-- LUA Script - precede every function and global member with lowercase name of script + '_main'
local U = require "scriptbank\\utillib"
local Q = require "scriptbank\\quatlib"

local rad  = math.rad
local deg  = math.deg
local abs  = math.abs
local rnd  = math.random
local sqrt = math.sqrt
local modf = math.modf

math.randomseed(os.time())
rnd(); rnd(); rnd()

local new_moonlander_list = {}

function new_moonlander_init( e )
	Include( "utillib.lua" )
	Include( "quatlib.lua" )
	new_moonlander_list[ e ] = nil
end

local controlsState = { UThrust = false, FThrust = false, DThrust = false, LTurn = false, RTurn = false }

local function DisplayCrashedML( e, de )
	CollisionOff( e )
	
	de.quat = Q.FromEuler( 0, 0, 0 )
	
	DE_Show( e, 'Moonlander Crashed')
	
	DE_Update( e, de.x, de.y, de.z, de.quat )

	local list = DE_GetEnts ( e, 'Moonlander Crashed')
	
	if #list > 0 then
		StartParticleEmitter ( list[1] ) -- assume only one 'crashed' entity present
	end
	
	-- move 'new' moonlander to random position
	de.x, de.z = U.RandomPos( 3000, de.x, de.z )
	
	-- reposition moonlander	
	ResetRotation( e, 0, 0, 0 )
	ResetPosition( e, de.x, GetTerrainHeight( de.x, de.z ), de.z )
	CollisionOn( e )
end

local function AttachPlayer( de )

	local ldquat = Q.FromEuler( 0, rad( de.playerAngle ), 0 )

	ldquat = Q.Mul( de.quat, ldquat )
	
	xa, ya, za = Q.ToEuler( ldquat )
        	
    local xo, yo, zo = U.Rotate3D( 0, 0, -800, xa, ya, za )

    local y = GetTerrainHeight( de.x + xo, de.z + zo )
    
	if de.y + yo > y then y = de.y + yo end
	
    SetFreezePosition( de.x + xo, y + 400, de.z + zo )

	xa, ya, za = Q.ToEuler( Q.Mul( ldquat, Q.FromEuler( rad ( 15), 0, 0 ) ) )
	
	ya = deg( ya )
	
	-- avoid Euler gimble lock angles
	if abs( 90 - ya ) < 0.1 or 
	   abs( 90 + ya ) < 0.1 then
			ya = ya + 0.01
	end
	
    SetFreezeAngle( deg( xa ), ya, deg( za ) )
    TransportToFreezePosition()
end

local function GetControls( e, de )

	local controls = {}
	
	if g_KeyPressE == 1 then
		DE_Show( e, 'Main' )
		controlsState.UThrust = true
		controls[#controls + 1] = 'Main'
	elseif controlsState.UThrust then
		controlsState.UThrust = false
		DE_Hide( e, 'Main' )	
	end
	
	if g_KeyPressR == 1 then
		DE_Show( e, 'Down' )
		controlsState.DThrust = true
		controls[#controls + 1] = 'Down'
	elseif controlsState.DThrust then
		controlsState.DThrust = false
		DE_Hide( e, 'Down' )	
	end
	
	if g_MouseClick == 1 then
		DE_Show( e, 'Fwrd' )
		controlsState.FThrust = true
		controls[#controls + 1] = 'Fwrd'
	elseif controlsState.FThrust then
		controlsState.FThrust = false
		DE_Hide( e, 'Fwrd' )	
	end
	
	if g_MouseClick == 2 then
		DE_Show( e, 'Back' )
		controlsState.RThrust = true
		controls[#controls + 1] = 'Back'
	elseif controlsState.RThrust then
		controlsState.RThrust = false
		DE_Hide( e, 'Back' )	
	end
	
	local mx = MouseMoveX()
	
	if mx < 0 then
		DE_Show( e, 'Left' )
		controlsState.LTurn = true
		controls[#controls + 1] = 'Left'
	elseif controlsState.LTurn and  g_Time > de.mouseTimer then
		controlsState.LTurn = false
		DE_Hide( e, 'Left' )
	end
	
