SM5StreamParser.lua

-- GLOBAL DYNAMIC VARIABLES
-- Which note types are counted as part of the stream?
streamNotes = {1,2,4}

--REMOVE--
function getSimfileString(simfilePath)
	-- Open the file
	local file, errorString = io.open(simfilePath, "r"), simfileString
	
	if not file then
		-- Error opening file
		print("File error: " .. errorString)
	else
		simfileString = file:read("*a")
	end
		
	return simfileString
end
local simfilePath = ".\\Electric Angel.ssc"
simfileString = getSimfileString(simfilePath)
--/REMOVE--

-- Utility function to replace regex special characters with escaped characters
function regexEncode(var) 
	return (var:gsub('%%', '%%%'):gsub('%^', '%%^'):gsub('%$', '%%$'):gsub('%(', '%%('):gsub('%)', '%%)'):gsub('%.', '%%.'):gsub('%[', '%%['):gsub('%]', '%%]'):gsub('%*', '%%*'):gsub('%+', '%%+'):gsub('%-', '%%-'):gsub('%?', '%%?'))
end

-- Parse the measures section out of our sim file
function getSimfileChartString(simfileString, gameType, gameDifficulty)
	local measuresString = nil

	if(simfileString:match("#NOTEDATA")) then
		-- SSC File
		-- Loop through each chart in the SSC file
		for chart in simfileString:gmatch("#NOTEDATA.-#NOTES:[^;]*") do
			-- Find the chart that matches our difficulty and game type
			if(chart:match("#STEPSTYPE:"..regexEncode(gameType)) and chart:match("#DIFFICULTY:"..regexEncode(gameDifficulty))) then
				--Find just the notes and remove comments
				measuresString = chart:match("#NOTES:\n([^;]*)\n$"):gsub("\\[^\n]*","")
			end
		end
	else
		-- SM FILE
		-- Loop through each chart in the SM file
		for chart in simfileString:gmatch("#NOTES[^;]*") do
			if(chart:match(regexEncode(gameType)..":") and chart:match(regexEncode(gameDifficulty)..":")) then
				-- Find just the notes and remove comments
				measuresString = chart:match("#NOTES:.*:\n(.*)\n$"):gsub("//[^\n]*","")
			end
		end
	end
	
	return measuresString
end

-- Figure out which measures are considered a stream of notes
function getStreamMeasures(measuresString, notesPerMeasure)	
	-- Make our stream notes array into a string for regex
	local streamNotesString = ""
	for k, v in pairs(streamNotes) do 
		streamNotesString = streamNotesString .. v
	end

	-- Which measures are considered a stream?
	local streamMeasures = {}
	
	-- Keep track of the measure and its timing (8ths, 16ths, etc)
	local measureCount = 1
	local measureTiming = 0
	-- Keep track of the notes in a measure
	local measureNotes = {}
	
	-- How many 
	
	-- Loop through each line in our string of measures
	for line in measuresString:gmatch("[^\r\n]+")
	do
		-- If we hit a comma or a semi-colon, then we've hit the end of our measure
		if(line:match("^[,;]%s*")) then
			-- Does this measure contain a stream of notes based on our notesPerMeasure global?
			if(#measureNotes >= notesPerMeasure) then
				local isStream = true
				
				-- What can the gap be between notes?
				local noteGapThreshold = measureTiming / notesPerMeasure
				
				-- Loop through our notes and see if they're placed correctly to be considered a stream (every 8th, every 16th, etc.)
				for i=1,(#measureNotes - 1),1 do
					-- Is the gap between this note and the next note greater than what's allowed?
					if((measureNotes[i+1] - measureNotes[i]) > noteGapThreshold) then
						isStream = false
					end
				end
				
				-- This measure is a stream
				if(isStream == true) then
					table.insert(streamMeasures, measureCount)
				end
			end
		
			-- Reset iterative variables
			measureTiming = 0
			measureCount = measureCount + 1
			measureNotes = {}
		else
			-- Iterate the measure timing
			measureTiming = measureTiming + 1
			
			-- Is this a note?
			if(line:match("["..streamNotesString.."]")) then
				table.insert(measureNotes, measureTiming)
			end
		end
	end
	
	return streamMeasures
end

-- Get the start/end of each stream sequence in our table of measures
function getStreamSequences(streamMeasures, measureSequenceThreshold)
	local streamSequences = {}

	local counter = 1
	local streamEnd = nil
	-- Which sequences of measures are considered a stream?
	for k,v in pairs(streamMeasures) do
		-- Are we still in sequence?
		if(streamMeasures[k-1] == (streamMeasures[k] - 1)) then
			counter = counter + 1
			streamEnd = streamMeasures[k]
		end
		
		-- Are we out of sequence OR at the end of the array?
		if(streamMeasures[k+1] == nil or streamMeasures[k-1] ~= (streamMeasures[k] - 1)) then
			if(counter >= measureSequenceThreshold) then
				streamStart = (streamEnd - counter)
				table.insert(streamSequences, {streamStart=streamStart,streamEnd=streamEnd})
			end
			counter = 1
		end
	end

	return streamSequences
end

function getStreams(simfileString, gameType, gameDifficulty, notesPerMeasure, measureSequenceThreshold)
	-- Parse out just the contents of the notes
	chartString = getSimfileChartString(simfileString, gameType, gameDifficulty)
	-- Which measures have enough notes to be considered as part of a stream?
	streamMeasures = getStreamMeasures(chartString, notesPerMeasure)
	for k,v in pairs(streamMeasures) do
		print(v)
	end
	-- Which sequences of measures are considered a stream?
	return (getStreamSequences(streamMeasures, measureSequenceThreshold))
end

streamSequences = getStreams(simfileString, "dance-single", "Challenge", 12, 4)

print("-------------------------------------------")
for k,v in pairs(streamSequences) do
	print("Stream position: "..v.streamStart .. " / " .. v.streamEnd)
end
print("-------------------------------------------")