######################################################
# CS 463: Homework 7 Checker
# Uses Python 3
######################################################

import re
import sys

filename = sys.argv[1] # grabs the 1st argument as the filename (or "stdin")

if filename=="stdin":
    f = sys.stdin
else:
    f = open (filename)

lines = f.readlines()
f.close()


num_lines = len(lines) # number of lines in the file
num_players = 0 # total number of players
num_players_left = 0 # number of players left after each round
player_list = [] # list of all the players still in the game
players_not_seated = [] # list of all the players not seated yet
chair_list = [] # list of all the chairs available
num_errors = 0 # number of errors


line = lines[0]
i = 1 # line number
j = 0 # round line number
round_count = 1 # round number
words = [] # words on a specific line

#------------------ WHILE ------------------#
while line:
    # checks if its the beginning of the file
    if(i == 1): 
        words = line.strip().split() 
        # check that it starts with "begin" keyword
        if(words[0].lower() != "begin"): 
            print("Line 1: Missing BEGIN keyword at the beginning")
            num_errors += 1
            break
        
        # checks that if the student only wrote one word or all three
        if(len(words) != 3 and len(words) == 1): 
            print("Line 1: The number of player and the keyword \"players\" needs to be printed.")
            num_errors += 1
            break
        
        # checks that the student wrote the number of players
        if(words[1].isdigit()):
            num_players = int(words[1])
            num_players_left = num_players
            player_list = [i+1 for i in range(num_players)] # initializes all players in the list
            
            # checks if the there is a word after the number
            if(len(words) != 3 and len(words) == 2):
                print("Line 1: After BEGIN and the number of players, the \"players\" keyword needs to be printed.")
                num_errors += 1
            
            # checks if the word after the number is the keyword "players"
            elif((words[2].lower() != "players".lower()) and (words[2].lower() != "player".lower())):
                print("Line 1: After BEGIN and the number of players, the keyword after the number should be \"players\" not \""+words[2]+"\".")
                num_errors += 1
        
        # the student wrote only "begin" at the beginning of the file
        else:
            print("Line 1: After BEGIN, the number of players needs to be stated.")
            num_errors += 1
            break
    
    # checks that the end of the file has the keyword "end"                     
    elif(i == num_lines):
        if(line.strip().lower() != "end"):
            print("Line "+str(i)+": Missing END keyword at the ending")
            num_errors += 1
    
    # checks that we are in a round
    elif(line.strip() != "" and num_players != round_count):
        # checks that first line of the round is "round #"
        if(j == 0):
            players_not_seated = player_list[:]
            # print(str(players_not_seated)+" <-- BEGIN ") # Debugger statement
            chair_list = [i+1 for i in range(num_players_left-1)] 
            words = line.strip().split() 
            
            m = re.match(r"P(\d+) wins!",line.strip())
            # checks that the game does not end too soon 
            if(m):
                print("Line "+str(i)+": Game ended too early. There are more rounds available.")
                num_errors += 1
                break
            
            # checks that the beginning of a round starts with the "round" keyword
            if(words[0].lower() != "round"):
                print("Line "+str(i)+": In the beginning of each round, \"round #\" needs to be stated.")
                num_errors += 1
            
            # checks that after the keyword "round" there needs to be the round number
            if(len(words) == 1 or not(words[1].isdigit())):
                print("Line "+str(i)+": After the \"round\" keyword, there needs to be the round number.")
                num_errors += 1
            
            # checks that the round number is correct
            if(len(words) == 2 and int(words[1]) != round_count):
                print("Line "+str(i)+": Incorrect round count!")
                num_errors += 1
        
        # checks that the second line of the round is "music off"       
        elif(j == 1):
            if(line.strip().lower() != "music off"):
                print("Line "+str(i)+": The keywords \"music off\" needs to be printed on the next line after the round number.")
                num_errors += 1
                break
        
        # checks that the last line of the round, number of chairs (number of players left) + line (round #) + line (music off))    
        elif(j == (num_players_left-1)+2): 
            # print(str(players_not_seated)+" <-- END ") # Debugger statement
            m = re.match(r"P(\d+) lost",line.strip())
            # checks that it matches regular expression format
            if(m): 
                # checks the player lost was originally in the player list
                if(int(m.group(1)) not in player_list):
                    print("Line "+str(i)+": Player "+m.group(1)+" was removed from the game earlier or never existed.")
                    num_errors += 1
                else:
                    player_list.remove(int(m.group(1))) # remove player from list
                    num_players_left -= 1
            else:
                print("Line "+str(i)+": Wrong format! Should be \"P# lost\".")
                num_errors += 1
            j = -1 # reset counter for next round
            round_count += 1
        
        # line where it prints that the player sits in a specific chair
        else:
            # print(players_not_seated) # Debugger statement
            m = re.match(r"P(\d+) sat in C(\d+)",line.strip())
            # checks that it matches regular expression format
            if(m): 
                # check if player exist in the player list
                if(int(m.group(1)) not in player_list):
                    print("Line "+str(i)+": Player "+m.group(1)+" was removed from the game earlier or never existed.")
                    num_errors += 1
                    
                # checks if the player is already seated
                elif(int(m.group(1)) not in players_not_seated):
                    print("Line "+str(i)+": Player "+m.group(1)+" is aready seated and can't sit in more than one chair.")
                    num_errors += 1
                else:
                    players_not_seated.remove(int(m.group(1))) # remove player from players not seated list
                                    
                # checks that the chair exists
                if(int(m.group(2)) not in range(1,num_players_left)):
                    print("Line "+str(i)+": Chair "+m.group(2)+" does not exist.")
                    num_errors += 1
                
                # chair is not available
                elif(int(m.group(2)) not in chair_list):
                    print("Line "+str(i)+": Chair "+m.group(2)+" is not available.")
                    num_errors += 1
                
                # chair is available
                else:
                    chair_list.remove(int(m.group(2))) # remove chair from availability list
                                    
            # checks if the round ended too soon
            elif(re.match(r"P(\d+) lost",line.strip())):
                print("Line "+str(i)+": There is still a chair or chairs available: "+str(chair_list)+". There are also players not seated: "+str(player_list))
                num_errors += 1
                break   
            else:
                print("Line "+str(i)+": Wrong format! Should be: \"P# sat in C#.\"")
                num_errors += 1
        
        # Debugger statement        
        #if(j == 0):
        #   print("\tRound "+str(round_count)+": "+str(player_list))
            
        j += 1
    
    # checks that the last round was completed
    elif(line.strip() != "" and num_players == round_count):
        
        # Debugger statement
        #if(j == 0):
        #   print("\tRound "+str(round_count)+": "+str(player_list))
            
        m = re.match(r"P(\d+) wins!",line.strip())
        # checks that it matches regular expression format
        if(m):
            # check if the player number is correct
            if(int(m.group(1)) not in player_list):
                print("Line "+str(i)+": Player "+m.group(1)+" was removed from the game earlier or never existed.")
                num_errors += 1
        else:
            print("Line "+str(i)+": Wrong format! Should be \"P# wins!\".")
            num_errors += 1
    i += 1
    if i==len(lines):
        break
    line = lines[i-1]
    #------------------ END OF WHILE ------------------#

if(num_errors == 0):
    print("Everything looks good!")