MAX_DIST = 1000
DONE_TIMER = 2.0
BURN_TIME = 25
PLAYER_HIT_RADIUS = 0.2

buttonShape = 0
emitterShape = 0
emitterLocation = 0
vaultDoors = {}
deflectors = {}
laserLoop = 0
laserHitLoop = 0
laserHitSound = 0
laserSprite = 0
laserDist = 0
laserHitScale = 0
disableTimer = 0

function rnd(mi, ma)
	return math.random(1000)/1000*(ma-mi) + mi
end

function rndVec(t)
	return Vec(rnd(-t, t), rnd(-t, t), rnd(-t, t))
end 

function init()
	buttonShape = FindShape("button")
	emitterShape = FindShape("emitter")
	emitterLocation = FindLocation("emitter")
	vaultDoors = FindBodies("vaultdoor", true)
	
	laserLoop = LoadLoop("laser-loop.ogg")
	laserHitLoop = LoadLoop("laser-hit-loop.ogg")
	laserHitSound = LoadSound("light/spark0.ogg")
	
	laserSprite = LoadSprite("gfx/laser.png")

	setEnabled(false)
	
	deflectors = FindBodies("mirror2", true)
end


function setEnabled(e)
	enabled = e
	if enabled then
		SetShapeEmissiveScale(emitterShape, 1)
		SetTag(buttonShape, "interact", "loc@TURN_OFF")
	else
		SetShapeEmissiveScale(emitterShape, 0)
		SetTag(buttonShape, "interact", "loc@TURN_ON")
	end
end


function emitSmoke(pos)
	ParticleReset()
	ParticleType("smoke")
	ParticleColor(0.8, 0.8, 0.8)
	ParticleRadius(0.2, 0.4)
	ParticleAlpha(0.5, 0)
	ParticleDrag(0.5)
	ParticleGravity(rnd(0.0, 2.0))
	SpawnParticle(VecAdd(pos, rndVec(0.01)), rndVec(0.1), rnd(1.0, 3.0))

	ParticleReset()
	ParticleEmissive(5, 0, "easeout")
	ParticleGravity(-10)
	ParticleRadius(0.01, 0.0, "easein")
	ParticleColor(1, 0.4, 0.3)
	ParticleTile(4)
	local vel = VecAdd(Vec(0, 1, 0), rndVec(2.0))
	SpawnParticle(pos, vel, rnd(1.0, 2.0))
end


function getDistanceToLineSegment(point, p0, p1)
    local line_vec = VecSub(p1, p0)
    local pnt_vec = VecSub(point, p0)
    local line_len = VecLength(line_vec)
    local line_unitvec = VecNormalize(line_vec)
    local pnt_vec_scaled = VecScale(pnt_vec, 1.0/line_len)
    local t = VecDot(line_unitvec, pnt_vec_scaled)    
    if t < 0.0 then
        t = 0.0
    elseif t > 1.0 then
        t = 1.0
	end
    local nearest = VecScale(line_vec, t)
    local dist = VecLength(VecSub(nearest, pnt_vec))
    nearest = VecAdd(nearest, p0)
    return dist, nearest
end


function shootLaser(body, shape, origin, dir, currentLength, deflectorsHit)
	--Raycast
	QueryRequire("physical")
	if shape ~= 0 then
		QueryRejectShape(shape)
	end
	if body ~= 0 then
		QueryRejectBody(body)
	end
	local hit, hitDist, hitNormal, hitShape = QueryRaycast(origin, dir, MAX_DIST, 0.0, true)
	local length = MAX_DIST
	if hit then
		length = hitDist
	end
	local hitPoint = VecAdd(origin, VecScale(dir, length))
	
	local t = Transform(VecLerp(origin, hitPoint, 0.5))
	local xAxis = VecNormalize(VecSub(hitPoint, origin))
	local zAxis = VecNormalize(VecSub(origin, GetCameraTransform().pos))
	t.rot = QuatAlignXZ(xAxis, zAxis)
	DrawSprite(laserSprite, t, length, 0.05+math.random()*0.01, 8, 4, 4, 1, true, true)
	DrawSprite(laserSprite, t, length, 0.5, 1.0, 0.3, 0.3, 1, true, true)

