import math, sys, pygame, random
from math import *
from pygame import *
import sys
import random
import math
import copy
import numpy as np
import dubins_path_planning
import matplotlib.pyplot as plt


XDIM = 720
YDIM = 500
windowSize = [XDIM, YDIM]
delta = 10.0
GAME_LEVEL = 1
GOAL_RADIUS = 10
MIN_DISTANCE_TO_ADD = 1.0
NUMNODES = 5000
FPS = 1000
pygame.init()
fpsClock = pygame.time.Clock()
screen = pygame.display.set_mode(windowSize)
white = 255, 255, 255
black = 25, 25, 25
red = 255, 0, 0
blue = 0, 128, 0
green = 0, 0, 255
cyan = 0,180,105

show_animation = True
STEP_SIZE = 2
curvature = 10

count = 0
obs = []

def dist(p1,p2):    #distance between two points
    return sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1]))

def point_circle_collision(p1, p2, radius):
    distance = dist(p1,p2)
    if (distance <= radius):
        return True
    return False

def step_from_to(p1,p2):
    if dist(p1,p2) < delta:
        return p2
    else:
        theta = atan2(p2[1]-p1[1],p2[0]-p1[0])
        return p1[0] + delta*cos(theta), p1[1] + delta*sin(theta)

def collides(p):    #check if point collides with the obstacle
    return False


def init_obstacles(configNum):  #initialized the obstacle
    global obs
    obs = []
    obs.append((150,100,18))
    obs.append((150,130,18))
    obs.append((150,160,18))
    obs.append((150,190,18))
    obs.append((150,220,18))
    obs.append((150,250,18))
    obs.append((180,250,18))
    obs.append((210,250,18))
    obs.append((240,250,18))
    obs.append((270,250,18))
    obs.append((300,250,18))
    obs.append((330,250,18))
    obs.append((330,220,18))
    obs.append((330,190,18))
    obs.append((330,160,18))
    obs.append((330,130,18))
    obs.append((330,100,18))
    obs.append((300,100,18))
    obs.append((270,100,18))
    obs.append((240,100,18))
    obs.append((240,130,18))
    obs.append((240,160,18))
    obs.append((240,190,18))
    for (ox, oy, size) in obs:
            #plt.plot(ox, oy, "ok", ms=30 * size)
            pygame.draw.circle(screen, black, (ox, oy), size)


def reset():
    global count
    screen.fill(white)
    init_obstacles(GAME_LEVEL)
    count = 0

class RRT():
    """
    Class for RRT Planning
    """

    def __init__(self, start, goal, obstacleList, randArea,
                 goalSampleRate=10, maxIter=120):
        """
        Setting Parameter
        start:Start Position [x,y]
        goal:Goal Position [x,y]
        obstacleList:obstacle Positions [[x,y,size],...]
        randArea:Ramdom Samping Area [min,max]
        """
        self.start = Node(start[0], start[1], start[2])
        self.end = Node(goal[0], goal[1], goal[2])
        self.minrand = randArea[0]
        self.maxrand = randArea[1]
        self.goalSampleRate = goalSampleRate
        self.maxIter = maxIter
        self.obstacleList = obstacleList

    def Planning(self, animation=True):
        """
        Pathplanning
        animation: flag for animation on or off
        """

        self.nodeList = [self.start]
        for i in range(self.maxIter):
            if(i%10==0):
                print("Planning path",i)
			
            for e in pygame.event.get():
                if e.type == QUIT or (e.type == KEYUP and e.key == K_ESCAPE):
                    sys.exit("Exiting")

            rnd = self.get_random_point()
            nind = self.GetNearestListIndex(self.nodeList, rnd)

            newNode = self.steer(rnd, nind)
            if newNode is None:
                continue

            if self.CollisionCheck(newNode, self.obstacleList):
                nearinds = self.find_near_nodes(newNode)
                newNode = self.choose_parent(newNode, nearinds)
                if newNode is None:
                    continue
                self.nodeList.append(newNode)
                self.rewire(newNode, nearinds)

            if animation and i % 5 == 0:
                self.DrawGraph(rnd=rnd)
            #if(newNode.)

