if S.trains == nil then S.trains = {} end

F.odj = {}

-- F.dst - Get summer time
function F.dst()
  if os.date().isdst then return "CEST" else return "CET" end
end

function F.pccheck(pos, state)
  if is_passive(pos) then return true end
  return (getstate(pos) == state)
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 not event then return end
  if event.type == "train" then
    if atc_arrow then
      if (get_rc() or ""):match ("FREIGHT") then
        atc_send (reverse and "RSM" or "SM")
        return
      end
      local cmdstr=""
      local t_sched = ((optime or 15) + 1)
      if out then
        atc_set_text_outside (out)
      end
      local intext = "Unknown Station"
      if stn then
        intext = F.stnlist[stn] or stn
      end
      atc_set_text_inside (intext)
      cmdstr = "BBWO" .. (side or "R")
      if type (predepart) == "function" then 
        predepart ()
      end
      S.trains[atc_id] = {
        v = 1,
        l = (get_line() or ""),
        s = stn,
        t = (trk or "N/A"),
      }
      cmdstr = cmdstr .."D" .. math.floor((optime or 15)) .. "OCD1"
      if reverse then
        cmdstr = cmdstr .. "R"
      end
      cmdstr = cmdstr .. "S" .. (acc or "M")
      atc_send (cmdstr)
      interrupt (t_sched,"")
    end
  elseif event.type == "int" then
    if atc_id then
      local intext = ""
      if next then
        intext = "Next stop: " .. (F.stnlist[next] or next)
      end
      if type (postdepart) == "function" then
        postdepart ()
      end
      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

-- Second version of the station function
function F.stn2gen(stn, trk, door, ret, chout)
  if not stn then return end
  if not trk then return end
  if not door then return end
  if door~="L" and door~="R" and door~="C" then return end
  if not atc_arrow then return end
  if not F.stndet[stn] then return end
  if not F.stndet[stn][trk] then return end
  local t = F.stndet[stn][trk]
  local stop = false
  if #t==0 then return end
  local l = get_line()
  if (not l) or l==" " then return end
  local rc = get_rc() or ""
  if rc:match("FREIGHT") then
    atc_send (ret and "BBWRSM" or "SM")
    return
  end
  if event.type == "train" then
    for i = 1, #t, 1 do
      if t[i][1]==l then
        stop = true
        atc_send(string.format("BBWO%sD15OCD1%sSM", door, (ret and "R" or "")))
        local intext_nxt = F.stnlist[t[i][2]] and ("Next station:\n%s\n(Track: %s)"):format(F.stnlist[t[i][2]], t[i][3] or "?") or ""
        local intext = ("%s\n%s"):format(F.stnlist[stn] or stn, intext_nxt)
        local outtext = string.format("%s (%06d)",F.lines[l].name or l, atc_id)
        if t[i][4] then outtext = outtext.." - "..(F.stnlist[t[i][4]] or t[i][4]) end
        local timenow = os.time()
        t[i][5] = t[i][5] or (timenow-(F.depint[l] or 300))
        -- note that the "average" time is weighted
        t[i][6] = t[i][6] and (t[i][6]+timenow-t[i][5]+30)/2 or (timenow-t[i][5])
        t[i][5] = timenow
        atc_set_text_inside(intext)
        if chout then atc_set_text_outside(outtext) end
        S.trains[atc_id] = {
          v = 2,
          l = (get_line() or ""),
          s = stn,
          t = (trk or "N/A"),
        }
        schedule_in(15, intext_nxt)
        break
      end
    end
    if (not stop) then
      atc_send(ret and "BBWRSM" or "SM")
    end
  end
  if event.type == "schedule" then
    if type(event.msg) == "string" then
      atc_set_text_inside(event.msg)
      atc_send(ret and "OCD1RSM" or "OCD1SM")
    end
  end
end

function F.disp2gen(stn)
  if not stn then return end
  if not F.stndet[stn] then return end
  local s = F.stndet[stn]
  local sn = F.stnlist[stn] or stn
  local d={{sn.."\nTrack    Line\n", (string.sub(sn, 28, 54) or "").." \nDestination\n", " \nEstimated Arrival\n"}}
  local c=2
  local t={}
  for i,_ in pairs(s) do t[#t+1]=i end
  table.sort(t)
  for i = 1,#t,1 do
    local trkname = t[i]
    local trk = s[trkname]
    for j = 1,#trk,1 do
      local det = trk[j]
      local r = (c%4==0) and (c/4+1) or ((c-c%4)/4+1)
      if not d[r] then d[r]={"",""} end
      d[r][1] = d[r][1] .. string.format("%-8s %s\n", tostring(trkname), F.lines[det[1]].name)
      d[r][2] = d[r][2] .. (F.lines[det[1]].ring and "Ring Line" or (F.stnlist[det[4]] or det[4] or "")).."\n"
      c=c+1
      local earr = (det[5] or os.time())+(det[6] or F.depint[det[1]] or 600)
      d[r][3] = d[r][3] .. os.date("%Y-%m-%d %H:%M %Z", earr) .. "\n"
    end
  end
  for i = 1, #d, 1 do
    for j = 1, #d[1], 1 do
      digiline_send("d_"..tostring(i).."_"..tostring(j), d[i][j])
    end
  end
end

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

function F.atc (cmd, intext, outtext)
  if event.type == "train" then
    if atc_arrow then
      if cmd then
        atc_send (cmd)
      end
      if intext then
        atc_set_text_inside (intext)
      end
      if outtext then
        atc_set_text_outside (outtext)
      end
    end
  end
end

