[4.3] PISTON-1170: Update content type on media attachments (#6674)

The `kzm_message:forward_message/4` function branches, depending on
whether the user has recorded an additional message to be prepended to
the voicemail message being forwarded. Prepending the additional
message requires the two media files to be merged into a temporary
file. This is then written to the database as an attachment.

Prior to this fix, the code assumed that the merged media file has an
`mp3` format, which is not necessarily true. In addition, it did not
pass any content-type option to the `kz_datamgr:put_attachment/5`
function which actually writes the attachment. As a result, the
attachment metadata in the database always indicated a content-type of
`application/octet-stream`.

Calls to `kz_media_util:join_media_files/2` now ensure that the merged
output format is specified explicitly, rather than relying on default
behaviour. The same format is also mapped to the corresponding MIME
type which is passed to `kz_datamgr:put_attachment/5` to ensure the
attachment metadata is correct.

core/kazoo_media/include/kz_media.hrl

@@ -1,6 +1,7 @@
 -ifndef(KZ_MEDIA_HRL).
 
 -define(CHUNKSIZE, 24576).
+-define(NORMALIZATION_FORMAT, kapps_config:get_ne_binary(<<"crossbar.media">>, <<"normalization_format">>, <<"mp3">>)).
 
 -record(media_file, {stream_url = <<>> :: binary()
                     ,contents = <<>> :: binary()

core/kazoo_media/src/kz_media_util.erl

@@ -45,8 +45,6 @@
 -define(NORMALIZE_SOURCE_ARGS, kapps_config:get_binary(?CONFIG_CAT, <<"normalize_source_args">>, <<>>)).
 -define(NORMALIZE_DEST_ARGS, kapps_config:get_binary(?CONFIG_CAT, <<"normalize_destination_args">>, <<"-r 8000">>)).
 
--define(NORMALIZATION_FORMAT, kapps_config:get_ne_binary(<<"crossbar.media">>, <<"normalization_format">>, <<"mp3">>)).
-
 -define(USE_ACCOUNT_OVERRIDES, kapps_config:get_is_true(?CONFIG_CAT, <<"support_account_overrides">>, 'true')).
 
 -define(DEFAULT_MAX_RECORDING_LIMIT, 3*?SECONDS_IN_HOUR).

core/kazoo_voicemail/src/kvm_message.erl

@@ -18,6 +18,7 @@
         ]).
 
 -include("kz_voicemail.hrl").
+-include("kazoo_media/include/kz_media.hrl").
 
 -export_type([vm_folder/0]).
 
@@ -785,32 +786,35 @@ prepend_forward_message(Call, ForwardId, Metadata, _SrcBoxId, Props) ->
     {'ok', _} = kz_media_util:synthesize_tone(OrigSampleRate, <<"440">>, <<"0.5">>, TonePath),
 
     lager:debug("joining prepend to original message"),
-    case kz_media_util:join_media_files([TmpPath, TonePath, OrigPath], [{sample_rate, OrigSampleRate}]) of
+    JoinFormat = ?NORMALIZATION_FORMAT,
+    JoinOptions = [{'sample_rate', OrigSampleRate}, {'to_format', JoinFormat}],
+    case kz_media_util:join_media_files([TmpPath, TonePath, OrigPath], JoinOptions) of
         {'ok', FileContents} ->
-            JoinFilename = <<(kz_binary:rand_hex(16))/binary, ".mp3">>,
+            JoinFilename = <<(kz_binary:rand_hex(16))/binary, ".", JoinFormat/binary>>,
+            FileProps = [{'content_type', kz_mime:from_extension(JoinFormat)}],
             _ = [kz_util:delete_file(F) || F <- [TmpPath, OrigPath, TonePath]],
             %%TODO: update forwarded doc with length and media_filename
-            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, 3);
+            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, FileProps, 3);
         {'error', _} ->
             _ = [kz_util:delete_file(F) || F <- [TmpPath, OrigPath, TonePath]],
             lager:warning("failed to join forward message media files"),
             {'error', 'join_failed'}
 
     end.
 
--spec try_put_fwd_attachment(kz_term:ne_binary(), kz_term:ne_binary(), kz_term:ne_binary(), iodata(), 1..3) -> db_ret().
-try_put_fwd_attachment(AccountId, ForwardId, _JoinFilename, _FileContents, 0) ->
+-spec try_put_fwd_attachment(kz_term:ne_binary(), kz_term:ne_binary(), kz_term:ne_binary(), iodata(), kz_term:proplist(), 1..3) -> db_ret().
+try_put_fwd_attachment(AccountId, ForwardId, _JoinFilename, _FileContents, _FileProps, 0) ->
     lager:error("max retries to save prepend forward voicemail attachment ~s in db ~s"
                ,[ForwardId, kvm_util:get_db(AccountId, ForwardId)]
                ),
     {'error', 'max_save_retries'};
-try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, Loop) ->
-    case kz_datamgr:put_attachment(kvm_util:get_db(AccountId, ForwardId), ForwardId, JoinFilename, FileContents) of
+try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, FileProps, Loop) ->
+    case kz_datamgr:put_attachment(kvm_util:get_db(AccountId, ForwardId), ForwardId, JoinFilename, FileContents, FileProps) of
         {'ok', _}=OK -> OK;
         {'error', 'conflict'} ->
-            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, Loop - 1);
+            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, FileProps, Loop - 1);
         {'error', 'timeout'} ->
-            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, Loop - 1);
+            try_put_fwd_attachment(AccountId, ForwardId, JoinFilename, FileContents, FileProps, Loop - 1);
         {'error', _Reason}=Error ->
             lager:error("failed to save prepend forward voicemail message ~s in db ~s : ~p"
                        ,[ForwardId, kvm_util:get_db(AccountId, ForwardId), _Reason]),