Raid

-- [WARNING] This is RAID 0 ! --
-- so if one drive fails. Everything is gone
local DEBUG = true
local ADEBUG =false -- I would not recommend enabling this :)
local DEBUG_FILE = "raid.debug"
local index_disk = "disk/"
local index_file = "index.raid"
local MAX_FILES = 10

-- Main Code --
local index_path = index_disk..index_file
local raid = {}
local total = 0
local disk_space = 4000000
local totalSpace = 0
local totalFreeSpace =0
index = {} -- Huh
local d = 0

function debug(str)
  local fd = fs.open(DEBUG_FILE,"a")
  fd.write(str)
  fd.close()
end

function updateArray()
  for i,v in ipairs(peripheral.getNames()) do
    if (peripheral.getType(v)=="drive") then
      local t=true
      for y,u in ipairs(raid) do
        if (peripheral.wrap(v).getDiskID()==u.id or index_disk==peripheral.wrap(v).getMountPath) then
          t = false
        end
      end
      if (t and peripheral.wrap(v).isDiskPresent()) then
        --BUG: Ignore empty disk drives!
        d=d+1
        raid[d] = {wrap=nil,freespace=0,id=0,mountPath=nil}
        raid[d].wrap=peripheral.wrap(v)
        raid[d].mountPath = raid[d].wrap.getMountPath()
        if (raid[d].wrap.getMountPath()==nil) then
          -- BUGFIX: Remove the empty disk
          raid[d]={wrap=nil,freespace=0,id=0,mountPath=nil}
          if (DEBUG) then print("[DBG] Removed empty disk drive from array ("..d..")") end
          d = d - 1
        else
          raid[d].freespace=fs.getFreeSpace(raid[d].mountPath) --peripheral.call(v,"getMounthPath"))
          totalFreeSpace = totalFreeSpace + raid[d].freespace
          raid[d].id = raid[d].wrap.getDiskID()
          totalSpace = totalSpace + disk_space
        end
      end
    end
  end
  total =d
  if (DEBUG) then print("[DBG] Added "..d.." to array, "..totalSpace..":"..totalFreeSpace) end
  return d
end

--[[ INDEX ]]--
function INDEX_INIT()
  -- Prepare index array and file
  for i=1,MAX_FILES do
    index[i] = {filename=nil,size=0,checksum=0,parts={}}
    if (ADEBUG) then print("[ADBG] Init for "..i) end
  end
end

-- Read index file and writes to mem
function INDEX_READ()
  -- Reads index file and stores it in mem
  local f = fs.open(index_file,"r")
  if (f~=nil) then
    local tdata = f.readAll()
    if (ADEBUG) then debug(tdata) end
      if (tdata~=nil) then
        index = textutils.unserialise(tdata)
      end
      f.close()
      return true
    else
    if (DEBUG) then print("[DBG] No index file found!") end
    return false
  end
end

-- Updates the index file
function INDEX_WRITE()
  f = fs.open(index_file,"w")
  local tdata = textutils.serialise(index)
  if (tdata~=nil) then
    if (ADEBUG) then debug(tdata) end
    f.write(tdata)
    f.close()
  end
end

-- Checks with checksum for dataloss
function INDEX_CHECKSUM()

end

--[[ FILESYSTEM ]]--
local function DISK_GETFROMID(id)
  for i,v in ipairs(raid) do
    if (v.id == id) then
      return v
    end
  end
end

local function FILE_WRITE(disk,filename,data,size,n)
  if ADEBUG then debug("[DBG] Disk: "..disk.id.."> "..data) end
  local flnm = disk.mountPath.."/"..filename.."&"..size.."&"..tostring(n)
  f = fs.open(flnm,"w")
  if (f~=nil) then
    f.write(data)
  else
    return nil
  end
  f.close()
end

local function FILE_READ(disk,filename,size,n)
  if (disk==nil) then
    if (DEBUG) then print("[DBG] Error: Data loss detected!") end
    return nil
  end
  local flnm = disk.mountPath.."/"..filename.."&"..size.."&"..tostring(n)
  -- ERROR: tostring(n) = nil in some!!!!
  local f = fs.open(flnm,"r")
  if (f==nil) then return nil end
  local data = f.readAll()
  f.close()
  return data
end

-- Adds a file
function FILE_ADD(filename,data)
  -- First find out if the file already exists
  for i,v in ipairs(index) do
    if (v.filename==filename) then
      return false
    end
  end
  -- Calculate amount of size per DISK
  local size = data:len()
  if (type(data)=="string") then
    if (size>total) then
      -- So we calculate the split size
      local s = math.floor((size/total))
      local ls = size-(s*(total-1)) --Size for the last disk
      -- Add in index
      for y,v in ipairs(index) do
        if (v.filename==nil) then
          -- Found a place. Now add everything in index
          v.size=size
          -- Split the data
          local t =1
          local p = 1
          for i=1,total-1 do
            tdata = data:sub(t,t+s-1)
            t=t+s
            -- Write it
            -- TODO: Add check if successfull?
            FILE_WRITE(raid[i],filename,tdata,s,p)
            v.parts[p]={id=raid[i].id,part=p}
            p = p + 1
          end
          tdata=data:sub(t,size)
          v.parts[total]={id=raid[total].id,part=p}
          FILE_WRITE(raid[total],filename,tdata,ls,p)
          -- Checksum?
          v.filename=filename
          return true
        end
      end
    end
  end
  return false
end

function FILE_GET(filename)
  -- First check if file exists
  for i,v in ipairs(index) do
    if (v.filename==filename) then
      -- File found, Now get all parts!
      if (DEBUG) then print("[DBG][FILE_GET] File found!") end
      local tdata = ""
      local size = v.size
      local s = math.floor((size/total))-- Calculate size
      local ls = size-(s*(total-1))
      local p =1
      if (DEBUG) then print("[DBG][FILE_GET] s: "..s..", ls:"..ls) end
      for y,z in ipairs(v.parts) do
        --BugFix: Remove last one
        if (y~=#v.parts) then
          local id = DISK_GETFROMID(z.id)
          local tread = FILE_READ(id,filename,s,z.part)
          if (tread~=nil) then
            tdata = tdata..tread
          end
        else
          local id = DISK_GETFROMID(v.parts[#v.parts].id)
          local tread = FILE_READ(id,filename,ls,p)
          if (tread~=nil) then
            tdata = tdata..tread
          end
          return tdata
        end
        p=p+1
      end
      print("[FATAL] Arrays not matching!")
    end
  end
  print("[ERROR] File not found")
  return nil
end

function FILE_REM(filename)

end

-- Initialize array
function init()
  print("Init:")
  print(INDEX_INIT())
  print("Index_Read: ")
  print(INDEX_READ())
  print("Index Array: ")
  updateArray()

  FILE_ADD("Test","Hello world. Isn't it a nice day? And A GIANT Array? Oh yea I know this is a lot of text. But I need it for my tests. Since I need to go over 200 characters :O IKR?! Yea. So... How are you? I'm good. Just lot's of text ;)")
  FILE_ADD("Second_file","RANDOMDATA WE NEED TO FILL THIS WITH A LOT OF SHIT. UHM... bla bla bla bla bla bla bla bla bla bla bla bla oh.. right. This isn't enough data to store (split iot over all disks..)")
  print("=========FILE_GET=========")
  print(FILE_GET("Test"))
  print(FILE_GET("Second_file"))
  print("==========================")
  --totalSpace,totalSpace-totalFreeSpace
  INDEX_WRITE()
end

init()