Config API

--[[
Program: Config API
Version: 1.0
Author:  ben657
Support:

Description: This API allows you to easily make configs for
         your users to edit, rather than them having to
         read code and edit variables. These files can
             then be read by this API and the values can be
         used in your programs.

Note: Currently, tables cannot be written to configs, but in
      the future this functionality may be implemented.
--]]

loaded = false
dir = ""
file = ""
path = ""
internal = {}

 function create()
    local file = fs.open(path,"a")
    file.close()
 end

 --[[
 Attempts to load the config using the specified directory
 and file name, and load the contents into internal memory.
 If the path is not found, it will be created.
 --]]
function load(directory,fileName)
    dir = directory
    file = fileName
    path = dir.."/"..file
    fs.makeDir(dir)
    create(path)
    local file = fs.open(path, "r")
    repeat
        line = file.readLine()
        if(line ~= nil) then
            local asWords = line:gsub(":","")
            local parts = {}
            for word in asWords:gmatch("%w+") do table.insert(parts,word) end
            internal[parts[1]] = parts[2]
        end
    until line == nil
    loaded = true
    file.close()
end

--[[
Attempts to write the specified value to the specified key in the
internal config.
Returns true if successful.
Returns false if no config is loaded.
This only writes to the config in memory, not the file. To save
to file, call config.save().
--]]
function writeVal(key,value)
    if(loaded == false) then
        return false
    else
        local toWrite = value
        if(value == true) then toWrite = "true"
        elseif(value == false) then toWrite = "false" end
        internal[key] = toWrite
        return true
    end
end

--[[
Attempts to read a value from the internal config and return it.
Returns the value assigned to the specified key if successful.
Returns nil if no config is loaded or no value was found at the key.
--]]
function readVal(key)
    if(loaded == false) then
        return nil
    end
    toReturn = internal[key]
    if(toReturn == "true") then return true
    elseif(toReturn == "false") then return false
    else return internal[key] end
end

--[[
Attempts to save the internal config to the loaded file path.
Returns true if successful.
Returns false if no config is loaded.
The internal config is unloaded after saving, so config.load()
must be called again to use the config.
--]]
function save()
    if(loaded == true) then
        local file = fs.open(path,"w")
        for i,v in pairs(internal) do
            file.writeLine(i.." = "..v)
        end
        file.close()
        internal = {}
        loaded = false
        return true
    else
        return false
    end
end

--[[
Returns true if the config has no data.
Returns false if the config contains any data.
Returns nil if no config is loaded.
--]]
function isEmpty()
    if(loaded == false) then
        return nil
    end
    if(fs.getSize(path) == 0)then
        return true
    else return false end
end