-- LUA Script - precede every function and global member with lowercase name of script

g_lift_base_list = {}
g_player_Yoff    = 0

-- init when level first runs
function lift_base_init_name(e, name)

	g_lift_base_list[e] = {name       = name,
						   firstpass  = true,
						   hgt_min    = nil,
						   lifthight  = nil,
						   hgt_max    = nil,
						   rotation   = nil,
						   plrinlift  = false,
						   statechng  = false,
						   lift_state = 0,     -- 0=Down,   1=Ascending, 2=Up,   3=Descending
						   door_state = 0,     -- 0=Closed, 1=Opening,   2=Open, 3=Closing
						   dooroffset = 0,
						   allentsin  = false,
						   ents_list  = {}     -- 8 element array, 1-3=walls, 4=roof, 5-6=static door, 7-8=doors
						   }
	for i = 1, 8 do					   
		g_lift_base_list[e].ents_list[i] = {ent = nil, XO=0, YO=98, ZO=0, YR=0, SC=97}
	end
end


function position_doors (LB, x, y, z, offset)
	local md1, md2 = LB.ents_list[7], LB.ents_list[8]
	
	CollisionOff(md1.ent)
	CollisionOff(md2.ent)

	if LB.rotation == 90 then
		ResetPosition(md1.ent, x + md1.XO, y + md1.YO, z + (md1.ZO - offset))
		ResetRotation(md1.ent, 0, md1.YR, 0)
		ResetPosition(md2.ent, x + md2.XO, y + md2.YO, z + (md2.ZO + offset))
		ResetRotation(md2.ent, 0, md2.YR, 0)
	elseif LB.rotation == 180 then
		ResetPosition(md1.ent, x + (md1.XO - offset), y + md1.YO, z + md1.ZO)
		ResetRotation(md1.ent, 0, md1.YR, 0)
		ResetPosition(md2.ent, x + (md2.XO + offset), y + md2.YO, z + md2.ZO)
		ResetRotation(md2.ent, 0, md2.YR, 0)
	elseif LB.rotation == 270 then
		ResetPosition(md1.ent, x + md1.XO, y + md1.YO, z + (md1.ZO + offset))
		ResetRotation(md1.ent, 0, md1.YR, 0)
		ResetPosition(md2.ent, x + md2.XO, y + md2.YO, z + (md2.ZO - offset))
		ResetRotation(md2.ent, 0, md2.YR, 0)
	else
		ResetPosition(md1.ent, x + (md1.XO + offset), y + md1.YO, z + md1.ZO)
		ResetRotation(md1.ent, 0, md1.YR, 0)
		ResetPosition(md2.ent, x + (md2.XO - offset), y + md2.YO, z + md2.ZO)
		ResetRotation(md2.ent, 0, md2.YR, 0)
	end

	CollisionOn(md1.ent)
	CollisionOn(md2.ent)
end

function position_ents (LB, x, y, z)

	for k, e in ipairs (LB.ents_list) do
	
		CollisionOff(e.ent)

		ResetPosition(e.ent, x + e.XO, y + e.YO, z + e.ZO)
		ResetRotation(e.ent, 0, e.YR, 0)
		if k < 5 then
			Scale(e.ent, e.SC)
		end
		
		CollisionOn(e.ent)
	end
end

function calc_positions(LB)

	local wall1, wall2, wall3 = LB.ents_list[1], LB.ents_list[2], LB.ents_list[3]
	local sd1, sd2 = LB.ents_list[5], LB.ents_list[6]
	local md1, md2 = LB.ents_list[7], LB.ents_list[8]
	
	-- Position walls depending on angle
	if LB.rotation == 90 then
		-- x,y,z offsets
		wall1.XO, wall1.YO, wall1.ZO =   0,   2, -47 
		wall2.XO, wall2.YO, wall2.ZO = -47,   2,   0
		wall3.XO, wall3.YO, wall3.ZO =   0,   2,  47
		-- rotation
		wall1.YR, wall2.YR, wall3.YR = 180,  90, 180
		-- doors
		sd1.XO, sd1.YO, sd1.ZO =  47,  2,  -35
		sd2.XO, sd2.YO, sd2.ZO =  47,  2,   35
		sd1.YR, sd2.YR = 0, 180
		md1.XO, md1.YO, md1.ZO =  47.5,  2,  -12.25
		md2.XO, md2.YO, md2.ZO =  47.5,  2,   12.25
		md1.YR, md2.YR = 0, 180
		
