PortalApp

c = peripheral.wrap('bottom')
m = peripheral.wrap('top')
local controllerX, controllerY
buttons = {}
local currentApp = "keypad"
displayOffset = 0
local targetCount = 0
local destinations
local activeButton = 0

function resizeMon()
    controllerX, controllerY = m.getSize()
    m.setTextScale(0.5)
end

function clearAll()
    empty(m)
end

function empty()
    m.setBackgroundColor(colors.black)
    m.clear()
    m.setCursorPos(1,1)
end

function listDestinations()
    destinations={}
    for i=1,27 do
        if c.getStackInSlot(i) ~= nil then
            name = tostring(c.getStackInSlot(i).myst_book.destination)
            destinations[i]={}
            destinations[i]['name'] = name
            destinations[i]['favorite'] = false
            destinations[i]['active'] = false
            print(i.." - "..name)
        end
    end
    return destinations
end

function moveBook(InOrOut,bookNumber)
    local aaa = true
    if InOrOut == "in" then
        if c.pushItem('west',bookNumber,1) == 0 then
            print("There is already a book inside")
            aaa = false
        end
    elseif InOrOut == "out" then
        c.pullItem('west',1,1)
    end
    return aaa
end

function drawTitle(x, y, text, color_txt, color_bg, monitor)
    monitor.setBackgroundColor(color_bg)
    monitor.setTextColor(color_txt)
    monitor.setCursorPos(x,y)
    monitor.write(text)
    monitor.setCursorPos(1,1)
    monitor.setBackgroundColor(colors.black)
end

function drawLine(x, y, length, size, color_bar, monitor)
    for yPos = y, y+size-1 do
        monitor.setBackgroundColor(color_bar)
        monitor.setCursorPos(x, yPos)
        monitor.write(string.rep(" ", length))
        monitor.setBackgroundColor(colors.black)
    end
end

function drawProg(x, y, length, size, minVal, maxVal, color_bar, color_bg, monitor)
    drawLine(x, y, length, size, color_bg, monitor)
    local barSize = math.floor((minVal/maxVal)*length)
    drawLine(x, y, barSize, size, color_bar, monitor)
end

function drawContent(x, y, height, width, minVal, maxVal, color_bar, color_bg, monitor)
    drawGraph(x, y, height, width, color_bg, monitor)
    local a = math.floor((minVal/maxVal)*height)
    drawGraph(x, y, a, width, color_bar, monitor)
end

function drawGraph(x, y, height, width, color_bar, monitor)
    drawLine(x, y-height+1, width, height, color_bar, monitor)
end

function addButton(x,y,w,h,name,colorOn,colorOff,state,textOn,textOff,textX,textY,header)
    buttons[name] = {["x"] = x,["y"] = y,["width"] = w,["height"] = h,
                        ["colorOn"] = colorOn,["colorOff"] = colorOff,["state"] = state,
                        ["textOn"] = textOn,["textOff"] = textOff,
                        ["textX"] = textX,["textY"] = textY,["header"] = header}
end

function addButtons()
    for i=0,3 do
        addButton(2,6+i*4,13,3,"buttonPos"..i,colors.lime,colors.red,false,"TARGET","TARGET",3,7+i*4,"")
    end
    addButton(2,4,13,1,"buttonUP",colors.cyan,colors.lightGray,false,"     / \\","     / \\",2,4,"")
    addButton(2,22,13,1,"buttonDOWN",colors.cyan,colors.lightGray,true,"     \\ /","     \\ /",2,22,"")
end

function generateGUI(monitor)
    if currentApp == "keypad" then

        drawTitle(2, 2, 'Select Target', colors.white, colors.black, m)

        if targetCount-(displayOffset*4) >= 1 then
            buttons['buttonPos0'].textOn = destinations[1+(displayOffset*4)]['name']
            buttons['buttonPos0'].textOff = buttons['buttonPos0'].textOn
            if 1+(displayOffset*4) == activeButton then
                buttons['buttonPos0'].state = true
            else
                buttons['buttonPos0'].state = false
            end
            drawButton("buttonPos0",m)
        end
        if targetCount-(displayOffset*4) >= 2 then
            buttons['buttonPos1'].textOn = destinations[2+(displayOffset*4)]['name']
            buttons['buttonPos1'].textOff = buttons['buttonPos1'].textOn
            if 2+(displayOffset*4) == activeButton then
                buttons['buttonPos1'].state = true
            else
                buttons['buttonPos1'].state = false
            end
            drawButton("buttonPos1",m)
        end
        if targetCount-(displayOffset*4) >= 3 then
            buttons['buttonPos2'].textOn = destinations[3+(displayOffset*4)]['name']
            buttons['buttonPos2'].textOff = buttons['buttonPos2'].textOn
            if 3+(displayOffset*4) == activeButton then
                buttons['buttonPos2'].state = true
            else
                buttons['buttonPos2'].state = false
            end
            drawButton("buttonPos2",m)
        end
        if targetCount-(displayOffset*4) >= 4 then
            buttons['buttonPos3'].textOn = destinations[4+(displayOffset*4)]['name']
            buttons['buttonPos3'].textOff = buttons['buttonPos3'].textOn
            if 4+(displayOffset*4) == activeButton then
                buttons['buttonPos3'].state = true
            else
                buttons['buttonPos3'].state = false
            end
            drawButton("buttonPos3",m)
        end

