  def create(name) do
+    with :ok <- validate_not_empty([name]),
+         dir <- Path.join(emoji_path(), name),
+         :ok <- File.mkdir(dir) do
+      save_pack(%__MODULE__{pack_file: Path.join(dir, "pack.json")})
+    end
+  end
+
+  defp paginate(entities, 1, page_size), do: Enum.take(entities, page_size)
+
+  defp paginate(entities, page, page_size) do
+    entities
+    |> Enum.chunk_every(page_size)
+    |> Enum.at(page - 1)
+  end
+
+  @spec show(keyword()) :: {:ok, t()} | {:error, atom()}
+  def show(opts) do
+    name = opts[:name]
+
+    with :ok <- validate_not_empty([name]),
+         {:ok, pack} <- load_pack(name) do
+      shortcodes =
+        pack.files
+        |> Map.keys()
+        |> Enum.sort()
+        |> paginate(opts[:page], opts[:page_size])
+
+      pack = Map.put(pack, :files, Map.take(pack.files, shortcodes))
+
+      {:ok, validate_pack(pack)}
+    end
+  end
+
+  @spec delete(String.t()) ::
+          {:ok, [binary()]} | {:error, File.posix(), binary()} | {:error, :empty_values}
+  def delete(name) do
+    with :ok <- validate_not_empty([name]),
+         pack_path <- Path.join(emoji_path(), name) do
+      File.rm_rf(pack_path)
+    end
+  end
+
+  @spec unpack_zip_emojies(list(tuple())) :: list(map())
+  defp unpack_zip_emojies(zip_files) do
+    Enum.reduce(zip_files, [], fn
+      {_, path, s, _, _, _}, acc when elem(s, 2) == :regular ->
+        with(
+          filename <- Path.basename(path),
+          shortcode <- Path.basename(filename, Path.extname(filename)),
+          false <- Emoji.exist?(shortcode)
+        ) do
+          [%{path: path, filename: path, shortcode: shortcode} | acc]
+        else
+          _ -> acc
+        end
+
+      _, acc ->
+        acc
+    end)
+  end
+
+  @spec add_file(t(), String.t(), Path.t(), Plug.Upload.t()) ::
+          {:ok, t()}
+          | {:error, File.posix() | atom()}
+  def add_file(%Pack{} = pack, _, _, %Plug.Upload{content_type: "application/zip"} = file) do
+    with {:ok, zip_files} <- :zip.table(to_charlist(file.path)),
+         [_ | _] = emojies <- unpack_zip_emojies(zip_files),
+         {:ok, tmp_dir} <- Utils.tmp_dir("emoji") do
+      try do
+        {:ok, _emoji_files} =
+          :zip.unzip(
+            to_charlist(file.path),
+            [{:file_list, Enum.map(emojies, & &1[:path])}, {:cwd, tmp_dir}]
+          )
+
+        {_, updated_pack} =
+          Enum.map_reduce(emojies, pack, fn item, emoji_pack ->
+            emoji_file = %Plug.Upload{
+              filename: item[:filename],
+              path: Path.join(tmp_dir, item[:path])
+            }
+
+            {:ok, updated_pack} =
+              do_add_file(
+                emoji_pack,
+                item[:shortcode],
+                to_string(item[:filename]),
+                emoji_file
+              )
+
+            {item, updated_pack}
+          end)
+
+        Emoji.reload()
+
+        {:ok, updated_pack}
+      after
+        File.rm_rf(tmp_dir)
+      end
+    else
+      {:error, _} = error ->
+        error
+
+      _ ->
+        {:ok, pack}
+    end
+  end
+
+  def add_file(%Pack{} = pack, shortcode, filename, %Plug.Upload{} = file) do
+    with :ok <- validate_not_empty([shortcode, filename]),
+         :ok <- validate_emoji_not_exists(shortcode),
+         {:ok, updated_pack} <- do_add_file(pack, shortcode, filename, file) do
+      Emoji.reload()
+      {:ok, updated_pack}
+    end
+  end
+
+  defp do_add_file(pack, shortcode, filename, file) do
+    with :ok <- save_file(file, pack, filename) do
+      pack
+      |> put_emoji(shortcode, filename)
