-- todo
-- add support for bots

local EXTRA_LARGE_BUBBLE_RESPAWN_TIME = 2 * TICRATE
local EXTRA_LARGE_BUBBLE_INITIAL_SPAWN_TIME = 4 * TICRATE

local EXTRA_LARGE_BUBBLE_SPAWN_MOMZ = 2 * FRACUNIT + FRACUNIT / 2
local EXTRA_LARGE_BUBBLE_MOMZ_DECAY = FixedDiv(-1 * FRACUNIT, 20 * FRACUNIT)
local EXTRA_LARGE_BUBBLE_HOVER_LIMIT = FRACUNIT / 2
local EXTRA_LARGE_BUBBLE_HOVER_DIVISOR = 50 * FRACUNIT

local EXTRA_LARGE_BUBBLE_DEATH_STATE = mobjinfo[MT_EXTRALARGEBUBBLE].deathstate

local BUBBLE_SOUNDS =
{
	sfx_bubbl1;
	sfx_bubbl2;
	sfx_bubbl3;
	sfx_bubbl4;
	sfx_bubbl5;
}

states[S_BUBBLES1] =
{
	sprite = SPR_BBLS;
	frame = 0;
	tics = 8;
	action = nil;
	var1 = 0;
	var2 = 0;
	nextstate = S_BUBBLES2;
}

states[S_BUBBLES2] =
{
	sprite = SPR_BBLS;
	frame = 1;
	tics = 8;
	action = nil;
	var1 = 0;
	var2 = 0;
	nextstate = S_BUBBLES3;
}

states[S_BUBBLES3] =
{
	sprite = SPR_BBLS;
	frame = 2;
	tics = 8;
	action = nil;
	var1 = 0;
	var2 = 0;
	nextstate = S_BUBBLES4;
}

states[S_BUBBLES4] =
{
	sprite = SPR_BBLS;
	frame = 3;
	tics = 8;
	action = nil;
	var1 = 0;
	var2 = 0;
	nextstate = S_BUBBLES1;
}

-- port of P_GetFFloorTopZAt from p_slopes.c
-- Returns the height of the FOF top at (x, y)
local function getFFloorTopZAt(ffloor, x, y)
	if ffloor.t_slope ~= nil then
		return P_GetSlopeZAt(ffloor.t_slope, x, y)
	else
		return ffloor.topheight
	end
end

-- port of P_GetFFloorBottomZAt from p_slopes.c
-- Returns the height of the FOF bottom at (x, y)
local function getFFloorBottomZAt(ffloor, x, y)
	if ffloor.b_slope ~= nil then
		return P_GetSlopeZAt(ffloor.b_slope, x, y)
	else
		return ffloor.bottomheight
	end
end


-- port of P_SceneryCheckWater from p_mobj.c
local function sceneryCheckWater(mobj)
	-- see if we are in water, and set some flags for later
	local sector = mobj.subsector.sector

	-- Default if no water exists.
	mobj.watertop = mobj.z - 1000 * FRACUNIT
	mobj.waterbottom = mobj.watertop

	if sector.ffloors ~= nil then
		mobj.eflags = $ & ~(MFE_UNDERWATER|MFE_TOUCHWATER)

		for rover in sector.ffloors() do
			if not (rover.flags & FF_EXISTS) or not (rover.flags & FF_SWIMMABLE) or rover.flags & FF_BLOCKOTHERS then
				continue
			end

			local topheight = getFFloorTopZAt(rover, mobj.x, mobj.y)
			local bottomheight = getFFloorBottomZAt(rover, mobj.x, mobj.y)

			if topheight <= mobj.z or bottomheight > (mobj.z + (mobj.height >> 1)) then
				continue
			end

			if mobj.z + mobj.height > topheight then
				mobj.eflags = $ | MFE_TOUCHWATER
			else
				mobj.eflags = $ & ~MFE_TOUCHWATER
			end

			-- Set the watertop and waterbottom
			mobj.watertop = topheight
			mobj.waterbottom = bottomheight

			if mobj.z + (mobj.height >> 1) < topheight then
				mobj.eflags = $ | MFE_UNDERWATER
			else
				mobj.eflags = $ & ~MFE_UNDERWATER
			end
		end
	else
		mobj.eflags = $ & ~(MFE_UNDERWATER | MFE_TOUCHWATER)
	end
end


addHook("MobjSpawn", function(bubblePatch)
	bubblePatch.cooldown = EXTRA_LARGE_BUBBLE_INITIAL_SPAWN_TIME + P_RandomRange(0, 35)
end, MT_BUBBLES)

addHook("MobjThinker", function(bubblePatch)
	if bubblePatch.eflags & MFE_UNDERWATER then
		bubblePatch.flags2 = $ & ~MF2_DONTDRAW
	else
		bubblePatch.flags2 = $ | MF2_DONTDRAW
		return false
	end