        if displayOffset == 0 then
            buttons['buttonUP'].state = false
        else
            buttons['buttonUP'].state = true
        end
        if displayOffset + 4 == targetCount or targetCount < 4 then
            buttons['buttonDOWN'].state = false
        else
            buttons['buttonDOWN'].state = true
        end

        drawButton("buttonUP",m)
        drawButton("buttonDOWN",m)

    else error("App not found") end
end

function drawButton(button,monitor)
    local color = colors.red
    local text = ""
    if buttons[button].state==true then color = buttons[button].colorOn else color = buttons[button].colorOff end
    if buttons[button].state==true then text = buttons[button].textOn else text = buttons[button].textOff end
    drawLine(buttons[button].x, buttons[button].y, buttons[button].width, buttons[button].height, color, monitor)
    if buttons[button].header == "" then else
    drawTitle(buttons[button].x, buttons[button].y - 1, buttons[button].header, colors.white, colors.black, monitor) end
    drawTitle(buttons[button].textX, buttons[button].textY, text, colors.white, color, monitor)
end

function setupTargets()
    moveBook('out',0)
    destinations = listDestinations()
    targetCount = table.getn(destinations)
end

function touchAreas(x,y,side)
    if x >= buttons["buttonPos0"].x and x < buttons["buttonPos0"].x + buttons["buttonPos0"].width and
        y >= buttons["buttonPos0"].y and y < buttons["buttonPos0"].y + buttons["buttonPos0"].height then
            if buttons["buttonPos0"].textOn ~= "TARGET" then
                if activeButton == 0 then
                    if moveBook('in',1+(displayOffset*4)) then
                        activeButton = 1+(displayOffset*4)
                    end
                elseif activeButton == 1+(displayOffset*4) then
                    moveBook('out',1+(displayOffset*4))
                    activeButton = 0
                end
            end
    elseif x >= buttons["buttonPos1"].x and x < buttons["buttonPos1"].x + buttons["buttonPos1"].width and
        y >= buttons["buttonPos1"].y and y < buttons["buttonPos1"].y + buttons["buttonPos1"].height then
            if buttons["buttonPos1"].textOn ~= "TARGET" then
                if activeButton == 0 then
                    if moveBook('in',2+(displayOffset*4)) then
                        activeButton = 2+(displayOffset*4)
                    end
                elseif activeButton == 2+(displayOffset*4) then
                    moveBook('out',2+(displayOffset*4))
                    activeButton = 0
                end
            end
    elseif x >= buttons["buttonPos2"].x and x < buttons["buttonPos2"].x + buttons["buttonPos2"].width and
        y >= buttons["buttonPos2"].y and y < buttons["buttonPos2"].y + buttons["buttonPos2"].height then
            if buttons["buttonPos2"].textOn ~= "TARGET" then
                if activeButton == 0 then
                    if moveBook('in',3+(displayOffset*4)) then
                        activeButton = 3+(displayOffset*4)
                    end
                elseif activeButton == 3+(displayOffset*4) then
                    moveBook('out',3+(displayOffset*4))
                    activeButton = 0
                end
            end
    elseif x >= buttons["buttonPos3"].x and x < buttons["buttonPos3"].x + buttons["buttonPos3"].width and
        y >= buttons["buttonPos3"].y and y < buttons["buttonPos3"].y + buttons["buttonPos3"].height then
            if buttons["buttonPos3"].textOn ~= "TARGET" then
                if activeButton == 0 then
                    if moveBook('in',4+(displayOffset*4)) then
                        activeButton = 4+(displayOffset*4)
                    end
                elseif activeButton == 4+(displayOffset*4) then
                    moveBook('out',4+(displayOffset*4))
                    activeButton = 0
                end
            end
    elseif x >= buttons["buttonUP"].x and x < buttons["buttonUP"].x + buttons["buttonUP"].width and
        y >= buttons["buttonUP"].y and y < buttons["buttonUP"].y + buttons["buttonUP"].height then
            if displayOffset ~= 0 then displayOffset = displayOffset - 1 end
    elseif x >= buttons["buttonDOWN"].x and x < buttons["buttonDOWN"].x + buttons["buttonDOWN"].width and
        y >= buttons["buttonDOWN"].y and y < buttons["buttonDOWN"].y + buttons["buttonDOWN"].height then
            if 4 + displayOffset < targetCount then
                displayOffset = displayOffset + 1
            end
    else

    end
    clearAll()
end

function waitForInput()
    parallel.waitForAny(wait,getTouch)
end

function getTouch()
    event, side, xPos, yPos = os.pullEvent("monitor_touch")
    touchAreas(xPos, yPos, side)
end

function wait()
 sleep(1)
end

function init()
    clearAll()
    resizeMon()
    addButtons()
    clearAll()
    setupTargets()
    while true do
        generateGUI(m)
        waitForInput()
        clearAll()
    end
end

init()