--[[
	Library for simple audio reading, writing and analysing.
	
	Copyright © 2014, Christoph "Youka" Spanknebel
	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
	The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]
wav = {
	--[[
		Reads or writes audio file in WAVE format with PCM integer samples.
		
		Function 'create_context' requires 2 arguments: a filename and a mode, which can be "r" (read) or "w" (write).
		A call returns one table with methods depending on the used mode.
		On reading, following methods are callable:
		- get_filename()
		- get_mode()
		- get_file_size()
		- get_channels_number()
		- get_sample_rate()
		- get_byte_rate()
		- get_block_align()
		- get_bits_per_sample()
		- get_samples_per_channel()
		- get_sample_from_ms(ms)
		- get_ms_from_sample(sample)
		- get_min_max_amplitude()
		- get_position()
		- set_position(pos)
		- get_samples_interlaced(n)
		- get_samples(n)
		On writing, following methods are callable:
		- get_filename()
		- get_mode()
		- init(channels_number, sample_rate, bits_per_sample)
		- write_samples_interlaced(samples)
		- finish()
		
		(WAVE format: https://ccrma.stanford.edu/courses/422/projects/WaveFormat/)
	]]
	create_context = function(filename, mode)
		-- Check function parameters
		if type(filename) ~= "string" or not (mode == "r" or mode == "w") then
			error("invalid function parameters, expected filename and mode \"r\" or \"w\"", 2)
		end
		-- Audio file handle
		local file = io.open(filename, mode == "r" and "rb" or "wb")
		if not file then
			error(string.format("couldn't open file %q", filename), 2)
		end
		-- Byte-string(unsigend integer,little endian)<->Lua-number converters
		local function bton(s)
			local bytes = {s:byte(1,#s)}
			local n, bytes_n = 0, #bytes
			for i = 0, bytes_n-1 do
				n = n + bytes[1+i] * 2^(i*8)
			end
			return n
		end
		local unpack = table.unpack or unpack	-- Lua 5.1 or 5.2 table unpacker
		local function ntob(n, len)
			local n, bytes = math.max(math.floor(n), 0), {}
			for i=1, len do
				bytes[i] = n % 256
				n = math.floor(n / 256)
			end
			return string.char(unpack(bytes))
		end
		-- Check for integer
		local function isint(n)
			return type(n) == "number" and n == math.floor(n)
		end
		-- Initialize read process
		if mode == "r" then
			-- Audio meta informations
			local file_size, channels_number, sample_rate, byte_rate, block_align, bits_per_sample, samples_per_channel
			-- Audio samples file area
			local data_begin, data_end
			-- Read file type
			if file:read(4) ~= "RIFF" then
				error("not a RIFF file", 2)
			end
			file_size = file:read(4)
			if not file_size then
				error("file header incomplete (file size)")
			end
			file_size = bton(file_size) + 8
			if file:read(4) ~= "WAVE" then
				error("not a WAVE file", 2)
			end
			-- Read file chunks
			local chunk_id, chunk_size
			while true do
				-- Read chunk header
				chunk_id, chunk_size = file:read(4), file:read(4)
				if not chunk_size then
					break
				end
				chunk_size = bton(chunk_size)
				-- Identify chunk type
				if chunk_id == "fmt " then
					-- Read format informations
					local bytes = file:read(2)
					if not bytes or bton(bytes) ~= 1 then
						error("data must be in PCM format", 2)
					end
					bytes = file:read(2)
					if not bytes then
						error("channels number not found", 2)
					end
					channels_number = bton(bytes)
					bytes = file:read(4)
					if not bytes then
						error("sample rate not found", 2)
					end
					sample_rate = bton(bytes)
					bytes = file:read(4)
					if not bytes then
						error("byte rate not found", 2)
					end
					byte_rate = bton(bytes)
					bytes = file:read(2)
					if not bytes then
						error("block align not found", 2)
					end
					block_align = bton(bytes)
					bytes = file:read(2)
					if not bytes then
						error("bits per sample not found")
					end
					bits_per_sample = bton(bytes)
