Kensington To-Do

local m = peripheral.wrap("left")
m.clear()
term.clear()
local list = {}
local numEntries = 0
local endLoop2 = false

-- read list from file
local endLoop = false
local file = fs.open("list.txt", "r")
local j = 0
local lines = {}
if file ~= nil then
    local line = file.readLine()
    while line ~= "end" do
    list[j] = line
    j = j + 1
    line = file.readLine()
    print("Reading " .. line)
    numEntries = numEntries + 1
    end
end
file.close()

-- update the monitor
    m.setCursorPos(26,2)
    m.setTextColor(colors.lime)
    m.write("NOTICEBOARD")
    m.setCursorPos(26, 3)
    m.write("-----------")

local k = 0
while k < numEntries do
    m.setCursorPos(2,4+k)
    m.setTextColor(colors.white)
    m.write(tostring(k+1) .. " - " .. list[k])
    k = k + 1
end

-- main loop
local input
while not endLoop2 do
    term.setCursorPos(1,1)
    term.write("1 : Add an entry")
    term.setCursorPos(1,2)
    term.write("2 : Delete an entry")
    term.setCursorPos(1,3)
    term.write("3 : Clear the list")
    term.setCursorPos(1,4)
    term.write("4 : Print the list")
    term.setCursorPos(1, 5)
    term.write("5 : Exit")

    term.setCursorPos(1, 7)
        term.write("Enter a command: ")
    input = read()
    m.clear()
    term.clear()
    term.setCursorPos(1,8)

    if input == "1" then
        -- add an entry
        term.write("Enter the new item: ")
        input = read()
        term.setCursorPos(1, 9)
        term.write("Adding: " .. input)
        list[numEntries] = input
        numEntries = numEntries + 1
        term.setCursorPos(1, 10)
        term.write("There are now " .. tostring(numEntries) .. " entries.")

        -- update file --
        local file = fs.open("list.txt", "w")
        local i = 0
        while i < numEntries do
            file.writeLine(list[i])
        i = i + 1
        end
        file.writeLine("end")
        file.close()
        -- update file --

    elseif input == "2" then
        -- delete an entry
        term.write("Enter the number of the item to remove: ")
        input = tonumber(read())
        i = input - 1
        numEntries = numEntries - 1
        print("\nRemoving " .. list[i])
        while i < numEntries do
            list[i] = list[i+1]
            i = i + 1
        end
        list[i] = nil

    -- update file --
        local file = fs.open("list.txt", "w")
        local i = 0
        while i < numEntries do
            file.writeLine(list[i])
        i = i + 1
        end
        file.writeLine("end")
        file.close()
        -- update file --

    elseif input == "3" then
        -- clear the list
        term.write("Clearing list.")
    while 0 < numEntries do
        list[0] = nil
        numEntries = numEntries - 1
    end
    local file = fs.open("list.txt", "w")
    file.writeLine("end")
    file.close()

    elseif input == "4" then
        -- print the list
        term.clear()
        term.setCursorPos(1,1)
        local i = 0
        while i < numEntries do
            print(list[i])
            i = i + 1
        end

    elseif input == "5" then
        -- exit
        endLoop2 = true
    term.write("Exiting program.")
    else
        -- invalid input
        term.write("Invalid entry.")
    end

    -- update the monitor
    m.setCursorPos(26,2)
    m.setTextColor(colors.lime)
    m.write("NOTICEBOARD")
    m.setCursorPos(26, 3)
    m.write("-----------")

    local i = 0
    while i < numEntries do
        m.setCursorPos(2,4+i)
        m.setTextColor(colors.white)
        m.write(tostring(i+1) .. " - " .. list[i])
        i = i + 1
    end

    os.sleep(3)
end