rprints

-- RPrint Server by Tiin57
local requiredConfigValues = {"modemSide", "printerSide", "authUsername", "authPassword"}
function string.split(inputstr, sep) -- Taken from http://stackoverflow.com/questions/1426954/split-string-in-lua
    if sep == nil then
        sep = "%s"
    end
    local t = {}
    local i = 1
    for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
        t[i] = str
        i = i + 1
    end
    return t
end
local function createConfig()
    local defaultValues = {
        modemSide = "top",
        printerSide = "right",
        authUsername = "default",
        authPassword = ""
    }
    local text = ""
    for key, value in pairs(defaultValues) do
        text = text .. key .. "=" .. tostring(value) .. "\n"
    end
    local file = fs.open("rprint/server.cfg", "w")
    file.write(text)
    file.close()
end
local function parseConfig()
    local file = fs.open("rprint/server.cfg", "r")
    local lines = string.split(file.readAll(), "\n")
    file.close()
    local config = {}
    for k, line in pairs(lines) do
        local tokens = string.split(line, "=")
        config[tokens[1]] = tokens[2]
    end
    return config
end
local function validateConfig(config)
    for _, key in pairs(requiredConfigValues) do
        if config[key] == nil then
            return key
        end
    end
    return false
end
local function splitByInterval(str, interval)
    local tbl = {}
    local iterator = 1
    for i=1, string.len(str) do
        if (i % interval) == 1 then
            iterator = iterator + 1
            tbl[iterator] = ""
        end
        tbl[iterator] = tbl[iterator] .. string.sub(str, i, i)
    end
    return tbl
end
local function beginPrint(config, id, title, body)
    sleep(0.5)
    if peripheral.getType(config.printerSide) ~= "printer" then
        rednet.send(id, "error:noprinter", "rprint")
        return
    end
    local printer = peripheral.wrap(config.printerSide)
    if printer.getInkLevel() == 0 or printer.getPaperLevel() == 0 then
        rednet.send(id, "error:noresources", "rprint")
        return
    end
    local key = tostring(math.random())
    local height = 1
    local pageCount = 1
    local lines = string.split(body, "\n")
    printer.newPage()
    local pageWidth = ({printer.getPageSize()})[1]
    local pageHeight = ({printer.getPageSize()})[2]
    local totalPageCount = math.ceil((#lines) / pageHeight)
    if printer.getPaperLevel() < totalPageCount then
        rednet.send(id, "error:morepaper", "rprint")
        printer.endPage()
        return
    end
    printer.setPageTitle(title .. " " .. pageCount .. "/" .. totalPageCount)
    for key, line in pairs(lines) do
        if height >= pageHeight then
            printer.endPage()
            printer.newPage()
            printer.setPageTitle(title .. " " .. pageCount .. "/" .. totalPageCount)
            height = 1
            pageCount = pageCount + 1
        end
        line = string.gsub(line, "\t", "")
        printer.write(line)
        local currentPos = {printer.getCursorPos()}
        printer.setCursorPos(1, currentPos[2] + 1)
        height = height + 1
    end
    printer.endPage()
    rednet.send(id, "success:" .. key, "rprint")
end
local function startServer(config)
    if peripheral.getType(config.modemSide) ~= "modem" then
        print("A modem is not connected on the " .. config.modemSide .. " side!")
        return
    end
    rednet.open(config.modemSide)
    local authedIDs = {}
    while true do
        local id, message = rednet.receive("rprint")
        sleep(0.5)
        local tokens = string.split(message, ":")
        local header = tokens[1]
        table.remove(tokens, 1)
        local body = table.concat(tokens, ":")
        if header == "auth" then
            if authedIDs[id] then
                rednet.send(id, "auth:true", "rprint")
            else
                body = string.split(body, ",")
                if #body >= 2 then
                    local username = body[1]
                    local password = body[2]
                    if username == config.authUsername and password == config.authPassword then
                        authedIDs[id] = true
                        rednet.send(id, "auth:true", "rprint")
                    else
                        rednet.send(id, "auth:false", "rprint")
                    end
                else
                    rednet.send(id, "auth:false", "rprint")
                end
            end
        elseif header == "print" then
            if not authedIDs[id] then
                rednet.send(id, "auth:false", "rprint")
            else
                tokens = string.split(body, "@")
                local title = tokens[1]
                table.remove(tokens, 1)
                body = table.concat(tokens, "@")
                beginPrint(config, id, title, body)
            end
        end
    end
end
local function main()
    if fs.exists("rprint") and not fs.isDir("rprint") then
        fs.delete("rprint")
    end
    if not fs.exists("rprint") then
        fs.makeDir("rprint")
    end
    if not fs.exists("rprint/server.cfg") then
        createConfig()
    end
    local config = parseConfig()
    local missingKey = validateConfig(config)
    if missingKey then
        print("rprint/server.cfg is missing required key " .. missingKey)
        return
    end
    startServer(config)
end
main()