# 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'

run do |opts, args, cmd|
  Nanoc3::CLI::Commands::Update.call(opts, args, cmd)
end

module Nanoc3::CLI::Commands

  class Update < ::Nanoc3::CLI::Command

    def run
      # Check arguments
      if arguments.size != 0
        $stderr.puts "usage: #{usage}"
        exit 1
      end

      # Make sure we are in a nanoc site directory
      self.require_site

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

      # Check for -y switch
      unless options.has_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 "nanoc3 ' +
                     'update -y".'
        exit 1
      end

      # Update
      self.site.data_sources.each do |data_source|
        data_source.update
      end
    end

  end

end