RailStatus : IG Server

--    ___              _       _      ___     _               _
--   | _ \   __ _     (_)     | |    / __|   | |_    __ _    | |_    _  _     ___
--   |   /  / _` |    | |     | |    \__ \   |  _|  / _` |   |  _|  | +| |   (_-<
--   |_|_\  \__,_|   _|_|_   _|_|_   |___/   _\__|  \__,_|   _\__|   \_,_|   /__/_
-- _|"""""|_|"""""|_|"""""|_|"""""|_|"""""|_|"""""|_|"""""|_|"""""|_|"""""|_|"""""|
-- "`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'"`-0-0-'
--
--                              RailStatus : IG Server
--
-- La seconde génération de RailStatus (http://pastebin.com/js3pN87r), un programme permettant
-- de connaître en temps réel et en jeu (in game) le statut des aiguillages d'un réseau ferroviaire en
-- utilisant RailCraft, ComputerCraft et RedPower
--
-- Utilisation :
-- 1. Dans un ordinateur, importer ce programme depuis Pastebin :
--     pastebin get KAy0Kqfw railstatusigs
-- 2. Lancer le programme :
--     railstatusig [ID de la carte] [URL de base d'appel vers l'API]
--     Exemple : railstatusigs 1 http://exemple.fr/api
--
-- Client : http://pastebin.com/KsJ9gukb
-- Dépôt Github : https://github.com/EaSyCompanyFr/RailStatus

term.clear()
term.setCursorPos(1,1)

print("RailStatus : IG Server is starting...")

-- Arguments passés au programme
args = {...}

if table.getn(args) < 2 then
  print("  One or more parameters are missing")
  return
end

-- --------------------------------------------------------
-- Constantes

-- Tableau de correspondance nom de couleur > identifiant décimal
COLORS_ARRAY = {}

COLORS_ARRAY["white"] = colors.white
COLORS_ARRAY["orange"] = colors.orange
COLORS_ARRAY["magenta"] = colors.magenta
COLORS_ARRAY["lightBlue"] = colors.lightBlue
COLORS_ARRAY["yellow"] = colors.yellow
COLORS_ARRAY["lime"] = colors.lime
COLORS_ARRAY["pink"] = colors.pink
COLORS_ARRAY["gray"] = colors.gray
COLORS_ARRAY["lightGray"] = colors.lightGray
COLORS_ARRAY["cyan"] = colors.cyan
COLORS_ARRAY["purple"] = colors.purple
COLORS_ARRAY["blue"] = colors.blue
COLORS_ARRAY["brown"] = colors.brown
COLORS_ARRAY["green"] = colors.green
COLORS_ARRAY["red"] = colors.red
COLORS_ARRAY["black"] = colors.black

-- Récupération du premier type de périphérique détecté
function getFirstPeripheralSide(peripheral_type)
  for k,side in pairs(redstone.getSides()) do
    if peripheral.isPresent(side) and peripheral.getType(side) == peripheral_type then
      return side
    end
  end

  return false
end

-- De quel côté est branché le moniteur avancé pour afficher la carte
MONITOR_SIDE = getFirstPeripheralSide("monitor")

if not MONITOR_SIDE then
  print("  Advanced monitor not detected on this computer")
  return
end

MONITOR = peripheral.wrap(MONITOR_SIDE)

-- Si le moniteur n'est pas de type avancé
if not MONITOR.isColor() then
  print("  And advanced monitor is required")
  return
end

print("  Advanced monitor side : "..MONITOR_SIDE)

-- Modem
MODEM_SIDE = getFirstPeripheralSide("modem")

if not MODEM_SIDE then
  print(" Modem not detected on this computer")
  return
end

print("  Modem side : "..MODEM_SIDE)

-- ID de la carte à utiliser
MAP_ID = args[1]

print("  Map ID : "..MAP_ID)

-- URL de base d'appel vers l'API
API_ENDPOINT = args[2]

print("  Endpoint : "..API_ENDPOINT)

print("  Computer ID : "..os.getComputerID())

print("")
print("To stop RailStatus : IG, hold CTRL+T for some seconds.")

