Menu Library (2023/07/23)

version = 20230723.1200
--[[
    Last edited: see version YYYYMMDD.HHMM
    This is meant to be used as a library for any of your programs.
    Save it as menu.lua preferably in a subfolder called 'lib'
    To use it:
    local menu = require("lib.menu")

    local prompt = "Choose your option:"
    -- table of options, whatever text you like from 1 to 10 for turtles, 1 to 16 for computers
    local options = {"First choice", "Second choice", "Third choice", "Fourth choice", "Fifth choice",
                    "Sixth choice","Seventh choice", "Eighth choice", "Ninth choice", "Tenth choice"}
    local choice = menu.new(prompt, options) OR local choice = menu.menu(prompt, options)
    if choice == nil then
        print ("You chose to cancel the menu")
    else
        print("You chose option no "..choice..": "..options[choice])
    end

    menu.clear()
    local line, test, age = 1, "", 0, 0
    test, line = menu.getString("Type your name", true, 2, 10, line, colors.green, colors.black)
    line = line + 1
    age, line = menu.getInteger("Type your age", 5, 99, line, colors.black, colors.green)
    line = line + 1
]]
local menuPrompt = "Type number (q to quit) + Enter "
local width, height  = term.getSize()
local blank = (" "):rep(width)
local delay = 2
local sep   = "~"
local lib = {}

function lib.clear()
    -- clear the terminal and reset cursor
    term.clear()
    term.setCursorPos(1, 1)
end

function lib.clearInputField(row)
    --[[ use setCursorPos to delete a line of text ]]
    local cols, rows = term.getSize()
    term.setCursorPos(1, row)
    print(blank)                    -- module variable
    if rows - row > 1 then
        term.setCursorPos(1, row + 1)   -- next line in case overflow
        print(blank)
    end
    term.setCursorPos(1, row)       -- reset
end

function lib.formatPrompt(prompt)
    if prompt:endsWith(" ") then
        return prompt
    end

    return prompt.." "
end

function lib.padLeft(text, length, char)
    --[[Pads str to length len with char from left]]
    if char == nil then char = ' ' end
    local padding = ''
    for i = 1, length - #text do
        padding = padding..char
    end
    return padding..text
end

function lib.padRight(text, length, char)
    --[[
    Pads string to length len with chars from right
    test = lib.padRight("test", 10, "+") -> "test++++++"]]
    char = char or " "
    --if char == nil then char = ' ' end
    local padding = ''
    for i = 1, length - #text do
        padding = padding..char
    end
    return text..padding
end

function lib.resetColors()
    if term.isColor() then
        term.setTextColor(colors.white)
        term.setBackgroundColor(colors.black)
    end
end

function lib.trim(text)
    --[[ trim leading and trailing spaces ]]
    return (text:gsub("^%s*(.-)%s*$", "%1"))
end

function lib.print(text, fg, bg, width)
    local cols, rows = term.getSize()
    width = width or cols
    if width == 0 then width = cols end
    if width > cols then width = cols end
    local currentbg = colors.black
    local currentfg = colors.white
    if term.isColor() then
        fg = fg or term.getTextColor()
        bg = bg or term.getBackgroundColor()
        currentbg = term.getBackgroundColor()
        currentfg = term.getTextColor()
        term.setTextColor(fg)
        term.setBackgroundColor(bg)
    end
    print(lib.padRight(text, width, " "))
    if term.isColor() then
        term.setTextColor(currentfg)
        term.setBackgroundColor(currentbg)
    end
end

function lib.enterToContinue(prompt, fg, bg)
    prompt = prompt or "Enter to continue "
    term.setCursorPos(1, height)
    lib.write(prompt, fg , bg, nil, true)
    read()
end

function lib.write(text, fg, bg, width, isInput, cr)
    cr = cr or false
    local cols, rows = term.getSize()
    isInput = isInput or false
    width = width or cols
    if width == 0 then width = cols end
    if width > cols then width = cols end
    local currentbg = colors.black
    local currentfg = colors.white
    if term.isColor() then
        fg = fg or term.getTextColor()
        bg = bg or term.getBackgroundColor()
        currentbg = term.getBackgroundColor()
        currentfg = term.getTextColor()
        term.setTextColor(fg)
        term.setBackgroundColor(bg)
    end
    write(lib.padRight(text, width, " "))
    if term.isColor() then
        term.setTextColor(currentfg)
        term.setBackgroundColor(currentbg)
    end
    local _, row = term.getCursorPos()
    if isInput then
        term.setCursorPos(#text + 1, row)
    end
    if cr then
        term.setCursorPos(1, row)
    end
end