	if leveltime % 8 == 0 then
		local bubble
		local randomNumber = P_RandomRange(1, 8)
		if randomNumber >= 6 then
			bubble = P_SpawnMobj(
				bubblePatch.x, bubblePatch.y, bubblePatch.z + bubblePatch.height / 2,
				MT_SMALLBUBBLE
			)
		elseif randomNumber == 5 then
			bubble = P_SpawnMobj(
				bubblePatch.x, bubblePatch.y, bubblePatch.z + bubblePatch.height / 2,
				MT_MEDIUMBUBBLE
			)
		end
		if bubble then
			bubble.scale = bubblePatch.scale
		end
	end

	local extraLargeBubble = bubblePatch.extralargebubble
	if extraLargeBubble ~= nil and not extraLargeBubble.valid then
		extraLargeBubble = nil
	end
	if extraLargeBubble == nil then
		if bubblePatch.cooldown ~= nil and bubblePatch.cooldown > 0 then
			bubblePatch.cooldown = $ - 1
		else
			extraLargeBubble = P_SpawnMobj(
				bubblePatch.x, bubblePatch.y, bubblePatch.z + bubblePatch.height / 2,
				MT_EXTRALARGEBUBBLE
			)
			bubblePatch.extralargebubble = extraLargeBubble
			extraLargeBubble.bubblepatch = bubblePatch
			extraLargeBubble.scale = bubblePatch.scale
			extraLargeBubble.state = S_LARGEBUBBLE1
			P_SetObjectMomZ(extraLargeBubble, EXTRA_LARGE_BUBBLE_SPAWN_MOMZ, false)
			S_StartSound(bubblePatch, BUBBLE_SOUNDS[P_RandomRange(1, #BUBBLE_SOUNDS)])
		end
	end
end, MT_BUBBLES)

addHook("MobjThinker", function(extraLargeBubble)
	if extraLargeBubble.state == EXTRA_LARGE_BUBBLE_DEATH_STATE then
		return false
	end

	if extraLargeBubble.bubblepatch ~= nil then
		if extraLargeBubble.bubblepatch.valid then
			sceneryCheckWater(extraLargeBubble)
			if not (extraLargeBubble.eflags & MFE_UNDERWATER) then
				P_RemoveMobj(extraLargeBubble)
				return false
			end

			if extraLargeBubble.state == S_LARGEBUBBLE1 or extraLargeBubble.state == S_LARGEBUBBLE2 then
				extraLargeBubble.tics = $ - 1
				if extraLargeBubble.tics == 0 then
					P_SetMobjStateNF(extraLargeBubble, states[extraLargeBubble.state].nextstate)
				end
			elseif extraLargeBubble.state == S_EXTRALARGEBUBBLE then
				if extraLargeBubble.hoverdirection ~= nil then
					P_SetObjectMomZ(
						extraLargeBubble,
						FixedDiv(extraLargeBubble.hoverdirection, EXTRA_LARGE_BUBBLE_HOVER_DIVISOR),
						true
					)
					if abs(extraLargeBubble.momz) >= FixedMul(EXTRA_LARGE_BUBBLE_HOVER_LIMIT, extraLargeBubble.scale) then
						extraLargeBubble.hoverdirection = $ * -1
					end
				else
					P_SetObjectMomZ(extraLargeBubble, EXTRA_LARGE_BUBBLE_MOMZ_DECAY, true)
					if extraLargeBubble.momz <= 0 then
						P_SetObjectMomZ(extraLargeBubble, 0, false)
						extraLargeBubble.hoverdirection = FRACUNIT * -1
					end
				end

				if extraLargeBubble.momx ~= 0 or extraLargeBubble.momy ~= 0 then
					P_XYMovement(extraLargeBubble)
				end
				if extraLargeBubble.momz ~= 0 then
					P_ZMovement(extraLargeBubble)
				end
			end
		else
			extraLargeBubble.bubblepatch = nil
		end
		return true
	end
end, MT_EXTRALARGEBUBBLE)

-- this is to prevent bots from becoming stuck in air bubbles; in vanilla, bots
-- do not delete air bubbles when touching them, but they still refill their air
-- as a compromise, i'll make it so that bots will delete bubbles, but the next
-- bubble will spawn immediately afterwards
addHook("MobjCollide", function(extraLargeBubble, playerMobj)
	local bubblePatch = extraLargeBubble.bubblepatch
	if bubblePatch ~= nil and bubblePatch.valid then
		local player = playerMobj.player
		if player ~= nil and player.bot ~= 0 and playerMobj.state == S_PLAY_GASP then
			extraLargeBubble.immediaterespawn = true
			P_KillMobj(extraLargeBubble)
		end
	end
end, MT_EXTRALARGEBUBBLE)

addHook("MobjRemoved", function(extraLargeBubble)
	local bubblePatch = extraLargeBubble.bubblepatch
	if bubblePatch ~= nil and bubblePatch.valid then
		if extraLargeBubble.immediaterespawn then
			bubblePatch.cooldown = 0
		else
			bubblePatch.cooldown = EXTRA_LARGE_BUBBLE_RESPAWN_TIME
		end
	end
end, MT_EXTRALARGEBUBBLE)