Receipt API

--[[Shop Receipt API

Sylvyrfysh - All Rights Reserved
Unauthorized copying, and/or redistribution of this file, via any medium without express written permission of Sylvyrfysh (Nicholas Johnson) is strictly prohibited
Proprietary and confidential
Written by Nicholas Johnson <johnnic431@gmail.com>, June 24 2015

]]

--[[ ex.
----Milianlou's  Shop----

Item                Price
Item1                 f25
Item2                 f30

Total                 f55

Created at Day 6 12:55

--Thanks for shopping!--
]]

local printer=peripheral.wrap("left")
local line=4;

local function checkEnd(line)
    if line==25 then
        printer.endPage()
        line=1;
        if not printer.newPage() then return false; end
        printer.setPageTitle("Receipt")
    end
end

local function writeLeft(str,line)
    checkEnd(line)
    printer.setCursorPos(1,line)
    printer.write(str)
end

local function writeRight(str,line)
    checkEnd(line)
    printer.setCursorPos(26-#str,tonumber(line) or line)
    printer.write(str)
end

function printReceipt(cart)
    if not printer.newPage() then return false; end
    printer.setPageTitle("Receipt")
    printer.setCursorPos(1,1)
    printer.write("----Milianlou's  Shop----")
    printer.setCursorPos(1,3)
    printer.write("Item                Price")
    local tPrice=0;
    for t,y in pairs(cart) do
        writeLeft(y["itemName"],line)
        price="f"..y["price"]
        writeRight(price,line)
        line=line+1;
        tPrice=tPrice+y["price"]
    end
    line=line+1;
    writeLeft("Total",line)
    writeRight("f"..tPrice,line)
    line=line+1
    writeLeft("Created at Day "..os.day().." "..os.time(),line)
    printer.endPage()
    return true
end