					if bits_per_sample ~= 8 and bits_per_sample ~= 16 and bits_per_sample ~= 24 and bits_per_sample ~= 32 then
						error("bits per sample must be 8, 16, 24 or 32", 2)
					end
					file:seek("cur", chunk_size-16)
				elseif chunk_id == "data" then
					-- Read samples
					if not block_align then
						error("format informations must be defined before sample data", 2)
					end
					samples_per_channel = chunk_size / block_align
					data_begin = file:seek()
					data_end = data_begin + chunk_size
					break	-- Stop here for later reading
				else
					-- Skip chunk
					file:seek("cur", chunk_size)
				end
			end
			-- Enough informations available?
			if not bits_per_sample then
				error("no format informations found", 2)
			end
			-- Return audio handler
			local obj
			obj = {
				get_filename = function()
					return filename
				end,
				get_mode = function()
					return mode
				end,
				get_file_size = function()
					return file_size
				end,
				get_channels_number = function()
					return channels_number
				end,
				get_sample_rate = function()
					return sample_rate
				end,
				get_byte_rate = function()
					return byte_rate
				end,
				get_block_align = function()
					return block_align
				end,
				get_bits_per_sample = function()
					return bits_per_sample
				end,
				get_samples_per_channel = function()
					return samples_per_channel
				end,
				get_sample_from_ms = function(ms)
					if not isint(ms) or ms < 0 then
						error("positive integer expected", 2)
					end
					return ms * 0.001 * sample_rate
				end,
				get_ms_from_sample = function(sample)
					if not isint(sample) or sample < 0 then
						error("positive integer expected", 2)
					end
					return sample / sample_rate * 1000
				end,
				get_min_max_amplitude = function()
					local half_level = 2^bits_per_sample / 2
					return -half_level, half_level - 1
				end,
				get_position = function()
					if not data_begin then
						error("no samples available", 2)
					end
					return (file:seek() - data_begin) / block_align
				end,
				set_position = function(pos)
					if not isint(pos) or pos < 0 then
						error("positive integer expected", 2)
					elseif not data_begin then
						error("no samples available", 2)
					elseif data_begin + pos * block_align > data_end then
						error("tried to set position behind data end", 2)
					end
					file:seek("set", data_begin + pos * block_align)
				end,
				get_samples_interlaced = function(n)
					if not isint(n) or n <= 0 then
						error("positive integer greater zero expected", 2)
					elseif not data_begin then
						error("no samples available", 2)
					elseif file:seek() + n * block_align > data_end then
						error("tried to read over data end", 2)
					end
					local bytes, sample, output = file:read(n * block_align), nil, {n = 0}
					local bytes_n = #bytes
					if bits_per_sample == 8 then
						for i=1, bytes_n, 1 do
							sample = bton(bytes:sub(i,i))
							output.n = output.n + 1
							output[output.n] = sample > 127 and sample - 256 or sample
						end
					elseif bits_per_sample == 16 then
						for i=1, bytes_n, 2 do
							sample = bton(bytes:sub(i,i+1))
							output.n = output.n + 1
							output[output.n] = sample > 32767 and sample - 65536 or sample
						end
					elseif bits_per_sample == 24 then
						for i=1, bytes_n, 3 do
							sample = bton(bytes:sub(i,i+2))
							output.n = output.n + 1
							output[output.n] = sample > 8388607 and sample - 16777216 or sample
						end
					else	-- if bits_per_sample == 32 then
						for i=1, bytes_n, 4 do
							sample = bton(bytes:sub(i,i+3))
							output.n = output.n + 1
							output[output.n] = sample > 2147483647 and sample - 4294967296 or sample
						end
					end
					return output
				end,
				get_samples = function(n)
					local success, samples = pcall(obj.get_samples_interlaced, n)
					if not success then
						error(samples, 2)
					end
