model.py

# Written by Michelle Blom, 2019
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
from utils import *

import numpy
import random
import abc
import copy


# We use the tile display class to represent both factory displays and 
# the pool of tiles in the centre of the playing area. 
class TileDisplay:
    def __init__(self):
        # Map between tile colour and number in the display
        self.tiles = {}

        # Total number of tiles in the display
        self.total = 0

        for tile in Tile:
            self.tiles[tile] = 0

    def RemoveTiles(self, number, tile_type):
        assert number > 0
        assert tile_type in Tile
        assert tile_type in self.tiles

        self.tiles[tile_type] -= number
        self.total -= number

        assert self.tiles[tile_type] >= 0
        assert self.total >= 0

    def AddTiles(self, number, tile_type):
        assert number > 0
        assert tile_type in Tile
        assert tile_type in self.tiles
        
        self.tiles[tile_type] += number
        self.total += number



# We use the PlayerState class to represent a player's game state:
# their score; the state of their pattern lines; the state of their
# wall grid; and their floor line.
class PlayerState:
    GRID_SIZE = 5
    FLOOR_SCORES = [-1,-1,-2,-2,-2,-3,-3]
    ROW_BONUS = 2
    COL_BONUS = 7
    SET_BONUS = 10

    def __init__(self, _id):
        self.id = _id
        self.score = 0
        self.lines_number = [0]*self.GRID_SIZE
        self.lines_tile = [-1]*self.GRID_SIZE

        self.player_trace = PlayerTrace(_id)

        #self.grid_scheme = [
        #    [Tile.BLUE,Tile.YELLOW,Tile.RED,Tile.BLACK,Tile.WHITE],
        #    [Tile.WHITE,Tile.BLUE,Tile.YELLOW,Tile.RED,Tile.BLACK],
        #    [Tile.BLACK,Tile.WHITE,Tile.BLUE,Tile.YELLOW,Tile.RED],
        #    [Tile.RED,Tile.BLACK,Tile.WHITE,Tile.BLUE,Tile.YELLOW],
        #    [Tile.YELLOW,Tile.RED,Tile.BLACK,Tile.WHITE,Tile.BLUE]
        #]
        self.grid_scheme = numpy.zeros((self.GRID_SIZE,self.GRID_SIZE))
        self.grid_scheme[0][Tile.BLUE] = 0
        self.grid_scheme[1][Tile.BLUE] = 1
        self.grid_scheme[2][Tile.BLUE] = 2
        self.grid_scheme[3][Tile.BLUE] = 3
        self.grid_scheme[4][Tile.BLUE] = 4

        self.grid_scheme[1][Tile.WHITE] = 0
        self.grid_scheme[2][Tile.WHITE] = 1
        self.grid_scheme[3][Tile.WHITE] = 2
        self.grid_scheme[4][Tile.WHITE] = 3 
        self.grid_scheme[0][Tile.WHITE] = 4
        
        self.grid_scheme[2][Tile.BLACK] = 0 
        self.grid_scheme[3][Tile.BLACK] = 1
        self.grid_scheme[4][Tile.BLACK] = 2
        self.grid_scheme[0][Tile.BLACK] = 3
        self.grid_scheme[1][Tile.BLACK] = 4

        self.grid_scheme[3][Tile.RED] = 0
        self.grid_scheme[4][Tile.RED] = 1
        self.grid_scheme[0][Tile.RED] = 2
        self.grid_scheme[1][Tile.RED] = 3
        self.grid_scheme[2][Tile.RED] = 4

        self.grid_scheme[4][Tile.YELLOW] = 0
        self.grid_scheme[0][Tile.YELLOW] = 1
        self.grid_scheme[1][Tile.YELLOW] = 2
        self.grid_scheme[2][Tile.YELLOW] = 3
        self.grid_scheme[3][Tile.YELLOW] = 4

        # Matrix representing state of the player's grid (ie. which
        # slots have tiles on them -- 1s -- and which don't -- 0s).
        self.grid_state = numpy.zeros((self.GRID_SIZE,self.GRID_SIZE))

        # State of the player's floor line, a 1 indicates there is
        # a tile sitting in that position in their floor line.
        self.floor = [0,0,0,0,0,0,0]
        self.floor_tiles = []

        # Record of the number of tiles of each colour the player
        # has placed in their grid (useful for end-game scoring)
        self.number_of = {}
        for tile in Tile:
            self.number_of[tile] = 0