	--Check if player if hit by laser
	local ppos = GetPlayerCameraTransform().pos
	ppos[2] = ppos[2] - PLAYER_HIT_RADIUS*0.5
	local pdist, phit = getDistanceToLineSegment(ppos, origin, hitPoint)
	if pdist < PLAYER_HIT_RADIUS then
		--Disance to player, without vertical component
		local pdir = VecSub(ppos, phit)
		pdir[2] = 0
		pdir = VecNormalize(pdir)

		--Move player and give a nudge
		local pt = GetPlayerTransform(true)
		pt.pos = VecAdd(pt.pos, VecScale(pdir, PLAYER_HIT_RADIUS-pdist+0.1))
		SetPlayerTransform(pt, true)
		SetPlayerVelocity(VecScale(pdir, 5))

		--Play hit sound
		PlaySound(laserHitSound, ppos)
	end
	
	--Check if directed
	local hitBody = GetShapeBody(hitShape)
	if HasTag(hitBody, "mirror2") and currentLength < MAX_DIST then
		--Only allow the beam to hit a deflector once
		local alreadyHit = false
		for i=1, #deflectorsHit do
			if deflectorsHit[i] == hitBody then
				alreadyHit = true
				break
			end
		end
		if not alreadyHit then
			deflectorsHit[#deflectorsHit+1] = hitBody
			local ht = GetBodyTransform(hitBody)
			local refDir = TransformToParentVec(ht, Vec(0, 0, 1))
			SetShapeEmissiveScale(hitShape, 1)
			return shootLaser(hitBody, hitShape, ht.pos, refDir, currentLength + length, deflectorsHit)
		end
	end

	--Check if reflected
	if HasTag(hitBody, "mirror") and currentLength < MAX_DIST then
		local refDir = VecSub(dir, VecScale(hitNormal, VecDot(hitNormal, dir)*2))
		return shootLaser(hitBody, hitShape, hitPoint, refDir, currentLength + length, deflectorsHit)
	end

	return currentLength + length, hitPoint, hitBody, hitShape
end

function tick(dt)
	for i=1, #deflectors do
		local shapes = GetBodyShapes(deflectors[i])
		if #shapes > 0 then
			SetShapeEmissiveScale(shapes[1], 0)
		end
	end

	if GetPlayerInteractShape() == buttonShape and InputPressed("interact") then
		setEnabled(not enabled)
	end
	
	if enabled then
		local emitTransform = GetLocationTransform(emitterLocation)
		local origin = emitTransform.pos
		PlayLoop(laserLoop, origin, 0.5)
		local dir = TransformToParentVec(emitTransform, Vec(0, 0, -1))
		local length, hitPoint, hitBody, _hitShape = shootLaser(0, emitterShape, origin, dir, 0, {})
		if length ~= laserDist then
			laserHitScale = 1
			laserDist = length
		end
		laserHitScale = math.max(0.0, laserHitScale - dt)
		if laserHitScale > 0 then
			PlayLoop(laserHitLoop, hitPoint, laserHitScale)
			PointLight(hitPoint, 1, 0.2, 0.2, rnd(2.0, 4.0)*laserHitScale)
		end
		PointLight(hitPoint, 1, 0.2, 0.2, rnd(0.5, 1.0))

		for i = 1, #vaultDoors do
			if hitBody == vaultDoors[i] then
				RemoveTag(vaultDoors[i], "unbreakable")
			end
		end
	
		emitSmoke(hitPoint)
		MakeHole(hitPoint, 0.5, 0.3, 0, true)
	end
	
	SetBool("level.laser", enabled)

	if GetBool("level.vaultbroken") then
		disableTimer = disableTimer + dt
		if disableTimer > 3 then
			setEnabled(false)
			SetBool("level.vaultbroken", false)
		end
	end
end