--@client
--@include /libs/task.txt
local Task = require('/libs/task.txt')

local Sound = class('Sound')

local function map(x, a, b, c, d)
	return (x - a) / (b - a) * (d - c) + c
end

local function fade(n, min, mid, max)
	if n < min or n > max then
		return 0
	end

	if n > mid then
		min = mid - (max - mid)
	end

	return math.cos((1 - ((n - min) / (mid - min))) * (math.pi / 2))
end

function Sound:initialize(redline, parent, sounds)
	local sounds = sounds
		or {
			[900] = 'https://raw.githubusercontent.com/koptilnya/gmod-data/main/engine_sounds/bmw_s54/ext_e30s54_idle.ogg',
			[2500] = 'https://raw.githubusercontent.com/koptilnya/gmod-data/main/engine_sounds/bmw_s54/ext_e30s54_on_2500.ogg',
			[4000] = 'https://raw.githubusercontent.com/koptilnya/gmod-data/main/engine_sounds/bmw_s54/ext_e30s54_on_4000.ogg',
			[6750] = 'https://raw.githubusercontent.com/koptilnya/gmod-data/main/engine_sounds/bmw_s54/ext_e30s54_on_6750.ogg',
			[8500] = 'https://raw.githubusercontent.com/koptilnya/gmod-data/main/engine_sounds/bmw_s54/ext_e30s54_on_8500.ogg',
		}
	local redline = redline or 7000
	self.active = false
	local soundObjects = {}
	local soundRpms = {}
	local maxValue = 0
	local throttle = 0
	local engineRpm = 0
	local smoothRpm = 0
	local smoothThrottle = 0

	Task.run(function()
		for soundRpm, soundPath in pairs(sounds) do
			local sound = await * soundLoad(soundPath, '3d noblock noplay')
			soundObjects[soundRpm] = sound
			table.insert(soundRpms, soundRpm)
			if maxValue < soundRpm then
				maxValue = soundRpm
			end
		end

		table.sort(soundRpms)

		hook.add('think', table.address({}), function()
			if not self.active then
				return
			end

			smoothRpm = smoothRpm * (1 - 0.2) + engineRpm * 0.2
			smoothThrottle = smoothThrottle * (1 - 0.1) + throttle * 0.1

			for n, rpm in ipairs(soundRpms) do
				if not soundObjects[rpm] or not soundObjects[rpm].Bass then
					goto CONTINUE
				end
				local min = n == 1 and -100000 or soundRpms[n - 1]
				local max = n == #soundRpms and 100000 or soundRpms[n + 1]
				local c = fade(smoothRpm, min - 10, rpm, max + 10)
				local vol = c * map(smoothThrottle, 0, 1, 0.5, 1)
				local soundObject = soundObjects[rpm].Bass
				soundObject:setVolume(vol)
				soundObject:setPitch(smoothRpm / rpm)
				soundObject:setPos(parent:getPos())
				soundObject:pause()
				soundObject:play()
				::CONTINUE::
			end
		end)
	end)

	net.receive('ENGINE_FULLRPM', function()
		local rpm = net.readUInt(16)
		engineRpm = rpm * (maxValue / redline)
		throttle = math.max(net.readFloat(), 0)
	end)
end

return Sound