    # Add given tiles to the player's floor line. After calling this 
    # method, 'tiles' will contain tiles that could not be added to
    # the player's floor line.
    def AddToFloor(self, tiles):
        number = len(tiles)
        for i in range(len(self.floor)):
            if self.floor[i] == 0:
                self.floor[i] = 1
                tt = tiles.pop(0)
                self.floor_tiles.append(tt)
                number -= 1
            if number == 0:
                break

    # Add given number of given tile type to the specified pattern line
    def AddToPatternLine(self, line, number, tile_type):
        assert line >= 0 and line < self.GRID_SIZE

        assert (self.lines_tile[line] == -1 or 
            self.lines_tile[line] == tile_type)

        self.lines_number[line] += number
        self.lines_tile[line] = tile_type

        assert self.lines_number[line] <= line + 1 


    # Assign first player token to this player
    def GiveFirstPlayerToken(self):
        for i in range(len(self.floor)):
            if self.floor[i] == 0:
                self.floor[i] = 1
                break


    # Compute number of completed rows in the player's grid
    def GetCompletedRows(self):
        completed = 0
        for i in range(self.GRID_SIZE):
            allin = True
            for j in range(self.GRID_SIZE):
                if self.grid_state[i][j] == 0:
                    allin = False
                    break
            if allin:
                completed += 1
        return completed

    
    # Compute number of completed columns in the player's grid
    def GetCompletedColumns(self):
        completed = 0
        for i in range(self.GRID_SIZE):
            allin = True
            for j in range(self.GRID_SIZE):
                if self.grid_state[j][i] == 0:
                    allin = False
                    break
            if allin:
                completed += 1
        return completed


    # Compute the number of completed tile sets in the player's grid
    def GetCompletedSets(self):
        completed = 0
        for tile in Tile:
            if self.number_of[tile] == self.GRID_SIZE:
                completed += 1
        return completed


    # Return the set of moves available to this player given the
    # current game state. 
    def GetAvailableMoves(self, game_state):
        moves = []

        # Look at each factory display with available tiles
        fid = 0
        for fd in game_state.factories:
            # Look at each available tile set
            for tile in Tile:
                num_avail = fd.tiles[tile]
            
                if num_avail == 0:
                    continue

                # A player can always take tiles, as they can be 
                # added to their floor line (if their floor line is 
                # full, the extra tiles are placed in the used bag).

                # First look through each pattern line, create moves 
                # that place the tiles in each appropriate line (with
                # those that cannot be placed added to the floor line).
                for i in range(self.GRID_SIZE):
                    # Can tiles be added to pattern line i?
                    if self.lines_tile[i] != -1 and \
                        self.lines_tile[i] != tile:
                        # these tiles cannot be added to this pattern line
                        continue

                    # Is the space on the grid for this tile already
                    # occupied?
                    grid_col = int(self.grid_scheme[i][tile])
                    if self.grid_state[i][grid_col] == 1:
                        # It is, so we cannot place this tile type
                        # in this pattern line!
                        continue

                    slots_free = (i+1) - self.lines_number[i]
                    tg = TileGrab()
                    tg.number = num_avail
                    tg.tile_type = tile
                    tg.pattern_line_dest = i
                    tg.num_to_pattern_line = min(num_avail, slots_free)
                    tg.num_to_floor_line = tg.number - tg.num_to_pattern_line

                    moves.append((Move.TAKE_FROM_FACTORY, fid, tg))
        
                # Default move is to place all the tiles in the floor line
                tg = TileGrab()
                tg.number = num_avail
                tg.tile_type = tile
                tg.num_to_floor_line = tg.number
                moves.append((Move.TAKE_FROM_FACTORY, fid, tg))

            fid += 1    

        # Alternately, the player could take tiles from the centre pool.
        # Note that we do not include the first player token in the 
        # collection of tiles recorded in each TileGrab. This is managed
        # by the game running class. 
        for tile in Tile:
            # Number of tiles of this type in the centre
            num_avail = game_state.centre_pool.tiles[tile]

            if num_avail == 0:
                continue

            # First look through each pattern line, create moves 
            # that place the tiles in each appropriate line (with
            # those that cannot be placed added to the floor line).
            for i in range(self.GRID_SIZE):
                # Can tiles be added to pattern line i?
                if self.lines_tile[i] != -1 and \
                    self.lines_tile[i] != tile:
                    # these tiles cannot be added to this pattern line
                    continue

