Elevator!

--[[
Elevator Control Setup by Hamish Robertson
Aliases: OminousPenguin, MC username: Peren

Licence: Creative Commons Attribution-NonCommercial-ShareAlike (http://creativecommons.org/licenses/by-nc-sa/3.0/)

This is a LUA program for ComputerCraft, a Minecraft mod by Daniel Ratcliffe aka dan200 (http://www.computercraft.info/)
This program is for controlling elevators from the Railcraft mod (http://www.railcraft.info/)
For help and feedback please use this forum thread: http://www.computercraft.info/forums2/index.php?/topic/1302-railcraft-mod-elevator-control/

This is version 2b. It is in the beta release stage and so there may be bugs. If you believe you have found a bug, please report it at the above forum thread.

You are permitted to modify and or build upon this work.
If you make your own version publicly available, then please also publish it at the above forum thread. Thank you and happy coding!

NOTE: This is the setup program. It will create a file called elevator.cfg and download the main program to elevator-main.lua

Use Ctrl+T to terminate the program
--]]

CHANNEL_ELEVATOR = 34080

function writeToPos(x, y, str)
    term.setCursorPos(x, y)
    term.write(str)
end
function clearArea(x1,y1,x2,y2)
    for i=y1,y2 do
        writeToPos(x1,i,string.rep(" ",x2-x1))
    end
end
function eventHandle(tHandlers, f, ...)
    f = tHandlers[f]
    if type(f) == "function" then return f(...) end
end
function debug(msg)
    print(msg)
    os.pullEvent("key")
end
function printSetupHeader(saving)
    term.clear()
    writeToPos(2,2,"====================[ Setup ]====================")
    if saving then writeToPos(5,5,"Saving data... "); term.setCursorBlink(true) end
end

function getModemSide()
    -- Find all attached modems
    local sides = {"left","right","top","bottom","back","front"}
    local i = 1
    while i <= #sides do
        if peripheral.getType(sides[i]) ~= "modem" then
            table.remove(sides,i)
        else
            i = i + 1
        end
    end

    if #sides == 0 then
        return nil
    elseif #sides == 1 then
        return sides[1]
    end

    -- If there is more than one modem attached, ask user to choose one
    local selected = 1
    local function redraw()
        printSetupHeader()
        writeToPos(7,9,"Use the modem on the          side")
        for i=1,#sides do
            if (i == selected) then
                writeToPos(29,9,sides[i])
            else
                if (9-selected+i)<9 then
                    term.setCursorPos(29,(8-selected+i))
                else
                    term.setCursorPos(29,(10-selected+i))
                end
                term.write(sides[i])
            end
        end--for
        writeToPos(4,18,"[ Arrow keys to select, Enter to confirm ]")
    end--redraw()

    redraw(); -- First draw

    while true do
        local _, keycode = os.pullEvent ("key")
        if (keycode == 200) then -- up
            if selected > 1 then selected = selected-1 end
        elseif (keycode == 208) then -- down
            if selected < 6 then selected = selected+1 end
        elseif (keycode == 28) then -- enter
            return sides[selected]
        end
        redraw()
    end
end--getModemSide()

function getElevatorID()
    local elevatorID
    printSetupHeader()
    writeToPos(3, 4, "Searching for other elevators.")
    writeToPos(3, 6, "This may take a few seconds...")
    writeToPos(5, 10, "(Remember that rain reduces modem range)")
    local modem = peripheral.wrap(modemSide)
    modem.open(os.getComputerID())
    modem.transmit(CHANNEL_ELEVATOR, os.getComputerID(), "ELEV\030ALL\030DISCOVER") -- Ask all elevator terminals in range to tell us their elevator ID
    local tElevatorIDs = {}
    local mt = {
        tMeta = {},
        iIndex = 1,
        __newindex = function(t,k,v)
            this = getmetatable(t)
            if this.tMeta[k] ~= true then
                this.tMeta[k] = true
                rawset(t,this.iIndex,k)
                this.iIndex = this.iIndex + 1
            end
        end,
    }
    setmetatable(tElevatorIDs,mt)
    local _, _, sChannel, sReplyChannel, sMessage
    local discoveryTimer
    local tHandlers = {
        modem_message = function (_, sChannel, sReplyChannel, sMessage, nDistance)
            discoveryTimer = os.startTimer(3) -- Reset timer
            local iter = string.gmatch(sMessage, "([^\030]+)")
            if sChannel == os.getComputerID() and iter() == "ELEV" then
                local eID = iter()
                if iter() == "ID" then
                    tElevatorIDs[eID] = true
                end
            end
        end,
        timer = function (timerID)
            if timerID == discoveryTimer then   return true end
        end
    }
    discoveryTimer = os.startTimer(3) -- Loop will timeout after three seconds of not receiving an event
    while true do
        local v = eventHandle(tHandlers, os.pullEvent())
        if v then break end
    end
    writeToPos(3, 6, "Press any key to continue...  ") -- Pause to let them read the message about rain
    os.pullEvent("key")

