--[[
This environment has programs that can be separated to three parts:
I) Common functions
II) Common variables
III) ATL/CRT Bronze Line
]]

-- I) Common Functions
if S.trains == nil then S.trains = {} end
if S.corrratio == nil then S.corrratio = 1 end
if S.corrratio > 1 then S.corrratio = 1 end
if S.corrratio <= 0 then S.corrratio = 1 end

-- F.dst - Get summer time
function F.dst()
  if os.date().isdst then return "CEST" else return "CET" end
end
-- F.error - Send error with error code
function F.error(errorcode)
  error(F.errlist[errorcode])
end
--[[ F.stnbasic - Basis for all station functions:
(By default, nil is defined as false or "no changes")
stn        = Station Code
side       = Door opening side
optime     = Length of time before train departs
reverse    = Reverse train before departing
acc        = Departure Speed
out        = Change outside text
reventry   = Allow trains to pass from the reverse direction
predepart  = Function to execute before departure
postdepart = Function to execute after departure
next       = Next stop
]]
function F.stnbasic(stn, side, optime, reverse, acc, out, reventry, predepart, postdepart, next,track)
  if event.train then
    if atc_arrow then
      local t_start = os.clock()
      local cmdstr=""
      local corr = S.corrratio
      local t_sched = ((optime or 15)+1)-- commented out due to trouble *corr
      if out~=nil then atc_set_text_outside(out) end
      local intext = "Unknown Station"
      if stn and F.stnlist[stn] then intext = F.stnlist[stn] end
      --intext = intext .. "\nCorrection: " .. S.corrratio
      atc_set_text_inside(intext)
      cmdstr="BBWO"..(side or "R")
      if predepart~=nil then predepart() end
      S.trains[atc_id] = "P "..stn.." "..(track or "x")
      cmdstr=cmdstr.."D"..math.floor((optime or 15))-- comment out due to trouble *S.corrratio)
      cmdstr=cmdstr.."OCD1"
      if reverse then cmdstr=cmdstr.."R" end
      cmdstr=cmdstr.."S"..(acc or "M")
      atc_send(cmdstr)
      interrupt(t_sched,{sched=t_sched,start=t_start,corr=corr})
    else
      if reventry==nil then F.error("wrong_direction")
      else
        if not reventry then F.error("wrong_direction") end
      end
    end
  end
  if event.int then
    if atc_id ~= nil then
      local intext = ""
      if next ~= nil then intext = "Next stop: "..(F.stnlist[next] or "???") end
      if postdepart~=nil then postdepart() end
      --[[
      if event.msg and event.msg.start and event.msg.sched and event.msg.corr then
        local t_end = os.clock()
        S.corrratio = event.msg.sched/event.msg.corr/(t_end-event.msg.start)
        if S.corrratio > 1 then S.corrratio = 1 end
      end
      ]]
      --atc_set_text_inside(intext.."\nCorrection: "..S.corrratio)
      atc_set_text_inside(intext)
    end
  end
end

-- F.hst - preset function for small stations (Haltestelle)
function F.hst(cur, nxt, side, spd, out, trk)
  F.stnbasic(cur, side, 10, false, spd, out, true, nil, nil, nxt, trk)
end

-- F.bhf - preset function for large stations (Bahnhof)
function F.bhf(cur, nxt, side, spd, out, trk)
  F.stnbasic(cur, side, 15, false, spd, out, true, nil, nil, nxt, trk)
end

-- F.kbhf - preset function for termini
function F.kbhf(cur, nxt, side, spd, out, trk)
  F.stnbasic(cur, side, 15, true, spd, out, true, nil, nil, nxt, trk)
end

-- F.timing - station with timing
function F.timing(d_off, d_int, cur, nxt, side, spd, out, trk, term, pre, post)
		  local timenow = os.time()
	  	local timesincelast = (timenow+d_off) % d_int
  local wait = d_int - timesincelast
  F.stnbasic(cur, side, wait, term, spd, out, true, pre, post, nxt, trk)
end

-- F.brk(direction) - sends ATC B2 command
function F.brk(dir)
  if event.type == "train" then
    if atc_arrow == dir then
      atc_send("B2S2")
    end
  end
end

--[[ F.eval - similar to the ? : operator in C
expr     = the expression to evaluate
rettrue  = the value to return if expr is true
retfalse = the value to return if expr is false
]]
function F.eval(expr, rettrue, retfalse)
  if expr then return rettrue else return retfalse end
end

function F.checkpoint(name,arrow,opp)
  if event.train then
    S.trains[atc_id] = "C "..name.." "
    if atc_arrow then
      S.trains[atc_id] = S.trains[atc_id]..arrow
    else
      S.trains[atc_id] = S.trains[atc_id]..opp
    end
  end
end

