Module pacai.core.layout

import os
import random

from pacai.core.distance import manhattan
from pacai.core.grid import Grid

# By default, the layout directory is adjacent to this file.
DEFAULT_LAYOUT_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'layouts')

GHOST_NUMS = ['1', '2', '3', '4']

class Layout(object):
    """
    A Layout manages the static information about the game board.
    """

    def __init__(self, layoutText, maxGhosts = None):
        self.width = len(layoutText[0])
        self.height = len(layoutText)
        self.walls = Grid(self.width, self.height, initialValue = False)
        self.food = Grid(self.width, self.height, initialValue = False)
        self.capsules = []
        self.agentPositions = []
        self.numGhosts = 0
        self.layoutText = layoutText

        self.processLayoutText(layoutText, maxGhosts)

    def getNumGhosts(self):
        return self.numGhosts

    def isWall(self, pos):
        x, col = pos
        return self.walls[x][col]

    def getHeight(self):
        return self.height

    def getWidth(self):
        return self.width

    def getRandomLegalPosition(self):
        x = random.choice(list(range(self.width)))
        y = random.choice(list(range(self.height)))
        while self.isWall((x, y)):
            x = random.choice(list(range(self.width)))
            y = random.choice(list(range(self.height)))
        return (x, y)

    def getRandomCorner(self):
        poses = [
            (1, 1),
            (1, self.height - 2),
            (self.width - 2, 1),
            (self.width - 2, self.height - 2)
        ]

        return random.choice(poses)

    def getFurthestCorner(self, pacPos):
        poses = [
            (1, 1),
            (1, self.height - 2),
            (self.width - 2, 1),
            (self.width - 2, self.height - 2)
        ]

        dist, pos = max([(manhattan(p, pacPos), p) for p in poses])
        return pos

    def isVisibleFrom(self, ghostPos, pacPos, pacDirection):
        row, col = [int(x) for x in pacPos]
        return ghostPos in self.visibility[row][col][pacDirection]

    def __str__(self):
        return "\n".join(self.layoutText)

    def deepCopy(self):
        return Layout(self.layoutText[:])

    def processLayoutText(self, layoutText, maxGhosts):
        """
        Coordinates are flipped from the input format to the (x, y) convention here

        The shape of the maze.
        Each character represents a different type of object:
        ```
            % - Wall
            . - Food
            o - Capsule
            G - Ghost
            P - Pacman
        ```
        Other characters are ignored.
        """

        maxY = self.height - 1
        for y in range(self.height):
            for x in range(self.width):
                layoutChar = layoutText[maxY - y][x]
                self.processLayoutChar(x, y, layoutChar, maxGhosts)
        self.agentPositions.sort()
        self.agentPositions = [(i == 0, pos) for i, pos in self.agentPositions]

    def processLayoutChar(self, x, y, layoutChar, maxGhosts):
        if (layoutChar == '%'):
            self.walls[x][y] = True
        elif (layoutChar == '.'):
            self.food[x][y] = True
        elif (layoutChar == 'o'):
            self.capsules.append((x, y))
        elif (layoutChar == 'P'):
            self.agentPositions.append((0, (x, y)))
        elif (layoutChar in ['G'] and (maxGhosts is None or self.numGhosts < maxGhosts)):
            self.agentPositions.append((1, (x, y)))
            self.numGhosts += 1
        elif (layoutChar in GHOST_NUMS and (maxGhosts is None or self.numGhosts < maxGhosts)):
            self.agentPositions.append((int(layoutChar), (x, y)))
            self.numGhosts += 1

def getLayout(name, layout_dir = DEFAULT_LAYOUT_DIR, maxGhosts = None):
    if (not name.endswith('.lay')):
        name += '.lay'

    path = os.path.join(layout_dir, name)
    if (not os.path.isfile(path)):
        raise Exception("Could not locate layout file: '%s'." % (path))

    rows = []
    with open(path, 'r') as file:
        for line in file:
            line = line.strip()
            if (line != ''):
                rows.append(line)

    return Layout(rows, maxGhosts)