                # Is the space on the grid for this tile already
                # occupied?
                grid_col = int(self.grid_scheme[i][tile])
                if self.grid_state[i][grid_col] == 1:
                    # It is, so we cannot place this tile type
                    # in this pattern line!
                    continue

                slots_free = (i+1) - self.lines_number[i]
                tg = TileGrab()
                tg.number = num_avail
                tg.tile_type = tile
                tg.pattern_line_dest = i
                tg.num_to_pattern_line = min(num_avail, slots_free)
                tg.num_to_floor_line = tg.number - tg.num_to_pattern_line

                moves.append((Move.TAKE_FROM_CENTRE, -1, tg))
        
            # Default move is to place all the tiles in the floor line
            tg = TileGrab()
            tg.number = num_avail
            tg.tile_type = tile
            tg.num_to_floor_line = tg.number
            moves.append((Move.TAKE_FROM_CENTRE, -1, tg))

        return moves
         

    # Complete scoring process for player at round end: 
    # 2. Move tiles across from pattern lines to the grid and score each;
    #
    # 3. Clear remaining tiles on pattern lines (where appropriate) and
    # return to be added to "used" tiles bag;
    #
    # 4. Score penalties for tiles in floor line and return these tiles
    # to be added to the "used" tiles bag.
    #
    # Returns a pair: the change in the player's score; and the set of 
    # tiles to be returned to the "used" tile bag. The players internal
    # representation of their score is updated in the process. 
    def ScoreRound(self):
        used_tiles = []

        score_inc = 0

        # 1. Move tiles across from pattern lines to the wall grid
        for i in range(self.GRID_SIZE):
            # Is the pattern line full? If not it persists in its current
            # state into the next round.
            if self.lines_number[i] == i+1:
                tc = self.lines_tile[i]
                col = int(self.grid_scheme[i][tc])

                # Record that the player has placed a tile of type 'tc'
                self.number_of[tc] += 1

                # Clear the pattern line, add all but one tile into the
                # used tiles bag. The last tile will be placed on the 
                # players wall grid.  
                for j in range(i):
                    used_tiles.append(tc)

                self.lines_tile[i] = -1
                self.lines_number[i] = 0

                # Tile will be placed at position (i,col) in grid
                self.grid_state[i][col] = 1

                # count the number of tiles in a continguous line
                # above, below, to the left and right of the placed tile.
                above = 0
                for j in range(col-1, -1, -1):
                    val = self.grid_state[i][j]
                    above += val
                    if val == 0:
                        break
                below = 0
                for j in range(col+1,self.GRID_SIZE,1):
                    val = self.grid_state[i][j]
                    below +=  val
                    if val == 0:
                        break
                left = 0
                for j in range(i-1, -1, -1):
                    val = self.grid_state[j][col]
                    left += val
                    if val == 0:
                        break
                right = 0
                for j in range(i+1, self.GRID_SIZE, 1):
                    val = self.grid_state[j][col]
                    right += val
                    if val == 0:
                        break

                # If the tile sits in a contiguous vertical line of 
                # tiles in the grid, it is worth 1*the number of tiles
                # in this line (including itself).
                if above > 0 or below > 0:
                    score_inc += (1 + above + below)

                # In addition to the vertical score, the tile is worth
                # an additional H points where H is the length of the 
                # horizontal contiguous line in which it sits.
                if left > 0 or right > 0:
                    score_inc += (1 + left + right)

                # If the tile is not next to any already placed tiles
                # on the grid, it is worth 1 point.                
                if above == 0 and below == 0 and left == 0 \
                    and right == 0:
                    score_inc += 1

        # Score penalties for tiles in floor line
        penalties = 0
        for i in range(len(self.floor)):
            penalties += self.floor[i]*self.FLOOR_SCORES[i]
            self.floor[i] = 0
            
        used_tiles.extend(self.floor_tiles)
        self.floor_tiles = []
        
        # Players cannot be assigned a negative score in any round.
        score_change = score_inc + penalties
        if score_change < 0 and self.score < -score_change:
            score_change = -self.score
        
        self.score += score_change
        self.player_trace.round_scores[-1] = score_change

        return (self.score, used_tiles) 


