program menu

--[[Settings]]--
--true for blacklist mode, programs table is the blacklist
--false for whitelist mode, programs table is whitelist
local blacklistMode = true
local programs = {}
local selector = {"[", "]"}

--[[Variables & peripherals]]--
local width, height = term.getSize()
local list = {}
if blacklistMode then
    for i, name in pairs(fs.list("/")) do
        if not fs.isDir(name) then
            allowed = true
            for j, black in pairs(programs) do
                if black == name then
                    allowed = false
                end
            end
            if allowed then
                table.insert(list, name)
            end
        end
    end
else
    list = programs
end

--[[Functions]]--
local function round(number)
    return math.floor(number + .5)
end

local function spaces(number)
        for i = 1, number do
                write(" ")
        end
end

local function menu(list, selector)
        local selector = selector or {"[", "]"}
        local longestItem = 0
        local width, height = term.getSize()
        for i, item in pairs(list) do
                if #item > longestItem then
                        longestItem = #item
                end
        end
        local selected = 1
        local startX = round((width / 2) - (longestItem / 2)) - 2
        local startY = round((height / 2) - (#list / 2))
        for i, j in pairs(list) do
                if #j > longestItem then
                        longestItem = #j
                end
        end
        local running = true
        while running do
                curX = startX
                curY = startY
                for i, item in pairs(list) do
                        term.setCursorPos(curX, curY)
                        if i == selected then
                                write(selector[1].." "..item)
                                spaces(longestItem - #item + 1)
                                write(selector[2])
                        else
                                spaces(2)
                                write(item)
                                spaces(longestItem - #item + 2)
                        end
                        curY = curY + 1
                end
                event, key = os.pullEvent("key")
                if key == keys.up and selected > 1 then
                        selected =  selected - 1
                elseif key == keys.down and selected < #list then
                        selected =  selected + 1
                elseif key == keys.enter then
                        return list[selected]
                elseif key == keys.q then
                        return "quit"
                end
        end
end

local function centerPrint(text, y)
    local width, height = term.getSize()
    term.setCursorPos(round(( width / 2 ) - ( #text / 2 )), y)
    print(text)
end


--[[Main program]]--
shell.run("clear")
centerPrint("Which program do you want to run?", 2)
local option = menu(list, selector)
shell.run("clear")
shell.run(option)