# Copyright (C) 2013-2016 all contributors <yahns-public@yhbt.net>
# License: GPL-3.0+ (https://www.gnu.org/licenses/gpl-3.0.txt)
require 'tempfile'
include Rake::DSL

gendocs = %w(NEWS NEWS.atom.xml)
task rsync_docs: gendocs do
  dest = ENV["RSYNC_DEST"] || "yhbt.net:/srv/yhbt/yahns/"
  top = %w(INSTALL HACKING README COPYING)

  # git-set-file-times is distributed with rsync,
  # Also available at: https://yhbt.net/git-set-file-times
  # on Debian systems: /usr/share/doc/rsync/scripts/git-set-file-times.gz
  sh("git", "set-file-times", "Documentation", "examples", *top)
  make = ENV['MAKE'] || 'make'
  sh(%Q(#{make} -C Documentation))

  do_gzip = lambda do |txt|
    gz = "#{txt}.gz"
    tmp = "#{gz}.#$$"
    sh("gzip --rsyncable -9 < #{txt} > #{tmp}")
    st = File.stat(txt)
    File.utime(st.atime, st.mtime, tmp) # make nginx gzip_static happy
    File.rename(tmp, gz)
    gz
  end

  files = `git ls-files Documentation/*.txt`.split(/\n/)
  files.concat(top)
  files.concat(gendocs)
  files.concat(%w(yahns yahns-rackup yahns_config).map! { |x|
    "Documentation/#{x}.txt"
  })
  gzfiles = files.map { |txt| do_gzip.call(txt) }
  files.concat(gzfiles)

  sh("rsync --chmod=Fugo=r -av #{files.join(' ')} #{dest}")

  examples = `git ls-files examples`.split(/\n/)
  gzex = examples.map { |txt| do_gzip.call(txt) }
  examples.concat(gzex)

  sh("rsync --chmod=Fugo=r -av #{examples.join(' ')} #{dest}/examples/")
end

def tags
  timefmt = '%Y-%m-%dT%H:%M:%SZ'
  @tags ||= `git tag -l`.split(/\n/).map do |tag|
    if %r{\Av[\d\.]+} =~ tag
      header, subject, body = `git cat-file tag #{tag}`.split(/\n\n/, 3)
      header = header.split(/\n/)
      tagger = header.grep(/\Atagger /).first
      body ||= "initial"
      time = Time.at(tagger.split(/ /)[-2].to_i).utc
      {
        time_obj: time,
        time: time.strftime(timefmt),
        tagger_name: %r{^tagger ([^<]+)}.match(tagger)[1].strip,
        tagger_email: %r{<([^>]+)>}.match(tagger)[1].strip,
        id: `git rev-parse refs/tags/#{tag}`.chomp!,
        tag: tag,
        subject: subject,
        body: body,
      }
    end
  end.compact.sort { |a,b| b[:time] <=> a[:time] }
end

def xml(dst, tag, text = nil, attrs = nil)
  if Hash === text
    attrs = text
    text = nil
  end
  if attrs
    attrs = attrs.map { |k,v| "#{k}=#{v.encode(xml: :attr)}" }
    attrs = "\n#{attrs.join("\n")}"
  end
  case text
  when nil
    if block_given?
      dst << "<#{tag}#{attrs}>"
      yield
      dst << "</#{tag}>"
    else
      dst << "<#{tag}#{attrs}/>"
    end
  else
    dst << "<#{tag}#{attrs}>#{text.encode(xml: :text)}</#{tag}>"
  end
end

desc 'prints news as an Atom feed'
task "NEWS.atom.xml" do
  require 'uri'
  cgit_uri = URI('https://yhbt.net/yahns.git')
  uri = URI('https://yhbt.net/yahns/')
  new_tags = tags[0,10]
  time = nil
  project_name = 'yahns'
  short_desc = File.readlines('README')[0].split(' - ')[0]
  new_tags = tags[0,10]
  atom_uri = uri.dup
  atom_uri.path += 'NEWS.atom.xml'
  news_uri = uri.dup
  news_uri.path += 'NEWS.html'
  dst = ''
  xml(dst, 'feed', xmlns: 'http://www.w3.org/2005/Atom') do
    xml(dst, 'id', atom_uri.to_s)
    xml(dst, 'title', "#{project_name} news")
    xml(dst, 'subtitle', short_desc)
    xml(dst, 'link', rel: 'alternate', type: 'text/html', href: news_uri.to_s)
    xml(dst, 'updated', new_tags.empty? ? '1970-01-01:00:00:00Z'
                                      : new_tags[0][:time])
    new_tags.each do |tag|
      xml(dst, 'entry') do
        xml(dst, 'title', tag[:subject])
        xml(dst, 'updated', tag[:time])
        xml(dst, 'published', tag[:time])
        xml(dst, 'author') do
          xml(dst, 'name', tag[:tagger_name])
          xml(dst, 'email', tag[:tagger_email])
        end
        uri = cgit_uri.dup
        uri.path += '/tag/'
        uri.query = "id=#{tag[:tag]}"
        uri = uri.to_s
        xml(dst, 'link', rel: 'alternate', type: 'text/html', href: uri)
        xml(dst, 'id', uri)
        xml(dst, 'content', type: 'xhtml') do
          xml(dst, 'div', xmlns: 'http://www.w3.org/1999/xhtml') do
            xml(dst, 'pre', tag[:body])
          end # div
        end # content
      end # entry
    end # new_tags.each
  end # feed

  fp = Tempfile.new('NEWS.atom.xml', '.')
  fp.sync = true
  fp.write(dst)
  fp.chmod 0644
  File.utime(time, time, fp.path) if time
  File.rename(fp.path, 'NEWS.atom.xml')
  fp.close!
end

desc 'prints news as a text file'
task 'NEWS' do
  fp = Tempfile.new('NEWS', '.')
  fp.sync = true
  time = nil
  tags.each do |tag|
    time ||= tag[:time_obj]
    line = tag[:subject] + ' / ' + tag[:time].sub(/T.*/, '')
    fp.puts line
    fp.puts('-' * line.length)
    fp.puts
    fp.puts tag[:body]
    fp.puts
  end
  fp.write("Unreleased\n\n") unless fp.size > 0
  fp.puts "COPYRIGHT"
  fp.puts "---------"
  fp.puts "Copyright (C) 2013-2017 all contributors <yahns-public@yhbt.net>"
  fp.puts "License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>"
  fp.chmod 0644
  File.utime(time, time, fp.path) if time
  File.rename(fp.path, 'NEWS')
  fp.close!
end