    # Complete additional end of game scoring (add bonuses). Return
    # computed bonus, and add to internal score representation.
    def EndOfGameScore(self):
        rows = self.GetCompletedRows()
        cols = self.GetCompletedColumns()
        sets = self.GetCompletedSets()

        bonus = (rows * self.ROW_BONUS) + (cols * self.COL_BONUS) + \
            (sets * self.SET_BONUS)

        self.player_trace.bonuses = bonus
        self.score += bonus
        return bonus 


# The GameState class encapsulates the state of the game: the game 
# state for each player; the state of the factory displays and 
# centre tile pool; and the state of the tile bags. 
class GameState:
    NUM_FACTORIES = [5,7,9]
    NUM_TILE_TYPE = 20
    NUM_ON_FACTORY = 4

    def __init__(self, num_players):
        # Create player states
        self.players = []
        for i in range(num_players):
            ps = PlayerState(i)
            self.players.append(ps)
            
        # Tile bag contains NUM_TILE_TYPE of each tile colour
        self.bag = []
        for i in range(self.NUM_TILE_TYPE):
            self.bag.append(Tile.BLUE)
            self.bag.append(Tile.YELLOW)
            self.bag.append(Tile.RED)
            self.bag.append(Tile.BLACK)
            self.bag.append(Tile.WHITE)

        # Shuffle contents of tile bag
        random.shuffle(self.bag)

        # "Used" bag is initial empty
        self.bag_used = []

        # In a 2/3/4-player game, 5/7/9 factory displays are used
        self.factories = []
        for i in range(self.NUM_FACTORIES[num_players-2]):
            td = TileDisplay()
            
            # Initialise factory display: add NUM_ON_FACTORY randomly
            # drawn tiles to the factory (if available). 
            self.InitialiseFactory(td)
            self.factories.append(td)

        self.centre_pool = TileDisplay()
        self.first_player_taken = False
        self.first_player = random.randrange(num_players)
        self.next_first_player = -1


    def TilesRemaining(self):
        if self.centre_pool.total > 0:
            return True
        for fac in self.factories:
            if fac.total > 0:
                return True
        return False

    # Place tiles from the main bag (and used bag if the main bag runs
    # out of tiles) onto the given factory display.
    def InitialiseFactory(self, factory):
        # Reset contents of factory display
        factory.total = 0
        for tile in Tile:
            factory.tiles[tile] = 0

        # If there are < NUM_ON_FACTORY tiles in the bag, shuffle the 
        # tiles in the "used" bag and add them to the main bag (we still
        # want the tiles that were left in the main bag to be drawn first).
        # Fill the factory display with tiles, up to capacity, if possible.
        # If there are less than NUM_ON_FACTORY tiles available in both
        # bags, the factory will be left at partial capacity.
        if len(self.bag) < self.NUM_ON_FACTORY and len(self.bag_used) > 0:
            random.shuffle(self.bag_used)
            self.bag.extend(self.bag_used)
            self.bag_used = []

        for i in range(min(self.NUM_ON_FACTORY,len(self.bag))):
            # take tile out of the bag
            tile = self.bag.pop(0)
            factory.tiles[tile] += 1
            factory.total += 1


    # Setup a new round of play be resetting each of the factory displays
    # and the centre tile pool
    def SetupNewRound(self):
        # Reset contents of each factory display
        for fd in self.factories:
            self.InitialiseFactory(fd)

        for tile in Tile:
            self.centre_pool.tiles[tile] = 0

        self.first_player_taken = False
        self.first_player = self.next_first_player
        self.next_first_player = -1

        for plr in self.players:
            plr.player_trace.StartRound()


    # Execute end of round actions (scoring and clean up)
    def ExecuteEndOfRound(self):
        # Each player scores for the round, and we add tiles to the 
        # used bag (if appropriate).
        for plr in self.players:
            _,used = plr.ScoreRound()
            self.bag_used.extend(used)


    # Execute move by given player
    def ExecuteMove(self, player_id, move):
        plr_state = self.players[player_id]
        plr_state.player_trace.moves[-1].append(move)