					local output, channel_samples = {n = channels_number}
					for c=1, output.n do
						channel_samples = {n = samples.n / channels_number}
						for s=1, channel_samples.n do
							channel_samples[s] = samples[c + (s-1) * channels_number]
						end
						output[c] = channel_samples
					end
					return output
				end
			}
			return obj
		-- Initialize write process
		else
			-- Audio meta informations
			local channels_number_private, bytes_per_sample
			-- Return audio handler
			return {
				get_filename = function()
					return filename
				end,
				get_mode = function()
					return mode
				end,
				init = function(channels_number, sample_rate, bits_per_sample)
					-- Check function parameters
					if not isint(channels_number) or channels_number < 1 or
						not isint(sample_rate) or sample_rate < 2 or
						not (bits_per_sample == 8 or bits_per_sample == 16 or bits_per_sample == 24 or bits_per_sample == 32) then
						error("valid channels number, sample rate and bits per sample expected", 2)
					-- Already finished?
					elseif not file then
						error("already finished", 2)
					-- Already initialized?
					elseif file:seek() > 0 then
						error("already initialized", 2)
					end
					-- Write file type
					file:write("RIFF????WAVE")	-- file size to insert later
					-- Write format chunk
					file:write("fmt ",
								ntob(16, 4),
								ntob(1, 2),
								ntob(channels_number, 2),
								ntob(sample_rate, 4),
								ntob(sample_rate * channels_number * (bits_per_sample / 8), 4),
								ntob(channels_number * (bits_per_sample / 8), 2),
								ntob(bits_per_sample, 2))
					-- Write data chunk (so far)
					file:write("data????")	-- data size to insert later
					-- Set format memory
					channels_number_private, bytes_per_sample = channels_number, bits_per_sample / 8
				end,
				write_samples_interlaced = function(samples)
					-- Check function parameters
					if type(samples) ~= "table" then
						error("samples table expected", 2)
					end
					local samples_n = #samples
					if samples_n == 0 or samples_n % channels_number_private ~= 0 then
						error("valid number of samples expected (multiple of channels)", 2)
					-- Already finished?
					elseif not file then
						error("already finished", 2)
					-- Already initialized?
					elseif file:seek() == 0 then
						error("initialize before writing samples", 2)
					end
					-- All samples are numbers?
					for i=1, samples_n do
						if type(samples[i]) ~= "number" then
							error("samples have to be numbers", 2)
						end
					end
					-- Write samples to file
					local sample
					if bytes_per_sample == 1 then
						for i=1, samples_n do
							sample = samples[i]
							file:write(ntob(sample < 0 and sample + 256 or sample, 1))
						end
					elseif bytes_per_sample == 2 then
						for i=1, samples_n do
							sample = samples[i]
							file:write(ntob(sample < 0 and sample + 65536 or sample, 2))
						end
					elseif bytes_per_sample == 3 then
						for i=1, samples_n do
							sample = samples[i]
							file:write(ntob(sample < 0 and sample + 16777216 or sample, 3))
						end
					else	-- if bytes_per_sample == 4 then
						for i=1, samples_n do
							sample = samples[i]
							file:write(ntob(sample < 0 and sample + 4294967296 or sample, 4))
						end
					end
				end,
				finish = function()
					-- Already finished?
					if not file then
						error("already finished", 2)
					-- Already initialized?
					elseif file:seek() == 0 then
						error("initialize before finishing", 2)
					end
					-- Get file size
					local file_size = file:seek()
					-- Save file size
					file:seek("set", 4)
					file:write(ntob(file_size - 8, 4))
					-- Save data size
					file:seek("set", 40)
					file:write(ntob(file_size - 44, 4))
					-- Finalize file for secure reading
					file:close()
					file = nil
				end
			}
		end
	end,
	--[[
		Analyses frequencies of audio samples.
		
