extends Node3D
class_name HexGrid

@onready var placement_visualizer = $PlacementVisualizer

const DIR_N: Vector3 = Vector3(0, 1, -1)
const DIR_NE: Vector3 = Vector3(1, 0, -1)
const DIR_SE: Vector3 = Vector3(1, -1, 0)
const DIR_S: Vector3 = Vector3(0, -1, 1)
const DIR_SW: Vector3 = Vector3(-1, 0, 1)
const DIR_NW: Vector3 = Vector3(-1, 1, 0)
const DIR_ALL: Array[Vector3] = [DIR_N, DIR_NE, DIR_SE, DIR_S, DIR_SW, DIR_NW]

#const size = Vector2(1, sqrt(3.0)/2.0)

const size: float = 0.5

var used_cells: Dictionary = {}

@export var layer_height: float = 0.4
 
# have all used_cells be saved as Vector4i (q, r, s, y)

class TileStorage:
	var tiles: Dictionary = {}
	# we use a vector4i for coordinates
	# q r s y (layer)
	
	func add_tile(tile: InsectTile, coords: CubeCoordinates, layer: int = 0) -> void:
		tiles[Vector4i(coords.q, coords.r, coords.s, layer)] = tile
		pass
		
	func remove_tile(coords: CubeCoordinates, layer: int = 0) -> void:
		pass
	
	func has_tile(coords: CubeCoordinates, layer: int = 0) -> bool:
		return tiles.has(Vector4i(coords.q, coords.r, coords.s, layer))
		
	func get_tile(coords: CubeCoordinates, layer: int = 0) -> InsectTile:
		return tiles[Vector4i(coords.q, coords.r, coords.s, layer)]
	

class CubeCoordinates:
	var q: float
	var r: float
	var s: float

	func _init(_q: float, _r: float, _s: float):
		q = _q
		r = _r
		s = _s

class AxialCoordinates:
	var q: float
	var r: float
	
	func _init(_q: float, _r: float):
		q = _q
		r = _r
		
func flat_hex_corner(center: Vector2, size: float, corner_num: int) -> Vector2:
	var angle_deg: int = 60 * corner_num
	var angle_rad: float = deg_to_rad(angle_deg)
	return Vector2(center.x + size * cos(angle_rad), center.y + size * sin(angle_rad))

func flat_hex_to_world_position(coords: AxialCoordinates) -> Vector2:
	var x = size * (3.0/2.0 * coords.q)
	var y = size * (sqrt(3.0)/2.0 * coords.q + sqrt(3.0) * coords.r)
	return Vector2(x, y)
	
func cube_to_world_pos(coords: CubeCoordinates) -> Vector2:
	return flat_hex_to_world_position(cube_to_axial(coords))

#func world_to_hex_tile(world_pos: Vector3) -> Vector2:
#	var q = (2.0/3.0 * world_pos.x)
#	var r = (-1.0/3.0 * world_pos.x + sqrt(3.0)/3.0 * world_pos.z)
#	
#	return cube_round()
#	
#	return 

const INSECT_TILE = preload("res://InsectTiles/InsectTile.tscn")

func world_to_hex_tile(coords: Vector2) -> AxialCoordinates:
	var q = (2.0/3.0 * coords.x) / size
	var r = (-1.0/3.0 * coords.x + sqrt(3.0)/3.0 * coords.y) / size
	return axial_round(AxialCoordinates.new(q, r))

func axial_to_cube(coords: AxialCoordinates) -> CubeCoordinates:
	var q = coords.q
	var r = coords.r
	var s = -q-r
	return CubeCoordinates.new(q, r, s)

func cube_to_axial(coords: CubeCoordinates) -> AxialCoordinates:
	var q = coords.q
	var r = coords.r
	return AxialCoordinates.new(q, r)

func axial_round(coords: AxialCoordinates) -> AxialCoordinates:
	return cube_to_axial(cube_round(axial_to_cube(coords)))

func cube_round(coords: CubeCoordinates) -> CubeCoordinates:
	var q: float = round(coords.q)
	var r: float = round(coords.r)
	var s: float = round(coords.s)
	
	var q_diff: float = abs(q - coords.q)
	var r_diff: float = abs(r - coords.r)
	var s_diff: float = abs(s - coords.s)
	
	if q_diff > r_diff and q_diff > s_diff:
		q = -r-s
	elif r_diff > s_diff:
		r = -q-s
	else:
		s = -q-r
		
	return CubeCoordinates.new(q, r, s)