+      |> save_pack()
+    end
+  end
+
+  @spec delete_file(t(), String.t()) ::
+          {:ok, t()} | {:error, File.posix() | atom()}
+  def delete_file(%Pack{} = pack, shortcode) do
+    with :ok <- validate_not_empty([shortcode]),
+         :ok <- remove_file(pack, shortcode),
+         {:ok, updated_pack} <- pack |> delete_emoji(shortcode) |> save_pack() do
+      Emoji.reload()
+      {:ok, updated_pack}
+    end
+  end
+
+  @spec update_file(t(), String.t(), String.t(), String.t(), boolean()) ::
+          {:ok, t()} | {:error, File.posix() | atom()}
+  def update_file(%Pack{} = pack, shortcode, new_shortcode, new_filename, force) do
+    with :ok <- validate_not_empty([shortcode, new_shortcode, new_filename]),
+         {:ok, filename} <- get_filename(pack, shortcode),
+         :ok <- validate_emoji_not_exists(new_shortcode, force),
+         :ok <- rename_file(pack, filename, new_filename),
+         {:ok, updated_pack} <-
+           pack
+           |> delete_emoji(shortcode)
+           |> put_emoji(new_shortcode, new_filename)
+           |> save_pack() do
+      Emoji.reload()
+      {:ok, updated_pack}
+    end
+  end
+
+  @spec import_from_filesystem() :: {:ok, [String.t()]} | {:error, File.posix() | atom()}
+  def import_from_filesystem do
+    emoji_path = emoji_path()
+
+    with {:ok, %{access: :read_write}} <- File.stat(emoji_path),
+         {:ok, results} <- File.ls(emoji_path) do
+      names =
+        results
+        |> Enum.map(&Path.join(emoji_path, &1))
+        |> Enum.reject(fn path ->
+          File.dir?(path) and File.exists?(Path.join(path, "pack.json"))
+        end)
+        |> Enum.map(&write_pack_contents/1)
+        |> Enum.reject(&is_nil/1)
+
+      {:ok, names}
+    else
+      {:ok, %{access: _}} -> {:error, :no_read_write}
+      e -> e
+    end
+  end
+
+  @spec list_remote(keyword()) :: {:ok, map()} | {:error, atom()}
+  def list_remote(opts) do
+    uri = opts[:url] |> String.trim() |> URI.parse()
+
+    with :ok <- validate_shareable_packs_available(uri) do
+      uri
+      |> URI.merge("/api/pleroma/emoji/packs?page=#{opts[:page]}&page_size=#{opts[:page_size]}")
+      |> http_get()
+    end
+  end
+
+  @spec list_local(keyword()) :: {:ok, map(), non_neg_integer()}
+  def list_local(opts) do
+    with {:ok, results} <- list_packs_dir() do
+      all_packs =
+        results
+        |> Enum.map(fn name ->
+          case load_pack(name) do
+            {:ok, pack} -> pack
+            _ -> nil
+          end
+        end)
+        |> Enum.reject(&is_nil/1)
+
+      packs =
+        all_packs
+        |> paginate(opts[:page], opts[:page_size])
+        |> Map.new(fn pack -> {pack.name, validate_pack(pack)} end)
+
+      {:ok, packs, length(all_packs)}
+    end
+  end
+
+  @spec get_archive(String.t()) :: {:ok, binary()} | {:error, atom()}
+  def get_archive(name) do
+    with {:ok, pack} <- load_pack(name),
+         :ok <- validate_downloadable(pack) do
+      {:ok, fetch_archive(pack)}
+    end
+  end
+
+  @spec download(String.t(), String.t(), String.t()) :: {:ok, t()} | {:error, atom()}
+  def download(name, url, as) do
+    uri = url |> String.trim() |> URI.parse()
+
+    with :ok <- validate_shareable_packs_available(uri),
+         {:ok, remote_pack} <-
+           uri |> URI.merge("/api/pleroma/emoji/pack?name=#{name}") |> http_get(),
+         {:ok, %{sha: sha, url: url} = pack_info} <- fetch_pack_info(remote_pack, uri, name),
+         {:ok, archive} <- download_archive(url, sha),
+         pack <- copy_as(remote_pack, as || name),
+         {:ok, _} = unzip(archive, pack_info, remote_pack, pack) do
