From e68386830c8812f80cb4b3af9871170226b916b4 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Thu, 9 Jun 2022 22:38:58 +0200
Subject: [PATCH] Add Film::last_written_by_earlier_than()

---
 src/lib/film.cc | 40 ++++++++++++++++++++++++++++++++++++++++
 src/lib/film.h  |  4 ++++
 2 files changed, 44 insertions(+)

diff --git a/src/lib/film.cc b/src/lib/film.cc
index 1aba68eeb..4084ca59c 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -534,6 +534,8 @@ Film::read_metadata (optional<boost::filesystem::path> path)
 		}
 	}
 
+	_last_written_by = f.optional_string_child("LastWrittenBy");
+
 	_name = f.string_child ("Name");
 	if (_state_version >= 9) {
 		_use_isdcf_name = f.bool_child ("UseISDCFName");
@@ -2167,3 +2169,41 @@ Film::set_dirty (bool dirty)
 	}
 }
 
+
+/** @return true if the metadata was (probably) last written by a version earlier
+ *  than the given one; false if it definitely was not.
+ */
+bool
+Film::last_written_by_earlier_than(int major, int minor, int micro) const
+{
+	if (!_last_written_by) {
+		return true;
+	}
+
+	vector<string> parts;
+	boost::split(parts, *_last_written_by, boost::is_any_of("."));
+
+	if (parts.size() != 3) {
+		/* Not sure what's going on, so let's say it was written by an old version */
+		return true;
+	}
+
+	if (boost::ends_with(parts[2], "pre")) {
+		parts[2] = parts[2].substr(0, parts[2].length() - 3);
+	}
+
+	int our_major = dcp::raw_convert<int>(parts[0]);
+	int our_minor = dcp::raw_convert<int>(parts[1]);
+	int our_micro = dcp::raw_convert<int>(parts[2]);
+
+	if (our_major != major) {
+		return our_major < major;
+	}
+
+	if (our_minor != minor) {
+		return our_minor < minor;
+	}
+
+	return our_micro < micro;
+}
+
diff --git a/src/lib/film.h b/src/lib/film.h
index 5318d6a12..72d6d5e8d 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -210,6 +210,8 @@ public:
 		return _tolerant;
 	}
 
+	bool last_written_by_earlier_than(int major, int minor, int micro) const;
+
 	/** Identifiers for the parts of our state;
 	    used for signalling changes.
 	*/
@@ -516,6 +518,8 @@ private:
 	 */
 	boost::optional<boost::filesystem::path> _directory;
 
+	boost::optional<std::string> _last_written_by;
+
 	/** Name for DCP-o-matic */
 	std::string _name;
 	/** True if a auto-generated ISDCF-compliant name should be used for our DCP */
-- 
2.30.2