	if mx > 0 then
		DE_Show( e, 'Rght' )
		controlsState.RTurn = true
		controls[#controls + 1] = 'Rght'
	elseif controlsState.RTurn and g_Time > de.mouseTimer then
		controlsState.RTurn = false
		DE_Hide( e, 'Rght' )
	end	
	
	return controls
end

local function AddVect( vv, x, y, z , val)
	return {x = vv.x + x * val, 
	        y = vv.y + y * val,
			z = vv.z + z * val}
end


local function VectDist( v )
	return sqrt( v.x*v.x + v.y*v.y + v.z*v.z )
end

function HitTerrain( de )
	return GetTerrainHeight(de.x + 100, de.z + 100) >= de.y or
	       GetTerrainHeight(de.x + 100, de.z - 100) >= de.y or
	       GetTerrainHeight(de.x - 100, de.z + 100) >= de.y or
	       GetTerrainHeight(de.x - 100, de.z - 100) >= de.y
end

local startPress = false

function new_moonlander_main( e )

	local de = new_moonlander_list[ e ] 
	
	if de == nil then

		local Ent = g_Entity[e]

		-- model is forced to default rotation on purpose so that the 
		-- jet positioning abgles work properly.
		new_moonlander_list[ e ] = { state = 'init', timer = math.huge,
                                     quat = Q.FromEuler( 0, 0, 0 ),
									 x = Ent.x, y = Ent.y, z = Ent.z,
									 vv = { x = 0, y = 0, z =  0},
									 velocity = 0, mouseTimer = math.huge,
									 turnSpeed = 0, landed = true,
									 playerAngle = -75
								   }
		return
	end
	
	if de.state == 'init' then
			
		G_MoonlanderJetsInitialisation( e )
		
		DE_Register( e, 'Moonlander Crashed', 
						 { xo = 0, yo = 0, zo = 0, angQ = Q.FromEuler( 0, 0, 0 ) } )
		
		de.state = 'idle'
		
		return

	elseif de.state == 'idle' then
	
		if U.PlayerLookingNear( e, 500, 100 ) then
			Prompt( "Press E to Fly Moonlander")
	
			if g_KeyPressE == 1 then
				startPressed = true
				de.state = 'play'
				
				-- need to put all this in a 'level init' function
				g_PlayerWobble = GetGamePlayerControlWobbleHeight()
				SetGamePlayerControlWobbleHeight( 0 )

				de.turnSpeed = 0
				de.velocity  = 0
				
				DE_Hide( e, 'Moonlander Crashed')
				local list = DE_GetEnts ( e, 'Moonlander Crashed')
	
				if #list > 0 then
					StopParticleEmitter ( list[1] ) -- assume only one 'crashed' entity present
				end

			else
				startPressed = false
			end
		end
			
	elseif de.state == 'play' then 
	
		if startPressed and g_KeyPressE == 1 then
			return
		else
			startPressed = false
		end
		
		if g_KeyPressA == 1 then
			de.playerAngle = de.playerAngle + 0.47
		end
		if g_KeyPressD == 1 then
			de.playerAngle = de.playerAngle - 0.47
		end
				
		-- get existing Euler angles
		local xa, ya, za = Q.ToEuler( de.quat )

		local con = GetControls( e, de )
		
		for _,v in pairs( con ) do
			
			if v == 'Main' then 
				-- figure out which way is 'UP'
				local ux, uy, uz = U.Rotate3D( 0, 1, 0, xa, ya, za )

				de.vv = AddVect( de.vv, ux, uy, uz , 0.04)
				de.landed = false
			end	
			
			if v == 'Down' then
				-- figure out which way is 'Down'
				local ux, uy, uz = U.Rotate3D( 0, -1, 0, xa, ya, za )

				de.vv = AddVect( de.vv, ux, uy, uz , 0.01)
			end
			
			if v == 'Fwrd' then
				-- figure out which way is 'Forward' for the model
				local ux, uy, uz = U.Rotate3D( -1, 0, 0, xa, ya, za )

