Connect4

repeat
print("Which player are you? (1 or 2)")
compplayer = read()
compplayer = compplayer+1-1
if compplayer == 1 then otherplayer = 2 end
if compplayer == 2 then otherplayer = 1 end
until compplayer == 1 or compplayer == 2

player = 2
onarow = 1
fiar = false
nmds = 0
nmdg = 0
lmc = 0
lmr = 0
field = {}
for i=1,7 do
 field[i] = {}
 for j=1,6 do
  field[i][j] = 0
 end
end

for s=1, 6 do
 if s == 1 then sidecheck = fs.exists("disk/connectmp")
 else sidecheck = fs.exists("disk"..s.."/connectmp")
 end
 if sidecheck == true
 then
  if s == 1 then path = "disk/"
  else
   path = ("disk"..s.."/")
  end
 end
end
file = fs.open(path.."moveplayerone", "w")
file:close()
file = fs.open(path.."moveplayertwo", "w")
file:close()


function printfield()
 term.clear()
 term.setCursorPos(1,1)
 for i=1,6 do
  for j=1,7 do
   write(field[j][i].." ")
  end
 print()
 end
end

function hasemptyspot(column)
 check = 1
 for n=1, 6 do
  check = check * field[column][n]
 end
 if check == 0
 then
  return true
 end
end

function setpiece(column)
 n = 6
column = column + 1 - 1
 while true do
  if field[column][n] == 0 then break end
  n=n-1
 end
 field[column][n] = player
 lmc = column
 lmr = n
end

function changeplayer()
 if player == 2
 then player = 1
 else
  if player == 1 then player = 2 end
 end
end

function cfwhelp(n,i,j)
 lmch = lmc + n*i
 lmrh = lmr + n*j
 if i ~= 0 or j ~= 0 then
 if lmch >= 1 and lmch <= 7 and lmrh >= 1 and lmrh <= 6
 then
  if  field[lmch][lmrh] == player
  then
   onarow = onarow + 1
   inrow = true
   if onarow >= 4 then fiar = true end
  end
 end end
end


function checkforwin()
for i=-1, 1 do
 for j=-1, 1 do
  onarow = 1
  for n=1, 3 do
   inrow = false
   cfwhelp(n,i,j)
   if inrow == false then break end
  end
  for n=-1, -3, -1 do
   inrow = false
   cfwhelp(n,i,j)
   if inrow == false then break end
  end
 end
end
if fiar
then
 return true
end
end


function sendmove(column)
 if compplayer == 1
 then
  file = io.open(path.."moveplayerone", "w")
  file:write(column)
  file:close()
 end
 if compplayer == 2
 then
  file = io.open(path.."moveplayertwo", "w")
  file:write(column)
  file:close()
 end
 redstone.setOutput("back", true)
 sleep(0.15)
 redstone.setOutput("back", false)
end


function getmove()
print()
print()
print("Waiting for other player. Press Q to exit if he takes too long.")
while true do
event,argument = os.pullEvent()
if event == "char" and argument == "q" then os.reboot() end
if event == "redstone" and redstone.getInput("back")
then
 if otherplayer == 1
 then
  file = io.open(path.."moveplayerone", "r")
  column = file:read()
  file:close()
  break
 end
 if otherplayer == 2
 then
  file = io.open(path.."moveplayertwo", "r")
  column = file:read()
  file:close()
  break
 end
end
end
end


function doturn()
pieceset = false
repeat
print("Turn: "..turn..". Player "..player.."'s turn. Choose a column.")
column = read()
if column == "quit" then os.shutdown() end
if column ~= "1" and column ~= "2" and column ~= "3" and column ~= "4" and column ~= "5" and column ~= "6" and column ~= "7"
then
 print("Invalid column.")
else
 column = column + 1 - 1
 if hasemptyspot(column)
 then
  setpiece(column)
  pieceset = true
 else
  print("Column is already full.")
 end
end
until pieceset
end

turn = 0
printfield()
repeat
 changeplayer()
 if player == compplayer
 then
  turn = turn+1
  doturn()
  sendmove(column)
  printfield()
  print("You've set a new piece in column "..lmc..".")
 end
 if player == otherplayer
 then
  getmove()
  setpiece(column)
  printfield()
  print("Player "..player.." has set a new piece in column "..lmc..".")
 end
until checkforwin()
print("Player "..player.." has a four in a row and wins!")


fs.delete( (path.."moveplayerone") )
fs.delete( (path.."moveplayertwo") )