require "singleton"
require "json"

module Brief
  class Configuration
    include Singleton

    DefaultSettings = {
      github_username: "",
      github_api_token: ""
    }

    def self.method_missing meth, *args, &block
      if instance.respond_to?(meth)
        return instance.send meth, *args, &block
      end

      nil
    end

    def initialize!
      FileUtils.mkdir_p home_config_path.dirname
    end

    def method_missing meth, *args, &block
      if current.has_key?(meth.to_s)
        return current.fetch(meth)
      end

      super
    end

    def current_github_repository
      value = current.github_repository

      return value if value

      if value.nil?
        if guess = Brief::Git.current_github_repository
          set "github_repository", guess
          return guess
        end
      end

      current.github_repository
    end

    def current
      @current ||= begin
                     home_config.merge(cwd_config)
                   end
    end

    def current_config
      cwd_config_path.exist? ? cwd_config : home_config
    end

    def set setting, value, persist=true
      current_config[setting] = value
      save! if persist == true
      value
    end

    def unset setting, persist=true
      current_config.delete(setting)
      save! if persist == true
    end

    def current
      Hashie::Mash.new(home_config.merge(cwd_config).merge(applied_config))
    end

    def apply_config_from_path path
      path = Pathname(path)
      parsed = JSON.parse(path.read) rescue {}
      applied_config.merge!(parsed)
      nil
    end

    def save!
      save_home_config
      save_cwd_config
    end

    def save_cwd_config
      return nil unless cwd_config_path.exist?

      File.open(cwd_config_path,'w+') do |fh|
        fh.write JSON.generate(cwd_config.to_hash)
      end
    end

    def save_home_config
      File.open(home_config_path,'w+') do |fh|
        fh.write JSON.generate(home_config.to_hash)
      end
    end

    # Applied config is configuration values passed in context
    # usually from the cli, but also in the unit tests
    def applied_config
      @applied_config ||= {}
    end

    def cwd_config
      @cwd_config ||= begin
        (cwd_config_path.exist? rescue false) ? JSON.parse(cwd_config_path.read) : {}
      rescue
        {}
      end
    end

    def home_config
      @home_config ||= begin
        (home_config_path.exist? rescue false) ? JSON.parse(home_config_path.read) : {}
      rescue
        {}
      end
    end

    def home_folder
      Pathname(ENV['HOME']).join('.brief')
    end

    def home_config_path
      Pathname(ENV['HOME']).join('.brief','config.json')
    end

    def cwd_config_path
      Pathname(Dir.pwd).join('.briefrc')
    end
  end
end