#!/usr/bin/env python3
#(height, width)
import random as rnd
import os
from enum import Enum
import time
import math

DEBUG=True

class SquareType(Enum):
    AISLE = 0
    SEAT = 1
    WALL = 2

height=0
width=0

grid=[]
# entries=[(3,0)]
entries=[(0,3)]

class GridSquare:
    #typ: SquareType, occupant: index
    def __init__(self, typ, occupant):
        self.typ = typ
        self.occupant = occupant
    def __str__(self):
        return "(%s|%s)" % (str(self.typ), str(self.occupant))
    def __repr__(self):
        return str(self)

def makeGrid():
    return [[GridSquare(SquareType.AISLE, None) for x in range(0,width)] for y in range(0,height)]

class Passenger:
    shuffled = 0
    inter = None
    #dest and curr are both 2-tuples
    def __init__(self, dest, curr):
        self.dest = dest
        self.curr = curr
    def __str__(self):
        return "(%s|%s)" % (dest, curr)

def manhattanDistance(pos1, pos2):
    return abs(pos1[0] - pos2[0]) + abs(pos1[1] - pos2[1])

def mooreNeighbourhood(pos):
    return [i for i in [(pos[0]+1, pos[1]), (pos[0], pos[1]+1), (pos[0]-1, pos[1]), (pos[0], pos[1]-1)] if
            i[0] >= 0 and i[1] >= 0 and i[0] < height and i[1] < width]

def nextSquare(passenger, grid):
    #simple behaviour for now
    candidati = []
    dest = None
    if passenger.inter == None:
        dest = passenger.dest
    else:
        dest = passenger.inter
    for i in mooreNeighbourhood(passenger.curr):
        if manhattanDistance(dest, i) < manhattanDistance(dest, passenger.curr):
            # if grid[passenger.curr[0]][passenger.curr[1]].typ == SquareType.SEAT and i[1] != passenger.curr[1] and False:
            if grid[passenger.curr[0]][passenger.curr[1]].typ == SquareType.SEAT and i[1] != passenger.curr[1]:
                pass
            else:
                candidati.append(i)
    for i in candidati:
        if grid[i[0]][i[1]].typ == SquareType.AISLE and grid[i[0]][i[1]].occupant != None: #this should work well enough for one aisle plane
            return i
    #todo: implement shufflin'
    return candidati[0]

def GenPassList():
    global height
    global width
    global grid
    border=[]
    arrFile = open("figure2.txt")

    height=int(arrFile.readline())
    width=int(arrFile.readline())
    print(height)
    print(width)

    grid = [[GridSquare(SquareType.AISLE, None) for x in range(0,width)] for y in range(0,height)]

    for y in range(0,height):
        for x in range(0,width+1):
            char = arrFile.read(1);
            match char:
                case 'S':
                    grid[y][x].typ = SquareType.SEAT
                    border.append(Passenger((y,x),(-1,-1)))
                case 'W':
                    grid[y][x].typ = SquareType.WALL
                case '.':
                    grid[y][x].typ = SquareType.AISLE
    
    for x in border:
        for i in range(1,7):
            inc = (-1)**i * -math.floor((i+1)/2)
            if (inc + x.dest[0] > 0) and (inc + x.dest[0] < height) and (grid[x.dest[0]+inc][x.dest[1]].typ == SquareType.AISLE):
                x.inter=(inc + x.dest[0], x.dest[1])

    return border 

#boarding order
passengers = GenPassList()

# rnd.seed(605)
# passengers.reverse()
rnd.shuffle(passengers)
toad = 0
btime = 3 #passengers board every btime ticks



def nunty(x):
    if x is None: return -1
    return x

def tick(t):
    done=True
    global toad
    global btime
    # print grid
    if DEBUG:
        for row in grid:
            for guy in row:
                if guy.occupant is not None:
                    print(chr(0x20000 + guy.occupant), end="")
                elif guy.typ == SquareType.SEAT:
                    print("：", end="")
                elif guy.typ == SquareType.WALL:
                    print("Ｗ", end="")
                else:
                    print("＿", end="")
            print()
        print("---")
        # print(grid[3][0].occupant, grid[3][1].occupant, passengers[nunty(grid[3][1].occupant)].dest)
    if t % btime == 0:
        for x in entries:
            if toad < len(passengers) and grid[x[0]][x[1]].occupant is None:
                grid[x[0]][x[1]].occupant = toad #added
                passengers[toad].curr = (x[0], x[1])
                toad += 1
    for (i, man) in enumerate(passengers):
        if man.curr == man.dest:
            continue
        if man.inter is not None and man.curr == man.inter:
            man.shuffled = 3
            man.inter = None
        if man.curr == (-1, -1):
            continue
        # if i == 36 and DEBUG:
        #     print(nextSquare(man, grid))
        print(str(man.curr) + ", " + str(man.inter) + ", " + str(man.dest))
        done=False
        #im sexist
        nextS=nextSquare(man,grid)
        if passengers[i].shuffled == 0 and not ( grid[nextS[0]][nextS[1]].typ == SquareType.AISLE and grid[nextS[0]][nextS[1]].occupant is not None):
            cp = man.curr
            man.curr = nextS
            other = grid[cp[0]][cp[1]]
            other.occupant = grid[man.curr[0]][man.curr[1]].occupant #they move out of there
            if other.occupant is not None:
                passengers[other.occupant].curr = cp
                passengers[other.occupant].shuffled = 5
            grid[man.curr[0]][man.curr[1]].occupant = i
    for man in passengers:
        if man.shuffled != 0:
            man.shuffled-=1
    if DEBUG:
        time.sleep(0.01)
        # time.sleep(0.05)
        os.system("clear")
    if done and toad >= len(passengers):
        print("Number of ticks: " + str(t))
        exit()

def run():
    t = 0
    while 1:
        tick(t)
        t += 1

run()