Now saving out statistics in the metadata file

Blockdown.coffee

@@ -797,6 +797,15 @@ Better is a Safari content blocker for <a href='https://itunes.apple.com/us/app/
 	# Saves the WebKit content blocking rule file, blockerList.json.
 	#
 	saveBlockerListJSON: (dataDirectory) =>
+
+		if @contentHasNotChanged
+			console.log("\t✓ Content has not changed. Not saving blocker list JSON or its metadata file.")
+			return Promise.resolve()
+
+		#
+		# Content has changed. Save the blocker list and metadata files.
+		#
+
 		blockerListJSONFilePath = path.join dataDirectory, 'blockerList.json'
 		metadataFilePath = path.join dataDirectory, 'metadata.json'
 
@@ -806,6 +815,8 @@ Better is a Safari content blocker for <a href='https://itunes.apple.com/us/app/
 		output = JSON.stringify.apply @, args
 		hash = checksum(output)
 
+		# TODO: Only update metadata if rules have been updated.
+
 		#
 		# Prepare metadata
 		#
@@ -854,26 +865,36 @@ Better is a Safari content blocker for <a href='https://itunes.apple.com/us/app/
 				if (key.indexOf SITES) > -1
 					trackersDeleted.add uniqueIdentifier
 
-		console.log("Rules added: #{rulesAdded.size}")
+		rulesChanged = rulesAdded.size + rulesUpdated.size + rulesDeleted.size
+		trackersChanged = trackersAdded.size + trackersUpdated.size + trackersDeleted.size
+		sitesChanged = sitesAdded.size + sitesUpdated.size + sitesDeleted.size
+
+		console.log("")
+		console.log("Rules changed    : #{rulesChanged}")
+		console.log("Trackers changed : #{trackersChanged}")
+		console.log("Sites changed    : #{sitesChanged}")
+		console.log("")
+		console.log("Rules added (#{rulesAdded.size}):")
 		console.log(rulesAdded)
-		console.log("Ruled updated: #{rulesUpdated.size}")
+		console.log("Ruled updated (#{rulesUpdated.size}):")
 		console.log(rulesUpdated)
-		console.log("Rules deleted: #{rulesDeleted.size}")
+		console.log("Rules deleted (#{rulesDeleted.size}):")
 		console.log(rulesDeleted)
-
-		console.log("Trackers added: #{trackersAdded.size}")
+		console.log("")
+		console.log("Trackers added (#{trackersAdded.size}):")
 		console.log(trackersAdded)
-		console.log("Trackers updated: #{trackersUpdated.size}")
+		console.log("Trackers updated (#{trackersUpdated.size}):")
 		console.log(trackersUpdated)
-		console.log("Trackers deleted: #{trackersDeleted.size}")
+		console.log("Trackers deleted (#{trackersDeleted.size}):")
 		console.log(trackersDeleted)
-
-		console.log("Sites added: #{sitesAdded.size}")
+		console.log("")
+		console.log("Sites added (#{sitesAdded.size}):")
 		console.log(sitesAdded)
-		console.log("Sites updated: #{sitesUpdated.size}")
+		console.log("Sites updated (#{sitesUpdated.size}):")
 		console.log(sitesUpdated)
-		console.log("Sites deleted: #{sitesDeleted.size}")
+		console.log("Sites deleted (#{sitesDeleted.size}):")
 		console.log(sitesDeleted)
+		console.log("")
 
 		# Calculate the last update time based on the content cache.
 		# Since timestamps have lexographical order, we can use a reduce
@@ -882,11 +903,25 @@ Better is a Safari content blocker for <a href='https://itunes.apple.com/us/app/
 		lastModifiedTimes = `Object.values(this.contentCurrentModifiedTimes)`
 		lastModifiedTime = `lastModifiedTimes.reduce ((x,y) => { return (x > y ? x : y) })`
 
-		metadata = JSON.stringify({
+		metadata = `JSON.stringify({
 			md5: hash,
-			lastUpdated: lastModifiedTime 
-		})
-
+			lastUpdate: lastModifiedTime, 
+			stats: {
+				rulesChanged: rulesChanged,
+				trackersChanged: trackersChanged,
+				sitesChanged: sitesChanged,
+				trackers: {
+					added: [...trackersAdded],
+					updated: [...trackersUpdated],
+					deleted: [...trackersDeleted]
+				},
+				sites: {
+					added: [...sitesAdded],
+					updated: [...sitesUpdated],
+					deleted: [...sitesDeleted]
+				}
+			}
+		})`
 
 		# Save the blocker list file and its metadata.
 		(fs.outputFileAsync blockerListJSONFilePath, output).then =>