Some file IO routines

--------------------------------------------------------------
-- PROTOTYPES AND LOCAL VARIABLES ----------------------------

local JSON = require( "json" )
local LFS  = require( "lfs" )

local class = {}

--------------------------------------------------------------
-- FILE FUNCTIONS --------------------------------------------

-- Encode table to JSON string
function class.JSONEncode( data )

    return JSON.encode(data)

end

-- Decode JSON string to table
function class.JSONDecode( data )

    return JSON.decode(data)

end

-- Save data to a file
function class.saveData( filePath, data )

    -- Save file
    local file = io.open( system.pathForFile( filePath, system.DocumentsDirectory ), "w" )
    file:write(data)
    io.close( file )

end

-- Load data from a file, returning a table
function class.loadData( filePath, directory )

    -- Get file path and check it exists
    local fullPath = system.pathForFile( filePath, class.getDirectory( directory ) )
    if fullPath == nil then return false ; end

    -- Load file
    local file = io.open( fullPath, "r" )
    if file then
        local data = file:read( "*a" )
        io.close( file )
        return data
    end

    -- Some sort of error, so return false
    return false

end

-- Get correct path
function class.getDirectory( directory )

    -- Allow for missed parameter
    if directory == nil then directory = "docs" ; end

    -- Return the correct path
    if directory == "docs" or directory == "documents" then return system.DocumentsDirectory
    else                                                    return system.ResourceDirectory ; end

end

-- Find if a file exists
function class.fileExists( filePath, directory )

    -- Does file exist?
    local results  = false
    local filePath = system.pathForFile( filePath, class.getDirectory( directory ) )
    if filePath then
        local file = io.open( filePath, "r" )
        if file then
            file:close()
            results = true
        end
    end

    return results

end

-- Remove a file ( also checks if it exists)
function class.deleteFile( filePath, directory )

    -- Allow for missed parameter
    directory = directory or "docs"

    -- Get file path and check it exists
    local file, fullPath
    if directory == "docs" or directory == "documents" then fullPath = system.pathForFile( filePath, system.DocumentsDirectory )
    else                                                    fullPath = system.pathForFile( filePath, system.ResourceDirectory ) ; end

    -- Attempt to remove the file
    return os.remove( fullPath )

end

--------------------------------------------------------------
-- RETURN CLASS DEFINITION -----------------------------------

return class