+      # Fallback can't contain a pack.json file, since that would cause the fallback-src-sha256
+      # in it to depend on itself
+      if pack_info[:fallback] do
+        save_pack(pack)
+      else
+        {:ok, pack}
+      end
+    end
+  end
+
+  @spec save_metadata(map(), t()) :: {:ok, t()} | {:error, File.posix()}
+  def save_metadata(metadata, %__MODULE__{} = pack) do
+    pack
+    |> Map.put(:pack, metadata)
+    |> save_pack()
+  end
+
+  @spec update_metadata(String.t(), map()) :: {:ok, t()} | {:error, File.posix()}
+  def update_metadata(name, data) do
+    with {:ok, pack} <- load_pack(name) do
+      if fallback_sha_changed?(pack, data) do
+        update_sha_and_save_metadata(pack, data)
+      else
+        save_metadata(data, pack)
+      end
+    end
+  end
+
+  @spec load_pack(String.t()) :: {:ok, t()} | {:error, :file.posix()}
+  def load_pack(name) do
+    name = Path.basename(name)
+    pack_file = Path.join([emoji_path(), name, "pack.json"])
+
+    with {:ok, _} <- File.stat(pack_file),
+         {:ok, pack_data} <- File.read(pack_file) do
+      pack =
+        from_json(
+          pack_data,
+          %{
+            pack_file: pack_file,
+            path: Path.dirname(pack_file),
+            name: name
+          }
+        )
+
+      files_count =
+        pack.files
+        |> Map.keys()
+        |> length()
+
+      {:ok, Map.put(pack, :files_count, files_count)}
+    end
+  end
+
+  @spec emoji_path() :: Path.t()
+  defp emoji_path do
+    [:instance, :static_dir]
+    |> Pleroma.Config.get!()
+    |> Path.join("emoji")
+  end
+
+  defp validate_emoji_not_exists(shortcode, force \\ false)
+  defp validate_emoji_not_exists(_shortcode, true), do: :ok
+
+  defp validate_emoji_not_exists(shortcode, _) do
+    if Emoji.exist?(shortcode) do
+      {:error, :already_exists}
+    else
+      :ok
+    end
+  end
+
+  defp write_pack_contents(path) do
+    pack = %__MODULE__{
+      files: files_from_path(path),
+      path: path,
+      pack_file: Path.join(path, "pack.json")
+    }
+
+    case save_pack(pack) do
+      {:ok, _pack} -> Path.basename(path)
+      _ -> nil
+    end
+  end
+
+  defp files_from_path(path) do
+    txt_path = Path.join(path, "emoji.txt")
+
+    if File.exists?(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 file
+
+      # FIXME: Copy-pasted from Pleroma.Emoji/load_from_file_stream/2
+
+      # Create a map of shortcodes to filenames from emoji.txt
+      txt_path
+      |> File.read!()
+      |> 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 | _] ->
+            file_dir_name = Path.dirname(file)
+
+            if String.ends_with?(path, file_dir_name) do
+              {name, Path.basename(file)}
+            else
+              {name, file}
+            end
+
+          _ ->
+            nil
+        end
+      end)
+      |> Enum.reject(&is_nil/1)
+      |> Map.new()
+    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])
+      Emoji.Loader.make_shortcode_to_file_map(path, pack_extensions)
+    end
+  end
+
+  defp validate_pack(pack) do
+    info =
+      if downloadable?(pack) do
+        archive = fetch_archive(pack)
+        archive_sha = :crypto.hash(:sha256, archive) |> Base.encode16()
+
+        pack.pack
+        |> Map.put("can-download", true)
+        |> Map.put("download-sha256", archive_sha)
+      else
+        Map.put(pack.pack, "can-download", false)
+      end
+
+    Map.put(pack, :pack, info)
+  end
+
+  defp downloadable?(pack) 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 {_, file} ->
