global function Spectator_Init

// stuff called by _base_gametype_mp and such
global function InitialisePrivateMatchSpectatorPlayer
global function PlayerBecomesSpectator
global function RespawnPrivateMatchSpectator

// custom spectator state functions
// yes, GM_SetSpectatorFunc does exist in vanilla and serves roughly the same purpose, but using custom funcs here seemed better
global function Spectator_SetDefaultSpectatorFunc
global function Spectator_SetCustomSpectatorFunc
global function Spectator_ClearCustomSpectatorFunc

// helper funcs
global function HACKCleanupStaticObserverStuff

global typedef SpectatorFunc void functionref( entity player )

struct {
	array<entity> staticSpecCams 
	SpectatorFunc defaultSpectatorFunc
	SpectatorFunc nextSpectatorFunc = null
	
	int newestFuncIndex = 0 // used to track which players have finished the most recent spectator func
} file

void function Spectator_Init()
{
	Spectator_SetDefaultSpectatorFunc( SpectatorFunc_Default )

	AddCallback_EntitiesDidLoad( SetStaticSpecCams )

	RegisterSignal( "ObserverTargetChanged" )
	RegisterSignal( "SpectatorFuncChanged" )
	AddClientCommandCallback( "spec_next", ClientCommandCallback_spec_next )
	AddClientCommandCallback( "spec_prev", ClientCommandCallback_spec_prev )
	AddClientCommandCallback( "spec_mode", ClientCommandCallback_spec_mode )
}

void function SetStaticSpecCams()
{
	// spec cams are called spec_cam1,2,3 etc by default, so this is the easiest way to get them imo
	int camNum = 1 
	entity lastCam = null
	do {
		lastCam = GetEnt( "spec_cam" + camNum++ )
		
		if ( IsValid( lastCam ) )
			file.staticSpecCams.append( lastCam )
	} while ( IsValid( lastCam ) )
}

void function Spectator_SetDefaultSpectatorFunc( SpectatorFunc func )
{
	file.defaultSpectatorFunc = func
}

// sets the current spectator func, stopping any currently running spectator funcs to start this one
void function Spectator_SetCustomSpectatorFunc( SpectatorFunc func )
{
	file.nextSpectatorFunc = func
	svGlobal.levelEnt.Signal( "SpectatorFuncChanged" ) // spectator funcs need to listen to this manually
	file.newestFuncIndex++
}

void function Spectator_ClearCustomSpectatorFunc()
{
	Spectator_SetCustomSpectatorFunc( null )
}

void function HACKCleanupStaticObserverStuff( entity player )
{
	// this may look like horrible awful pointless code at first glance, and while it is horrible and awful, it's not pointless
	// 3.402823466E38 is 0xFFFF7F7F in memory, which is the value the game uses to determine whether the current static observer pos/angles are valid ( i.e. 0xFFFF7F7F = invalid/not initialised )
	// in my experience, not cleaning this up after setting static angles will break OBS_MODE_CHASE-ing non-player entities which is bad for custom spectator funcs
	// this is 100% way lower level than what script stuff should usually be doing, but it's needed here
	// i sure do hope this won't break in normal use :clueless:
	player.SetObserverModeStaticPosition( < 3.402823466e38, 3.402823466e38, 3.402823466e38 > )
	player.SetObserverModeStaticAngles( < 3.402823466e38, 3.402823466e38, 3.402823466e38 > )
}

void function InitialisePrivateMatchSpectatorPlayer( entity player )
{
	thread PlayerBecomesSpectator( player )
}

// this should be called when intros respawn players normally to handle fades and stuff
void function RespawnPrivateMatchSpectator( entity player )
{
	ScreenFadeFromBlack( player, 0.5, 0.5 )
}

void function PlayerBecomesSpectator( entity player )
{
	player.StopPhysics()

	player.EndSignal( "OnRespawned" )
	player.EndSignal( "OnDestroy" )
	player.EndSignal( "PlayerRespawnStarted" )
	
	OnThreadEnd( function() : ( player ) 
	{
		if ( IsValid( player ) )
			player.StopObserverMode()
	})
	