		Function 'create_frequency_analyzer' requires 2 arguments: a table with audio samples and the relating sample rate.
		A call returns one table with following methods:
		- get_frequencies()
		- get_frequency_weight(freq)
		- get_frequency_range_weight(freq_min, freq_max)
		
		(FFT: http://www.relisoft.com/science/physics/fft.html)
	]]
	create_frequency_analyzer = function(samples, sample_rate)
		-- Check function parameters
		if type(samples) ~= "table" or
			type(sample_rate) ~= "number" or sample_rate ~= math.floor(sample_rate) or sample_rate < 2 then
			error("samples table and sample rate expected", 2)
		end
		local samples_n = #samples
		if samples_n ~= math.ceil_pow2(samples_n) then
			error("table size has to be a power of two", 2)
		end
		for _, sample in ipairs(samples) do
			if type(sample) ~= "number" then
				error("table has only to contain numbers", 2)
			elseif sample > 1 or sample < -1 then
				error("numbers should be normalized / limited to -1 until 1", 2)
			end
		end
		-- Complex numbers
		local complex_t
		do
			local complex = {}
			local function tocomplex(a, b)
				if getmetatable(b) ~= complex then return a, {r = b, i = 0}
				elseif getmetatable(a) ~= complex then return {r = a, i = 0}, b
				else return a, b end
			end
			complex.__add = function(a, b)
				local c1, c2 = tocomplex(a, b)
				return setmetatable({r = c1.r + c2.r, i = c1.i + c2.i}, complex)
			end
			complex.__sub = function(a, b)
				local c1, c2 = tocomplex(a, b)
				return setmetatable({r = c1.r - c2.r, i = c1.i - c2.i}, complex)
			end
			complex.__mul = function(a, b)
				local c1, c2 = tocomplex(a, b)
				return setmetatable({r = c1.r * c2.r - c1.i * c2.i, i = c1.r * c2.i + c1.i * c2.r}, complex)
			end
			complex.__index = complex
			complex_t = function(r, i)
				return setmetatable({r = r, i = i}, complex)
			end
		end
		local function polar(theta)
			return complex_t(math.cos(theta), math.sin(theta))
		end
		local function magnitude(c)
			return math.sqrt(c.r^2 + c.i^2)
		end
		-- Fast Fourier Transform
		local function fft(x)
			-- Check recursion break
			local N = x.n
			if N > 1 then
				-- Divide
				local even, odd = {n = 0}, {n = 0}
				for i=1, N, 2 do
					even.n = even.n + 1
					even[even.n] = x[i]
				end
				for i=2, N, 2 do
					odd.n = odd.n + 1
					odd[odd.n] = x[i]
				end
				-- Conquer
				fft(even)
				fft(odd)
				--Combine
				local t
				for k = 1, N/2 do
					t = polar(-2 * math.pi * (k-1) / N) * odd[k]
					x[k] = even[k] + t
					x[k+N/2] = even[k] - t
				end
			end
		end
		-- Numbers to complex numbers
		local data = {n = samples_n}
		for i = 1, data.n do
			data[i] = complex_t(samples[i], 0)
		end
		-- Process FFT
		fft(data)
		-- Complex numbers to numbers
		for i = 1, data.n do
			data[i] = magnitude(data[i])
		end
		-- Calculate ordered frequencies
		local frequencies, frequency_sum, sample_rate_half = {n = data.n / 2}, 0, sample_rate / 2
		for i=1, frequencies.n do
			frequency_sum = frequency_sum + data[i]
		end
		if frequency_sum > 0 then
			for i=1, frequencies.n do
				frequencies[i] = {freq = (i-1) / (frequencies.n-1) * sample_rate_half, weight = data[i] / frequency_sum}
			end
		else
			frequencies[1] = {freq = 0, weight = 1}
			for i=2, frequencies.n do
				frequencies[i] = {freq = (i-1) / (frequencies.n-1) * sample_rate_half, weight = 0}
			end
		end
		-- Return frequencies getter
		return {
			get_frequencies = function()
				local out = {n = frequencies.n}
				for i=1, frequencies.n do
					out[i] = {freq = frequencies[i].freq, weight = frequencies[i].weight}
				end
				return out
			end,
			get_frequency_weight = function(freq)
				if type(freq) ~= "number" or freq < 0 or freq > sample_rate_half then
					error("valid frequency expected", 2)
				end
				for i, frequency in ipairs(frequencies) do
					if frequency.freq == freq then
						return frequency.weight
					elseif frequency.freq > freq then
						local frequency_last = frequencies[i-1]
						return (freq - frequency_last.freq) / (frequency.freq - frequency_last.freq) * (frequency.weight - frequency_last.weight) + frequency_last.weight
					end
				end
			end,
			get_frequency_range_weight = function(freq_min, freq_max)
				if type(freq_min) ~= "number" or freq_min < 0 or freq_min > sample_rate_half or
					type(freq_max) ~= "number" or freq_max < 0 or freq_max > sample_rate_half or
					freq_min > freq_max then
					error("valid frequencies expected", 2)
				end
				local weight_sum = 0
				for _, frequency in ipairs(frequencies) do
					if frequency.freq >= freq_min and frequency.freq <= freq_max then
						weight_sum = weight_sum + frequency.weight
					end
				end
				return weight_sum
			end
		}
	end
}
--[[
	Rounds up number to power of 2.
]]
function math.ceil_pow2(x)
	if type(x) ~= "number" then
		error("number expected", 2)
	end
	local p = 2
	while p < x do
		p = p * 2
	end
	return p
end
--[[
	Rounds down number to power of 2.
]]
function math.floor_pow2(x)
	if type(x) ~= "number" then
		error("number expected", 2)
	end
	local y = math.ceil_pow2(x)
	return x == y and x or y / 2
end
--[[
	Rounds number nearest to power of 2.
]]
function math.round_pow2(x)
	if type(x) ~= "number" then
		error("number expected", 2)
	end
	local min, max = math.floor_pow2(x), math.ceil_pow2(x)
	return (x - min) / (max-min) < 0.5 and min or max
end
--[[
	Converts samples into an ASS (Advanced Substation Alpha) subtitle shape code.
]]
function audio_to_ass(samples, wave_width, wave_height_scale, wave_thickness)
	-- Check function parameters
	if type(samples) ~= "table" or not samples[1] or
		type(wave_width) ~= "number" or wave_width <= 0 or
		type(wave_height_scale) ~= "number" or
		type(wave_thickness) ~= "number" or wave_thickness <= 0 then
		error("samples table, positive wave width, height scale and thickness expected", 2)
	end
	for _, sample in ipairs(samples) do
		if type(sample) ~= "number" then
			error("table has only to contain numbers", 2)
		end
	end
	-- Better fitting forms of known variables for most use
	local thick2, samples_n = wave_thickness / 2, #samples
	-- Build shape
	local shape = string.format("m 0 %d l", samples[1] * wave_height_scale - thick2)
	for i=2, samples_n do
		shape = string.format("%s %d %d", shape, (i-1) / (samples_n-1) * wave_width, samples[i] * wave_height_scale - thick2)
	end
	for i=samples_n, 1, -1 do
		shape = string.format("%s %d %d", shape, (i-1) / (samples_n-1) * wave_width, samples[i] * wave_height_scale + thick2)
	end
	return shape
end