				de.vv = AddVect( de.vv, ux, uy, uz , 0.02)
			end
			
			if v == 'Back' then
				-- figure out which way is 'Backward' for the model
				local ux, uy, uz = U.Rotate3D( 1, 0, 0, xa, ya, za )

				de.vv = AddVect( de.vv, ux, uy, uz , 0.02)
			end
		
			if v == 'Left' then
				de.turnSpeed = de.turnSpeed - rnd() * 0.0005
				de.mouseTimer = g_Time + 200
			elseif v == 'Rght' then
				de.turnSpeed = de.turnSpeed + rnd() * 0.0005
				de.mouseTimer = g_Time + 200
			end
		end
		
		Prompt( modf( abs( de.turnSpeed ) * 10000) .. ",  " .. 
		        modf( de.y - GetTerrainHeight( de.x, de.z ) ) .. ",  " .. 
				modf( de.velocity * 100 ) )
		
		if de.landed or g_Time > de.mouseTimer and abs( de.turnSpeed ) < 0.001 then 
			de.turnSpeed = 0
		end
		
		-- process turning
		if de.turnSpeed ~= 0 then
			de.quat = Q.Mul( de.quat, Q.FromEuler( 0, de.turnSpeed, 0) )
		end
		
		-- do some basic gravity style stuff here
		if not de.landed then
			de.vv.y = de.vv.y - 0.002
		end

		-- calculate new position
		local nx, ny, nz = de.x + de.vv.x, de.y + de.vv.y, de.z + de.vv.z

		if de.vv.y > 0 or not HitTerrain( de ) then 
			de.x = nx 
			de.y = ny
			de.z = nz
			
			de.velocity = VectDist( de.vv )
		else
			de.landed = true
			de.vv = { x = 0, y = 0, z = 0 }
			
			if de.velocity > 1 or abs(de.turnSpeed) * 10000 > 30 then
				-- crashed!
				PromptDuration( "!! CRASHED !!", 2000)
				de.state = 'idle'
				de.playerAngle = -89
				DE_Hide( e )   -- hide all attached entities
				
				SetGamePlayerControlWobbleHeight( g_PlayerWobble )

				DisplayCrashedML( e, de )
				return
			end
			de.turnSpeed = 0
			de.velocity  = 0
		end
		
		-- get new Euler angles
		local xa, ya, za = Q.ToEuler( de.quat )
		
		-- reposition moonlander
		CollisionOff( e )
		ResetRotation( e, deg( xa ), deg( ya ), deg( za ) )
		ResetPosition( e, de.x, de.y, de.z )
		CollisionOn( e )

		-- update 'attached' decals
		DE_Update( e, de.x, de.y, de.z, de.quat )
		
		AttachPlayer( de )
	end
end
		
-- This all looks really daunting but it is quite simple.
-- The following lists contain details for each nozzle position on the moonlander model
-- (and there are a lot of them), x,y,z offsets from the models origin, the Euler angles
-- at which to place jets and 'tweak' values to align the second rotated jet decal properly.
-- (note:   these tweak values depend oon the scale of the decal!)
-- (note2:  the Euler angles are only valid for the default mode rotation when first dropped
--          into the editor)
 
