require 'yaml'

module Hobo
  class Env
    HOBOFILE_NAME = "hobofile"
    HOME =  File.expand_path('~/.hobo')
    CONFIG = { File.join(HOME, 'config.yml') => '/config/default.yml' }
    ENSURE = {
      :files => CONFIG.merge({}), #additional files go mhia!
      :dirs => [HOME] #additional dirs go mhia!
    }

    # Initialize class variables used
    @@persisted_vm = nil
    @@root_path = nil

    class << self
      def persisted_vm; @@persisted_vm; end
      def root_path; @@root_path; end
      def dotfile_path; File.join(root_path, Hobo.config[:dotfile_name]); end

      def load!
        load_root_path!
        load_config!
        load_vm!
      end

      def ensure_directories
        ENSURE[:dirs].each do |name|
          Dir.mkdir(name) unless File.exists?(name)
        end
      end

      def ensure_files
        ENSURE[:files].each do |target, default|
          File.copy(File.join(PROJECT_ROOT, default), target) unless File.exists?(target)
        end
      end

      def load_config!
        ensure_directories
        ensure_files

        HOBO_LOGGER.info "Loading config from #{CONFIG.keys.first}"
        parsed = YAML.load_file(CONFIG.keys.first)
        Hobo.config!(parsed)
      end

      def load_vm!
        File.open(dotfile_path) do |f|
          @@persisted_vm = Hobo::VM.find(f.read)
        end
      rescue Errno::ENOENT
        @@persisted_vm = nil
      end

      def persist_vm(vm)
        File.open(dotfile_path, 'w+') do |f|
          f.write(vm.uuid)
        end
      end

      def load_root_path!(path=Pathname.new(Dir.pwd))
        if path.to_s == '/'
          error_and_exit(<<-msg)
A `Hobofile` was not found! This file is required for hobo to run
since it describes the expected environment that hobo is supposed
to manage. Please create a Hobofile and place it in your project
root.
msg
          return
        end

        file = "#{path}/#{HOBOFILE_NAME}"
        if File.exist?(file)
          @@root_path = path.to_s
          return
        end

        load_root_path!(path.parent)
      end

      def require_persisted_vm
        if !persisted_vm
          error_and_exit(<<-error)
The task you're trying to run requires that the hobo environment
already be created, but unfortunately this hobo still appears to
have no box! You can setup the environment by setting up your
Hobofile and running `hobo up`
error
          return
        end
      end

      def error_and_exit(error)
        puts <<-error
=====================================================================
Hobo experienced an error!

#{error.chomp}
=====================================================================
error
        exit
      end
    end
  end
end