local function clear()
    lib.clear()
    return 1, 1
end

function string:count(c)
    --[[ count number of occurences of c ]]
    local _,n = self:gsub(c,"")
    return n
end

function string:endsWith(ending)
    --[[ get ending character of a string ]]
    return ending == "" or self:sub(-#ending) == ending
end

function string:split(sSeparator, nMax, bRegexp, noEmpty)
    --[[return a table split with sSeparator. noEmpty removes empty elements
        use: tblSplit = SplitTest:split('~',[nil], [nil], false) or tblSplit = string.split(SplitTest, '~')]]
    assert(sSeparator ~= '','separator must not be empty string')
    assert(nMax == nil or nMax >= 1, 'nMax must be >= 1 and not nil')
    if noEmpty == nil then noEmpty = true end

    local aRecord = {}
    local newRecord = {}
    -- self refers to the 'string' being split
    if self:len() > 0 then
        local bPlain = not bRegexp
        nMax = nMax or -1

        local nField, nStart = 1, 1
        local nFirst,nLast = self:find(sSeparator, nStart, bPlain)
        while nFirst and nMax ~= 0 do
            aRecord[nField] = self:sub(nStart, nFirst-1)
            nField = nField+1
            nStart = nLast+1
            nFirst,nLast = self:find(sSeparator, nStart, bPlain)
            nMax = nMax-1
        end
        aRecord[nField] = self:sub(nStart)

        if noEmpty then --split on newline preserves empty values
            for i = 1, #aRecord do
                if aRecord[i] ~= "" then
                    table.insert(newRecord, aRecord[i])
                end
            end
        else
            newRecord = aRecord
        end
    end

    return newRecord
end

local function colourText(row, text, reset)
    --[[
        This uses the default char ~ to separate colour strings
        change the line:  sep = "~" as required
        other possibles are ` (backtick) ¬ (NOT) or any character you will not use in text
        example text = "~red~This is a line of red text"
    ]]
    row = row or 1
    term.setCursorPos(1, row)
    local newline = false
    if reset == nil then reset = true end
    row = row + text:count('\n')        -- account for embedded newline characters
    if text:find(sep) ~= nil then                   -- text has colour tags in it eg  hello ~red~world
        local lineParts = text:split(sep)
        for i = 1, #lineParts do
            part = lineParts[i]
            if colors[part]~= nil then      -- is 'red' in the colors dictionary?
                -- change the TextColour
                if term.isColor() then
                    term.setTextColor(colors[part])
                end
            else                                    -- not a colour command so print it out without newline
                write(part) -- NOT term.write as this does not use \n
            end
        end
        if reset and term.isColor() then
            term.setTextColor(colors.white)
        end
    else -- no colour tags in the text
        write(text)
        if not text:endsWith("\n") then
            newline = true
        end
    end
    if newline then
        write("\n")    -- Add newline to complete the print command
        row = row + 1
    end

    return row
end

local function errorMessage(row, errorType, userInput, minValue, maxValue)
    --local function drawError(prompt, options, width, height, errorNo, currentLine)
    --[[ Display error message to the user for <delay> seconds ]]
    minValue = minValue or 0
    maxValue = maxValue or 0
    local message = "Just Enter or spacebar doesn't work" -- default for "noinput"
    if errorType == "string" then
        message = "Text length -> "..minValue.." to "..maxValue.." characters"
    elseif errorType == "bool" then
        message = "Answer must start with y or n"
    elseif errorType == "nan" then
        message = "Enter a number "..userInput.." -> ?"
    elseif errorType == "notint" then
        message = "Enter a whole number only"
    elseif errorType == "range" then
        message = "Enter number from "..minValue.." to "..maxValue
    elseif errorType == "modifier" then
        message = "Number "..minValue.." to "..maxValue.." with 'h' or 'i' eg 3h"
    end

    lib.clearInputField(row)        -- clear row just used
    lib.write(message, colors.white, colors.red, width, false)
    sleep(delay)
    lib.clearInputField(row)
end