	elseif LB.rotation == 180 then
		-- x,y,z offsets
		wall1.XO, wall1.YO, wall1.ZO = -47,   2,   0 
		wall2.XO, wall2.YO, wall2.ZO =   0,   2,  47
		wall3.XO, wall3.YO, wall3.ZO =  47,   2,   0
		-- rotation
		wall1.YR, wall2.YR, wall3.YR =  90, 180,  90
		-- doors
		sd1.XO, sd1.YO, sd1.ZO =  -35,  2,  -47
		sd2.XO, sd2.YO, sd2.ZO =   35,  2,  -47
		sd1.YR, sd2.YR = 90, 270
		md1.XO, md1.YO, md1.ZO =  -12.25,  2,  -47.5
		md2.XO, md2.YO, md2.ZO =   12.25,  2,  -47.5
		md1.YR, md2.YR = 90, 270
		
	elseif LB.rotation == 270 then
		-- x,y,z offsets
		wall1.XO, wall1.YO, wall1.ZO =   0,   2,  47 
		wall2.XO, wall2.YO, wall2.ZO =  47,   2,   0
		wall3.XO, wall3.YO, wall3.ZO =   0,   2, -47
		-- rotation
		wall1.YR, wall2.YR, wall3.YR = 180,  90, 180
		-- doors
		sd1.XO, sd1.YO, sd1.ZO =  -47,  2,   35
		sd2.XO, sd2.YO, sd2.ZO =  -47,  2,  -35
		sd1.YR, sd2.YR = 180, 0
		md1.XO, md1.YO, md1.ZO =  -47.5,  2,   12.25
		md2.XO, md2.YO, md2.ZO =  -47.5,  2,  -12.25
		md1.YR, md2.YR = 180, 0
		
	else
		-- x,y,z offsets
		wall1.XO, wall1.YO, wall1.ZO =  47,   2,   0 
		wall2.XO, wall2.YO, wall2.ZO =   0,   2, -47
		wall3.XO, wall3.YO, wall3.ZO = -47,   2,   0
		-- rotation
		wall1.YR, wall2.YR, wall3.YR =  90, 180,  90
		-- doors
		sd1.XO, sd1.YO, sd1.ZO =   35,  2,  47
		sd2.XO, sd2.YO, sd2.ZO =  -35,  2,  47
		sd1.YR, sd2.YR = 270, 270
		md1.XO, md1.YO, md1.ZO =   12.25,  2,  47.5
		md2.XO, md2.YO, md2.ZO =  -12.25,  2,  47.5
		md1.YR, md2.YR = 270, 90
		
	end
end
	
function position_base (e, Ent, LB)
	CollisionOff(e)
	ResetPosition(e, Ent.x, LB.lifthight, Ent.z)
	ResetRotation(e, 0, LB.rotation, 0)
	CollisionOn(e)
end
		
function lift_base_main(e)
		
	local Ent = g_Entity[e]
	
	if Ent.health == nil then return end
	
	local Px, Py, Pz = g_PlayerPosX, g_PlayerPosY, g_PlayerPosZ
	local LB = g_lift_base_list[e]
	
	-- Work out lift angle
	if LB.rotation == nil then
	
		local lift_angle = g_Entity[e].angley
	
		while lift_angle > 360 do
			lift_angle = lift_angle - 360
		end
		while lift_angle < 0 do
			lift_angle = lift_angle + 360
		end
		LB.rotation = lift_angle
	end
	
	-- Work out lift heights	
	if LB.lifthight == nil then
		LB.lifthight = Ent.y
		if Ent.health > LB.lifthight then
			LB.hgt_max = Ent.health - LB.lifthight
			LB.hgt_min = LB.lifthight
		else
			LB.hgt_max = LB.lifthight - Ent.health
			LB.hgt_min = LB.lifthight - LB.hgt_max
			LB.lift_state = 2             -- Lift Up
		end
	end
	
	-- find entities associated with this lift
	if not LB.allentsin then
		local entsincount = 0
		for i = 1, 8 do
			if LB.ents_list[i].ent ~= nil then
				entsincount = entsincount + 1
			else
				for j, v in pairs (g_lift_entity_pos_list) do
					if v.name == LB.name and
					   v.number == i then
						LB.ents_list[i].ent = j
						entsincount = entsincount + 1
					end
				end
			end
		end
		if entsincount == 8 then
			LB.allentsin = true
			
			-- now we have all the ents initialise the array positions
			calc_positions(LB)
			
		else
			return
		end
	end
	
	if LB.firstpass then
		position_ents (LB, Ent.x, Ent.y, Ent.z)
		LB.firstpass = false
	end
	
