from os import path
import heapq
import copy

from settings import *
from sprites import Direction


class PlanRoute():
    """ The problem of moving the Agent from one place to other """

    def __init__(self, initial, goal, allowed, puddles=None, dimrow=None):
        """ Define goal state and initialize a problem """
        self.initial = initial
        self.goal = goal
        self.dimrow = dimrow
        self.goal = goal
        self.allowed = allowed
        self.puddles = puddles

    def actions(self, state):
        possible_actions = ['Forward', 'Left', 'Right']
        x, y = state.get_location()
        orientation = state.get_orientation()

        # Prevent Bumps
        if y == 0 and orientation == 'LEFT':
            if 'Forward' in possible_actions:
                possible_actions.remove('Forward')
        if x == 0 and orientation == 'DOWN':
            if 'Forward' in possible_actions:
                possible_actions.remove('Forward')
        if y == self.dimrow and orientation == 'RIGHT':
            if 'Forward' in possible_actions:
                possible_actions.remove('Forward')
        if x == self.dimrow and orientation == 'UP':
            if 'Forward' in possible_actions:
                possible_actions.remove('Forward')

        return possible_actions

    def result(self, state, action):
        """ Given state and action, return a new state that is the result of the action.
        Action is assumed to be a valid action in the state """
        x, y = state.get_location()
        proposed_loc = list()
        #proposed_loc = []

        # Move Forward
        if action == 'Forward':
            if state.get_orientation() == 'UP':
                proposed_loc = [x + 1, y]
            elif state.get_orientation() == 'DOWN':
                proposed_loc = [x - 1, y]
            elif state.get_orientation() == 'LEFT':
                proposed_loc = [x, y - 1]
            elif state.get_orientation() == 'RIGHT':
                proposed_loc = [x, y + 1]
            else:
                raise Exception('InvalidOrientation')

        # Rotate counter-clockwise
        elif action == 'Right':
            if state.get_orientation() == 'UP':
                state.set_orientation('LEFT')
            elif state.get_orientation() == 'DOWN':
                state.set_orientation('RIGHT')
            elif state.get_orientation() == 'LEFT':
                state.set_orientation('DOWN')
            elif state.get_orientation() == 'RIGHT':
                state.set_orientation('UP')
            else:
                raise Exception('InvalidOrientation')

        # Rotate clockwise
        elif action == 'Left':
            if state.get_orientation() == 'UP':
                state.set_orientation('RIGHT')
            elif state.get_orientation() == 'DOWN':
                state.set_orientation('LEFT')
            elif state.get_orientation() == 'LEFT':
                state.set_orientation('UP')
            elif state.get_orientation() == 'RIGHT':
                state.set_orientation('DOWN')
            else:
                raise Exception('InvalidOrientation')
        

        if(proposed_loc):
            tupled_proposed_loc = tuple([proposed_loc[0], proposed_loc[1]])
        
            if tupled_proposed_loc in self.allowed:
                state.set_location(proposed_loc[0], proposed_loc[1])

        return state

    def goal_test(self, state):
        """ Given a state, return True if state is a goal state or False, otherwise """

        return state.get_location() == self.goal.get_location()

    def path_cost(self, c, state1, action, state2):
        if action == "Forward" or action == "Left" or action == "Right":

            
            x1, y1 = state1.get_location()
            location1 = tuple([x1, y1])
            x2, y2 = state2.get_location()
            location2 = tuple([x1, y1])
            

            if location2 in self.puddles:
                return c + 2
            if location1 == location2 and state1 in self.puddles:
                return c + 2
            return c+1

    def h(self, node):
        """ Return the heuristic value for a given state."""

        # Manhattan Heuristic Function
        x1, y1 = node.state.get_location()
        x2, y2 = self.goal.get_location()

        return abs(x2 - x1) + abs(y2 - y1)


class Node:
    def __init__(self, state, parent=None, action=None, path_cost=0):
        """Create a search tree Node, derived from a parent by an action."""
        self.state = state #AgentPosition?
        self.parent = parent
        self.action = action
        self.path_cost = path_cost

    def __repr__(self):
        return "<Node {}>".format(self.state)

    def solution(self):
        """Return the sequence of actions to go from the root to this node."""
        return [node.action for node in self.path()[1:]]


    def expand(self, problem):
        """List the nodes reachable in one step from this node."""
        test_node_list = [self.child_node(problem, action)
                for action in problem.actions(self.state)]

        return [self.child_node(problem, action)
                for action in problem.actions(self.state)]

    def child_node(self, problem, action):
        

        next_state = problem.result(copy.deepcopy(self.state), action)
        next_node = Node(next_state, self, action, problem.path_cost(
            self.path_cost, self.state, action, next_state))
        #print(problem.path_cost(
        #   self.path_cost, self.state, action, next_state))
        return next_node

    def __eq__(self, other):
        return isinstance(other, Node) and self.state == other.state

    def __lt__(self, other):
        return isinstance(other, Node) and self.state == other.state

