local args={...}


local delay = 0.5

local grid={} -- stores cell states
local gridActions={} -- used to store births and deaths

local aliveColor = colors.lime
local deadColor = colors.black

local xSize,ySize = term.getSize()

-- 0,dimSize+1 because we index
-- using offsets xOff and yOff later
-- which can be -1!

for i=0,xSize+1 do
  grid[i]={}
  gridActions[i]={}
end

for i=0,xSize+1 do
  for j=0,ySize+1 do
    grid[i][j]=false
  end
end

if args[1]=="monitor" then
  term.redirect(peripheral.wrap(args[2]))
elseif args[1]== "load" then
  local name = fs.getName(args[2])

  local ext = string.match(name,".-[^\\/]-%.?([^%.\\/]*)$")

  local f = fs.open(shell.resolve(args[2]),"r")
  if ext == "cells" then
    local line
    local y = 1
    while line do
      line = f.readLine()
      if line:sub(1,1) ~= "!" then
        for x=1,#line do
          grid[x][y] = line:sub(x,x) == "O"
        end
        y = y + 1
      end
    end
  elseif ext == "rle" then
    local line
    local origX,x,y
    line = f.readLine() -- header

    local j = 1

    while line do
      if line:sub(1,1) == "x" then
        -- header
        local patternXSize,patternYSize = string.match(line,"x = (%d+), y = (%d+)")
        origX = math.floor(xSize / 2) - math.floor(tonumber(patternXSize) / 2)
        x=origX
        y=math.floor(ySize / 2) - math.floor(tonumber(patternYSize) / 2)
      elseif line:sub(1,1) ~= "#" then -- just ignore those..
        for i=1,#line do
          local c = line:sub(i,i)
          if c == "o" then
            print("Alive, x="..x.." y="..y.." j="..j)
            for k=1,j do
              grid[x][y] = true
              x = x + 1
            end
            j=1
          elseif c == "b" then
            print("Dead, x="..x.." y="..y.." j="..j)
            for k=1,j do
              grid[x][y] = false
              x = x + 1
            end
            j=1
          elseif c == "$" then
            x = origX
            y = y + 1
            print("New line, y ="..y)
          elseif c == "!" then
           break
          else
            local s = c
            i=i+1
            while true do
              local c = line:sub(i,i)
              if c ~= "o"
                and c ~= "b"
                and c ~= "$"
                and c ~= "!" then
                s = s .. c
              else
                break
              end
              i=i+1
            end
            j = tonumber(s)
          end
        end
      end
      line = f.readLine()
    end
  elseif ext == "lif" then
    local line = f.readLine() -- header
    if line ~= "" then
      error("Malformed Life 1.06 file!")
    end
    while line do
      line = f.readLine()
      local x,y = string.gmatch("^(%d-) (%d-)$")
      grid[x][y] = true
    end
  end
  f.close()
elseif args[1] == "get" then
  -- use http.get to load.. LATER
end

term.clear()
term.setCursorBlink(false)

local paused = true

os.startTimer(0.1) -- makes screen draw the first time

while true do
  local _,__,x,y = os.pullEvent()

  if _ == "key" then
    if __ == 197 then -- pause key ( exit! )
      break
    end

    paused = not paused
    term.setCursorPos(1,10)
    io.write(paused and "Paused" or "      ")
  elseif _ == "monitor_touch" or _ == "mouse_click" then
    grid[x][y] = not grid[x][y]
  end

  if _ ~= "timer" then
    local ev
    while ev ~= "timer" do
      ev = os.pullEvent()
    end
  end

  if not paused then
    for x=1,xSize do
      for y=1,ySize do
        local neighbors = 0
        for xOff = -1,1 do
          for yOff = -1,1 do
            if not (xOff == 0 and yOff == 0) and grid[x+xOff][y+yOff] then
              neighbors = neighbors + 1
            end
          end
        end
        if not grid[x][y] and neighbors == 3 then
          gridActions[x][y]="birth"
        elseif neighbors < 2 or neighbors > 3 then
          gridActions[x][y]="die"
        end
      end
    end

    for x=1,xSize do
      for y=1,ySize do
        if gridActions[x][y]=="die" then
          grid[x][y]=false
        elseif gridActions[x][y]=="birth" then
          grid[x][y]=true
        end
        gridActions[x][y]=nil
      end
    end
  end

  for x=1,xSize do
    for y=1,ySize do
      term.setCursorPos(x,y)
      if grid[x][y] then
        term.setBackgroundColor(aliveColor)
      end
      if paused and y == ySize then
        if x == 1 then io.write("P")
        elseif x==2 then io.write("a")
        elseif x==3 then io.write("u")
        elseif x==4 then io.write("s")
        elseif x==5 then io.write("e")
        elseif x == 6 then io.write("d")
        end
      else
        io.write(" ")
      end

      term.setBackgroundColor(deadColor)
    end
  end

  os.startTimer(delay)
end

term.restore()