--Snake 1.2 by Hilmvhal

require "os"
local term = require("term")
local keyboard =require("keyboard")

function init()
 score = 0

 Height = 12
 Width = 25

 facing = 0
 xpos = 5
 ypos = 6

 length = 3
 tailx = {}
 taily = {}

 fruitx = 10
 fruity = 10

 Gameover = false
 started = false
end

function fruit()
 fruitx = math.random(Width-2)+1
 fruity = math.random(Height-2)+1
 while fruitx == posx or fruity == posy or tail(fruitx, fruity) == true do
  fruitx = math.random(Width-2)+1
  fruity = math.random(Height-2)+1
 end
 length = length + 1
 score = score + 50
end

function input()
 if keyboard.isKeyDown(keyboard.keys.up) == true then facing = 1
 elseif keyboard.isKeyDown(keyboard.keys.right) == true then facing = 2
 elseif keyboard.isKeyDown(keyboard.keys.left) == true then facing = 3
 elseif keyboard.isKeyDown(keyboard.keys.down) == true then facing = 4
 end
 if facing > 0 then started = true end
end

function Gamelogic()
 local oldx = xpos
 local oldy = ypos
 if facing == 1 then ypos = ypos - 1
 elseif facing == 2 then xpos = xpos + 1
 elseif facing == 3 then xpos = xpos - 1
 elseif facing == 4 then ypos = ypos + 1
 end
 -- tail
 for z = 1 , length do
  tailx[z] = tailx[z+1]
  taily[z] = taily[z+1]
 end
 tailx[length] = oldx
 taily[length] = oldy
 collision()
end

function collision()
 if xpos == 1 or xpos == Width then Gameover = true end
 if ypos == 1 or ypos == Height then Gameover = true end
 if tail(xpos , ypos) == true then Gameover = true end
 if xpos == fruitx and ypos == fruity then fruit() end
end

function tail(x , y)
 for i=1 , length do
  if x == tailx[i] and y == taily[i] then return true
  end
 end
 return false
end

function Draw()
 local str = ""
 for j=1 , Height do
 str = ""
  for i=1 , Width do
   local chr = '.'
   if i==1 or i==Width or j==1 or j==Height then chr = '#'
   elseif i==xpos and j==ypos then chr = 'O'
   elseif tail(i , j) == true then chr = 'o'
   elseif i==fruitx and j==fruity then chr = '@'
   else chr = '.'
   end
   str = str .. chr
  end
 str = str
 print(str)
 end
print("score: ", score)
end

function Start()
 local x = false
 while x == false do
  input();
end

function game()
 start();
 while Gameover == false do
  term.clear()
  input()
  Gamelogic()
  Draw()
  os.sleep(1/4)
 end
 print("GameOver Man")
 print("You scored "..score.." points!")
end

while quit == false do
 init()
 game()
end