120 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
			
		
		
	
	
			120 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			Elixir
		
	
	
	
	
	
| # Pleroma: A lightweight social networking server
 | |
| # Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
 | |
| # SPDX-License-Identifier: AGPL-3.0-only
 | |
| 
 | |
| defmodule Pleroma.MIME do
 | |
|   @moduledoc """
 | |
|   Returns the mime-type of a binary and optionally a normalized file-name.
 | |
|   """
 | |
|   @default "application/octet-stream"
 | |
|   @read_bytes 35
 | |
| 
 | |
|   @spec file_mime_type(String.t()) ::
 | |
|           {:ok, content_type :: String.t(), filename :: String.t()} | {:error, any()} | :error
 | |
|   def file_mime_type(path, filename) do
 | |
|     with {:ok, content_type} <- file_mime_type(path),
 | |
|          filename <- fix_extension(filename, content_type) do
 | |
|       {:ok, content_type, filename}
 | |
|     end
 | |
|   end
 | |
| 
 | |
|   @spec file_mime_type(String.t()) :: {:ok, String.t()} | {:error, any()} | :error
 | |
|   def file_mime_type(filename) do
 | |
|     File.open(filename, [:read], fn f ->
 | |
|       check_mime_type(IO.binread(f, @read_bytes))
 | |
|     end)
 | |
|   end
 | |
| 
 | |
|   def bin_mime_type(binary, filename) do
 | |
|     with {:ok, content_type} <- bin_mime_type(binary),
 | |
|          filename <- fix_extension(filename, content_type) do
 | |
|       {:ok, content_type, filename}
 | |
|     end
 | |
|   end
 | |
| 
 | |
|   @spec bin_mime_type(binary()) :: {:ok, String.t()} | :error
 | |
|   def bin_mime_type(<<head::binary-size(@read_bytes), _::binary>>) do
 | |
|     {:ok, check_mime_type(head)}
 | |
|   end
 | |
| 
 | |
|   def bin_mime_type(_), do: :error
 | |
| 
 | |
|   def mime_type(<<_::binary>>), do: {:ok, @default}
 | |
| 
 | |
|   defp fix_extension(filename, content_type) do
 | |
|     parts = String.split(filename, ".")
 | |
| 
 | |
|     new_filename =
 | |
|       if length(parts) > 1 do
 | |
|         Enum.drop(parts, -1) |> Enum.join(".")
 | |
|       else
 | |
|         Enum.join(parts)
 | |
|       end
 | |
| 
 | |
|     cond do
 | |
|       content_type == "application/octet-stream" ->
 | |
|         filename
 | |
| 
 | |
|       ext = List.first(MIME.extensions(content_type)) ->
 | |
|         new_filename <> "." <> ext
 | |
| 
 | |
|       true ->
 | |
|         Enum.join([new_filename, String.split(content_type, "/") |> List.last()], ".")
 | |
|     end
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, _::binary>>) do
 | |
|     "image/png"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x47, 0x49, 0x46, 0x38, _, 0x61, _::binary>>) do
 | |
|     "image/gif"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0xFF, 0xD8, 0xFF, _::binary>>) do
 | |
|     "image/jpeg"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x1A, 0x45, 0xDF, 0xA3, _::binary>>) do
 | |
|     "video/webm"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x00, 0x00, 0x00, _, 0x66, 0x74, 0x79, 0x70, _::binary>>) do
 | |
|     "video/mp4"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x49, 0x44, 0x33, _::binary>>) do
 | |
|     "audio/mpeg"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<255, 251, _, 68, 0, 0, 0, 0, _::binary>>) do
 | |
|     "audio/mpeg"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(
 | |
|          <<0x4F, 0x67, 0x67, 0x53, 0x00, 0x02, 0x00, 0x00, _::size(160), 0x80, 0x74, 0x68, 0x65,
 | |
|            0x6F, 0x72, 0x61, _::binary>>
 | |
|        ) do
 | |
|     "video/ogg"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<0x4F, 0x67, 0x67, 0x53, 0x00, 0x02, 0x00, 0x00, _::binary>>) do
 | |
|     "audio/ogg"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<"RIFF", _::binary-size(4), "WAVE", _::binary>>) do
 | |
|     "audio/wav"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<"RIFF", _::binary-size(4), "WEBP", _::binary>>) do
 | |
|     "image/webp"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(<<"RIFF", _::binary-size(4), "AVI.", _::binary>>) do
 | |
|     "video/avi"
 | |
|   end
 | |
| 
 | |
|   defp check_mime_type(_) do
 | |
|     @default
 | |
|   end
 | |
| end
 | 