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 Terminus",
  crnsw            = "Crossroads North Station St. 9th Alley",
  crnsw2           = "Crossroads C. 2nd St./Station St. 9th Alley",
  crrathaus        = "Crossroads City Hall",
  crsmacker        = "Crossroads Smacker's Station",
  crwm             = "Crossroads West Mountains",
  crzn             = "Crossroads Central/North",
  elchateau        = "Erstaziland-Chateau d'Erstazi",
  elgp             = "Erstaziland-Greener Pastures",
  elsf             = "Erstaziland-Salt Factory",
  evo              = "EVO",
  grsc             = "Grassy Scarp",
  mushroom         = "Mushroom Land",
  neverbuild       = "Neverbuild",
  nvbcentral       = "Neverbuild Central",
  nvbold           = "Neverbuild Old Terminus",
  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",
  phsc             = "Personhood Southern Crossing",
  phwest           = "Personhood West",
  scc              = "Silver Coast Central",
  scn              = "Silver Coast North",
  scs              = "Silver Coast South",
  thecube          = "The Cube",
}

F.lines = {
  ["AB"] = {
    name = "ATL Bronze Line",
    ring = false,
    [1] = { {"crch","A1"}, --[[ {"crwm","3"}, ]] {"scs","N2"}, {"scc","N2"}, {"scn","N2"}, {"cg","1"}, {"thecube","4"}, {"phsc","N"}, {"grsc", "4"}, {"phwest","1"} },
    [2] = { {"phwest","1"}, {"grsc", "3"}, {"phsc","S"}, {"thecube","1"}, {"cg","2"}, {"scn","S2"}, {"scc","S2"}, {"scs","S2"}, --[[ {"crwm","4"}, ]] {"crch","A1"} },
  },
  ["AZ"] = {
    name = "ATL Zinc Line",
    ring = false,
    [1] = { {"evo","N/A"}, {"scs","N1"}, {"scc","N1"}, {"scn","N1"}, {"oc","N"}, {"elgp","N"}, {"elsf","E"}, {"elchateau","S"} },
    [2] = { {"elchateau","S"}, {"elsf","W"}, {"elgp","S"}, {"oc","S"}, {"scn","S1"}, {"scc", "S1"}, {"scs","S1"}, {"evo","N/A"} },
  },
  ["CRT1"] = {
    name = "CRT 1",
    ring = false,
    [1] = { {"crsmacker", "R3"}, {"crch", "U1"}, {"crchs", "W"}, {"cras", "N"} },
    [2] = { {"cras", "N"}, {"crchs", "E"}, {"crch", "U2"}, {"crsmacker", "R3"} },
  },
  ['CRT2'] = {
    name = 'CRT 2',
    ring = false,
    [1] = { {'crch', 'U6'}, {'crbfsw', 'E'}, {'crnsw', 'R1'} },
    [2] = { {'crnsw', 'R1'}, {'crbfsw', 'W'}, {'crch', 'U6'} },
  },
}

F.stndet = {}
for i, l in pairs(F.lines) do
  for j = 1, #l, 1 do
    local dir = l[j]
    for k = 1, #dir, 1 do
      local s = dir[k][1]
      local t = dir[k][2]
      if not F.stndet[s] then F.stndet[s] = {} end
      if not F.stndet[s][t] then F.stndet[s][t] = {} end
      if k~=#dir or l.ring then
        local nxt = dir[k==#dir and 1 or k+1]
        F.stndet[s][t][#F.stndet[s][t]+1] = {i, nxt[1], nxt[2], dir[#dir][1]}
      else
        local addent = true
        for m = 1, #l, 1 do addent = addent and (l[m][1]==dir[k]) end
        if addent then F.stndet[s][t][#F.stndet[s][t]+1] = {i, nil, nil, s} end
      end
    end
  end
end

F.errlist = {
  ["incorrect_setup"]   = "Incorrect LuaATC track setup!",
  ["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"]   =  90,
  ["AG"]   =  120,
  ["CRT1"] =  30,
}


F.dpts = {
  ['CRT1'] = POS(1835,5,1000),
  ['AG'] = POS(1399,4,2020),
}

function F.odd(ln)
  if event.type=='ext_int' then
    if atc_id then
      set_rc(event.message.rc)
      atc_send('SM')
    else
      if type(F.odj[ln])~='table' then F.odj[ln] = {} end
      for i = 1,(#F.odj[ln]) do
        if F.odj[ln][i]==event then return end
      end
      table.insert(F.odj[ln],1,event)
    end
  end
  if event.type=='train' then
    if F.odj[ln] and #F.odj[ln]~=0 then
      ev = table.remove(F.odj[ln])
      if ev then
        set_rc(ev.message.rc)
        atc_send('BBWRSM')
        return
      else
        F.odj[ln] = {}
      end
    end
    atc_send('BBWR')
  end
end

function F.ods(rc, side, rev)
  if event.type=='train' then
    if atc_arrow then
      if string.find((get_rc() or ''),(rc or '')) then
        atc_send('BBWO' .. (side or 'R') .. 'D10OCD1' .. ((rev or string.find((get_rc() or ''), 'R' .. rc)) and 'R' or '')..'SM')
      elseif rev then
        atc_send('BBWRSM')
      end
    end
  end
end

function F.odc(ln, rc)
  interrupt_pos(F.dpts[ln],{['rc']=rc})
end