PlatformController - Installer

local w, h = term.getSize()

local function SettingParam(id, name, default, parser, validator)
    return {
        id = id,
        name = name,
        default = default,
        type = type(default),
        parser = parser,
        validator = validator
    }
end

local function ModuleReq(name, code, target)
    return {
        name = name,
        code = code,
        target = target
    }
end

local pastebinCode = 'ATgPXEFH'
local programName = 'Train Platform Controller'

local modules = {
    ModuleReq('Util Library', 'fE5Cb2WN', 'utils.lua')
}

local settingFields = {
    SettingParam(
        'train_direction',
        'Travel Direction',
        'NB',
        function(v) return v end,
        function (v)
            return (
                v == 'NB' or
                v == 'SB' or
                v == 'WB' or
                v == 'EB'
            )
        end
    )
}

local function getInput(prefix, parser)
    term.write(('%s> '):format(prefix))
    term.setTextColor(colors.yellow)
    local input = parser(read())
    term.setTextColor(colors.white)

    return input
end

-- Get the starting x value to perfectly center the provided string.
local function getHorizontalAlignment(value)
    return ((w / 2) - (string.len(value) / 2)) + 1
end

-- Build a header divider to write to the terminal.
local function buildDivider(length)
    local divider = ''

    for i = 1, (length + 2) do
        divider = divider .. (i % 2 == 0 and '-' or '=')
    end

    return divider
end

-- Write the header to the terminal at the current y-level.
local function writeHeader(title, titleColor, subtitle, subtitleColor, includeDividers)
    if not titleColor then titleColor = colors.white end
    if not subtitleColor then subtitleColor = colors.lightGray end

    local x, y = term.getCursorPos()
    local increment = 0
    local length = string.len(subtitle) > string.len(title) and string.len(subtitle) or string.len(title)

    -- Write the first divider if enabled
    if includeDividers then
        term.setCursorPos(getHorizontalAlignment(buildDivider(length)), y + increment)
        term.setTextColor(colors.white)
        term.write(buildDivider(length))
        increment = increment + 1
    end

    -- Write the title
    term.setCursorPos(getHorizontalAlignment(title), y + increment)
    term.setTextColor(titleColor)
    term.write(title)
    term.setTextColor(colors.white)
    increment = increment + 1

    -- Write the subtitle, if enabled.
    if subtitle then
        term.setCursorPos(getHorizontalAlignment(subtitle), y + increment)
        term.setTextColor(subtitleColor)
        term.write(subtitle)
        term.setTextColor(colors.white)

        if includeDividers then
            increment = increment + 1
        else
            increment = increment + 2
        end
    end

    -- Write the second divider if enabled
    if includeDividers then
        term.setCursorPos(getHorizontalAlignment(buildDivider(length)), y + increment)
        term.setTextColor(colors.white)
        term.write(buildDivider(length))
        increment = increment + 2
    end

    term.setCursorPos(1, y + increment)
end

local function resetTerminal()
    term.clear()
    term.setCursorPos(1, 1)

    writeHeader('Software Installer', colors.white, programName, colors.lightGray, true)
end

for i, setting in ipairs(settingFields) do
    settings.define(setting.id, {
        default = setting.default,
        type = setting.type
    });

    local isValid = false
    repeat
        resetTerminal()

        local v = getInput(setting.name, setting.parser)
        if setting.validator(v) then
            settings.set(setting.id, v)
            isValid = true
        end
    until isValid

    settings.save()
end

if #modules > 0 then
    for i = 1, #modules do
        print(('Downloading required module: %s'):format(modules[i].name))
        shell.run('pastebin', 'get', modules[i].code, modules[i].target)
    end
end

print(('Required settings configured. Installing %s software.'):format(programName))
shell.run('pastebin', 'get', pastebinCode, 'startup.lua')

print(('%s software installed successfully. Rebooting...'):format(programName))
sleep(3)

os.reboot()