# encoding: utf-8

usage 'update [options]'
summary 'update the data stored by the data source to a newer version'
description <<-EOS
Update the data stored by the data source to a newer format. The format in
which data is stored can change between releases, and even though backward
compatibility is usually preserved, it is often a good idea to store the site
data in a newer format so newer features can be taken advantage of.

This command will change data, and it is therefore recommended to make a
backup in case something goes wrong.
EOS

required :c, :vcs, 'select the VCS to use'
flag :y, :yes, 'update the data without warning'

module Nanoc::CLI::Commands
  class Update < ::Nanoc::CLI::CommandRunner
    def run
      # Check arguments
      if arguments.size != 0
        raise Nanoc::Errors::GenericTrivial, "usage: #{command.usage}"
      end

      # Make sure we are in a nanoc site directory
      require_site

      # Set VCS if possible
      set_vcs(options[:vcs])

      # Check for -y switch
      unless options.key?(:yes)
        $stderr.puts '*************'
        $stderr.puts '** WARNING **'
        $stderr.puts '*************'
        $stderr.puts
        $stderr.puts 'Are you absolutely sure you want to update the ' \
                     'content for this site? Updating the site content ' \
                     'will change the structure of existing data. This ' \
                     'operation is destructive and cannot be reverted. ' \
                     'Please do not interrupt this operation; doing so can ' \
                     'result in data loss. As always, consider making a ' \
                     'backup copy.'
        $stderr.puts
        $stderr.puts 'If this nanoc site is versioned using a VCS ' \
                     'supported by nanoc, consider using the --vcs option ' \
                     'to have nanoc perform add/delete/move operations ' \
                     'using the specified VCS. To get a list of VCSes ' \
                     'supported by nanoc, issue the "info" command.'
        $stderr.puts
        $stderr.puts 'To continue, use the -y/--yes option, like "nanoc ' \
                     'update -y".'
        exit 1
      end

      # Update
      site.data_sources.each(&:update)
    end
  end
end

runner Nanoc::CLI::Commands::Update