        # The player is taking tiles from the centre
        if move[0] == Move.TAKE_FROM_CENTRE: 
            tg = move[2]

            if not self.first_player_taken:
                plr_state.GiveFirstPlayerToken()
                self.first_player_taken = True
                self.next_first_player = player_id

            if tg.num_to_floor_line > 0:
                ttf = []
                for i in range(tg.num_to_floor_line):
                    ttf.append(tg.tile_type)
                plr_state.AddToFloor(ttf)
                self.bag_used.extend(ttf)

            if tg.num_to_pattern_line > 0:
                plr_state.AddToPatternLine(tg.pattern_line_dest, 
                    tg.num_to_pattern_line, tg.tile_type)

            # Remove tiles from the centre
            self.centre_pool.RemoveTiles(tg.number, tg.tile_type)

        elif move[0] == Move.TAKE_FROM_FACTORY:
            tg = move[2]
            if tg.num_to_floor_line > 0:
                ttf = []
                for i in range(tg.num_to_floor_line):
                    ttf.append(tg.tile_type)
                plr_state.AddToFloor(ttf)
                self.bag_used.extend(ttf)

            if tg.num_to_pattern_line > 0:
                plr_state.AddToPatternLine(tg.pattern_line_dest, 
                    tg.num_to_pattern_line, tg.tile_type)

            # Remove tiles from the factory display
            fid = move[1]
            fac = self.factories[fid]
            fac.RemoveTiles(tg.number,tg.tile_type)

            # All remaining tiles on the factory display go into the 
            # centre!
            for tile in Tile:
                num_on_fd = fac.tiles[tile]
                if num_on_fd > 0:
                    self.centre_pool.AddTiles(num_on_fd, tile)
                    fac.RemoveTiles(num_on_fd, tile)
                    


# Class representing a policy for playing AZUL.  
class Player(object):
    def __init__(self, _id):
        self.id = _id
        super().__init__()

    # Given a set of available moves for the player to execute, and
    # a copy of the current game state (including that of the player),
    # select one of the moves to execute. 
    def SelectMove(self, moves, game_state):
        return random.choice(moves)


# Class that facilities a simulation of a game of AZUL. 
class GameRunner:
    def __init__(self, player_list, seed):
        random.seed(seed)

        # Make sure we are forming a valid game, and that player
        # id's range from 0 to N-1, where N is the number of players.
        assert(len(player_list) <= 4)
        assert(len(player_list) > 1)

        i = 0
        for plyr in player_list:
            assert(plyr.id == i)    
            i += 1

        self.game_state = GameState(len(player_list))
        self.players = player_list


    def Run(self, log_state):
        player_order = []
        for i in range(self.game_state.first_player, len(self.players)):
            player_order.append(i)

        for i in range(0, self.game_state.first_player):
            player_order.append(i)

        game_continuing = True
        for plr in self.game_state.players:
            plr.player_trace.StartRound()

        while game_continuing:
            for i in player_order:
                plr_state = self.game_state.players[i]
                moves = plr_state.GetAvailableMoves(self.game_state)

                gs_copy = copy.deepcopy(self.game_state)
                moves_copy = copy.deepcopy(moves)
                selected = self.players[i].SelectMove(moves_copy, gs_copy)

                assert(ValidMove(selected, moves))

                if log_state:
                    print("\nPlayer {} has chosen the following move:".format(
                        i))
                    print(MoveToString(i, selected))
                    print("\n")

                self.game_state.ExecuteMove(i, selected)
                if log_state:
                    print("The new player state is:")
                    print(PlayerToString(i, plr_state))

                if not self.game_state.TilesRemaining():
                    break

            # Have we reached the end of round?
            if self.game_state.TilesRemaining():
                continue

            # It is the end of round
            if log_state:
                print("ROUND HAS ENDED")

            self.game_state.ExecuteEndOfRound()

            # Is it the end of the game? 
            for i in player_order:
                plr_state = self.game_state.players[i]
                completed_rows = plr_state.GetCompletedRows()

                if completed_rows > 0:
                    game_continuing = False
                    break

            # Set up the next round
            if game_continuing:
                self.game_state.SetupNewRound()
                player_order = []
                for i in range(self.game_state.first_player,len(self.players)):
                    player_order.append(i)

                for i in range(0, self.game_state.first_player):
                    player_order.append(i)
                

        if log_state:
            print("THE GAME HAS ENDED")

        # Score player bonuses
        player_traces = {}
        for i in player_order:
            plr_state = self.game_state.players[i]
            plr_state.EndOfGameScore()
            player_traces[i] = (plr_state.score, plr_state.player_trace)
    
        # Return scores
        return player_traces