    local function getCustomID()
        writeToPos(5, 7, "Please specify an ID: ")
        writeToPos(2, 9, "IDs can have letters, numbers and other characters")
        term.setCursorPos(27, 7); term.setCursorBlink(true)
        return io.read()
    end

    printSetupHeader()
    if #tElevatorIDs == 0 then
        writeToPos(2, 5, "No existing elevators detected.")
        elevatorID = getCustomID()
    else
        writeToPos(2, 5, "The following elevator IDs were detected:")
        writeToPos(3, 18, "Press Enter to use the selected ID")
        writeToPos(3, 19, "Press Tab to create a new elevator ID")
        local selected = 1
        for k,v in ipairs(tElevatorIDs) do
            writeToPos(5, 6+k, v)
        end
        writeToPos(3,7,">")
        local function updateSelection(previousSelection)
            writeToPos(3,6+previousSelection," ")
            writeToPos(3,6+selected,">")
        end
        while true do
            local _, keycode = os.pullEvent ("key")
            if (keycode == 200) then -- up
                previousSelection = selected
                if selected > 1 then selected = selected-1 end
            elseif (keycode == 208) then -- down
                previousSelection = selected
                if selected < #tElevatorIDs then selected = selected+1 end
            elseif (keycode == 28) then -- enter
                elevatorID = tElevatorIDs[selected]
                break
            elseif (keycode == 15) then -- tab
                clearArea(2,5,52,9)
                elevatorID = getCustomID()
                break
            end
            updateSelection(previousSelection)
        end
    end
    return elevatorID
end--getElevatorID()

function getFloorName()
    printSetupHeader()
    writeToPos(7,9,"Enter a name/label for this floor: ")
    term.setCursorPos(14,11); term.setCursorBlink(true)
    local name
    repeat
        name = io.read()
    until name ~= ""
    return name
end--getFloorName()

function getGPS()
    printSetupHeader()
    writeToPos(5, 5, "Waiting for GPS response... ")
    term.setCursorPos(5,7)
    local x, y, z = gps.locate(2)
    if x ~= nil then
        term.write("... coordinates received")
        writeToPos(5, 9, "Start GPS host in the background?")
        local _, keycode, selected = nil, nil, 1
        writeToPos(14,11,"[ Yes ]             No")
        while true do
            term.setCursorPos(14,11)
            _, keycode = os.pullEvent ("key")
            if (keycode == 205) or (keycode == 49) then -- right
                if selected == 1 then
                    selected = 2
                    term.write("  Yes             [ No ]")
                end
            elseif (keycode == 203) or (keys.getName(keycode) == n) then -- left
                if selected == 2 then
                    selected = 1
                    term.write("[ Yes ]             No  ")
                end
            elseif (keycode == 28) then -- enter
                if selected == 1 then
                    return x,y,z
                else
                    return nil, y
                end
            end
        end--while
    else -- We didn't get coords from GPS
        term.write("... could not determine coordinates")
        return
    end
end--getGPS()

function getCoordsInput()
    printSetupHeader()
    writeToPos(8,7,"x coordinate:")
    writeToPos(8,8,"y coordinate:")
    writeToPos(8,9,"z coordinate:")
    writeToPos(4,13,"Important: If your GPS hosts are all in a")
    writeToPos(4,14,"vertical line (same x & y coordinates), then")
    writeToPos(4,15,"you need to place another host off to the side")
    writeToPos(4,16,"to enable an accurate GPS fix")
    writeToPos(4,17,"(Usage: gps host x y z")
    term.setCursorPos(22,7); term.setCursorBlink(true)

    local selected, inputs = 1, {"","",""}

    local function redraw()
        term.setCursorPos(22+inputs[selected]:len(),6+selected)
    end

    local eventHandlers = {
        key = function(keycode)
            if (keycode == 200) and (selected > 1) then -- up
                selected = selected-1
                redraw(selected);
            elseif (selected < 3) and ((keycode == 208) or (keycode == 28)) then -- down
                selected = selected+1
                redraw(selected);
            elseif (keycode == 28) then -- enter
                for i,input in ipairs(inputs) do
                    if inputs[selected] == "" then return end
                end
                return inputs[1], inputs[2], inputs[3]
            elseif (keycode == 14) and inputs[selected] ~= "" then -- backspace
                    inputs[selected] = inputs[selected]:sub(1,-2)
                    term.setCursorPos(22+inputs[selected]:len(),6+selected)
                    term.write(" ")
                    term.setCursorPos(22+inputs[selected]:len(),6+selected)
            end
        end,