    

    def __hash__(self):
        # We use the hash value of the state
        # stored in the node instead of the node
        # object itself to quickly search a node
        # with the same state in a Hash Table
        return hash(self.state)

    def path(self):
        """Return a list of nodes forming the path from the root to this node."""
        node, path_back = self, []
        while node:
            path_back.append(node)
            node = node.parent
        return list(reversed(path_back))


class AgentPosition:
    def __init__(self, x, y, orientation):
        self.X = x
        self.Y = y
        self.orientation = orientation

    def get_location(self):
        return self.X, self.Y

    def set_location(self, x, y):
        self.X = x
        self.Y = y

    def get_orientation(self):
        return self.orientation

    def set_orientation(self, orientation):
        self.orientation = orientation

    def __eq__(self, other):
        if (other.get_location() == self.get_location() and
                other.get_orientation() == self.get_orientation()):
            return True
        else:
            return False   


    def __hash__(self):
        return hash((self.X, self.Y, self.orientation))


class SweeperAgent:
    def __init__(self, dimensions=None):
        self.dimrow = dimensions
        self.current_position = None
        self.orientation = ""
        self.initial = set()
        self.goal = set()
        self.allowed_points = set()
        self.puddle_points = set()


    def where_am_i(self):
        temp_map = [list(item) for item in SweeperAgent.loadMap("map.txt")]

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == ">" or pos == "<" or pos == "^" or pos == "v":
                    self.row = row
                    self.column = column

                    return row, column
        
        # add orientation

    def where_to_go(self):
        temp_map = [list(item) for item in SweeperAgent.loadMap("goal_map.txt")]

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == ">" or pos == "<" or pos == "^" or pos == "v":
                    self.row = row
                    self.column = column

                    return row, column

    @staticmethod
    def set_allowed(allowed_points):
        temp_map = [list(item) for item in SweeperAgent.loadMap('map.txt')]

        a_row = 0
        a_column = 0

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == "." or pos == 'p' or pos == '>' or pos == '<' or pos == 'v' or pos == '^': 
                    a_row = row
                    a_column = column
                    location = tuple([a_row, a_column])
                    allowed_points.add(location)

    @staticmethod
    def set_puddles(puddle_points):
        temp_map = [list(item) for item in SweeperAgent.loadMap('map.txt')]

        a_row = 0
        a_column = 0

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == "p" :
                    a_row = row
                    a_column = column
                    location = tuple([a_row, a_column])
                    puddle_points.add(location)


    @staticmethod
    def get_goal():
        temp_map = [list(item) for item in SweeperAgent.loadMap('goal_map.txt')]

        a_row = 0
        a_column = 0

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == '>' or pos == '<' or pos == 'v' or pos == '^': 
                    a_row = row
                    a_column = column
                    return a_row, a_column


    @staticmethod
    def set_initial(initial):
        temp_map = [list(item) for item in SweeperAgent.loadMap('map.txt')]

        a_row = 0
        a_column = 0

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == '>' or pos == '<' or pos == 'v' or pos == '^': 
                    a_row = row
                    a_column = column
                    location = tuple([a_row, a_column])
                    initial.add(location)

     


    @staticmethod
    def set_orientation():
        temp_map = [list(item) for item in SweeperAgent.loadMap('map.txt')]

        orientation = ""

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == ">":
                    orientation = "RIGHT"
                if pos == "<":
                    orientation = "LEFT"
                if pos == "^":
                    orientation = "UP"
                if pos == "v":
                    orientation = "DOWN"

        return orientation

    @staticmethod
    def set_goal_orientation():
        temp_map = [list(item) for item in SweeperAgent.loadMap('goal_map.txt')]

        orientation = ""

        for row in range(MAP_SIZE):
            for column, pos in enumerate(temp_map[row]):
                if pos == ">":
                    orientation = "RIGHT"
                if pos == "<":
                    orientation = "LEFT"
                if pos == "^":
                    orientation = "UP"
                if pos == "v":
                    orientation = "DOWN"

        return orientation

        
    @staticmethod
    def run(self):
        self.orientation = SweeperAgent.set_orientation()
        goal_orientation = SweeperAgent.set_goal_orientation()
        #SweeperAgent.set_initial(self.initial)
        #SweeperAgent.set_goal(self.goal)
        SweeperAgent.set_allowed(self.allowed_points)
        SweeperAgent.set_puddles(self.puddle_points)

        x, y = self.where_am_i()
        x1, y1 = SweeperAgent.get_goal()

        agent_position = AgentPosition(x, y, self.orientation)
        goal_position = AgentPosition(x1, y1, goal_orientation)

        return self.plan_route(agent_position, goal_position, self.allowed_points, self.puddle_points)



