#!/usr/bin/env ruby
# Usage: script/package
#
# Packages `hub` for release for current platform

require "fileutils"
include FileUtils

module OS
  class << self
    def type
      if darwin?
        "darwin"
      elsif linux?
        "linux"
      elsif windows?
        "windows"
      else
        raise "Unknown OS type #{RUBY_PLATFORM}"
      end
    end

    def friendly_name
      if darwin?
        "mac"
      elsif linux?
        "linux"
      elsif windows?
        "windows"
      else
        raise "Unknown OS type #{RUBY_PLATFORM}"
      end
    end

    def windows?
      (/cygwin|mswin|mingw|bccwin|wince|emx/ =~ RUBY_PLATFORM) != nil
    end

    def windows_64?
      windows? && /x64/ =~ RUBY_PLATFORM
    end

    def darwin?
      (/darwin/ =~ RUBY_PLATFORM) != nil
    end

    def linux?
      (/linux/ =~ RUBY_PLATFORM) != nil
    end
  end
end

class Packer
  class << self
    def pack!
      self.new.pack!
    end
  end

  attr_reader :version

  def initialize
    @version = parse_version!
  end

  def pack!
    unless ENV["SKIP_TOOLCHAIN"]
      install_gox!
      build_toolchain!
    end
    run_tests! unless OS.windows? || ENV["SKIP_TEST"] # cukes don't run on Windows
    build_hub!
    cp_assets
    tar_gzip
  end

  private

  def exec!(cmd)
    io = IO.popen(cmd)
    begin
      while line = io.gets
        puts line.chomp
      end
    ensure
      io.close
    end

    raise "Fail to execute #{cmd}" unless $?.to_i == 0
  end

  # Returns the root path to paths
  def root_path(*paths)
    current = File.expand_path(File.dirname(__FILE__)) # current is the target folder
    File.expand_path File.join(current, "..", paths)
  end

  def glob_dir(path)
    Dir[path].select { |d| File.directory?(d) }
  end

  def parse_version!
    content = File.read root_path("version", "version.go")
    match = /var Version = "(.+)"/.match content
    raise "Fail to parse Hub version" unless match

    match[1]
  end

  def install_gox!
    puts "Installing github.com/mitchellh/gox"
    result = system "go get github.com/mitchellh/gox"
    raise "Fail to install gox" unless result
  end

  def build_toolchain!
    puts "Building Go toolchain"
    result = system "gox -build-toolchain -os=#{OS.type}"
    raise "Fail to build Go toolchain" unless result
  end

  def run_tests!
    puts "Running Hub tests"

    bootstrap_script = root_path("script", "bootstrap")
    exec!(bootstrap_script)

    test_script = root_path("script", "test")
    exec!(test_script)
  end

  def build_hub!
    puts "Building for #{OS.friendly_name}"
    release_version = `script/version`.strip
    output = root_path("target", "{{.Dir}}-#{OS.friendly_name}-{{.Arch}}-#{version}", "{{.Dir}}")
    # gox doesn't build for 64 bit and 32 bit on 64 bit Windows
    # specifying osarch for Windows
    # see https://github.com/mitchellh/gox/issues/19#issuecomment-68117016
    osarch = OS.windows? ? "windows/#{OS.windows_64? ? "amd64" : "386"}" : ""
    cmd = "gox -os=#{OS.type} -output=#{output} -ldflags \"-X github.com/github/hub/version.Version #{release_version}\""
    cmd += " -osarch=#{osarch}" unless osarch.empty?
    exec!(cmd)
  end

  def cp_assets
    path = root_path("target", "*#{OS.friendly_name}*")
    glob_dir(path).each do |dir|
      puts "Copying assets to #{dir}"
      ["README.md", "LICENSE", "etc/", "man/"].each do |f|
        cp_r f, File.join(dir, f)
      end
    end
  end

  def tar_gzip
    path = root_path("target", "*#{OS.friendly_name}*")
    glob_dir(path).each do |dir|
      puts "Archiving #{dir}"
      Dir.chdir(root_path("target")) do
        exec!("tar -zcf #{File.basename(dir)}.tar.gz #{File.basename(dir)}")
      end
    end
  end
end

Packer.pack!