lighttroupe/luz

#
# Settings provides a YAML-backed key value store of application-wide settings
#
#require 'yaml'

class Settings
    def initialize
        @settings = {}
        @setting_callbacks = {}
    end

    def on_change(key, &proc)
        @setting_callbacks[key] ||= []
        @setting_callbacks[key] << proc
    end

    def load(path)
        @path = path        # store for save, even if file doesn't exist
        File.open(path, 'r') { |file|
            load_settings_from_file(file)
            #puts "Loaded settings from #{path}..."
        } rescue Errno::ENOENT
        self
    end

    def save(path=nil)
        path ||= @path
        begin
            File.open(path, 'w') { |file|
                save_settings_to_file(file)
                @path = path
                #puts "Saved settings to #{path}..."
            }
        rescue => e
            puts "error saving"
            p e.report_format
        end
        self
    end

    def [](key)
        @settings[key]
    end

    def []=(key, value)
        #puts "$settings#{key} = #{value}"
        return if (@settings[key] && @settings[key] == value)
        @settings[key] = value
        @setting_callbacks[key].each { |proc| proc.call(value) } if @setting_callbacks[key]
    end

private

    def load_settings_from_file(file)
        settings = YAML.load(file)
        @settings = settings if settings.is_a? Hash
    end

    def save_settings_to_file(file)
        ZAML.dump(@settings, file)
    end
end