-- --------------------------------------------------------
-- Fonctions et librairies

-- JSON4Lua: JSON encoding / decoding support for the Lua language.
-- json Module.
-- Author: Craig Mason-Jones
-- Homepage: http://json.luaforge.net/
-- Version: 0.9.40
-- This module is released under the MIT License (MIT).

local base = _G
local decode_scanArray
local decode_scanComment
local decode_scanConstant
local decode_scanNumber
local decode_scanObject
local decode_scanString
local decode_scanWhitespace
local encodeString
local isArray
local isEncodable

local function encode (v)
  -- Handle nil values
  if v==nil then
    return "null"
  end

  local vtype = base.type(v)

  -- Handle strings
  if vtype=='string' then
    return '"' .. encodeString(v) .. '"'            -- Need to handle encoding in string
  end

  -- Handle booleans
  if vtype=='number' or vtype=='boolean' then
    return base.tostring(v)
  end

  -- Handle tables
  if vtype=='table' then
    local rval = {}
    -- Consider arrays separately
    local bArray, maxCount = isArray(v)
    if bArray then
      for i = 1,maxCount do
        table.insert(rval, encode(v[i]))
      end
    else        -- An object, not an array
      for i,j in base.pairs(v) do
        if isEncodable(i) and isEncodable(j) then
          table.insert(rval, '"' .. encodeString(i) .. '":' .. encode(j))
        end
      end
    end
    if bArray then
      return '[' .. table.concat(rval,',') ..']'
    else
      return '{' .. table.concat(rval,',') .. '}'
    end
  end

  -- Handle null values
  if vtype=='function' and v==null then
    return 'null'
  end

  base.assert(false,'encode attempt to encode unsupported type ' .. vtype .. ':' .. base.tostring(v))
end

local function decode(s, startPos)
  startPos = startPos and startPos or 1
  startPos = decode_scanWhitespace(s,startPos)
  base.assert(startPos<=string.len(s), 'Unterminated JSON encoded object found at position in [' .. s .. ']')
  local curChar = string.sub(s,startPos,startPos)
  -- Object
  if curChar=='{' then
    return decode_scanObject(s,startPos)
  end
  -- Array
  if curChar=='[' then
    return decode_scanArray(s,startPos)
  end
  -- Number
  if string.find("+-0123456789.e", curChar, 1, true) then
    return decode_scanNumber(s,startPos)
  end
  -- String
  if curChar==[["]] or curChar==[[']] then
    return decode_scanString(s,startPos)
  end
  if string.sub(s,startPos,startPos+1)=='/*' then
    return decode(s, decode_scanComment(s,startPos))
  end
  -- Otherwise, it must be a constant
  return decode_scanConstant(s,startPos)
end

local function null()
  return null -- so json.null() will also return null ;-)
end

function decode_scanArray(s,startPos)
  local array = {}      -- The return value
  local stringLen = string.len(s)
  base.assert(string.sub(s,startPos,startPos)=='[','decode_scanArray called but array does not start at position ' .. startPos .. ' in string:\n'..s )
  startPos = startPos + 1
  -- Infinite loop for array elements
  repeat
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen,'JSON String ended unexpectedly scanning array.')
    local curChar = string.sub(s,startPos,startPos)
    if (curChar==']') then
      return array, startPos+1
    end
    if (curChar==',') then
      startPos = decode_scanWhitespace(s,startPos+1)
    end
    base.assert(startPos<=stringLen, 'JSON String ended unexpectedly scanning array.')
    object, startPos = decode(s,startPos)
    table.insert(array,object)
  until false
end

function decode_scanComment(s, startPos)
  base.assert( string.sub(s,startPos,startPos+1)=='/*', "decode_scanComment called but comment does not start at position " .. startPos)
  local endPos = string.find(s,'*/',startPos+2)
  base.assert(endPos~=nil, "Unterminated comment in string at " .. startPos)
  return endPos+2
end

function decode_scanConstant(s, startPos)
  local consts = { ["true"] = true, ["false"] = false, ["null"] = nil }
  local constNames = {"true","false","null"}

  for i,k in base.pairs(constNames) do
    --print ("[" .. string.sub(s,startPos, startPos + string.len(k) -1) .."]", k)
    if string.sub(s,startPos, startPos + string.len(k) -1 )==k then
      return consts[k], startPos + string.len(k)
    end
  end
  base.assert(nil, 'Failed to scan constant from string ' .. s .. ' at starting position ' .. startPos)
end

