Todo list (ComputerCraft)

--[[    Written by NickM13
    Todo list for ComputerCraft terminal glasses

    Command list:
    $$add       [New TODO Item]
    $$finish    [Item ID(1-9)]
    $$clear     [Page(1-9) or nothing for current page]
    $$title     [New Page Title]
    $$delete    [Item ID(1-9)]
    $$page      [Page ID(1-9)]
--]]



local termbridge = nil

local ip = {}

local list = {}
for i=1, 9 do
    list[i] = {}
    for j=1, 10 do
        list[i][j] = ""
    end
    list[i][10] = "Todo List"
end

local itemcount = {}
for i=1, 9 do
    itemcount[i] = 0
end

local page = 1

todoitemfile = "list"

local function loadList()
    local loadingpage = 0
    if fs.exists(todoitemfile) then
        file = fs.open(todoitemfile, "r")
        for i=1, 9 do
            itemcount[i] = 0
            for j=1, 10 do
                list[i][j] = file.readLine()

                if list[i][j] ~= "" and j ~= 10 then
                    itemcount[i] = itemcount[i] + 1
                end
            end
        end
        file.close()
    end
end

local function saveList()
    file = fs.open(todoitemfile, "w")
    for i=1, 9 do
        for j=1, 10 do
            file.writeLine(list[i][j])
        end
    end
    file.close()
end

local function input()
    ip[1], ip[2], ip[3], ip[4], ip[5] = os.pullEvent()
    if (ip[1] == "glasses_chat_command") then
        return true
    end
    return false
end

local function update()
    if ip[5] ~= nil then
        if string.sub(ip[5], 1, 3) == "add" then
            if itemcount[page] < 9 and string.len(ip[5]) > 4 then
                itemcount[page] = itemcount[page] + 1
                list[page][itemcount[page]] = string.sub(ip[5], 5)
                print("Added item: "..string.sub(ip[5], 5))
            end
        elseif string.sub(ip[5], 1, 6) == "finish" then
            if tonumber(string.sub(ip[5], 8, 8)) ~= nil then
                finitem = tonumber(string.sub(ip[5], 8, 8))
                if itemcount[page] > 0 then
                    if finitem > 0 then
                        list[page][finitem] = list[page][finitem] .. " - [Done]"
                    end
                end
            end
            print("Item finished: "..string.sub(ip[5], 8, 8))
        elseif string.sub(ip[5], 1, 5) == "clear" then
            if string.len(ip[5]) < 7 then
                print("clearing page "..page)
                for i=1, itemcount[page] do
                    list[page][i] = ""
                end
                itemcount[page] = 0
                print("Page cleared: "..page)
            elseif tonumber(string.sub(ip[5], 7, 7)) ~= nil then
                pagetoclear = tonumber(string.sub(ip[5], 7, 7))
                if pagetoclear >= 1 and pagetoclear <= 5 then
                    print("clearing page "..string.sub(ip[5], 7, 7))
                    for i=1, itemcount[pagetoclear] do
                        list[pagetoclear][i] = ""
                    end
                    itemcount[pagetoclear] = 0
                    print("Page cleared: "..pagetoclear)
                end
            end
        elseif string.sub(ip[5], 1, 5) == "title" then
            if string.len(ip[5]) > 6 then
                list[page][10] = string.sub(ip[5], 7)
                print("Page "..page.." title set to "..string.sub(ip[5], 7))
            end
        elseif string.sub(ip[5], 1, 6) == "delete" then
            if string.len(ip[5]) >= 8 then
                alter = tonumber(string.sub(ip[5], 8, 8))
                if alter >= 1 and alter <= itemcount[page] then
                    list[page][alter] = ""
                    for i=alter, itemcount[page]-1 do
                        list[page][i] = list[page][i+1]
                    end
                    list[page][itemcount[page]] = ""
                    itemcount[page] = itemcount[page] - 1
                    print("Todo item deleted: "..alter)
                end
            end
        elseif string.sub(ip[5], 1, 4) == "page" then
            if string.len(ip[5]) >= 6 then
                newpage = tonumber(string.sub(ip[5], 6, 6))
                if newpage >= 1 and newpage <= 9 then
                    page = newpage
                    print("Paged turned to: "..page)
                end
            end
        elseif ip[5] == "Destroy bad todo list" then
            rs.setOutput("bottom", true)
        else
            if string.len(ip[5]) > 0 and itemcount[page] < 9 then
                itemcount[page] = itemcount[page] + 1
                list[page][itemcount[page]] = ip[5]
                print("New item: "..ip[5])
            end
        end
    end
end

local function render()
    termbridge.clear()

    termbridge.addBox(5, 5, 305, itemcount[page] * 8 + 11, 0x000000, 0.5)
    termbridge.addText(8, 7, list[page][10].." ("..page..")", 0xFFFFFF)
    if itemcount[page] ~= 0 then
        for i=1, itemcount[page] do
            termbridge.addText(8, i * 8 + 8, i..": "..list[page][i], 0xFFFFFF)
        end
    end

    termbridge.sync()
end

local function mainLoop()
    loadList()
    render()

    while true do
        if input() then
            update()
            render()
            saveList()
        end
    end
end

local function findBridge()
    for i,v in pairs(peripheral.getNames()) do
        if (peripheral.getType(v) == "openperipheral_bridge") then
            termbridge = peripheral.wrap(v)
            return true
        end
    end
    return false
end

if findBridge() then
    mainLoop()
else print("no connected terminal bridge") end