-- specific to current app
require 'wav'

165

174

play = function(word_idx)
	if Words[word_idx].recording then
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	elseif love.filesystem.exists(Words[word_idx].contents..'.wav') then
		Words[word_idx].recording = love.sound.newSoundData(Words[word_idx].contents..'.wav')
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	else
		Playing_source = love.audio.newSource('sample.wav', 'static')
	end
	Playing_source:play()
	Recording_device = nil
end

{"draw_new_word_button":117,"Font_height":8,"learn_mouse_press":57,"Line_height":9,"learn_mouse_release":58,"Recording_device":132,"learn_keychord_press":59,"learn_text_input":60,"learn_key_release":61,"Recording_word":138,"on.mouse_press":51,"draw_record_button":140,"on.mouse_release":52,"draw_play_button":141,"fw_parent":173,"on.key_release":55,"on.text_input":54,"Cursor_word":24,"play":174,"on_new_word_button":118,"new_word":64,"on_word":80,"to_word_idx":94,"record":172,"draw_recording_button":133,"draw_playing_button":130,"draw_teach_word":68,"on":1,"save_wav":171,"on.keychord_press":53,"on_record":95,"draw_teach_screen":110,"teach_mouse_release":46,"Mode":2,"teach_keychord_press":47,"teach_mouse_press":88,"teach_key_release":56,"on_play":96,"teach_text_input":49,"fw_app":"spell-cards","on.draw":5,"draw_learn_screen":4,"Words":12,"Playing_source":126,"on.initialize":7}

play = function(word_idx)
	if Words[word_idx].recording then
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	elseif love.filesystem.exists(Words[word_idx].contents..'.wav') then
		Words[word_idx].recording = love.sound.newSoundData(Words[word_idx].contents..'.sounddata')
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	else
		Playing_source = love.audio.newSource('sample.wav', 'static')
	end
	Playing_source:play()
	Recording_device = nil
end