@export var dragging_intersect_plane_normal: Vector3 = Vector3.UP
@export var dragging_intersect_plane_distance: float = 0.0

func get_3d_pos(position2D: Vector2):
	return Plane(dragging_intersect_plane_normal, dragging_intersect_plane_distance).intersects_ray(get_viewport().get_camera_3d().project_ray_origin(position2D), get_viewport().get_camera_3d().project_ray_normal(position2D))

var placements: Dictionary = {}

func is_cell_empty(coords: CubeCoordinates) -> bool:
	return !used_cells.has(Vector4i(coords.q, coords.r, coords.s, 0))

func is_cell_not_empty(coords: CubeCoordinates) -> bool:
	return !is_cell_empty(coords)

func get_empty_neighbours(coords: CubeCoordinates) -> Array[CubeCoordinates]:
	return get_neighbours(coords).filter(is_cell_empty)

func get_neighbours(coords: CubeCoordinates) -> Array[CubeCoordinates]:
	return [
				CubeCoordinates.new(coords.q + 1, coords.r, coords.s - 1),
				CubeCoordinates.new(coords.q + 1, coords.r - 1, coords.s),
				CubeCoordinates.new(coords.q, coords.r - 1, coords.s + 1),
				CubeCoordinates.new(coords.q - 1, coords.r, coords.s + 1),
				CubeCoordinates.new(coords.q - 1, coords.r + 1, coords.s),
				CubeCoordinates.new(coords.q, coords.r + 1, coords.s - 1)
			]

var current_tile: Node3D

const HEX_OUTLINE = preload("res://hex_outline.tscn")

func _on_insect_selected(insect_resource: TileResource, is_black: bool) -> void:
	# create a hexagon with insect resource data
	#var tile = INSECT_TILE.instantiate()
	#tile.resource = insect_resource
	#tile.is_black = is_black
	#current_tile = tile
	#add_child(tile)
	
	# spawn possible placement locations :)
	if used_cells.size() == 0: # we have no cells placed, display a placement outline at 0, 0
		var outline = HEX_OUTLINE.instantiate()
		var cubepos = CubeCoordinates.new(0, 0, 0)
		var hex_pos = cube_to_world_pos(cubepos)
		outline.position = Vector3(hex_pos.x, 0.0, hex_pos.y)
		outline.visible = true
		outline.insect_resource = insect_resource
		outline.is_black = is_black
		outline.coordinates = cubepos
		placement_visualizer.add_child(outline)
		placements[hex_pos] = outline
	elif used_cells.size() == 1: # we have ONE cell placed, this is a special case in which
		# the opposing player is allowed to place a tile that touches the enemy color
		# We display outline placement around all spaces of this single cell
		var single_cell = used_cells.keys().front()
		var neighbours = get_neighbours(CubeCoordinates.new(single_cell.x, single_cell.y, single_cell.z))
		for neighbour in neighbours:
			var outline = HEX_OUTLINE.instantiate()
			var hex_pos = cube_to_world_pos(neighbour)
			outline.position = Vector3(hex_pos.x, 0.0, hex_pos.y)
			outline.visible = true
			outline.insect_resource = insect_resource
			outline.is_black = is_black
			outline.coordinates = neighbour
			placement_visualizer.add_child(outline)
			placements[hex_pos] = outline
	else:
		# iterate over all used_cells, get all empty cells surrounding those cells
		# iterate over all those empty cells, check if they only neighbour the same color
		var possible_placements: Dictionary = {}
		
		for hex in used_cells.keys():
			#var eligible: bool = true
			for neighbour in get_empty_neighbours(CubeCoordinates.new(hex.x, hex.y, hex.z)):
				if not used_cells.has(Vector4(neighbour.q, neighbour.r, neighbour.s, 0)):
					possible_placements[Vector4i(neighbour.q, neighbour.r, neighbour.s, 0)] = true

		for p in possible_placements:
			#var neighbours = [
			#	Vector2i(p.x + 1, p.y), Vector2i(p.x + 1, p.y - 1), Vector2i(p.x, p.y - 1),
			#	Vector2i(p.x - 1, p.y), Vector2i(p.x - 1, p.y + 1), Vector2i(p.x, p.y + 1)
			#]
		
			var eligible: bool = true
		
			for neighbour in get_neighbours(CubeCoordinates.new(p.x, p.y, p.z)):
				if not used_cells.has(Vector4i(neighbour.q, neighbour.r, neighbour.s, 0)):
					continue
					
				if used_cells[Vector4i(neighbour.q, neighbour.r, neighbour.s, 0)].is_black != is_black:
					eligible = false
					break
					