	-- check if we are close to this lift
	local DX,DY,DZ = Px - Ent.x, math.abs(Py - Ent.y), Pz - Ent.z
	if LB.door_state == 0 and
	   (DY > 70 or (DX*DX + DZ*DZ) > 40000) then return end
		
	-- Check if player is on the lift
	if Px > Ent.x - 47 and Px < Ent.x + 47 and
	   Pz > Ent.z - 47 and Pz < Ent.z + 47 and
	   Py > Ent.y - 2  and Py < Ent.y + 40 then
	   
	    if not LB.plrinlift then
			LB.plrinlift = true
			g_player_Yoff = Py - Ent.y
			LB.statechng = true
		end
		
	else
		LB.plrinlift = false
		LB.statechng = false
		
		-- Check if player in front of lift
		local sd1Ent = g_Entity[LB.ents_list[5].ent]
		local sd2Ent = g_Entity[LB.ents_list[6].ent]
		local DX1, DZ1 = Px - sd1Ent.x, Pz - sd1Ent.z
		local DX2, DZ2 = Px - sd2Ent.x, Pz - sd2Ent.z

		if DY < 50 and 
		   (DX1*DX1 + DZ1*DZ1) < 8000 and
		   (DX2*DX2 + DZ2*DZ2) < 8000 then
			if LB.door_state == 0 then  -- Door closed
				LB.dooroffset = 0
				LB.door_state = 1       -- So open it
				-- TBD : play sound - door opening
			end
		else
			if LB.door_state == 2 then  -- Door open
				LB.door_state = 3       -- So close it
				-- TBD : play sound -- door closing
			end
		end
	end
		
	if LB.door_state == 1 then          -- Door opening
		if LB.dooroffset < 22 then
			LB.dooroffset = LB.dooroffset + 0.25
			position_doors (LB, Ent.x, LB.lifthight, Ent.z, LB.dooroffset)
		else
			LB.door_state = 2
			LB.dooroffset = 22
		end
	elseif LB.door_state == 3 then      -- Door closing
		if LB.dooroffset > 0 then
			LB.dooroffset = LB.dooroffset - 0.25
			position_doors (LB, Ent.x, LB.lifthight, Ent.z, LB.dooroffset)
		else
			LB.door_state = 0
			LB.dooroffset = 0
		end
	end	
	
	-- Now lets move lift
	if LB.plrinlift and LB.statechng then
		
		if LB.door_state == 2 then
			LB.door_state = 3
			-- TBD : play sound - Door closing
		end
		
		if LB.lift_state == 0 then                 -- Lift Down
			if LB.door_state == 0 then             -- Door closed
				LB.lift_state = 1                  -- Going Up
				-- TBD : play sound - lift moving
			end
		elseif LB.lift_state == 2 then             -- Lift Up
			if LB.door_state == 0 then             -- Door closed
				LB.lift_state = 3                  -- Going Down
				-- TBD : play sound - lift moving
			end
		end
	end	
	
	if LB.lift_state == 1 then                     -- Going Up

		if LB.lifthight < LB.hgt_min + LB.hgt_max then
		
			LB.lifthight = LB.lifthight + 1
			
			position_base (e, Ent, LB)
			
			position_ents (LB, Ent.x, LB.lifthight, Ent.z)
	
			if LB.plrinlift and (g_KeyPressW + g_KeyPressS + g_KeyPressA + g_KeyPressD) == 0 then
				SetFreezePosition (Px, LB.lifthight + g_player_Yoff, Pz)
				TransportToFreezePositionOnly()
			end		

		else
			LB.lift_state = 2                      -- Lift Up
			LB.door_state = 1
			-- TBD : play sound - door opening
			LB.statechng  = false
		end
			
	elseif LB.lift_state == 3 then                 -- Going Down
		
		if LB.lifthight > LB.hgt_min then
			LB.lifthight = LB.lifthight - 1
				
			position_base (e, Ent, LB)
			
			position_ents (LB, Ent.x, LB.lifthight, Ent.z)
			
			if LB.plrinlift and (g_KeyPressW + g_KeyPressS + g_KeyPressA + g_KeyPressD) == 0 then
				SetFreezePosition (Px, LB.lifthight + g_player_Yoff, Pz)
				TransportToFreezePositionOnly()
			end		

		else
			LB.lift_state = 0
			LB.door_state = 1
			-- TBD : play sound - door opening
			LB.statechng  = false
		end
	end
	
--	Prompt("Lift:"  .. LB.name .. 
--		   " LS="   .. LB.lift_state ..
--		   " DS="   .. LB.door_state ..
--		   " Hmin=" .. LB.hgt_min ..
--		   " Hmax=" .. LB.hgt_max)
		
end