{"draw_record_button":140,"draw_play_button":141,"on.mouse_press":51,"on.mouse_release":52,"fw_parent":172,"Playing_source":126,"fw_app":"spell-cards","on.key_release":55,"on_new_word_button":118,"on.text_input":54,"Cursor_word":24,"Recording_device":132,"on_word":80,"new_word":64,"Recording_word":138,"record":172,"on":1,"on_play":96,"on_record":95,"draw_teach_word":68,"draw_learn_screen":4,"to_word_idx":94,"teach_mouse_press":88,"play":173,"teach_mouse_release":46,"draw_recording_button":133,"teach_keychord_press":47,"save_wav":171,"teach_key_release":56,"learn_keychord_press":59,"teach_text_input":49,"draw_new_word_button":117,"on.draw":5,"learn_mouse_press":57,"Words":12,"learn_mouse_release":58,"on.initialize":7,"draw_playing_button":130,"Font_height":8,"learn_text_input":60,"Line_height":9,"learn_key_release":61,"Mode":2,"draw_teach_screen":110,"on.keychord_press":53}

record = function(word_idx)
	if Recording_device then
		Words[word_idx].recording = Recording_device:getData()
		Recording_device:stop()
		if Words[word_idx].recording then
			save_wav(Words[word_idx].contents..'.wav', Words[word_idx].recording)
		end
		Recording_device = nil
		Recording_word = nil
		return
	end
	local devices = love.audio.getRecordingDevices()
	if #devices == 0 then return end
	Recording_device = devices[1]
	Recording_device:start()
	Recording_word = Words[word_idx]
	Playing_source = nil
end

{"draw_record_button":140,"draw_play_button":141,"on.mouse_press":51,"on.mouse_release":52,"fw_parent":171,"Playing_source":126,"fw_app":"spell-cards","on.key_release":55,"on_new_word_button":118,"on.text_input":54,"Cursor_word":24,"Recording_device":132,"on_word":80,"new_word":64,"Recording_word":138,"record":172,"on":1,"on_play":96,"on_record":95,"draw_teach_word":68,"draw_learn_screen":4,"to_word_idx":94,"teach_mouse_press":88,"play":169,"teach_mouse_release":46,"draw_recording_button":133,"teach_keychord_press":47,"save_wav":171,"teach_key_release":56,"learn_keychord_press":59,"teach_text_input":49,"draw_new_word_button":117,"on.draw":5,"learn_mouse_press":57,"Words":12,"learn_mouse_release":58,"on.initialize":7,"draw_playing_button":130,"Font_height":8,"learn_text_input":60,"Line_height":9,"learn_key_release":61,"Mode":2,"draw_teach_screen":110,"on.keychord_press":53}

save_wav = function(filename, sounddata)
	-- credit to Intas and zorg on the LÖVE forum <3
	-- https://love2d.org/forums/viewtopic.php?t=86173
	local samples = {}
	for i = 0, sounddata:getSampleCount() - 1 do
		local sample = sounddata:getSample(i)
		local n
		local to16bit = sample * 32767
		if (to16bit > 0) then
			n = math.floor(math.min(to16bit, 32767))
		else
			n = math.floor(math.max(to16bit, -32768))
		end
		table.insert(samples, n)
	end
	local w = wav.create_context(filename, "w")
	w.init(sounddata:getChannelCount(), sounddata:getSampleRate(), sounddata:getBitDepth())
	w.write_samples_interlaced(samples)
	w.finish()
end

{"draw_record_button":140,"draw_play_button":141,"on.mouse_press":51,"on.mouse_release":52,"fw_parent":170,"Playing_source":126,"fw_app":"spell-cards","on.key_release":55,"on_new_word_button":118,"on.text_input":54,"Cursor_word":24,"Recording_device":132,"on_word":80,"new_word":64,"Recording_word":138,"record":167,"on":1,"on_play":96,"on_record":95,"draw_teach_word":68,"draw_learn_screen":4,"to_word_idx":94,"teach_mouse_press":88,"play":169,"teach_mouse_release":46,"draw_recording_button":133,"teach_keychord_press":47,"save_wav":171,"teach_key_release":56,"learn_keychord_press":59,"teach_text_input":49,"draw_new_word_button":117,"on.draw":5,"learn_mouse_press":57,"Words":12,"learn_mouse_release":58,"on.initialize":7,"draw_playing_button":130,"Font_height":8,"learn_text_input":60,"Line_height":9,"learn_key_release":61,"Mode":2,"draw_teach_screen":110,"on.keychord_press":53}