+        pack.path
+        |> Path.join(file)
+        |> File.exists?()
+      end)
+  end
+
+  defp create_archive_and_cache(pack, hash) do
+    files = ['pack.json' | Enum.map(pack.files, fn {_, file} -> to_charlist(file) end)]
+
+    {:ok, {_, result}} =
+      :zip.zip('#{pack.name}.zip', files, [:memory, cwd: to_charlist(pack.path)])
+
+    ttl_per_file = Pleroma.Config.get!([:emoji, :shared_pack_cache_seconds_per_file])
+    overall_ttl = :timer.seconds(ttl_per_file * Enum.count(files))
+
+    @cachex.put(
+      :emoji_packs_cache,
+      pack.name,
+      # if pack.json MD5 changes, the cache is not valid anymore
+      %{hash: hash, pack_data: result},
+      # Add a minute to cache time for every file in the pack
+      ttl: overall_ttl
+    )
+
+    result
+  end
+
+  defp save_pack(pack) do
+    with {:ok, json} <- Jason.encode(pack, pretty: true),
+         :ok <- File.write(pack.pack_file, json) do
+      {:ok, pack}
+    end
+  end
+
+  defp from_json(json, attrs) do
+    map = Jason.decode!(json)
+
+    pack_attrs =
+      attrs
+      |> Map.merge(%{
+        files: map["files"],
+        pack: map["pack"]
+      })
+
+    struct(__MODULE__, pack_attrs)
+  end
+
+  defp validate_shareable_packs_available(uri) do
+    with {:ok, %{"links" => links}} <- uri |> URI.merge("/.well-known/nodeinfo") |> http_get(),
+         # Get the actual nodeinfo address and fetch it
+         {:ok, %{"metadata" => %{"features" => features}}} <-
+           links |> List.last() |> Map.get("href") |> http_get() do
+      if Enum.member?(features, "shareable_emoji_packs") do
+        :ok
+      else
+        {:error, :not_shareable}
+      end
+    end
+  end
+
+  defp validate_not_empty(list) do
+    if Enum.all?(list, fn i -> is_binary(i) and i != "" end) do
+      :ok
+    else
+      {:error, :empty_values}
+    end
+  end
+
+  defp save_file(%Plug.Upload{path: upload_path}, pack, filename) do
+    file_path = Path.join(pack.path, filename)
+    create_subdirs(file_path)
+
+    with {:ok, _} <- File.copy(upload_path, file_path) do
+      :ok
+    end
+  end
+
+  defp put_emoji(pack, shortcode, filename) do
+    files = Map.put(pack.files, shortcode, filename)
+    %{pack | files: files, files_count: length(Map.keys(files))}
+  end
+
+  defp delete_emoji(pack, shortcode) do
+    files = Map.delete(pack.files, shortcode)
+    %{pack | files: files}
+  end
+
+  defp rename_file(pack, filename, new_filename) do
+    old_path = Path.join(pack.path, filename)
+    new_path = Path.join(pack.path, new_filename)
+    create_subdirs(new_path)
+
+    with :ok <- File.rename(old_path, new_path) do
+      remove_dir_if_empty(old_path, filename)
+    end
+  end
+
+  defp create_subdirs(file_path) do
+    with true <- String.contains?(file_path, "/"),
+         path <- Path.dirname(file_path),
+         false <- File.exists?(path) do
+      File.mkdir_p!(path)
+    end
+  end
+
+  defp remove_file(pack, shortcode) do
+    with {:ok, filename} <- get_filename(pack, shortcode),
+         emoji <- Path.join(pack.path, filename),
+         :ok <- File.rm(emoji) do
+      remove_dir_if_empty(emoji, filename)
+    end
+  end
+
+  defp remove_dir_if_empty(emoji, filename) do
+    dir = Path.dirname(emoji)
+
+    if String.contains?(filename, "/") and File.ls!(dir) == [] do
+      File.rmdir!(dir)
+    else
+      :ok
+    end
+  end
+
+  defp get_filename(pack, shortcode) do
+    with %{^shortcode => filename} when is_binary(filename) <- pack.files,
+         file_path <- Path.join(pack.path, filename),
+         {:ok, _} <- File.stat(file_path) do