function decode_scanNumber(s,startPos)
  local endPos = startPos+1
  local stringLen = string.len(s)
  local acceptableChars = "+-0123456789.e"
  while (string.find(acceptableChars, string.sub(s,endPos,endPos), 1, true)
        and endPos<=stringLen
        ) do
    endPos = endPos + 1
  end
  local stringValue = 'return ' .. string.sub(s,startPos, endPos-1)
  local stringEval = base.loadstring(stringValue)
  base.assert(stringEval, 'Failed to scan number [ ' .. stringValue .. '] in JSON string at position ' .. startPos .. ' : ' .. endPos)
  return stringEval(), endPos
end

function decode_scanObject(s,startPos)
  local object = {}
  local stringLen = string.len(s)
  local key, value
  base.assert(string.sub(s,startPos,startPos)=='{','decode_scanObject called but object does not start at position ' .. startPos .. ' in string:\n' .. s)
  startPos = startPos + 1
  repeat
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly while scanning object.')
    local curChar = string.sub(s,startPos,startPos)
    if (curChar=='}') then
      return object,startPos+1
    end
    if (curChar==',') then
      startPos = decode_scanWhitespace(s,startPos+1)
    end
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly scanning object.')
    -- Scan the key
    key, startPos = decode(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    base.assert(string.sub(s,startPos,startPos)==':','JSON object key-value assignment mal-formed at ' .. startPos)
    startPos = decode_scanWhitespace(s,startPos+1)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    value, startPos = decode(s,startPos)
    object[key]=value
  until false   -- infinite loop while key-value pairs are found
end

function decode_scanString(s,startPos)
  base.assert(startPos, 'decode_scanString(..) called without start position')
  local startChar = string.sub(s,startPos,startPos)
  base.assert(startChar==[[']] or startChar==[["]],'decode_scanString called for a non-string')
  local escaped = false
  local endPos = startPos + 1
  local bEnded = false
  local stringLen = string.len(s)
  repeat
    local curChar = string.sub(s,endPos,endPos)
    -- Character escaping is only used to escape the string delimiters
    if not escaped then
      if curChar==[[\]] then
        escaped = true
      else
        bEnded = curChar==startChar
      end
    else
      -- If we're escaped, we accept the current character come what may
      escaped = false
    end
    endPos = endPos + 1
    base.assert(endPos <= stringLen+1, "String decoding failed: unterminated string at position " .. endPos)
  until bEnded
  local stringValue = 'return ' .. string.sub(s, startPos, endPos-1)
  local stringEval = base.loadstring(stringValue)
  base.assert(stringEval, 'Failed to load string [ ' .. stringValue .. '] in JSON4Lua.decode_scanString at position ' .. startPos .. ' : ' .. endPos)
  return stringEval(), endPos
end

function decode_scanWhitespace(s,startPos)
  local whitespace=" \n\r\t"
  local stringLen = string.len(s)
  while ( string.find(whitespace, string.sub(s,startPos,startPos), 1, true)  and startPos <= stringLen) do
    startPos = startPos + 1
  end
  return startPos
end

function encodeString(s)
  s = string.gsub(s,'\\','\\\\')
  s = string.gsub(s,'"','\\"')
  s = string.gsub(s,'\n','\\n')
  s = string.gsub(s,'\t','\\t')
  return s
end

function isArray(t)
  -- Next we count all the elements, ensuring that any non-indexed elements are not-encodable
  -- (with the possible exception of 'n')
  local maxIndex = 0
  for k,v in base.pairs(t) do
    if (base.type(k)=='number' and math.floor(k)==k and 1<=k) then      -- k,v is an indexed pair
      if (not isEncodable(v)) then return false end     -- All array elements must be encodable
      maxIndex = math.max(maxIndex,k)
    else
      if (k=='n') then
        if v ~= table.getn(t) then return false end  -- False if n does not hold the number of elements
      else -- Else of (k=='n')
        if isEncodable(v) then return false end
      end  -- End of (k~='n')
    end -- End of k,v not an indexed pair
  end  -- End of loop across all pairs
  return true, maxIndex
end

function isEncodable(o)
  local t = base.type(o)
  return (t=='string' or t=='boolean' or t=='number' or t=='nil' or t=='table') or (t=='function' and o==null)
end

-- Convertit un table en chaîne de caractères paramètres POST
function tableToURIString(t)
  local ret = ""
  local i = 1

  for key,value in pairs(t) do
    ret = ret..textutils.urlEncode(key).."="..textutils.urlEncode(value)

    if table.getn(t) ~= i then
      ret = ret.."&"
    end

    i = i + 1
  end

  return ret
end

-- Explose une chaîne de caractères selon un séparateur
function split(pString, pPattern)
  local Table = {}
  local fpat = "(.-)" .. pPattern
  local last_end = 1
  local s, e, cap = pString:find(fpat, 1)
  while s do
    if s ~= 1 or cap ~= "" then
     table.insert(Table,cap)
    end
    last_end = e+1
    s, e, cap = pString:find(fpat, last_end)
  end
  if last_end <= #pString then
    cap = pString:sub(last_end)
    table.insert(Table, cap)
  end
  return Table
end