        # generate coruse
        lastIndex = self.get_best_last_index()
        if lastIndex is None:
            return None
        path = self.gen_final_course(lastIndex)
        print("Path planning done")
        return path

    def choose_parent(self, newNode, nearinds):
        if len(nearinds) == 0:
            return newNode

        dlist = []
        for i in nearinds:
            tNode = self.steer(newNode, i)
            if tNode is None:
                continue

            if self.CollisionCheck(tNode, self.obstacleList):
                dlist.append(tNode.cost)
            else:
                dlist.append(float("inf"))

        mincost = min(dlist)
        minind = nearinds[dlist.index(mincost)]

        if mincost == float("inf"):
            print("mincost is inf")
            return newNode

        newNode = self.steer(newNode, minind)

        return newNode

    def pi_2_pi(self, angle):
        return (angle + math.pi) % (2 * math.pi) - math.pi

    def steer(self, rnd, nind):

        nearestNode = self.nodeList[nind]

        px, py, pyaw, mode, clen = dubins_path_planning.dubins_path_planning(
            nearestNode.x, nearestNode.y, nearestNode.yaw, rnd.x, rnd.y, rnd.yaw, curvature)

        if px is None:
            return None

        newNode = copy.deepcopy(nearestNode)
        newNode.x = px[-1]
        newNode.y = py[-1]
        newNode.yaw = pyaw[-1]

        newNode.path_x = px
        newNode.path_y = py
        newNode.path_yaw = pyaw
        newNode.cost += clen
        newNode.parent = nind

        return newNode

    def get_random_point(self):

        if random.randint(0, 100) > self.goalSampleRate:
            rnd = [random.uniform(self.minrand, self.maxrand),
                   random.uniform(self.minrand, self.maxrand),
                   random.uniform(-math.pi, math.pi)
                   ]
        else:  # goal point sampling
            rnd = [self.end.x, self.end.y, self.end.yaw]

        node = Node(rnd[0], rnd[1], rnd[2])

        return node

    def get_best_last_index(self):
        #  print("get_best_last_index")

        YAWTH = np.deg2rad(3.0)
        XYTH = 0.5

        goalinds = []
        for (i, node) in enumerate(self.nodeList):
            if self.calc_dist_to_goal(node.x, node.y) <= XYTH:
                goalinds.append(i)
        #  print("OK XY TH num is")
        #  print(len(goalinds))

        # angle check
        fgoalinds = []
        for i in goalinds:
            if abs(self.nodeList[i].yaw - self.end.yaw) <= YAWTH:
                fgoalinds.append(i)
        #  print("OK YAW TH num is")
        #  print(len(fgoalinds))

        if len(fgoalinds) == 0:
            return None

        mincost = min([self.nodeList[i].cost for i in fgoalinds])
        for i in fgoalinds:
            if self.nodeList[i].cost == mincost:
                return i

        return None

    def gen_final_course(self, goalind):
        path = [[self.end.x, self.end.y]]
        while self.nodeList[goalind].parent is not None:
            node = self.nodeList[goalind]
            for (ix, iy) in zip(reversed(node.path_x), reversed(node.path_y)):
                path.append([ix, iy])
            #  path.append([node.x, node.y])
            goalind = node.parent
        path.append([self.start.x, self.start.y])
        return path

    def calc_dist_to_goal(self, x, y):
        return np.linalg.norm([x - self.end.x, y - self.end.y])

    def find_near_nodes(self, newNode):
        nnode = len(self.nodeList)
        r = 50.0 * math.sqrt((math.log(nnode) / nnode))
        #  r = self.expandDis * 5.0
        dlist = [(node.x - newNode.x) ** 2 +
                 (node.y - newNode.y) ** 2 +
                 (node.yaw - newNode.yaw) ** 2
                 for node in self.nodeList]
        nearinds = [dlist.index(i) for i in dlist if i <= r ** 2]
        return nearinds

    def rewire(self, newNode, nearinds):

        nnode = len(self.nodeList)

        for i in nearinds:
            nearNode = self.nodeList[i]
            tNode = self.steer(nearNode, nnode - 1)
            if tNode is None:
                continue

            obstacleOK = self.CollisionCheck(tNode, self.obstacleList)
            imporveCost = nearNode.cost > tNode.cost

            if obstacleOK and imporveCost:
                #  print("rewire")
                self.nodeList[i] = tNode

    def DrawGraph(self, rnd=None):
        """
        Draw Graph
        """
        reset()
        if rnd is not None:
            plt.plot(rnd.x, rnd.y, "^k")
        for node in self.nodeList:
            if node.parent is not None:
                plt.plot(node.path_x, node.path_y, "-g")
                for i in range(1, len(node.path_x)):
                    pygame.draw.line(screen,blue,(node.path_x[i-1], node.path_y[i-1]), (node.path_x[i], node.path_y[i]))
                #  plt.plot([node.x, self.nodeList[node.parent].x], [
                #  node.y, self.nodeList[node.parent].y], "-g")

        for (ox, oy, size) in self.obstacleList:
            #plt.plot(ox, oy, "ok", ms=30 * size)
            pygame.draw.circle(screen, black, (ox, oy), size)

