basic-computer-games/29_Craps/lua/craps.lua

--[[
Craps

From: BASIC Computer Games (1978)
Edited by David H. Ahl

    This game simulates the games of craps played according to standard
    Nevada craps table rules. That is:
    1. A 7 or 11 on the first roll wins
    2. A 2, 3, or 12 on the first roll loses
    3. Any other number rolled becomes your "point." You continue to roll;
    if you get your point you win. If you roll a 7, you lose and the dice
    change hands when this happens.

    This version of craps was modified by Steve North of Creative Computing.
    It is based on an original which appeared one day one a computer at DEC.


Lua port by Alex Conconi, 2022
--]]


--- Throw two dice and return their sum.
local function throw_dice()
	return math.random(1, 6) + math.random(1, 6)
end


--- Print prompt and read a number > 0 from stdin.
local function input_number(prompt)
	while true do
		io.write(prompt)
		local number = tonumber(io.stdin:read("*l"))
		if number and number > 0 then
			return number
		else
			print("Please enter a number greater than zero.")
		end
	end
end


--- Play a round and return winnings or losings.
local function play_round()
    -- Input the wager
    local wager = input_number("Input the amount of your wager: ")

	-- Roll the die for the first time.
	print("I will now throw the dice")
	local first_roll = throw_dice()

	-- A 7 or 11 on the first roll wins.
	if first_roll == 7 or first_roll == 11 then
		print(string.format("%d - natural.... a winner!!!!", first_roll))
		print(string.format("%d pays even money, you win %d dollars", first_roll, wager))
		return wager
	end

	-- A 2, 3, or 12 on the first roll loses.
	if first_roll == 2 or first_roll == 3 or first_roll == 12 then
		if first_roll == 2 then
			-- Special 'you lose' message for 'snake eyes'
			print(string.format("%d - snake eyes.... you lose.", first_roll))
		else
			-- Default 'you lose' message
			print(string.format("%d - craps.... you lose.", first_roll))
		end
		print(string.format("You lose %d dollars", wager))
		return -wager
	end

	-- Any other number rolled becomes your "point." You continue to roll;
	-- if you get your point you win. If you roll a 7, you lose and the dice
	-- change hands when this happens.
	print(string.format("%d is the point. I will roll again", first_roll))
	local second_roll
	repeat
		second_roll = throw_dice()
		if second_roll == first_roll then
			-- Player gets point and wins
			print(string.format("%d - a winner.........congrats!!!!!!!!", first_roll))
			print(string.format("%d at 2 to 1 odds pays you...let me see... %d dollars", first_roll, 2 * wager))
			return 2 * wager
		end
		if second_roll == 7 then
			-- Player gets 7 and loses
			print(string.format("%d - craps. You lose.", second_roll))
			print(string.format("You lose $ %d", wager))
			return -wager
		end
		--  Continue to roll
		print(string.format("%d  - no point. I will roll again", second_roll))
	until second_roll == first_roll or second_roll == 7
end


--- Main game function.
local function craps_main()
	-- Print the introduction to the game
	print(string.rep(" ", 32) .. "Craps")
    print(string.rep(" ", 14) .. "Creative Computing  Morristown, New Jersey\n\n")
	print("2,3,12 are losers; 4,5,6,8,9,10 are points; 7,11 are natural winners.")

	-- Initialize random number generator seeed
	math.randomseed(os.time())

    -- Initialize balance to track winnings and losings
	local balance = 0

	-- Main game loop
    local keep_playing = true
	while keep_playing do
		-- Play a round
		balance = balance + play_round()

		-- If player's answer is 5, then stop playing
		keep_playing = (input_number("If you want to play again print 5 if not print 2: ") == 5)

		-- Print an update on money won
		if balance < 0 then
			print(string.format("You are now under $%d", -balance))
		elseif balance > 0 then
			print(string.format("You are now ahead $%d", balance))
		else
			print("You are now even at 0")
		end
	end

	-- Game over, print the goodbye message
	if balance < 0 then
		print("Too bad, you are in the hole. Come again.")
	elseif balance > 0 then
		print("Congratulations---you came out a winner. Come again.")
	else
		print("Congratulations---you came out even, not bad for an amateur")
	end
end


--- Run the game.
craps_main()