	// keeps track of the most recent func this player has completed
	// this is to ensure that custom spectator funcs are only run once per player even before being cleared
	int funcIndex = 0
	
	while ( true )
	{
		SpectatorFunc nextSpectatorFunc = file.defaultSpectatorFunc
		if ( file.nextSpectatorFunc != null && funcIndex != file.newestFuncIndex )
			nextSpectatorFunc = file.nextSpectatorFunc

		waitthread nextSpectatorFunc( player )
		funcIndex = file.newestFuncIndex // assuming this will be set before file.newestFuncIndex increments when the spectator func is ended by SpectatorFuncChanged
		// surely this will not end up being false in practice :clueless:
		
		// cleanup
		player.StopObserverMode()
		HACKCleanupStaticObserverStuff( player ) // un-initialise static observer positions/angles
		
		WaitFrame() // always wait at least a frame in case an observer func exits immediately to prevent stuff locking up
	}
}

void function SpectatorFunc_Default( entity player )
{
	svGlobal.levelEnt.EndSignal( "SpectatorFuncChanged" )
	int targetIndex
	
	table result = { next = false }
		
	while ( true )
	{
		array<entity> targets
		targets.extend( file.staticSpecCams )
			
		if ( IsFFAGame() )
			targets.extend( GetPlayerArray_Alive() )
		else
			targets.extend( GetPlayerArrayOfTeam_Alive( player.GetTeam() ) )
		
		if ( targets.len() > 0 )
		{
			if ( result.next )
				targetIndex = ( targetIndex + 1 ) % targets.len()
			else
			{
				if ( targetIndex == 0 )
					targetIndex = ( targets.len() - 1 )
				else
					targetIndex--
			}
			
			if ( targetIndex >= targets.len() )
				targetIndex = 0
			
			entity target = targets[ targetIndex ]
			
			player.StopObserverMode()
			if ( player.IsWatchingSpecReplay() )
				player.SetSpecReplayDelay( 0.0 ) // clear spectator replay
			
			if ( target.IsPlayer() )
			{		
				try
				{
					player.SetObserverTarget( target )
					player.StartObserverMode( OBS_MODE_CHASE )
				}
				catch ( ex ) { }
			}
			else
			{
				player.SetObserverModeStaticPosition( target.GetOrigin() )
				player.SetObserverModeStaticAngles( target.GetAngles() )
				player.StartObserverMode( OBS_MODE_STATIC )
			}
		}
		
		player.StopPhysics()
		result = player.WaitSignal( "ObserverTargetChanged" )
	}
}

bool function ClientCommandCallback_spec_next( entity player, array<string> args )
{
	if ( player.GetObserverMode() == OBS_MODE_CHASE || player.GetObserverMode() == OBS_MODE_STATIC || player.GetObserverMode() == OBS_MODE_IN_EYE )
		player.Signal( "ObserverTargetChanged", { next = true } )
		
	return true
}

bool function ClientCommandCallback_spec_prev( entity player, array<string> args )
{
	if ( player.GetObserverMode() == OBS_MODE_CHASE || player.GetObserverMode() == OBS_MODE_STATIC || player.GetObserverMode() == OBS_MODE_IN_EYE )
		player.Signal( "ObserverTargetChanged", { next = false } )
		
	return true
}

bool function ClientCommandCallback_spec_mode( entity player, array<string> args )
{
	// currently unsure how this actually gets called on client, works through console and has references in client.dll tho
	if ( player.GetObserverMode() == OBS_MODE_CHASE )
	{
		// set to first person spectate		
		player.SetSpecReplayDelay( FIRST_PERSON_SPECTATOR_DELAY )
		player.SetViewEntity( player.GetObserverTarget(), true )
		player.StartObserverMode( OBS_MODE_IN_EYE )
	}
	else if ( player.GetObserverMode() == OBS_MODE_IN_EYE )
	{	
		// set to third person spectate
		player.SetSpecReplayDelay( 0.0 )
		player.StartObserverMode( OBS_MODE_CHASE )
	}
	
	return true
}