        '''reeds_shepp_path_planning.plot_arrow(self.start.x, self.start.y, self.start.yaw)
        reeds_shepp_path_planning.plot_arrow(self.end.x, self.end.y, self.end.yaw)'''
        pygame.draw.circle(screen, red, (self.start.x, self.start.y), GOAL_RADIUS)
        pygame.draw.circle(screen, green, (self.end.x, self.end.y), GOAL_RADIUS)

        '''plt.axis([-2, 15, -2, 15])
        plt.grid(True)
        plt.pause(0.01)'''
        pygame.display.update()
        #  plt.show()
        #  input()

    def GetNearestListIndex(self, nodeList, rnd):
        dlist = [(node.x - rnd.x) ** 2 +
                 (node.y - rnd.y) ** 2 +
                 (node.yaw - rnd.yaw) ** 2 for node in nodeList]
        minind = dlist.index(min(dlist))

        return minind

    def CollisionCheck(self, node, obstacleList):

        for (ox, oy, size) in obstacleList:
            for (ix, iy) in zip(node.path_x, node.path_y):
                dx = ox - ix
                dy = oy - iy
                d = dx * dx + dy * dy
                if d <= size ** 2:
                    return False  # collision

        return True  # safe


class Node():
    """
    RRT Node
    """

    def __init__(self, x, y, yaw):
        self.x = x
        self.y = y
        self.yaw = yaw
        self.path_x = []
        self.path_y = []
        self.path_yaw = []
        self.cost = 0.0
        self.parent = None




def main():
    global count
    
    initPoseSet = False
    initialPoint = Node(None, None, 0)
    goalPoseSet = False
    goalPoint = Node(None, None, 0)
    currentState = 'init'
    rrt = None
    path = None

    nodes = []
    reset()

    while True:
        if currentState == 'init':
            pygame.display.set_caption('Select Starting Point and then Goal Point')
            fpsClock.tick(10)
        elif currentState == 'goalFound':
            pygame.display.set_caption('Goal Reached')
            rrt.DrawGraph()
            for i in range(1, len(path)):
                pygame.draw.line(screen, red, path[i-1], path[i])
            optimizePhase = True
        elif currentState == 'optimize':
            fpsClock.tick(0.5)
            pass
        elif currentState == 'buildTree':
            rrt = RRT((initialPoint.x, initialPoint.y, initialPoint.yaw), (goalPoint.x, goalPoint.y, goalPoint.yaw), randArea=[0, 500], obstacleList=obs)
            path = rrt.Planning(True)
            if(path != None):
                currentState = 'goalFound'

        for e in pygame.event.get():
            if e.type == QUIT or (e.type == KEYUP and e.key == K_ESCAPE):
                sys.exit("Exiting")
            if e.type == MOUSEBUTTONDOWN:
                print('mouse down')
                if currentState == 'init':
                    if initPoseSet == False:
                        nodes = []
                        if collides(e.pos) == False:
                            print('initiale point set: '+str(e.pos))

                            initialPoint = Node(e.pos[0], e.pos[1], np.deg2rad(0.0))
                            initPoseSet = True
                            pygame.draw.circle(screen, red, (initialPoint.x, initialPoint.y), GOAL_RADIUS)
                    elif goalPoseSet == False:
                        print('goal point set: '+str(e.pos))
                        if collides(e.pos) == False:
                            goalPoint = Node(e.pos[0], e.pos[1], np.deg2rad(90.0))
                            goalPoseSet = True
                            pygame.draw.circle(screen, green, (goalPoint.x, goalPoint.y), GOAL_RADIUS)
                            #pygame.display.update()
                            currentState = 'buildTree'
                else:
                    currentState = 'init'
                    initPoseSet = False
                    goalPoseSet = False
                    reset()

        pygame.display.update()
        fpsClock.tick(FPS)



if __name__ == '__main__':
    main()
    