save_wav = function(filename, sounddata)
	-- credit to Intas and zorg on the LÖVE forum <3
	-- https://love2d.org/forums/viewtopic.php?t=86173
	local samples = {}
	for i = 0, sounddata:getSampleCount() - 1 do
		local sample = sounddata:getSample(i)
		local n
		local to16bit = sample * 32767
		if (to16bit > 0) then
			n = math.floor(math.min(to16bit, 32767))
		else
			n = math.floor(math.max(to16bit, -32768))
		end
		table.insert(samples, n)
	end
	local w = wav.create_context("test.wav", "w")
	w.init(sounddata:getChannelCount(), sounddata:getSampleRate(), sounddata:getBitDepth())
	w.write_samples_interlaced(samples)
	w.finish()
end

{"draw_record_button":140,"draw_play_button":141,"on.mouse_press":51,"on.mouse_release":52,"fw_parent":169,"Playing_source":126,"fw_app":"spell-cards","on.key_release":55,"on_new_word_button":118,"on.text_input":54,"Cursor_word":24,"Recording_device":132,"on_word":80,"new_word":64,"Recording_word":138,"record":167,"on":1,"on_play":96,"on_record":95,"draw_teach_word":68,"draw_learn_screen":4,"to_word_idx":94,"teach_mouse_press":88,"play":169,"teach_mouse_release":46,"draw_recording_button":133,"teach_keychord_press":47,"save_wav":170,"teach_key_release":56,"learn_keychord_press":59,"teach_text_input":49,"draw_new_word_button":117,"on.draw":5,"learn_mouse_press":57,"Words":12,"learn_mouse_release":58,"on.initialize":7,"draw_playing_button":130,"Font_height":8,"learn_text_input":60,"Line_height":9,"learn_key_release":61,"Mode":2,"draw_teach_screen":110,"on.keychord_press":53}

play = function(word_idx)
	if Words[word_idx].recording then
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	elseif love.filesystem.exists(Words[word_idx].contents..'.sounddata') then
		Words[word_idx].recording = love.sound.newSoundData(Words[word_idx].contents..'.sounddata')
		Playing_source = love.audio.newSource(Words[word_idx].recording)
	else
		Playing_source = love.audio.newSource('test.wav', 'static')
	end
	Playing_source:play()
	Recording_device = nil
end

{"record":167,"new_word":64,"on":1,"save_wav":168,"on_record":95,"draw_teach_word":68,"teach_mouse_press":88,"teach_mouse_release":46,"draw_new_word_button":117,"draw_teach_screen":110,"teach_keychord_press":47,"draw_recording_button":133,"fw_parent":168,"on.draw":5,"fw_app":"spell-cards","Words":12,"teach_key_release":56,"on.initialize":7,"on.keychord_press":53,"Font_height":8,"learn_mouse_press":57,"Line_height":9,"learn_mouse_release":58,"Mode":2,"learn_keychord_press":59,"Recording_device":132,"learn_text_input":60,"Playing_source":126,"learn_key_release":61,"Recording_word":138,"draw_playing_button":130,"teach_text_input":49,"on_play":96,"on.mouse_press":51,"draw_record_button":140,"on_new_word_button":118,"draw_play_button":141,"play":169,"on.mouse_release":52,"on.key_release":55,"on_word":80,"on.text_input":54,"Cursor_word":24,"to_word_idx":94,"draw_learn_screen":4}

save_wav = function(filename, sounddata)
	local channelCount = sounddata:getChannelCount()
	local sampleRate   = sounddata:getSampleRate()
	local bitDepth     = sounddata:getBitDepth()
	local samples = {}
	for i = 0, sounddata:getSampleCount() - 1 do
		local sample = sounddata:getSample(i)
		local n
		local to16bit = sample * 32767
		if (to16bit > 0) then
			n = math.floor(math.min(to16bit, 32767))
		else
			n = math.floor(math.max(to16bit, -32768))
		end
		table.insert(samples, n)
	end
	local w = wav.create_context("test.wav", "w")
	w.init(channelCount, sampleRate, bitDepth)
	w.write_samples_interlaced(samples)
	w.finish()
end

