Encanted Book Database

json = require("/json")

function createDatabase(dbName)
    if not io.open(dbName, "r") then
        db = io.open(dbName, "w")
        io.close(db)
    end
end

function jsonFileToTable(fileName)
    aTable = {}
    jsonFile = io.open(fileName, "r")
    jsonString = jsonFile:read("*all")
    if jsonString:len() > 0 then
        aTable =  json.decode(jsonString)
    end
    io.close(jsonFile)
    return aTable
end

function tableToJSONFile(dbTable, fileName)
    jsonString = json.encode(dbTable)
    jsonFile = io.open(fileName, "w")
    io.output(jsonFile)
    io.write(jsonString)
    io.close(jsonFile)
end

-- yoinked from user Michal Kottman on stackoverflow, iterator to sort a table
function spairs(t)
    -- collect the keys
    local keys = {}
    for k in pairs(t) do keys[#keys+1] = k end

    -- sort the keys
    table.sort(keys)

    -- return the iterator function
    local i = 0
    return function()
        i = i + 1
        if keys[i] then
            return keys[i], t[keys[i]]
        end
    end
end

function printDatabase(db)
    for k, v in spairs(db) do
        print(k..":")
        for x, y in ipairs(v) do
            print("    "..y["Level"]..": "..y["Amount"])
        end
        print("")
    end
end

function stripLevel(enchantName)
    s = enchantName:find("%sI") or enchantName:find("%sV")
    if s then
        enchantName = enchantName:sub(0, s-1)
    end
    return enchantName
end

function insertEnchant(db, enchant)
    noLevel = stripLevel(enchant)
    if db[noLevel] then
        for k, v in ipairs(db[noLevel]) do
            if v["Level"] == enchant then
                v["Amount"] = v["Amount"] + 1
                return
            end
        end
        table.insert(db[noLevel], {Level = enchant, Amount = 1})
    else
        db[noLevel] = {{Level = enchant, Amount = 1}}
    end
end

function removeEnchant(db, enchantLevel)
    noLevel = stripLevel(enchantLevel)
    if db[noLevel] then
        for k, v in ipairs(db[noLevel]) do
            if v["Level"] == enchantLevel then
                if v["Amount"] > 0 then
                    v["Amount"] = v["Amount"] - 1
                else
                    print("No "..enchantLevel.." books remaining.")
                end
                return
            end
        end
    end
end

createDatabase("database.json")
local database = jsonFileToTable("database.json")

insertEnchant(database, "Sharpness V")
insertEnchant(database, "Sharpness V")

insertEnchant(database, "Soul Stealer III")
removeEnchant(database, "Sharpness V")
insertEnchant(database, "Sharpness IV")
insertEnchant(database, "Sharpness I")
insertEnchant(database, "Sharpness III")
insertEnchant(database, "Efficiency IV")
insertEnchant(database, "Silk Touch")
removeEnchant(database, "LOL III")

tableToJSONFile(database, "database.json")
local database = jsonFileToTable("database.json")
printDatabase(database)