use strafesnet_common::mouse::MouseState;
use strafesnet_common::physics::Instruction as PhysicsInputInstruction;
use strafesnet_common::integer::Time;
use strafesnet_common::instruction::TimedInstruction;
use strafesnet_common::timer::{Scaled,Timer,TimerState};

#[derive(Debug)]
pub enum InputInstruction{
	MoveMouse(glam::IVec2),
	MoveRight(bool),
	MoveUp(bool),
	MoveBack(bool),
	MoveLeft(bool),
	MoveDown(bool),
	MoveForward(bool),
	Jump(bool),
	Zoom(bool),
	Restart,
	Spawn(strafesnet_common::gameplay_modes::ModeId,strafesnet_common::gameplay_modes::StageId),
	PracticeFly,
}
pub enum Instruction{
	Input(InputInstruction),
	Render,
	Resize(winit::dpi::PhysicalSize<u32>,crate::settings::UserSettings),
	GenerateModels(strafesnet_common::map::CompleteMap),
	ClearModels,
	SetPaused(bool),
	//Graphics(crate::graphics_worker::Instruction),
}
pub struct MouseInterpolator{
	timeline:std::collections::VecDeque<TimedInstruction<PhysicsInputInstruction>>,
	last_mouse_time:Time,//this value is pre-transformed to simulation time
	mouse_blocking:bool,
	timer:Timer<Scaled>,
}
impl MouseInterpolator{
	fn push_mouse_instruction(&mut self,physics:&crate::physics::PhysicsContext,ins:&TimedInstruction<Instruction>,m:glam::IVec2){
		if self.mouse_blocking{
			//tell the game state which is living in the past about its future
			self.timeline.push_front(TimedInstruction{
				time:self.last_mouse_time,
				instruction:PhysicsInputInstruction::SetNextMouse(MouseState{time:self.timer.time(ins.time),pos:m}),
			});
		}else{
			//mouse has just started moving again after being still for longer than 10ms.
			//replace the entire mouse interpolation state to avoid an intermediate state with identical m0.t m1.t timestamps which will divide by zero
			self.timeline.push_front(TimedInstruction{
				time:self.last_mouse_time,
				instruction:PhysicsInputInstruction::ReplaceMouse(
					MouseState{time:self.last_mouse_time,pos:physics.get_next_mouse().pos},
					MouseState{time:self.timer.time(ins.time),pos:m}
				),
			});
			//delay physics execution until we have an interpolation target
			self.mouse_blocking=true;
		}
		self.last_mouse_time=self.timer.time(ins.time);
	}
	/// returns the mapped physics input instruction
	/// may or may not mutate internal state XD!
	fn map_instruction(&mut self,physics:&crate::physics::PhysicsContext,ins:&TimedInstruction<Instruction>)->Option<PhysicsInputInstruction>{
		match &ins.instruction{
			Instruction::Input(input_instruction)=>match input_instruction{
				&InputInstruction::MoveMouse(m)=>{
					if !self.timer.is_paused(){
						self.push_mouse_instruction(physics,ins,m);
					}
					None
				},
				&InputInstruction::MoveForward(s)=>Some(PhysicsInputInstruction::SetMoveForward(s)),
				&InputInstruction::MoveLeft(s)=>Some(PhysicsInputInstruction::SetMoveLeft(s)),
				&InputInstruction::MoveBack(s)=>Some(PhysicsInputInstruction::SetMoveBack(s)),
				&InputInstruction::MoveRight(s)=>Some(PhysicsInputInstruction::SetMoveRight(s)),
				&InputInstruction::MoveUp(s)=>Some(PhysicsInputInstruction::SetMoveUp(s)),
				&InputInstruction::MoveDown(s)=>Some(PhysicsInputInstruction::SetMoveDown(s)),
				&InputInstruction::Jump(s)=>Some(PhysicsInputInstruction::SetJump(s)),
				&InputInstruction::Zoom(s)=>Some(PhysicsInputInstruction::SetZoom(s)),
				&InputInstruction::Spawn(mode_id,stage_id)=>Some(PhysicsInputInstruction::Spawn(mode_id,stage_id)),
				InputInstruction::Restart=>Some(PhysicsInputInstruction::Restart),
				InputInstruction::PracticeFly=>Some(PhysicsInputInstruction::PracticeFly),
			},
			//do these really need to idle the physics?
			//sending None dumps the instruction queue
			Instruction::GenerateModels(_)=>Some(PhysicsInputInstruction::Idle),
			Instruction::ClearModels=>Some(PhysicsInputInstruction::Idle),
			Instruction::Resize(_,_)=>Some(PhysicsInputInstruction::Idle),
			Instruction::Render=>Some(PhysicsInputInstruction::Idle),
			&Instruction::SetPaused(paused)=>{
				if let Err(e)=self.timer.set_paused(ins.time,paused){
					println!("Cannot pause: {e}");
				}
				Some(PhysicsInputInstruction::Idle)
			},
		}
	}
	fn update_mouse_blocking(&mut self,physics:&crate::physics::PhysicsContext,ins:&TimedInstruction<Instruction>)->bool{
		if self.mouse_blocking{
			//assume the mouse has stopped moving after 10ms.
			//shitty mice are 125Hz which is 8ms so this should cover that.
			//setting this to 100us still doesn't print even though it's 10x lower than the polling rate,
			//so mouse events are probably not handled separately from drawing and fire right before it :(
			if Time::from_millis(10)<self.timer.time(ins.time)-physics.get_next_mouse().time{
				//push an event to extrapolate no movement from
				self.timeline.push_front(TimedInstruction{
					time:self.last_mouse_time,
					instruction:PhysicsInputInstruction::SetNextMouse(MouseState{time:self.timer.time(ins.time),pos:physics.get_next_mouse().pos}),
				});
				self.last_mouse_time=self.timer.time(ins.time);
				//stop blocking. the mouse is not moving so the physics does not need to live in the past and wait for interpolation targets.
				self.mouse_blocking=false;
				true
			}else{
				false
			}
		}else{
			//keep this up to date so that it can be used as a known-timestamp
			//that the mouse was not moving when the mouse starts moving again
			self.last_mouse_time=self.timer.time(ins.time);
			true
		}
	}
	/// returns whether or not to empty the instruction queue
	fn handle_physics_input(&mut self,physics:&crate::physics::PhysicsContext,ins:&TimedInstruction<Instruction>,phys_input_option:Option<PhysicsInputInstruction>)->bool{
		if let Some(phys_input)=phys_input_option{
			//non-mouse event
			self.timeline.push_back(TimedInstruction{
				time:self.timer.time(ins.time),
				instruction:phys_input,
			});