local function processInput(prompt, minValue, maxValue, dataType, row, fg, bg, default)
    --[[ validate input, raise error messages until input is valid ]]
    minValue = minValue or 0
    maxValue = maxValue or 1000000000
    dataType = dataType or "string"
    fg       = fg or colors.white
    bg       = bg or colors.black
    local col, line = term.getCursorPos()
    row = row or line
    local startRow = row
    local validInput = false
    local userInput
    if type(prompt) == "table" then
        assert(type(fg)  == "table", "Prompt is a table. Matching number of fg colours required")
    end
    while not validInput do
        for i = startRow, row do
            lib.clearInputField(row)
        end
        lib.clearInputField(row)
        if type(prompt) == "table" then
            row = startRow
            term.setCursorPos(1, row)
            for i = 1, #prompt do
                if i < #prompt then
                    lib.print(prompt[i], fg[i], bg)
                    row = row + 1
                else -- last line of multi-line prompt
                    prompt[i] = lib.formatPrompt(prompt[i])
                    lib.write(prompt[i], fg[i], bg, 0, true)
                end
            end
        else
            prompt = lib.formatPrompt(prompt)
            lib.write(prompt, fg, bg, width, true)
        end
        --lib.write(prompt..">", fg, bg, width, true)
        userInput = read():trim()
        local output = userInput
        if dataType == "string" then
            if userInput:len() == 0 and minValue > 0 then
                if default ~= nil then
                    return default, row
                else
                    errorMessage(row, "noinput", output, minValue, maxValue)
                end
            else
                if userInput:len() < minValue or userInput:len() > maxValue then
                    errorMessage(row, "string", output, minValue, maxValue)
                else
                    validInput = true
                end
            end
        else
            if userInput:len() == 0 then
                if default ~= nil then
                    return default, row
                else
                    errorMessage(row, "noinput", output, minValue, maxValue)
                end
            else
                if dataType == "bool" then
                    if userInput:sub(1, 1):lower() == "y" then
                        userInput = true
                        validInput = true
                    elseif userInput:sub(1, 1):lower() == "n" then
                        userInput = false
                        validInput = true
                    else
                        errorMessage(row, "bool", output, minValue, maxValue)
                    end
                else
                    if dataType == "int" or dataType == "float" then
                        userInput = tonumber(userInput)
                    end
                    if userInput == nil then
                        errorMessage(row, "nan", output, minValue, maxValue)
                    else
                        if userInput >= minValue and userInput <= maxValue then
                            if math.floor(userInput / 1) ~= userInput and dataType == "int"  then
                                errorMessage(row, "notint", output, minValue, maxValue)
                            else
                                validInput = true
                            end
                        else
                            errorMessage(row, "range", output, minValue, maxValue)
                        end
                    end
                end
            end
        end
    end
    return userInput, row
end

local function drawMenu(prompt, options, width, height, pp, altMenuPrompt)
    local mPrompt = menuPrompt -- assign local variable to global value
    if altMenuPrompt ~= nil then
        mPrompt = lib.formatPrompt(altMenuPrompt) -- use different prompt
    else
        if not pp.allowModifier then
            mPrompt = "Type number + Enter "
        end
    end
    local numOptions = #options
    if numOptions > height - 3 then
        numOptions = height - 3
    end
    lib.clear()
    lib.print(prompt, pp.prompt, colors.black, width)
    for i = 1, numOptions do
        local trimOption = string.sub(options[i], 1, width - 5)
        if i < 10 then
            lib.print("\t"..i..") ".."\t"..trimOption, pp.itemColours[i], colors.black, width)
        else
            lib.print("\t"..i..") "..trimOption, pp.itemColours[i], colors.black, width)
        end
    end
    lib.write(mPrompt, pp.menuPrompt, colors.black, width, true)
    lib.resetColors()