        """print("allowed: ")
        print("(row, column)")
        print(sorted(self.allowed_points))
        print("puddles:")
        print(sorted(self.puddle_points))
        print("initial:")
        print(self.initial)
        print("goal:")
        print(self.goal)
        print("orientation:")
        print(self.orientation)"""
        
        
    def plan_route(self, current, goals, allowed, puddles):
        problem = PlanRoute(current, goals, allowed, puddles, MAP_SIZE-1)
        return SweeperAgent.astar_search(problem, problem.h)
        #return SweeperAgent.astar_search(problem, problem.h)





    """TODO""" 
    # liczenie kosztów
    # 

    @staticmethod
    def loadMap(map_name=''):
            maze = []
            map_folder = path.dirname(__file__)
            with open(path.join(map_folder, map_name), 'rt') as f:
                for line in f:
                    maze.append(line.rstrip('\n'))
            
            # print(maze)
            return maze

    @staticmethod
    def astar_search(problem, h=None):
        """A* search is best-first graph search with f(n) = g(n)+h(n).
        You need to specify the h function when you call astar_search, or
        else in your Problem subclass."""
        # h = memoize(h or problem.h, 'h')
        return SweeperAgent.best_first_graph_search(problem, lambda n: n.path_cost + h(n))
        #return best_first_graph_search(problem)

    @staticmethod
    #def best_first_graph_search(problem, f, display=False):
    def best_first_graph_search(problem, f, display=True):
        

        """TODO"""
        # Zaimplementować klasę Node dla Astar

        history = []

        node = Node(problem.initial)
        frontier = PriorityQueue('min', f)
        frontier.append(node)
        explored = set()
        while frontier:
            node = frontier.pop()
            if problem.goal_test(node.state):
                if display:
                    print(len(explored), "paths have been expanded and", len(frontier), "paths remain in the frontier")
                    while(node.parent != None):
                        history.append(node.action)
                        node = node.parent
                    #return child
                    history.reverse()
                    print(history)
                    return history
                    #return history
                    #break
                #return node
                #break
            explored.add(copy.deepcopy(node.state))
            test_child_chamber = node.expand(problem)
            for child in node.expand(problem):
                if child.state not in explored and child not in frontier:
                    frontier.append(copy.deepcopy(child))
                elif child in frontier:
                    if f(child) < frontier[child]:
                        del frontier[child]
                        frontier.append(child)

        return history
        #return None



class PriorityQueue:
    """A Queue in which the minimum (or maximum) element (as determined by f and
    order) is returned first.
    If order is 'min', the item with minimum f(x) is
    returned first; if order is 'max', then it is the item with maximum f(x).
    Also supports dict-like lookup."""

    def __init__(self, order='min', f=lambda x: x):
        self.heap = []
        if order == 'min':
            self.f = f
        elif order == 'max':  # now item with max f(x)
            self.f = lambda x: -f(x)  # will be popped first
        else:
            raise ValueError("Order must be either 'min' or 'max'.")

    def append(self, item):
        """Insert item at its correct position."""
        heapq.heappush(self.heap, (self.f(item), item))

    def extend(self, items):
        """Insert each item in items at its correct position."""
        for item in items:
            self.append(item)

    def pop(self):
        """Pop and return the item (with min or max f(x) value)
        depending on the order."""
        if self.heap:
            return heapq.heappop(self.heap)[1]
        else:
            raise Exception('Trying to pop from empty PriorityQueue.')

    def __len__(self):
        """Return current capacity of PriorityQueue."""
        return len(self.heap)

    def __contains__(self, key):
        """Return True if the key is in PriorityQueue."""
        return any([item == key for _, item in self.heap])

    def __getitem__(self, key):
        """Returns the first value associated with key in PriorityQueue.
        Raises KeyError if key is not present."""
        for value, item in self.heap:
            if item == key:
                return value
        raise KeyError(str(key) + " is not in the priority queue")

    def __delitem__(self, key):
        """Delete the first occurrence of key."""
        try:
            del self.heap[[item == key for _, item in self.heap].index(True)]
        except ValueError:
            raise KeyError(str(key) + " is not in the priority queue")
        heapq.heapify(self.heap)


class Test:
    @staticmethod
    def run():
        
        allowed_points = set()
        puddle_points = set()
        
        initial = set()
        goal = set()

        orientation = SweeperAgent.set_orientation()

        SweeperAgent.set_initial(initial)
        SweeperAgent.set_goal(goal)

        SweeperAgent.set_allowed(allowed_points)
        SweeperAgent.set_puddles(puddle_points)


        
        print("allowed: ")
        print("(row, column)")
        print(sorted(allowed_points))
        print("puddles:")
        print(sorted(puddle_points))
        print("initial:")
        print(initial)
        print("goal:")
        print(goal)
        print("orientation:")
        print(orientation)