			//this returns the bool for us
			self.update_mouse_blocking(physics,ins)
		}else{
			//mouse event
			true
		}
	}
	fn empty_queue(&mut self,physics:&mut crate::physics::PhysicsContext){
		while let Some(instruction)=self.timeline.pop_front(){
			physics.run_input_instruction(instruction);
		}
	}
	fn handle_instruction(&mut self,physics:&mut crate::physics::PhysicsContext,ins:&TimedInstruction<Instruction>){
		let physics_input_option=self.map_instruction(physics,ins);
		let should_empty_queue=self.handle_physics_input(physics,ins,physics_input_option);
		if should_empty_queue{
			self.empty_queue(physics);
		}
	}
}

pub fn new(mut physics:crate::physics::PhysicsContext,mut graphics_worker:crate::compat_worker::INWorker<crate::graphics_worker::Instruction>)->crate::compat_worker::QNWorker<TimedInstruction<Instruction>>{
	let mut interpolator=MouseInterpolator{
		mouse_blocking:true,
		last_mouse_time:physics.get_next_mouse().time,
		timeline:std::collections::VecDeque::new(),
		timer:Timer::from_state(Scaled::identity(),false),
	};
	crate::compat_worker::QNWorker::new(move |ins:TimedInstruction<Instruction>|{
		interpolator.handle_instruction(&mut physics,&ins);
		match ins.instruction{
			Instruction::Render=>{
				graphics_worker.send(crate::graphics_worker::Instruction::Render(physics.output(),interpolator.timer.time(ins.time),physics.get_next_mouse().pos)).unwrap();
			},
			Instruction::Resize(size,user_settings)=>{
				graphics_worker.send(crate::graphics_worker::Instruction::Resize(size,user_settings)).unwrap();
			},
			Instruction::GenerateModels(map)=>{
				physics.generate_models(&map);
				//important!
				//bots will not work properly without this exact restart + spawn setup
				//reset the physics state to start a new run on the new map
				physics.restart();
				//generate a spawn event so bots work properly on the first run
				//no run started so does not invalidate the run
				physics.spawn();
				graphics_worker.send(crate::graphics_worker::Instruction::GenerateModels(map)).unwrap();
			},
			Instruction::ClearModels=>{
				physics.clear();
				graphics_worker.send(crate::graphics_worker::Instruction::ClearModels).unwrap();
			},
			_=>(),
		}
	})
}