        char = function(c)
            if (inputs[selected]:len() < 4) and (string.find(c, "[%d\-]") ~= nil) then -- number entered
                inputs[selected] = inputs[selected]..c
                term.write(c)
            end
        end,

        handle = function (self, f, ...)
            f = self[f]
            if type(f) == "function" then return f(...) end
        end
    }
    while true do
        local x,y,z = eventHandlers:handle(os.pullEvent())
        if x then return x,y,z end
    end
end--getCoordsInput

function getFloorCoords()
    -- We need at least the y (height) coordinate so we can know what order the floors are in
    printSetupHeader()
    writeToPos(4,4,"The y (height) coordinate is required so that")
    writeToPos(4,5,"floors can be listed in the correct order.")
    writeToPos(4,7,"You have a few options:")
    writeToPos(6,10,"1. Enter y coordinate:")
    writeToPos(6,12,"2. Use GPS (requires 4 GPS hosts)")
    writeToPos(6,14,"3. Enter x,y,z and then this computer")
    writeToPos(13,15,"can become a GPS host.")
    writeToPos(7,16,"(recommended if you have over 4 floors)")
    writeToPos(2,19,"(Press F3 to view player coordinates)")

    local selected, line, y = 1, {10,12,14}, ""

    local function redraw(i, clear)
        term.setCursorPos(3,8+(2*i))
        local t = (clear and write(" ")) or write("[")
        term.setCursorPos(49,8+(2*i))
        local t = clear and write(" ") or write("]")
        term.setCursorPos(29,10)
    end

    redraw(1)
    term.setCursorBlink(true)

    local eventHandlers = {
        key = function(keycode)
            if (keycode == 200) then -- up
                if selected > 1 then
                    redraw(selected, true)
                    selected = selected-1
                    if selected == 1 then term.setCursorBlink(true) end
                    redraw(selected);
                end
            elseif (keycode == 208) then -- down
                if selected < 3 then
                    redraw(selected, true)
                    selected = selected+1
                    term.setCursorBlink(false)
                    redraw(selected);
                end
            elseif (keycode == 28) then -- enter
                if ((selected == 1) and (y ~= "")) then
                    return true, nil, y
                elseif selected == 2 then
                    return true, getGPS()
                elseif selected == 3 then
                    return true, getCoordsInput() -- input all 3
                end
            elseif (keycode == 14) then -- backspace
                if ((selected == 1) and (y ~= "")) then
                    y = y:sub(1,-2)
                    term.setCursorPos(29+y:len(),10)
                    term.write(" ")
                    term.setCursorPos(29+y:len(),10)
                end
            end
        end,

        char = function(c)
            if (selected == 1) and ((y:len() < 4) and (string.find(c, "%d") ~= nil)) then -- number entered
                y = y..c
                term.setCursorPos(28+y:len(),10)
                term.write(c)
            end
        end,

        handle = function (self, f, ...)
            f = self[f]
            if type(f) == "function" then return f(...) end
        end
    }
    while true do
        local RETURN,x,y,z = eventHandlers:handle(os.pullEvent())
        if RETURN then return x,y,z end
    end
end--getFloorCoords()

fs.delete("elevator-main.lua")
if not shell.run("pastebin", "get", "iJWyUQVr", "elevator-main.lua") then
    print("Failed to download main program. Try manually from pastebin: iJWyUQVr\n(this is just the setup component)")
    return
end

modemSide = getModemSide()
if modemSide == nil then
    printSetupHeader()
    writeToPos(15,6,"! No modem detected !")
    writeToPos(8,9,"A modem is required for")
    writeToPos(8,11,"communication with the other floors")
    writeToPos(4,13,"Please attach a modem then try again")
    return -- terminate program
end

local elevatorID = getElevatorID()

local floorName = getFloorName()

local x,y,z

while true do
    x,y,z = getFloorCoords()
    if y==nil then
        writeToPos(5, 11, "Press any key to continue...")
        os.pullEvent("key")
    else
        break
    end
end
local coords = y
if x and y then
    coords = x.."\31"..y.."\31"..z
end

printSetupHeader(true)
configPath = shell.resolve(".").."/elevator.cfg"
fs.delete(configPath)
local file = io.open(configPath, "w")
file:write(modemSide.."\n")
file:write(elevatorID.."\n")
file:write(coords.."\n")
file:write(y.."\31"..floorName)
file:close()
term.write("Done")

writeToPos(5,7,"Setting elevator-main.lua to run on startup... ")

file = io.open("/startup", "w")
file:write("shell.run(\"/"..shell.resolve(".").."/elevator-main.lua\")")
file:close()
term.write("Done")

writeToPos(5, 9, "Press any key to reboot...")
os.pullEvent("key")
os.reboot()