local MLNozzlesList =
{
    -- main jets decals, i.e. 'lift'  there are 8 nozzles so 16 jets in all     ------------------------ #Decals
	{ name = 'Main', tx = 0, ty = 0, tz = 2.5, 
 	   pos = { xo = -70.1, yo = 8, zo = -12, angQ = Q.FromEuler( rad(   0), rad( 0 ), rad ( 142) ) } },  --  2
	{ name = 'Main', tx = 0, ty = 0, tz = 2.5,
	   pos = { xo = -70.1, yo = 8, zo =  12, angQ = Q.FromEuler( rad(   0), rad( 0 ), rad ( 142) ) } },  --  4
	{ name = 'Main', tx = 2.5, ty = 0, tz = -2.5,
	   pos = { xo = -14.8, yo = 8, zo = -72, angQ = Q.FromEuler( rad(-142), rad( 0 ), rad (   0) ) } },  --  6
	{ name = 'Main', tx = 2.5, ty = 0, tz = -2.5,
	   pos = { xo =  10.1, yo = 8, zo = -72, angQ = Q.FromEuler( rad(-142), rad( 0 ), rad (   0) ) } },  --  8
	{ name = 'Main', tx = -5, ty = 0, tz = 2.5,
	   pos = { xo =  74.1, yo = 8, zo =  12, angQ = Q.FromEuler( rad(   0), rad( 0 ), rad (-142) ) } },  --  10
	{ name = 'Main', tx = -5, ty = 0, tz = 2.5,
	   pos = { xo =  74.1, yo = 8, zo = -12, angQ = Q.FromEuler( rad(   0), rad( 0 ), rad (-142) ) } },  --  12
	{ name = 'Main', tx = 2.5, ty = 0, tz = -2.5,
	   pos = { xo =  10.1, yo = 8, zo =  72, angQ = Q.FromEuler( rad( 142), rad( 0 ), rad (   0) ) } },  --  14
	{ name = 'Main', tx = 2.5, ty = 0, tz = -2.5,
	   pos = { xo = -14.8, yo = 8, zo =  72, angQ = Q.FromEuler( rad( 142), rad( 0 ), rad (   0) ) } },  --  16

	   -- 'forward' jets
	{ name = 'Fwrd', tx = 0, ty = -1, tz = 1,
	   pos = { xo =  82.0, yo =  87.5, zo = 0.2, angQ = Q.FromEuler( rad(  0), rad (  0), rad (-90) ) } }, -- 2
	{ name = 'Fwrd', tx = 1, ty = 1, tz = 0,
	   pos = { xo =  74.0, yo = 209.2, zo = -71, angQ = Q.FromEuler( rad(-90), rad (-45), rad (  0) ) } }, -- 4
	{ name = 'Fwrd', tx = 0, ty = -1, tz = -1,
       pos = { xo =  74.0, yo = 208.9, zo =  55, angQ = Q.FromEuler( rad( 90), rad ( 45), rad (  0) ) } }, -- 6

	   -- 'reverse' jets
	{ name = 'Back', tx = 0, ty = 1, tz = 1,
	   pos = { xo = -82, yo =  86.0, zo = -0.3, angQ = Q.FromEuler( rad(  0), rad (  0), rad (90) ) } },    -- 2
	{ name = 'Back', tx = 1, ty = 1, tz = 0,
       pos = { xo = -50, yo = 209.0, zo = -71,  angQ = Q.FromEuler( rad(-90), rad ( 45), rad ( 0) ) } },    -- 4
	{ name = 'Back', tx = 1, ty = -1, tz = 0,
       pos = { xo = -50, yo = 208.9, zo =  55,  angQ = Q.FromEuler( rad( 90), rad (-45), rad ( 0) ) } },    -- 6

	   -- 'left' rotation jets
	{ name = 'Left', tx = 0, ty = 1, tz = 0,
	   pos = { xo =  66.5, yo =  87.2, zo = -15.0, angQ = Q.FromEuler( rad(-90), rad ( -8), rad ( 45) ) } },  -- 2
	{ name = 'Left', tx = 0, ty = -1, tz = 0,
	   pos = { xo = -69.5, yo =  88.3, zo =  15.0, angQ = Q.FromEuler( rad( 90), rad ( -8), rad (-45) ) } },  -- 4
	{ name = 'Left', tx = 0, ty = -1, tz = 1, 
       pos = { xo = -51.0, yo = 209.0, zo = -50.0, angQ = Q.FromEuler( rad( 90), rad (-45), rad (  0) ) } },  -- 6	   
	{ name = 'Left', tx = 1, ty = 1, tz = 0,
       pos = { xo =  76.5, yo = 208.8, zo =  31.0, angQ = Q.FromEuler( rad(-90), rad (-45), rad (  0) ) } },  -- 8
	{ name = 'Left', tx = 1, ty = -1, tz = 0,
       pos = { xo = -27.0, yo = 208.8, zo =  57.0, angQ = Q.FromEuler( rad( 90), rad ( 45), rad (  0) ) } },  -- 10
	{ name = 'Left', tx = 0, ty = 1, tz = -1,
       pos = { xo =  52.0, yo = 209.0, zo = -72.5, angQ = Q.FromEuler( rad(-90), rad ( 45), rad (  0) ) } },  -- 12

