private static SemVersion DetermineVersionFromType()

in src/Elastic.Transport/Requests/MetaData/ReflectionVersionInfo.cs [53:138]
57 lines of code
23 McCabe index (conditional complexity)

	private static SemVersion DetermineVersionFromType(Type type)
	{
		try
		{
			// Try to read the full version in 'major.minor.patch[.build][-prerelease][+build]' format. This format is semver2 compliant
			// except for the optional [.build] version number.

			var version = type.Assembly?.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion;

			if (string.IsNullOrEmpty(version) && !string.IsNullOrEmpty(type.Assembly?.Location))
			{
				var location = type.Assembly?.Location;
				version = FileVersionInfo.GetVersionInfo(location)?.ProductVersion;
			}

			if (!string.IsNullOrEmpty(version))
			{
				// Version string is already in semver format
				if (SemVersion.TryParse(version, out var result))
					return result;

				var prefix = GetVersionPrefixPart(version);

				// Version prefix is not in a valid 'major.minor[.build[.revision]]' form
				if (!System.Version.TryParse(prefix, out var prefixVersion))
					return Empty;

				// Version prefix '[.revision]' part is not present, but initial semver parsing failed anyways.
				// Nothing we can do here...
				if (prefixVersion.Revision < 0)
					return Empty;

				// Remove non semver compliant '[.revision]'
				version = $"{prefixVersion.Major}.{prefixVersion.Minor}.{prefixVersion.Build}{version.Substring(prefix.Length)}";
				if (!SemVersion.TryParse(version, out result))
					return Empty;

				// Prepend the 'revision' to metadata
				if (prefixVersion.Revision > 0)
				{
					var meta = $"rev{prefixVersion.Revision}";
					if (result.Metadata.Length != 0)
						meta = $"{meta}.{result.Metadata}";

					result = new SemVersion(result.Major, result.Minor, result.Patch, result.Prerelease, meta);
				}

				return result;
			}
		}
		catch
		{
			// ignore failures and fall through
		}

		try
		{
			// Try to read the assembly version in 'major.minor[.build[.revision]]' format.

			var version = type.Assembly?.GetCustomAttribute<AssemblyVersionAttribute>()?.Version;

			if (string.IsNullOrEmpty(version))
				version = type.Assembly?.GetName()?.Version?.ToString();

			if (!string.IsNullOrEmpty(version))
			{
				var parts = version.Split('.');

				var major = parts.Length >= 1 && int.TryParse(parts[0], out var majorVal) ? majorVal : 0;
				var minor = parts.Length >= 2 && int.TryParse(parts[1], out var minorVal) ? minorVal : 0;
				var build = parts.Length >= 3 && int.TryParse(parts[2], out var buildVal) ? buildVal : 0;
				var revision = parts.Length >= 4 && int.TryParse(parts[3], out var revisionVal) ? revisionVal : 0;

				// Use 'build' as the semver 'patch' part and add the 'revision' as metadata
				return (revision > 0)
					? new SemVersion(major, minor, build, null, $"rev{revision}")
					: new SemVersion(major, minor, build);
			}
		}
		catch
		{
			// ignore failures and fall through
		}

		return Empty;
	}