-- GAME LIBRARY START --
Running = true
GameOver = false
math.randomseed(os.time())
function IsAnInt(input)
  return tonumber(input, 10) ~= nil
end
function GetIntInput(prompt)
  while true do 
    print(prompt .. " ")
    ans = io.read();
    if IsAnInt(ans) then
      return tonumber(ans, 10)
    end
    print("YOU DID NOT ENTER AN INTEGER.")
  end
end
function IsEmpty(string)
  return string == nil or string == ''
end
function AskQuestion(prompt)
  while true do
    print(prompt .. "?")
    ans = io.read()
    if IsEmpty(ans) then
      print("PLEASE ANSWER THE QUESTION.")
    else 
      return string.upper(ans)
    end
  end
end
function AskToPlayAgain()
  while true do
    ans = AskQuestion("DO YOU WANT TO PLAY AGAIN")
    if ans == "YES" or ans == "Y" then
      return true
    elseif ans == "NO" or ans == "N" then
      return false
    else 
      print("PLEASE ANSWER \"YES\" OR \"NO\"")
    end
  end
end
function AskToSeeTheRules()
  while true do
    ans = AskQuestion("DO YOU WANT TO SEE THE RULES")
    if ans == "YES" or ans == "Y" then
      return true
    elseif ans == "NO" or ans == "N" then
      return false
    else 
      print("PLEASE ANSWER \"YES\" OR \"NO\"")
    end
  end
end
function GenerateRandomNumber(minimum, maximum, show)
  number = math.random(minimum, maximum)
  if show == true then
    print(number)
  end
  return number
end
-- GAME LIBRARY END --
YourGrid = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
EnemyGrid = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}
Outposts = {0,0}
Turn = 0

function DisplayTheRules()
  print("YOU ARE ON A BATTLEFIELD WITH 4 PLATOONS AND YOU")
  print("HAVE 25 OUTPOSTS AVAILABLE WHERE THEY MAY BE PLACED.")
  print("YOU CAN ONLY PLACE ONE PLATOON AT ANY ONE OUTPOST.")
  print("THE COMPUTER DOES THE SAME WITH ITS FOUR PLATOONS.")
  print("")
  print("THE OBJECT OF THE GAME IS TO FIRE MISSILES AT THE")
  print("OUTPOSTS OF THE COMPUTER. IT WILL DO THE SAME TO YOU.")
  print("THE ONE WHO DESTROYS ALL FOUR OF THE ENEMY'S PLATOONS")
  print("FIRST IS THE WINNER.")
  print("")
  print("GOOD LUCK...AND TELL US WHERE YOU WANT THE BODIES SENT.")
  print("")
end

function CheckWinner()
  if Outposts[1] == 0 then
    return 2
  elseif Outposts[2] == 0 then
    return 1
  end
  return 0  
end

function DisplayYourGrid()
  print("=======================")
  print("YOUR GRID")
  print("=======================")
  print("X | 1 | 2 | 3 | 4 | 5 |")
  print("Y |---+---+---+---+---|")
  for x = 1,5,1 do
    gStart = ((x - 1) * 5) + 1
    gEnd = x * 5
    displayLine = x.." |"
    for g = gStart,gEnd,1 do
      if YourGrid[g] == -1 then
        displayLine = displayLine.." X |"
      elseif YourGrid[g] == 1 then
        displayLine = displayLine.." O |"
      else
        displayLine = displayLine.."   |"
      end
    end
    print(displayLine)
  end  
  print("  |---+---+---+---+---|")
end


function DisplayEnemyGrid()
  print("=======================")
  print("ENEMY GRID")
  print("=======================")
  print("X | 1 | 2 | 3 | 4 | 5 |")
  print("Y |---+---+---+---+---|")
  for x = 1,5,1 do
    gStart = ((x - 1) * 5) + 1
    gEnd = x * 5
    displayLine = x.." |"
    for g = gStart,gEnd,1 do
      if EnemyGrid[g] == -1 then
        displayLine = displayLine.." X |"
      else
        displayLine = displayLine.."   |"
      end
    end
    print(displayLine)
  end  
  print("  |---+---+---+---+---|")
end

function ClearGrids()
  for g = 1,25,1 do
    YourGrid[g] = 0
    EnemyGrid[g] = 0
  end
end

