require 'digest'
require 'open-uri'
require 'tempfile'
require 'uri'

require 'escape'

require 'vendorificator/vendor'

class Vendorificator::Vendor::Archive < Vendorificator::Vendor
  arg_reader :url, :strip_root, :type, :checksum, :filename, :basename, :extname, :unpack
  attr_reader :conjured_checksum

  def initialize(environment, name, args={}, &block)
    no_url_given = !args[:url]

    args[:url] ||= name
    args[:filename] ||= URI::parse(args[:url]).path.split('/').last

    case args[:filename]
    when /\.(tar\.|t)gz$/
      args[:type] ||= :targz
      args[:unpack] ||= 'tar -xzf'
    when /\.tar\.bz2$/
      args[:type] ||= :tarbz2
      args[:unpack] ||= 'tar -xjf'
    when /\.zip$/
      args[:type] ||= :zip
      args[:unpack] ||= 'unzip'
    when /\.[^\.][^\.]?[^\.]?[^\.]?$/
      args[:type] ||=
        begin
          unless args[:unpack]
            raise RuntimeError,
            "Unknown file type #{$&.inspect}, please provide :unpack argument"
          end
          $&
        end
    else
      args[:basename] ||= args[:filename]
      args[:extname] ||= ''
      unless args[:unpack] || [:targz, :tarbz2, :zip].include?(args[:type])
        raise RuntimeError, "Unknown file type for #{args[:filename].inspect}, please provide :unpack or :type argument"
      end
    end
    args[:basename] ||= $`
    args[:extname] ||= $&

    name = args[:basename] if no_url_given

    super(environment, name, args, &block)
  end

  def conjure!
    shell.say_status :download, url
    archive = Tempfile.new([basename, extname])
    archive.write( open(url).read )
    archive.close
    @conjured_checksum = Digest::SHA256.file(archive.path).hexdigest
    raise RuntimeError, "Checksum error" if checksum && checksum!=conjured_checksum
    shell.say_status :unpack, filename
    system "#{unpack} #{Escape.shell_single_word archive.path}"
    if Dir.entries('.').length == 3 && !args[:no_strip_root]
      root = (Dir.entries('.') - %w(.. .)).first
      root_entries = Dir.entries(root) - %w(.. .)
      while root_entries.include?(root)
        FileUtils::mv root, root+"~"
        root << "~"
      end
      FileUtils::mv root_entries.map { |e| File.join(root, e) }, '.'
      FileUtils::rmdir root
    end
    super
  ensure
    archive.close
    archive.unlink
  end

  def upstream_version
    filename
  end

  def conjure_commit_message
    rv = "Conjured archive #{name} from #{filename}\nOrigin: #{url}\nChecksum: #{conjured_checksum}\n"
    rv << "Version: #{version}\n" if version
    rv
  end

  install!
end