require 'rubygems'
require 'rake'
require 'rake/gempackagetask'

task :default => [:buildext]

rule '.1' => ['.xml'] do |t|
  sh "xsltproc -nonet -o #{t.name} /usr/share/sgml/docbook/stylesheet/xsl/nwalsh/manpages/docbook.xsl #{t.source}"
end

task :manpages => ['man/rbot.1', 'man/rbot-remote.1']

SPECFILE = 'rbot.gemspec'
# The Rakefile is also used after installing the gem, to build
# the .mo files. Since in this case the SPECFILE is not available,
# we must (and can) skip defining the gem packaging tasks.
if File.exist? SPECFILE
  spec = eval(File.read(SPECFILE), nil, SPECFILE)
  Rake::GemPackageTask.new(spec) do |pkg|
    pkg.need_zip = true
    pkg.need_tar = true
  end
end

# normalize a po/pot file
def normalize_po(fn)
  content = File.read(fn)

  # sort the messages by file location
  if MSGCAT
    sorted = `#{MSGCAT} --width=79 --sort-by-file #{fn}`
    if sorted != content
      content = sorted
      modified = true
    end
  end

  # replace project-id-version placholder
  modified |= content.sub!(/^("Project-Id-Version: )PACKAGE VERSION(\\n")$/) {
    "#{$1}rbot#{$2}"
  }

  if modified
    File.open(fn, 'w') {|f| f.write content}
  end
end

PLUGIN_FILES = FileList['data/rbot/plugins/**/*.rb']
NON_PLUGIN_FILES = FileList["{lib,bin,data}/**/*.{rb,rhtml}"] - PLUGIN_FILES

# this task defines how po files and pot files are made. those rules are not defined
# normally because po and pot files should be only updated in the updatepo task,
# but po files are also prereqs for makemo
task :define_po_rules do
  # generate pot file from rb files
  rgettext_proc = proc do |t|
    require 'gettext/utils'
    source_files, pot_file = t.prerequisites, t.name
    new_pot_file = "#{pot_file}.new"
    puts "#{source_files.join(', ')} => #{pot_file}"
    GetText.rgettext(source_files, new_pot_file)

    # only use the new pot file if it contains unique messages
    if File.exists?(pot_file) && MSGCOMM && `#{MSGCOMM} --unique #{pot_file} #{new_pot_file}`.empty?
      rm new_pot_file
    else
      mv new_pot_file, pot_file
    end

    normalize_po(pot_file)
    
    # save all this work until rb files are updated again
    touch pot_file
  end

  # generate pot file for non-plugin files
  file('po/rbot.pot' => NON_PLUGIN_FILES, &rgettext_proc)

  # generate pot files for plugin files
  rule(%r'^po/.+\.pot$' => proc {|fn|
    PLUGIN_FILES.select {|f| f.pathmap('rbot-%n') == fn.pathmap('%n')}
  }, &rgettext_proc)

  # map the po file to its source pot file
  pot_for_po = proc {|fn| fn.pathmap '%{^po/.+/,po/}X.pot'}

  # update po file from pot file
  msgmerge_proc = proc do |t|
    require 'gettext/utils'
    po_file, pot_file = t.name, t.source
    puts "#{pot_file} => #{po_file}"
    if File.exists? po_file
      sh "#{MSGMERGE} --backup=off --update #{po_file} #{pot_file}"
    elsif MSGINIT
      locale = po_file[%r'^po/(.+)/.+\.po$', 1]
      sh "#{MSGINIT} --locale=#{locale} --no-translator --input=#{pot_file} --output-file=#{po_file}"
    else
      warn "#{po_file} is missing and cannot be generated without msginit"
      next
    end
    normalize_po(po_file)
    touch po_file
  end

  # generate English po files
  file(%r'^po/en/.+\.po$' => pot_for_po) do |t|
    po_file, pot_file = t.name, t.source
    if MSGEN
      sh "#{MSGEN} --output-file=#{po_file} #{pot_file}"
      normalize_po(po_file)
      touch po_file
    else
      msgmerge_proc.call t
    end
  end

  # update po files
  rule(%r'^po/.+/.+\.po$' => pot_for_po, &msgmerge_proc)
end

# generate mo files
rule(%r'^data/locale/.+/LC_MESSAGES/.+\.mo$' => proc {|fn|
  [ fn.pathmap('%{^data/locale,po;LC_MESSAGES/,}X.po'), 
    # the directory is created if not existing
    fn.pathmap('%d') ]
}) do |t|
  po_file, mo_file = t.source, t.name
  puts "#{po_file} => #{mo_file}"
  require 'gettext/utils'
  GetText.rmsgfmt po_file, mo_file
end

task :check_po_tools do
  have = {}

  po_tools = {
    'msgmerge' => {
      :options => %w[--backup= --update],
      :message => 'Cannot update po files' },
    'msginit' => {
      :options => %w[--locale= --no-translator --input= --output-file=],
      :message => 'Cannot generate missing po files' },
    'msgcomm' => {
      :options => %w[--unique],
      :message => 'Pot files may be modified even without message change' },
    'msgen' => {
      :options => %w[--output-file],
      :message => 'English po files will not be generated' },
    'msgcat' => {
      :options => %w[--width= --sort-by-file],
      :message => 'Pot files will not be normalized' }
  }

  po_tools.each_pair do |command, value|
    path = ENV["#{command.upcase}_PATH"] || command
    have_it = have[command] = value[:options].all? do |option|
      `#{path} --help`.include? option
    end
    Object.const_set(command.upcase, have_it ? path : false)
    warn "#{command} not found. #{value[:message]}" unless have_it
  end
  abort unless MSGMERGE
end

PLUGIN_BASENAMES = PLUGIN_FILES.map {|f| f.pathmap('%n')}
LOCALES = FileList['po/*/'].map {|d| d.pathmap('%n')}

LOCALES.each do |l|
  directory "data/locale/#{l}/LC_MESSAGES"
end

desc 'Update po files'
task :updatepo => [:define_po_rules, :check_po_tools] + LOCALES.map {|l|
  ["po/#{l}/rbot.po"] +
  PLUGIN_BASENAMES.map {|n| "po/#{l}/rbot-#{n}.po"}
}.flatten

desc 'Normalize po files'
task :normalizepo => :check_po_tools do
  FileList['po/*/*.po'].each {|fn| normalize_po(fn)}
end

# this task invokes makemo if ruby-gettext is available, but otherwise succeeds
# with a warning instead of failing. it is to be used by Gem's extension builder
# to make installation not fail because of lack of ruby-gettext
task :buildext do
  begin
    require 'gettext/utils'
    Rake::Task[:makemo].invoke
  rescue LoadError
    warn 'Ruby-gettext cannot be located, so mo files cannot be built and installed' 
  end
end

desc 'Generate mo files'
task :makemo =>
  FileList['po/*/*.po'].pathmap('%{^po,data/locale}d/LC_MESSAGES/%n.mo')