+      {:ok, filename}
+    else
+      {:error, _} = error ->
+        error
+
+      _ ->
+        {:error, :doesnt_exist}
+    end
+  end
+
+  defp http_get(%URI{} = url), do: url |> to_string() |> http_get()
+
+  defp http_get(url) do
+    with {:ok, %{body: body}} <- Pleroma.HTTP.get(url, [], pool: :default) do
+      Jason.decode(body)
+    end
+  end
+
+  defp list_packs_dir do
+    emoji_path = emoji_path()
+    # 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_path)},
+         {:ls, {:ok, results}} <- {:ls, File.ls(emoji_path)} do
+      {:ok, Enum.sort(results)}
+    else
+      {:create_dir, {:error, e}} -> {:error, :create_dir, e}
+      {:ls, {:error, e}} -> {:error, :ls, e}
+    end
+  end
+
+  defp validate_downloadable(pack) do
+    if downloadable?(pack), do: :ok, else: {:error, :cant_download}
+  end
+
+  defp copy_as(remote_pack, local_name) do
+    path = Path.join(emoji_path(), local_name)
+
+    %__MODULE__{
+      name: local_name,
+      path: path,
+      files: remote_pack["files"],
+      pack_file: Path.join(path, "pack.json")
+    }
+  end
+
+  defp unzip(archive, pack_info, remote_pack, local_pack) do
+    with :ok <- File.mkdir_p!(local_pack.path) do
+      files = Enum.map(remote_pack["files"], fn {_, path} -> to_charlist(path) end)
+      # Fallback cannot contain a pack.json file
+      files = if pack_info[:fallback], do: files, else: ['pack.json' | files]
+
+      :zip.unzip(archive, cwd: to_charlist(local_pack.path), file_list: files)
+    end
+  end
+
+  defp fetch_pack_info(remote_pack, uri, name) do
+    case remote_pack["pack"] do
+      %{"share-files" => true, "can-download" => true, "download-sha256" => sha} ->
+        {:ok,
+         %{
+           sha: sha,
+           url: URI.merge(uri, "/api/pleroma/emoji/packs/archive?name=#{name}") |> to_string()
+         }}
+
+      %{"fallback-src" => src, "fallback-src-sha256" => sha} when is_binary(src) ->
+        {:ok,
+         %{
+           sha: sha,
+           url: src,
+           fallback: true
+         }}
+
+      _ ->
+        {:error, "The pack was not set as shared and there is no fallback src to download from"}
+    end
+  end
+
+  defp download_archive(url, sha) do
+    with {:ok, %{body: archive}} <- Pleroma.HTTP.get(url) do
+      if Base.decode16!(sha) == :crypto.hash(:sha256, archive) do
+        {:ok, archive}
+      else
+        {:error, :invalid_checksum}
+      end
+    end
+  end
+
+  defp fetch_archive(pack) do
+    hash = :crypto.hash(:md5, File.read!(pack.pack_file))
+
+    case @cachex.get!(:emoji_packs_cache, pack.name) do
+      %{hash: ^hash, pack_data: archive} -> archive
+      _ -> create_archive_and_cache(pack, hash)
+    end
+  end
+
+  defp fallback_sha_changed?(pack, data) do
+    is_binary(data[:"fallback-src"]) and data[:"fallback-src"] != pack.pack["fallback-src"]
+  end
+
+  defp update_sha_and_save_metadata(pack, data) do
+    with {:ok, %{body: zip}} <- Pleroma.HTTP.get(data[:"fallback-src"]),
+         :ok <- validate_has_all_files(pack, zip) do
+      fallback_sha = :sha256 |> :crypto.hash(zip) |> Base.encode16()
+
+      data
+      |> Map.put("fallback-src-sha256", fallback_sha)
+      |> save_metadata(pack)
+    end
+  end
+
+  defp validate_has_all_files(pack, zip) do
+    with {:ok, f_list} <- :zip.unzip(zip, [:memory]) do
+      # Check if all files from the pack.json are in the archive
+      pack.files
+      |> Enum.all?(fn {_, from_manifest} ->
+        List.keyfind(f_list, to_charlist(from_manifest), 0)
+      end)
+      |> if(do: :ok, else: {:error, :incomplete})
+    end
+  end
+end