function SetOutposts()
  Outposts[1] = 4
  outpost = 0
  for o = 1,4,1 do
    DisplayYourGrid()
    outpostSet = false
    while outpostSet == false do
      print("PLACE YOUR OUTPOST #"..o)
      x = GetIntInput("X")
      if x < 1 or x > 5 then
        print ("X MUST BE BETWEEN 1 AND 5.")
      else
        y = GetIntInput("Y")
        if y < 1 or y > 5 then
          print ("Y MUST BE BETWEEN 1 AND 5.")
        else
          outpost = ((y - 1) * 5) + x
          if YourGrid[outpost] == 0 then
            YourGrid[outpost] = 1
            outpostSet = true
          else
            print("YOU ALREADY HAVE AN OUTPOST THERE.")
          end
        end
      end
    end
  end
end

function ComputerSetOutposts()
  Outposts[2] = 4
  outpost = 0
  for o = 1,4,1 do
    outpostSet = false
    while outpostSet == false do
      x = GenerateRandomNumber(1,5,false)
      y = GenerateRandomNumber(1,5,false)
      outpost = ((y - 1) * 5) + x
      if EnemyGrid[outpost] == 0 then
        EnemyGrid[outpost] = 1
        outpostSet = true
      end
    end
  end
end

function ComputerTurn()
  print("MY TURN...")
  loc = 0
  x = 0
  y = 0
  gotLoc = false
  while gotLoc == false do
    x = GenerateRandomNumber(1,5,false)
    y = GenerateRandomNumber(1,5,false)
    loc = ((y - 1) * 5) + x
    if YourGrid[loc] > -1 then
      gotLoc = true
    end
  end
  print("..........BOOM!")
  if YourGrid[loc] == 0 then
    print("I MISSED YOU, YOU DIRTY RAT.")
    print("I PICKED LOCATION ("..x..","..y..").")
  else
    print("I GOT YOU.  IT WON'T BE LONG NOW!")
    print("OUTPOST AT ("..x..","..y..") WAS HIT.")
    YourGrid[loc] = -1
    Outposts[1] = Outposts[1] - 1
    if Outposts[1] == 3 then
      print("YOU ONLY HAVE THREE OUTPOSTS LEFT.")
    elseif Outposts[1] == 2 then
      print("YOU ONLY HAVE TWO OUTPOSTS LEFT.")
    elseif Outposts[1] == 1 then
      print("YOU ONLY HAVE ONE OUTPOSTS LEFT.")
    else
      print("YOU ARE DEAD! YOU HAVE NO OUTPOSTS LEFT.")
    end
  end
end

function FireMissile()
  print("WHERE DO YOU WANT TO FIRE YOUR MISSILE?")
  loc = 0
  x = 0
  y = 0
  gotLoc = false
  while gotLoc == false do
    x = GetIntInput("X")
    if x < 1 or x > 5 then
      print ("X MUST BE BETWEEN 1 AND 5.")
    else
      gotLoc = true
    end
  end
  gotLoc = false
  while gotLoc == false do
    y = GetIntInput("Y")
    if y < 1 or y > 5 then
      print ("Y MUST BE BETWEEN 1 AND 5.")
    else
      gotLoc = true
    end
  end
  loc = ((y - 1) * 5) + x
  print("..........BOOM!")
  if EnemyGrid[loc] == -1 then
    print("YOU FOOL, YOU ALREADY ATTACKED THERE!")
  elseif EnemyGrid[loc] == 0 then
    print("HA HA, YOU MISSED!")
  else
    print("YOU GOT ONE OF MY OUTPOSTS!")
    EnemyGrid[loc] = -1
    Outposts[2] = Outposts[2] - 1
    if Outposts[2] == 3 then
      print("ONE DOWN, THREE TO GO.")
    elseif Outposts[2] == 2 then
      print("TWO DOWN, TWO TO GO.")
    elseif Outposts[2] == 1 then
      print("THREE DOWN, ONE TO GO.")
    else
      print("YOU GOT THEM ALL.")
    end
  end
end

print("*** BOMBARDMENT : LUA ***")
if AskToSeeTheRules() then
  DisplayTheRules()
end
Turn = 0
while Running == true do
  ClearGrids()
  ComputerSetOutposts()
  SetOutposts()
  GameOver = false
  print("--------- LET THE WAR BEGIN ----------")
  while GameOver == false do
    print("-----------------------")
    print("TURN #"..(Turn + 1))
    print("-----------------------")
    if Turn % 2 == 0 then
      DisplayYourGrid()
      DisplayEnemyGrid()
      FireMissile()
    else
      ComputerTurn()
    end
    winner = CheckWinner()
    if winner == 0 then
      Turn = Turn + 1
    else
      DisplayYourGrid()
      DisplayEnemyGrid()
      if winner == 1 then
        print("YOU WIN!!!")
      else
        print("TOO BAD, BETTER LUCK NEXT TIME.")
      end
      GameOver = true
    end
  end
  print("*** GAME OVER ***")
  Running = AskToPlayAgain()
end
print("THANKS FOR PLAYING!")