			if eligible:
				var outline = HEX_OUTLINE.instantiate()
				var hex_pos = cube_to_world_pos(CubeCoordinates.new(p.x, p.y, p.z))
				outline.position = Vector3(hex_pos.x, 0.0, hex_pos.y)
				outline.visible = true
				outline.insect_resource = insect_resource
				outline.is_black = is_black
				outline.coordinates = CubeCoordinates.new(p.x, p.y, p.z)
				placement_visualizer.add_child(outline)
				placements[p] = outline
		
		pass
	
	pass

func _on_insect_placement_cancelled() -> void:
	if current_tile:
		current_tile.queue_free()
		current_tile = null
		
	for child in placement_visualizer.get_children():
		child.queue_free()

func _on_insect_placed(resource: TileResource, is_black: bool, pos: CubeCoordinates) -> void:
	var tile_copy = INSECT_TILE.instantiate()
	var hex_pos = cube_to_world_pos(pos)

	tile_copy.position = Vector3(hex_pos.x, 20.0, hex_pos.y)
	tile_copy.resource = resource
	tile_copy.is_black = is_black
	tile_copy.coordinates = pos
	var target_pos = Vector3(hex_pos.x, 0.0, hex_pos.y)
	
	used_cells[Vector4i(pos.q, pos.r, pos.s, 0)] = tile_copy
	
	add_child(tile_copy)
	
	var tween = get_tree().create_tween()
	tween.tween_property(tile_copy, "position", target_pos, 1.0).set_ease(Tween.EASE_OUT).set_trans(Tween.TRANS_EXPO)

func _on_insect_tile_selected(tile: InsectTile) -> void:
	if tile.resource.movement_behaviour == null:
		return
		
	var spaces = tile.resource.movement_behaviour.get_available_spaces(tile.coordinates, self)
	
	print(spaces.size())
	
	if spaces.is_empty():
		GameEvents.insect_tile_selection_request_failed.emit(tile)
		return
	
	for space in spaces:
		var neighbours = get_neighbours(space)
		# if all neighbours are empty, move would disconnect us from the hive
		# so we discard it
		# also: if there are 5 empty space and the only remaining one is our current tile...
		# we would also be disconnected after the move
		# maybe the 6 check is not needed
		var non_empty_neighbours = neighbours.filter(is_cell_not_empty)
		var coords_vec4: Vector4i = Vector4i(tile.coordinates.q, tile.coordinates.r, tile.coordinates.s, 0)
		
		if non_empty_neighbours.size() == 1:
			var occupied_neighbour = non_empty_neighbours.front()
			var neighbour_vec4: Vector4i = Vector4i(occupied_neighbour.q, occupied_neighbour.r, occupied_neighbour.s, 0)
			if neighbour_vec4 == coords_vec4:
				continue
		
		var outline = HEX_OUTLINE.instantiate()
		var hex_pos = cube_to_world_pos(space) # flat_hex_to_world_position(AxialCoordinates.new(space.x, space.y))
		outline.position = Vector3(hex_pos.x, 0.0, hex_pos.y)
		outline.coordinates = space
		outline.visible = true
		outline.insect_tile = tile
		outline.is_moving = true
		outline.insect_resource = tile.resource
		outline.is_black = tile.is_black
		placement_visualizer.add_child(outline)
		placements[space] = outline
	
	
func _on_insect_tile_moved(tile: InsectTile, target: CubeCoordinates) -> void:
	used_cells.erase(Vector4i(tile.coordinates.q, tile.coordinates.r, tile.coordinates.s, 0))
	
	var new_hex_pos = cube_to_world_pos(target)
	var sky_new_hex_pos = Vector3(new_hex_pos.x, 20.0, new_hex_pos.y)
	var ground_new_hex_pos = Vector3(new_hex_pos.x, 0.0, new_hex_pos.y)
	#
	var current_hex_pos = tile.position
	var sky_current_hex_pos = tile.position + Vector3(0.0, 20.0, 0.0)
#
	var tween = get_tree().create_tween()
	tween.tween_property(tile, "position", sky_current_hex_pos, 0.5).set_ease(Tween.EASE_IN).set_trans(Tween.TRANS_EXPO)
	tween.tween_property(tile, "position", sky_new_hex_pos, 0.0)
	tween.tween_property(tile, "position", ground_new_hex_pos, 1.0).set_ease(Tween.EASE_OUT).set_trans(Tween.TRANS_EXPO)
	
	tile.coordinates = target
	
	used_cells[Vector4i(target.q, target.r, target.s, 0)] = tile

func can_hive_exist_without_tile(tile: InsectTile) -> bool:
	# TODO:  BFS-Search from random cell to see if all other cells could still be reached when this 
	# tile would be empty space
	if get_empty_neighbours(tile.coordinates).size() == 5: # we only have one real neighbour, so can't break anything
		return true
	
	var vector_coords: Vector4i = Vector4i(tile.coordinates.q, tile.coordinates.r, tile.coordinates.s, 0)
	
