from warehouse import Coordinates, Tile, Pack
from queue import PriorityQueue
from math import sqrt
import pdb

class Node:
	def __init__(self, coord_x, coord_y):
		self.x = coord_x
		self.y = coord_y
		self.parent = None
		self.g_cost = 0
		self.h_cost = 0
	def __eq__(self, other):
		if isinstance(other, Node):
			return self.x == other.x and self.y == self.y
		return False

	def __lt__(self, other):
		return isinstance(other, Node) and self.g_cost < other.g_cost

	def __repr__(self):
		return "Node:{}x{}".format(self.x, self.y)

class Agent:
	def __init__(self, start_x, start_y, assigned_warehouse, radius=5):
		self.x = start_x
		self.y = start_y
		self.radius = radius
		self.warehouse = assigned_warehouse
		self.is_loaded = False
		self.transported_package = None
		self.dest = Node(1, 1)
		self.closed = list()
		self.open = PriorityQueue()
		self.path = list()


	def find_path(self):
		self.closed = []
		self.open = PriorityQueue()
		start_node = Node(self.x, self.y)
		self.open.put((0, start_node))
		while self.open:
			_, current_node = self.open.get()
			print(current_node.x, current_node.y)
			self.closed.append(current_node)
			if current_node.x == self.dest.x and current_node.y == self.dest.y:
				while current_node.x != start_node.x or current_node.y != start_node.y:
					self.path.append(current_node)
					current_node = current_node.parent
				return True
			neighbour_list = self.get_neighbours(current_node)
			for neighbour in neighbour_list:
				cost = current_node.g_cost + self.heuristic(current_node, neighbour)
				if self.check_if_closed(neighbour):
					continue
				if self.check_if_open(neighbour):
					if neighbour.g_cost > cost:
						neighbour.g_cost = cost
						neighbour.parent = current_node
				else:
					neighbour.g_cost = cost
					neighbour.h_cost = self.heuristic(neighbour, self.dest)
					neighbour.parent = current_node
					self.open.put((neighbour.g_cost, neighbour))
		return False

	def heuristic(self, start: Node, goal: Node):
		diff_x = pow(goal.x - start.x, 2)
		diff_y = pow(goal.y - start.y, 2)
		return round(sqrt(diff_x + diff_y), 3)
		
	def check_if_open(self, node: Node):
		return (node.x, node.y) in [(n.x, n.y) for (_,n) in self.open.queue]

	def check_if_closed(self, node: Node):
		return (node.x, node.y) in [(n.x, n.y) for n in self.closed]

	def get_neighbours(self, node: Node):
		neighbours = []
		if self.check_if_can_move(Coordinates(node.x + 1, node.y)):
			neighbours.append(Node(node.x + 1, node.y))
		if self.check_if_can_move(Coordinates(node.x - 1, node.y)):
			neighbours.append(Node(node.x - 1, node.y))
		if self.check_if_can_move(Coordinates(node.x, node.y + 1)):
			neighbours.append(Node(node.x, node.y + 1))
		if self.check_if_can_move(Coordinates(node.x, node.y - 1)):
			neighbours.append(Node(node.x, node.y - 1))
		return neighbours
    	
	def move(self):
		if not self.path:
			if not self.find_path():
				return
		else:
			next = self.path.pop()
			print(next.x, next.y)
			self.x = next.x
			self.y = next.y
		self.closed = []
	def check_if_can_move(self, next_coords: Coordinates):
		tile_on_map = 0 <= next_coords.x < self.warehouse.width and 0 <= next_coords.y < self.warehouse.height
		if not tile_on_map:
			return False
		next_tile = self.warehouse.tiles[next_coords.x][next_coords.y]
		tile_passable = isinstance(next_tile, Tile) and next_tile.category.passable
		return tile_passable

	def pick_up_package(self, pack):
		tile = pack.lays_on_field
		self.assigned_warehouse.tiles[tile.x_position][tile.y_position] = tile
		self.is_loaded = True
		pack.lays_on_field = None
		self.transported_package = pack