-- --------------------------------------------------------
-- Démarrage du programme

rednet.open(MODEM_SIDE)

MONITOR.setTextScale(0.5);

-- Récupération de la carte
raw = http.get(API_ENDPOINT.."/"..MAP_ID)

if raw == nil then
  print("Unable to get the map data")
  return
end

map_data = decode(raw.readAll())

term.redirect(MONITOR)
term.clear()

-- Tableau contenant la liste des positions des aiguillages en fonction de l'identifiant de l'ordi et de la couleur de l'aiguillage
SWITCH_LIST = {}

-- Tableau contenant la liste des aiguillages en fonction de leur position
SWITCH_LIST_POS = {}

-- Affichage de la carte du réseau ferroviaire
for iy = 1, map_data["map_height"], 1 do
  for ix = 1, map_data["map_width"], 1 do
    local block = map_data["map_data"][iy..""][ix..""]

    if block["type"] == "switch" then
      color = colors.red

      if SWITCH_LIST[block["computer-id"]] == nil then
        SWITCH_LIST[block["computer-id"]] = {}
      end

      if SWITCH_LIST[block["computer-id"]][block["switch-color"]] == nil then
        SWITCH_LIST[block["computer-id"]][block["switch-color"]] = {}
      end

      SWITCH_LIST[block["computer-id"]][block["switch-color"]]["x"] = ix;
      SWITCH_LIST[block["computer-id"]][block["switch-color"]]["y"] = iy;

      if SWITCH_LIST_POS[iy..""] == nil then
        SWITCH_LIST_POS[iy..""] = {}
      end

      if SWITCH_LIST_POS[iy..""][ix..""] == nil then
        SWITCH_LIST_POS[iy..""][ix..""] = {}
      end

      SWITCH_LIST_POS[iy..""][ix..""]["computer-id"] = block["computer-id"];
      SWITCH_LIST_POS[iy..""][ix..""]["switch-color"] = block["switch-color"];
    elseif block["type"] == "rail" or block["type"] == "rail-bottom" or block["type"] == "rail-top" or block["type"] == "rail-left" or block["type"] == "rail-right" then
      color = colors.brown
    elseif block["type"] == "group" then
      color = colors.white
    else
      color = colors.black
    end

    paintutils.drawPixel(ix, iy, color)
  end
end

-- Mise à jour de la carte si aiguillage changé
while true do
  local event, p1, p2, p3 = os.pullEvent()

  if event == 'rednet_message' then
    local senderId = p1
    local message = p2
    local distance = p3

    local message_splitted = split(message, "|")

    local computer_sender_id = message_splitted[1]..""
    local bundled_cable = textutils.unserialize(message_splitted[2])
    local real_computer_id = message_splitted[3]

    for key,value in pairs(bundled_cable) do
      if SWITCH_LIST[computer_sender_id][key] ~= nil then
        if value == 1 then
          color = colors.lime
        else
          color = colors.red
        end

        local x = SWITCH_LIST[computer_sender_id][key]["x"]..""
        local y = SWITCH_LIST[computer_sender_id][key]["y"]..""

        SWITCH_LIST_POS[y][x]["real_computer_id"] = real_computer_id

        paintutils.drawPixel(SWITCH_LIST[computer_sender_id][key]["x"], SWITCH_LIST[computer_sender_id][key]["y"], color)
      end
    end

    http.request(API_ENDPOINT, "ci="..computer_sender_id.."&"..tableToURIString(bundled_cable)) -- Mise à jour de la carte web
  elseif event == 'monitor_touch' then
    local side = p1
    local xPos = p2..""
    local yPos = p3..""

    if SWITCH_LIST_POS[yPos] ~= nil and SWITCH_LIST_POS[yPos][xPos] ~= nil then
      rednet.send(tonumber(SWITCH_LIST_POS[yPos][xPos]["real_computer_id"]), COLORS_ARRAY[SWITCH_LIST_POS[yPos][xPos]["switch-color"]], true)
    end
  end
end