    return term.getCursorPos()
end

local function menu(prompt, options, pp, altMenuPrompt)
    --turtle   terminal size = 39 x 13 -- max menu options = 10, max option length = 34
    --computer terminal size = 51 x 19 -- max menu options = 16, max option length = 47
    --local width, height = term.getSize()
    local errorType = ""
    local choice = nil
    local modifier = ""
    local numOptions = #options
    if pp == nil then -- no prettyprint table supplied
        pp = {}
        pp.prompt = colors.green
        pp.itemColours = {}
        for i = 1, numOptions do
            table.insert(pp.itemColours, colors.white)
        end
        pp.menuPrompt = colors.yellow
        pp.allowModifier = false
    else
        assert(#options == #pp.itemColours, "Menu options (".. #options..") pp.itemColours (".. #pp.itemColours..") do not match")
    end
    prompt = lib.formatPrompt(prompt)
    while choice == nil and modifier == "" do
        local col, row = drawMenu(prompt, options, width, height, pp, altMenuPrompt)
        local isValid, isModifierValid, isNumberValid = false, false, false
        term.setCursorPos(col, row)
        if errorType ~= "" then
            errorMessage(row, errorType, choice, 1, #options)
            --lib.write(menuPrompt, pp.menuPrompt, colors.black, width, true)
            col, row = drawMenu(prompt, options, width, height, pp)
        end
        choice = read()
        if choice == "" then -- enter only
            errorType = "noinput"
            choice = nil
        else
            local test = tonumber(choice)
            if test == nil then -- may have 3h 5i 2help etc
                if pp.allowModifier then
                    if choice:lower():find("q") ~= nil then -- q(uit) entered
                        return nil, "q" -- quit chosen
                    elseif choice:lower():find("h") ~= nil then --h(elp)
                        modifier = "h"          -- help chosen
                        isModifierValid = true
                        choice = tonumber(choice:sub(1, #choice - 1))
                        if choice ~= nil then
                            isNumberValid = true
                        end
                    elseif choice:lower():find("i") ~= nil then
                        modifier = "i"          -- i(nventory) chosen
                        isModifierValid = true
                        choice = tonumber(choice:sub(1, #choice - 1))
                        if choice ~= nil then
                            isNumberValid = true
                        end
                    end
                else
                    errorType = "nan"
                    choice = nil
                end
            else -- user entered a number only
                choice = tonumber(choice)
                isNumberValid = true
            end
            if isNumberValid then -- number only or extracted number + modifier
                if math.floor(choice / 1) ~= choice then
                    errorType = "notint" -- integer only
                    choice = nil
                    modifier = ""
                elseif choice < 1 or choice > #options then
                    errorType = "range"
                    choice = nil
                    modifier = ""
                end
            else
                errorType = "modifier" -- number missing
                choice = nil
                modifier = ""
            end
        end
    end
    lib.clear()
    return choice, modifier -- nil, "q" = quit | #, "h" = help needed for that choice | #, "" number chosen
end

local function tchelper(first, rest)
    return first:upper()..rest:lower()
end

local function toTitle(inputText) --converts any string to Title Case
    return inputText:gsub("(%a)([%w_']*)", tchelper)
end

local function getBool(prompt, row, fg, bg, default)
    --[[ Return a boolean. Based on y(es)/ n(o) response ]]
    return processInput(prompt, 1, 3, "bool", row, fg, bg, default)
end

local function getFloat(prompt, minVal, maxVal, row, fg, bg, default)
    return getNumber(prompt, minVal, maxVal, row, fg, bg, default)
end

local function getInteger(prompt, minValue, maxValue, row, fg, bg, default)
    --[[ Return an integer. minValue and maxValue are given defaults if not passed ]]
    minValue = minValue or 0
    maxValue = maxValue or 65536

    return processInput(prompt, minValue, maxValue, "int", row, fg, bg, default) -- userInput, row
end

local function getNumber(prompt, minValue, maxValue, row, fg, bg, default)
    --[[ Return a real number. minValue and maxValue are given defaults if not passed ]]
    minValue = minValue or -1000000000
    maxValue = maxValue or  1000000000

    return processInput(prompt, minValue, maxValue, "float", row, fg, bg, default)
end

local function getString(prompt, withTitle, minValue, maxValue, row, fg, bg, default)
--[[ Return a string. withTitle, minValue and maxValue are given defaults if not passed ]]
    withTitle = withTitle or false
    minInt = minInt or 1
    maxInt = maxInt or 20

    local userInput, row = processInput(prompt, minValue, maxValue, "string", row, fg, bg, default)
    if withTitle then
        userInput = toTitle(userInput)
    end

    return userInput, row
end

string.trim = lib.trim
string.padRight = lib.padRight      -- if using as library: string.PadRight = Xconsole.PadRight
string.padLeft  = lib.padLeft       -- if using as library: string.PadLeft = Xconsole.PadLeft

return
{
    clear = clear,              -- clear terminal, return 1,1
    menu = menu,                -- call menu function
    new = menu,                 -- call menu function using new()
    getBool = getBool,          -- call getBool function
    getBoolean = getBool,       -- call getBool function using getBoolean()
    getNumber = getNumber,      -- call getNumber function
    getFloat = getNumber,       -- call getNumber function using getFloat()
    getInteger = getInteger,    -- call getInteger function
    getString = getString,      -- call getString function
    colourPrint = lib.print,    -- call lib.print function (print using specified colours)
    colorPrint = lib.print,     -- call lib.print function (print using specified colours) using colorPrint()
    colourWrite = lib.write,    -- call lib.write function (write using specified colours)
    colorWrite = lib.write,     -- call lib.write function (write using specified colours) using colorWrite()
    colourText = colourText,    -- call colourText function (print text with embedded colour strings)
    colorText = colourText,     -- call colourText function (print text with embedded colour strings) using colorText()
    enterToContinue = lib.enterToContinue, -- calls lib.enterToContinue to request user input
    padLeft = lib.padLeft,      -- call lib.padLeft
    padRight = lib.padRight     -- call lib.padRight
}