	   -- 'right' rotation jets
	{ name = 'Rght', tx = 1, ty = 0, tz = 0, 
       pos = { xo =  66.5, yo =  87.2, zo =  15.0, angQ = Q.FromEuler( rad( 90), rad (  8), rad ( 45) ) } },  -- 2
	{ name = 'Rght', tx = 1, ty = 0, tz = 0,
       pos = { xo = -69.5, yo =  88.3, zo = -15.0, angQ = Q.FromEuler( rad(-90), rad (  8), rad (-45) ) } },  -- 4
	{ name = 'Rght', tx = 1, ty = 1, tz = 1,
	   pos = { xo = -28.0, yo = 209.0, zo = -73.0, angQ = Q.FromEuler( rad(-90), rad (-45), rad (  0) ) } },  -- 6
	{ name = 'Rght', tx = 1, ty = -1, tz = 1,
	   pos = { xo =  53.0, yo = 208.8, zo =  54.3, angQ = Q.FromEuler( rad( 90), rad (-45), rad (  0) ) } },  -- 8
	{ name = 'Rght', tx = 1, ty = 1, tz = -1,
	   pos = { xo = -50.0, yo = 208.8, zo =  34.0, angQ = Q.FromEuler( rad(-90), rad ( 45), rad (  0) ) } },  -- 10
	{ name = 'Rght', tx = 1, ty = -1, tz = -1,
       pos = { xo =  75.5, yo = 208.8, zo = -48.5, angQ = Q.FromEuler( rad( 90), rad ( 45), rad (  0) ) } },  -- 12

	   -- 'down' jets  (first three are rear)
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
       pos = { xo =  64.5, yo = 221.0, zo = -60.5, angQ = Q.FromEuler( 0, 0, 0 ) } },  -- 2
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
	   pos = { xo =  64.5, yo = 221.0, zo =  44.5, angQ = Q.FromEuler( 0, 0, 0 ) } },  -- 4
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
	   pos = { xo =  66.0, yo = 100.0, zo =   0.2, angQ = Q.FromEuler( 0, 0, 0 ) } },  -- 6
	   --(second three are front)
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
	   pos = { xo = -39.0, yo = 221.0, zo =  44.5, angQ = Q.FromEuler( 0, 0, 0 ) } },  -- 8
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
	   pos = { xo = -39.0, yo = 221.0, zo = -60.5, angQ = Q.FromEuler( 0, 0, 0 ) } },  -- 10
	{ name = 'Down', tx = 0.5, ty = 0, tz = 0.5, 
	   pos = { xo = -68.3, yo = 100.0, zo =  -0.3, angQ = Q.FromEuler( 0, 0, 0 ) } }   -- 12   
}                                                        

local MLJetScales = 
{ Main = 300, Fwrd = 140, Back = 140, Left = 80, Rght = 80, Down = 100 }


local rotyQ = Q.FromEuler( 0, rad(90), 0 )			

-- Globals section
function G_MoonlanderJetsInitialisation( e )
		
	-- register for dynamic entities
	if DE_Register ~= nil then 
		
		-- register steam decals for exhaust ports
		for _, v in pairs( MLNozzlesList ) do
			local pos = v.pos
			
			-- two jets per nozzle, second rotated 90 degrees
			DE_Register( e, v.name, pos, { min = 10, max = MLJetScales[ v.name ], frames=10 } )
			
			DE_Register( e, v.name, 
						 { xo = pos.xo + v.tx, yo = pos.yo + v.ty, zo = pos.zo + v.tz, 
						   angQ = Q.Mul( pos.angQ, rotyQ ) },
						   { min = 10, max = MLJetScales[ v.name ], frames = 10 } )
		end
		
	end
end