Exporting iOS backups may ignore -c compatible

[ReagentX]

Discussed in #295

^{Originally posted by macramores July 21, 2024}
I can create a backup from my Mac and it correctly converts the -c compatible correctly, but when trying to create a backup from an iOS backup, it pulls the backup in 10 seconds (which is impressive) but ignores the -c compatible. Here's the line I'm running:

./imessage-exporter -f html -p ~/iphone_backup_latest/00008030-001445C43E60A02E -a iOS -o backup_export -c compatible

Thank you!

[ReagentX]

Report indicates HEIF extension files are not converted:

imessage-exporter/imessage-exporter/src/app/attachment_manager.rs

Lines 152 to 162 in 247e01e

	// Normal attachments always get converted to jpeg
	else if original_extension == "heic" || original_extension == "HEIC" {
	let output_type = ImageType::Jpeg;
	// Update extension for conversion
	to.set_extension(output_type.to_str());
	if convert_heic(from, to, converter, &output_type).is_none() {
	eprintln!("Unable to convert {from:?}");
	}
	} else {
	Self::copy_raw(from, to);
	}

[ReagentX]

On iOS, attachment files are stored with names as hashes without extensions, so the current detection code doesn't work in those cases:

imessage-exporter/imessage-database/src/tables/attachment.rs

Lines 410 to 420 in 247e01e

	/// Generate an iOS path for an attachment
	fn gen_ios_attachment(file_path: &str, db_path: &Path) -> Option<String> {
	let input = file_path.get(2..)?;
	let filename = format!(
	"{:x}",
	Sha1::digest(format!("MediaDomain-{input}").as_bytes())
	);
	let directory = filename.get(0..2)?;
	Some(format!("{}/{directory}/{filename}", db_path.display()))
	}

[ReagentX]

We can use the mime_type to parse the file type from the Attachment:

imessage-exporter/imessage-database/src/tables/attachment.rs

Lines 124 to 155 in 247e01e

	/// Get the media type of an attachment
	pub fn mime_type(&'_ self) -> MediaType<'_> {
	match &self.mime_type {
	Some(mime) => {
	if let Some(mime_str) = mime.split('/').next() {
	match mime_str {
	"image" => MediaType::Image(mime),
	"video" => MediaType::Video(mime),
	"audio" => MediaType::Audio(mime),
	"text" => MediaType::Text(mime),
	"application" => MediaType::Application(mime),
	_ => MediaType::Other(mime),
	}
	} else {
	MediaType::Other(mime)
	}
	}
	None => {
	// Fallback to `uti` if the MIME type cannot be inferred
	if let Some(uti) = &self.uti {
	match uti.as_str() {
	// This type is for audio messages, which are sent in `caf` format
	// https://developer.apple.com/library/archive/documentation/MusicAudio/Reference/CAFSpec/CAF_overview/CAF_overview.html
	"com.apple.coreaudio-format" => MediaType::Audio("x-caf; codecs=opus"),
	_ => MediaType::Unknown,
	}
	} else {
	MediaType::Unknown
	}
	}
	}
	}

We should use this to determine if the file should be converted or not.