namespace :guides do

  desc 'Generate guides (for authors), use ONLY=foo to process just "foo.md"'
  task :generate => 'generate:html'

  # Guides are written in UTF-8, but the environment may be configured for some
  # other locale, these tasks are responsible for ensuring the default external
  # encoding is UTF-8.
  #
  # Real use cases: Generation was reported to fail on a machine configured with
  # GBK (Chinese). The docs server once got misconfigured somehow and had "C",
  # which broke generation too.
  task :encoding do
    %w(LANG LANGUAGE LC_ALL).each do |env_var|
      ENV[env_var] = "en_US.UTF-8"
    end
  end

  namespace :generate do

    desc "Generate HTML guides"
    task :html => :encoding do
      ENV["WARN_BROKEN_LINKS"] = "1" # authors can't disable this
      ruby "rails_guides.rb"
    end

    desc "Generate .mobi file. The kindlegen executable must be in your PATH. You can get it for free from http://www.amazon.com/kindlepublishing"
    task :kindle => :encoding do
      unless `kindlerb -v 2> /dev/null` =~ /kindlerb 0.1.1/
        abort "Please `gem install kindlerb` and make sure you have `kindlegen` in your PATH"
      end
      unless `convert` =~ /convert/  
        abort "Please install ImageMagick`"
      end
      ENV['KINDLE'] = '1'
      Rake::Task['guides:generate:html'].invoke
    end
  end

  # Validate guides -------------------------------------------------------------------------
  desc 'Validate guides, use ONLY=foo to process just "foo.html"'
  task :validate => :encoding do
    ruby "w3c_validator.rb"
  end

  desc "Show help"
  task :help do
    puts <<-help

Guides are taken from the source directory, and the result goes into the
output directory. Assets are stored under files, and copied to output/files as
part of the generation process.

You can generate HTML, Kindle or both formats using the `guides:generate` task.

All this process is handled via rake tasks, here's a full list of them:

#{%x[rake -T]}
Some arguments may be passed via environment variables:

  WARNINGS=1
    Internal links (anchors) are checked, also detects duplicated IDs.

  ALL=1
    Force generation of all guides.

  ONLY=name
    Useful if you want to generate only one or a set of guides.

    Generate only association_basics.html:
      ONLY=assoc

    Separate many using commas:
      ONLY=assoc,migrations

  GUIDES_LANGUAGE
    Use it when you want to generate translated guides in
    source/<GUIDES_LANGUAGE> folder (such as source/es)

  EDGE=1
    Indicate generated guides should be marked as edge.

Examples:
  $ rake guides:generate ALL=1
  $ rake guides:generate EDGE=1
  $ rake guides:generate:kindle EDGE=1
  $ rake guides:generate GUIDES_LANGUAGE=es
    help
  end
end

task :default => 'guides:help'