	# DO BFS
	var tiles_reached: Array = []
	var tiles_available: Array = used_cells.keys().filter(func(coords): return coords != vector_coords)
	
	# tiles_available has all remaining tiles, we just need to visit every tile from a (random) starting tile
	# and compare the size with these of all tiles - 1 (our to be moved one)
	var start: Vector4i = tiles_available.front()
	tiles_reached.push_back(start)
	var queue: Array[Vector4i] = [start]
	
	while queue.size() > 0:
		var m = queue.pop_front()
		
		for neighbour in get_neighbours(CubeCoordinates.new(m.x, m.y, m.z)):
			var neighbour_vec4: Vector4i = Vector4i(neighbour.q, neighbour.r, neighbour.s, 0)
			if neighbour_vec4 not in tiles_reached and neighbour_vec4 != vector_coords:
				if used_cells.has(neighbour_vec4):
					tiles_reached.push_back(neighbour_vec4)
					queue.push_back(neighbour_vec4)
					
	return tiles_reached.size() == used_cells.size() - 1

func _on_insect_tile_request_selection(tile: InsectTile) -> void:
	if can_hive_exist_without_tile(tile):
		GameEvents.insect_tile_selection_request_successful.emit(tile)
	else:
		GameEvents.insect_tile_selection_request_failed.emit(tile)

func _ready() -> void:
	GameEvents.insect_selected.connect(_on_insect_selected)
	GameEvents.insect_placement_cancelled.connect(_on_insect_placement_cancelled)
	GameEvents.insect_placed.connect(_on_insect_placed)
	GameEvents.insect_tile_selected.connect(_on_insect_tile_selected)
	GameEvents.insect_tile_moved.connect(_on_insect_tile_moved)
	GameEvents.insect_tile_request_selection.connect(_on_insect_tile_request_selection)
	
#func spawn_random_tile() -> void:
	#var tile_copy = hex.duplicate()
	#var hex_pos = flat_hex_to_world_position(AxialCoordinates.new(randi_range(-20, 20), randi_range(-20, 20)))
#
	#tile_copy.position = Vector3(hex_pos.x, 20.0, hex_pos.y)
	#var target_pos = Vector3(hex_pos.x, 0.0, hex_pos.y)
	#
	#add_child(tile_copy)
	#
	#var tween = get_tree().create_tween()
	#tween.tween_property(tile_copy, "position", target_pos, 1.0).set_ease(Tween.EASE_OUT).set_trans(Tween.TRANS_EXPO)
	#
#func move_tile_to_random_position() -> void:
	#var new_hex_pos = flat_hex_to_world_position(AxialCoordinates.new(randi_range(-20, 20), randi_range(-20, 20)))
	#var sky_new_hex_pos = Vector3(new_hex_pos.x, 20.0, new_hex_pos.y)
	#var ground_new_hex_pos = Vector3(new_hex_pos.x, 0.0, new_hex_pos.y)
	#
	#var current_hex_pos = hex.position
	#var sky_current_hex_pos = hex.position + Vector3(0.0, 20.0, 0.0)
#
	#var tween = get_tree().create_tween()
	#tween.tween_property(hex, "position", sky_current_hex_pos, 0.5).set_ease(Tween.EASE_IN).set_trans(Tween.TRANS_EXPO)
	#tween.tween_property(hex, "position", sky_new_hex_pos, 0.0)
	#tween.tween_property(hex, "position", ground_new_hex_pos, 1.0).set_ease(Tween.EASE_OUT).set_trans(Tween.TRANS_EXPO)

func _process(delta) -> void:
	#if Input.is_action_just_pressed("ui_accept"):
	#	print("yay")
	#	spawn_random_tile()
	return
	
	if current_tile == null:
		return
	
	#var pos3d = get_3d_pos(get_viewport().get_mouse_position())
	#if pos3d:
		#var hex_pos = flat_hex_to_world_position(world_to_hex_tile(Vector2(pos3d.x, pos3d.z)))
		#current_tile.position = Vector3(hex_pos.x, 0.0, hex_pos.y)
		#coord_label.text = "%d, %d" % [hex_pos.x, hex_pos.y]