{"record":167,"new_word":64,"on":1,"save_wav":168,"on_record":95,"draw_teach_word":68,"teach_mouse_press":88,"teach_mouse_release":46,"draw_new_word_button":117,"draw_teach_screen":110,"teach_keychord_press":47,"draw_recording_button":133,"fw_parent":167,"on.draw":5,"fw_app":"spell-cards","Words":12,"teach_key_release":56,"on.initialize":7,"on.keychord_press":53,"Font_height":8,"learn_mouse_press":57,"Line_height":9,"learn_mouse_release":58,"Mode":2,"learn_keychord_press":59,"Recording_device":132,"learn_text_input":60,"Playing_source":126,"learn_key_release":61,"Recording_word":138,"draw_playing_button":130,"teach_text_input":49,"on_play":96,"on.mouse_press":51,"draw_record_button":140,"on_new_word_button":118,"draw_play_button":141,"play":165,"on.mouse_release":52,"on.key_release":55,"on_word":80,"on.text_input":54,"Cursor_word":24,"to_word_idx":94,"draw_learn_screen":4}

record = function(word_idx)
	if Recording_device then
		Words[word_idx].recording = Recording_device:getData()
		Recording_device:stop()
		if Words[word_idx].recording then
			save_wav(Words[word_idx].contents..'.sounddata', Words[word_idx].recording)
		end
		Recording_device = nil
		Recording_word = nil
		return
	end
	local devices = love.audio.getRecordingDevices()
	if #devices == 0 then return end
	Recording_device = devices[1]
	Recording_device:start()
	Recording_word = Words[word_idx]
	Playing_source = nil
end

{"record":167,"new_word":64,"on":1,"save_wav":166,"on_record":95,"draw_teach_word":68,"teach_mouse_press":88,"teach_mouse_release":46,"draw_new_word_button":117,"draw_teach_screen":110,"teach_keychord_press":47,"draw_recording_button":133,"fw_parent":166,"on.draw":5,"fw_app":"spell-cards","Words":12,"teach_key_release":56,"on.initialize":7,"on.keychord_press":53,"Font_height":8,"learn_mouse_press":57,"Line_height":9,"learn_mouse_release":58,"Mode":2,"learn_keychord_press":59,"Recording_device":132,"learn_text_input":60,"Playing_source":126,"learn_key_release":61,"Recording_word":138,"draw_playing_button":130,"teach_text_input":49,"on_play":96,"on.mouse_press":51,"draw_record_button":140,"on_new_word_button":118,"draw_play_button":141,"play":165,"on.mouse_release":52,"on.key_release":55,"on_word":80,"on.text_input":54,"Cursor_word":24,"to_word_idx":94,"draw_learn_screen":4}

save_wav = function(filename, soundData)
end

{"record":162,"new_word":64,"on":1,"save_wav":166,"on_record":95,"draw_teach_word":68,"teach_mouse_press":88,"teach_mouse_release":46,"draw_new_word_button":117,"draw_teach_screen":110,"teach_keychord_press":47,"draw_recording_button":133,"fw_parent":165,"on.draw":5,"fw_app":"spell-cards","Words":12,"teach_key_release":56,"on.initialize":7,"on.keychord_press":53,"Font_height":8,"learn_mouse_press":57,"Line_height":9,"learn_mouse_release":58,"Mode":2,"learn_keychord_press":59,"Recording_device":132,"learn_text_input":60,"Playing_source":126,"learn_key_release":61,"Recording_word":138,"draw_playing_button":130,"teach_text_input":49,"on_play":96,"on.mouse_press":51,"draw_record_button":140,"on_new_word_button":118,"draw_play_button":141,"play":165,"on.mouse_release":52,"on.key_release":55,"on_word":80,"on.text_input":54,"Cursor_word":24,"to_word_idx":94,"draw_learn_screen":4}