--[[ II) Common Variables
F.stnlist = List of stations
F.errlist = List of errors
F.depint  = Departure intervals
]]
F.stnlist = {
  cg               = "Colored Grasses",
  clockwise        = "Clockwise Route",
  counterclockwise = "Counterclockwise Route",
  cras             = "Crossroads ARSE7's Shop",
  crbfost          = "Crossroads Station East",
  crbfsm           = "Crossroads Station St. Central",
  crbfso           = "Crossroads Station St. East",
  crbfsw           = "Crossroads Station St. West",
  crch             = "Crossroads City Hall",
  crchs            = "Crossroads City Hall South",
  crmtrail         = "Crossroads Mountain Railway Termius",
  crnsw            = "CR-North Station St. 9th Alley",
  crrathaus        = "Crossroads City Hall",
  crsmacker        = "Crossroads Smacker's Station",
  crwm             = "Crossroads-West Mountains",
  crzn             = "Crossroads-Zentrum/Nordstadt",
  elchateau        = "Erstaziland-Chateau d'Erstazi",
  elgp             = "Erstaziland-Greener Pastures",
  elsf             = "Erstaziland-Salt Factory",
  evo              = "EVO",
  mushroom         = "Mushroom Land",
  neverbuild       = "Neverbuild",
  nvbcentral       = "Neverbuild Central",
  nvbold           = "Neverbuild Old Termius",
  nvboutskirts     = "Neverbuild Outskirts",
  oc               = "Ocean City",
  occh             = "Ocean City, City Hall",
  occrt            = "Ocean City, CRT Office",
  ocmushroom       = "Ocean City, Mushroom Market",
  ocoutskirts      = "Ocean City Outskirts",
  phwest           = "Personhood, West",
  scc              = "Silver Coast Central",
  scn              = "Silver Coast North",
  scs              = "Silver Coast South",
  thecube          = "The Cube",
}
F.errlist = {
  ["runaway_train"]     = "Runaway train found!",
  ["train_disappeared"] = "Train has disappeared!",
  ["unexpected_train"]  = "Train is not expected to pass!",
  ["wrong_direction"]   = "Train passed in wrong direction!",
}
F.depint = {
  ["AB"]   =  60,
  ["AG"]   =  120,
  ["CRT1"] =  30,
}

-- ATL/CRT Bronze Line

-- Colored Grasses
F.ab_cgw="--:-- "..F.dst()
F.ab_cge="--:-- "..F.dst()
F.ab_status = "Irregular operation"

F.cg_disp = function()
  if event.digiline then
    if event.digiline then if not event.channel=="upd" then return end end
    local t=os.date()
    local cg="Colored Grasses\nATL/CRT Bronze Line\n"
    local str = string.format("%26s\n%26s\n",os.date("%Y-%m-%d %H:%M %z",os.time()),F.ab_status)
    digiline_send("bstg1-1",cg.."<-- Personhood West\n[1] via The Cube")
    digiline_send("bstg1-2",string.format("%s%27s\n%27s",str,"Crossroads City Hall -->","via Silver Coast [2]"))
    digiline_send("bstg2-1",cg.."<-- Crossroads City Hall\n[2] via Silver Coast")
    digiline_send("bstg2-2",string.format("%s%27s\n%27s",str,"Personhood West -->","via The Cube [1]"))
    digiline_send("bstg3","Scheduled departure (Track\nScheduled departure (Track")
    digiline_send("bstg4",os.date("1): %H:%M %z%n2): %H:%M %z",os.time()+60))
    return
  end
  return
end

function F.cg_stn(gleis)
  if event.train and atc_arrow then
    if get_line()~="AB" then atc_send("SM") return end
    atc_send("B0 W OR")
    local time=os.date()
    if time.sec>50 then time.sec=time.sec-11 end
    local m=""
    if time.min>58 then
      m = string.format("%s%02d:%02d", m, F.eval(time.hour > 22, time.hour - 24, time.hour) + 1, time.min - 59)
    else
      m = string.format("%s%02d:%02d", m, time.hour, time.min + 1)
    end
    m = m .. " " .. F.dst()
    atc_set_text_inside("Colored Grasses\nThis train will depart at: "..m)
    interrupt(60-time.sec,"depart")
    if gleis==1 then F.ab_cgw=m
    else F.ab_cge=m
    end
  end
  if event.int and event.message=="depart" then
    atc_set_text_inside("")
    time = os.date()
    local nxt = string.format("%02d:%02d %s", F.eval(time.min>58, F.eval(time.hour>22, time.hour-23, time.hour+1), time.hour), F.eval(time.min>58, time.min-59, time.min+1), F.dst())
    atc_send("OC D1 SM")
    if gleis==1 then F.ab_cgw=nxt
    else F.ab_cge=nxt
    end
  end
end