require "fileutils"
require "json"
require "tmpdir"
require "shellwords"

def load_config
  begin
    $config_file ||= File.expand_path(ENV["CONFIG"] || "config.json")
    $tmp_config = JSON.parse(File.read($config_file))
    $datadir = $tmp_config["datadir"]
  rescue
    puts "Failed to load config: #{$config_file}"
    puts "You can specify config file with CONFIG environment variable"
    raise
  end
end

def add_compiler(lang, id, val)
  load_config
  list = $tmp_config["compilers"][lang] || {}
  list[id] = val
  $tmp_config["compilers"][lang] = list.sort.reverse.to_h
  File.write($config_file, JSON.pretty_generate($tmp_config) + "\n")
end

def retriable
  yield
rescue
  puts "An error occurred: #{$!}"
  puts "Current directory: #{`pwd`}"
  print "Press a key to retry:"
  $stdin.getc
  retry
end

def download(url, target)
  FileUtils.mkdir_p($datadir + "/cache")
  out = $datadir + "/cache/" + File.basename(url)
  system("curl -z #{Shellwords.escape(out)} -o #{Shellwords.escape(out)} -L #{Shellwords.escape(url)}") or
    raise("failed download: #{url}")
  FileUtils.copy(out, target)
end

load_config

RUBY_PATCHES = {
  ruby: [
    # core
    [/^(1.6.[5-8])/,            "eval-64bit-fix-165"],

    # ext/tcltklib
    [/^1.6.[5-8]/,              "disable-tcltklib-165"],
    [/^1.8.[01]/,               "disable-tcltklib-180"],

    # ext/openssl
    [/^1.8.[0-2]/,              "disable-openssl-180"],
    [/^1.8.[3-4]/,              "disable-openssl-183"],
    [/^1.8.[5-7]/,              "disable-openssl-185"],
    [/^1.9.0/,                  "r16422-New-OpenSSL-182"],
    [/^1.9.0/,                  "r16478-pkcs5-typo"],
    # OpenSSL 1.0 support
    [/^1.9.[01]/,               "r26781-OpenSSL10-181"],
    # apply SSLv2, then apply SSLv3
    [/^1.9.[01]/,               "r31346-r31528-SSLv2-183", "r51722-SSLv3-181"],
    [/^1.9.[23]/,               "r31346-r31528-SSLv2-192", "r51722-SSLv3-192"],
    [/^2.[012]/,                "r51722-SSLv3-200"],
    # EC2M
    [/^(1.9|2.[012])/,          "r41808-EC2M"],
  ]
}

RUBY_MIRROR = "https://cache.ruby-lang.org/pub/ruby"
desc "Install a ruby"
task :ruby, [:version] do |t, args|
  version = args[:version]
  id = "ruby-#{version}"
  if version =~ /^(1\.1[a-d]|1\.[02-9]|2\..)/
    archive_dir = id
    url = "#{RUBY_MIRROR}/#{$1}/#{id}.tar.gz"
  elsif version =~ /^0\./
    archive_dir = id
    url = "#{RUBY_MIRROR}/1.0/#{id}.tar.gz"
  elsif version =~ /snapshot/
    archive_dir = version
    url = "#{RUBY_MIRROR}/#{version}.tar.gz"
  else
    raise ArgumentError, "unknown ruby"
  end

  destdir = $datadir + "/env/ruby/#{id}"
  raise ArgumentError, "already installed?" if Dir.exist?(destdir.to_s)
  prefix = "/usr"

  Dir.mktmpdir { |tmpdir|
    FileUtils.chdir(tmpdir) {
      download(url, "archive.tar.gz")
      system("tar xf archive.tar.gz") or raise("failed to extract")
      FileUtils.chdir(archive_dir) {
        RUBY_PATCHES[:ruby].each { |regexp, *patch_names|
          next if regexp !~ version
          patch_names.each { |name|
            puts "applying patch #{name}..."
            patch_file = File.expand_path("../patches/ruby/#{name}.patch", __FILE__)
            retriable {
              system("patch --dry-run -R -N -p1 <#{patch_file}") or
                system("patch -N -p1 <#{patch_file}") or
                  raise("patch failed: #{name}")
            }
          }
        }
        retriable {
          system("./configure --prefix=#{prefix} --enable-shared --disable-install-doc --without-tk --without-tcllib --without-tklib") or raise("failed to configure")
          system("make -j6") or raise("failed to make")
          system("make install DESTDIR=#{destdir}") or raise("failed to install")
        }

        add_compiler("ruby", id, {
          version: `LD_LIBRARY_PATH=#{destdir}#{prefix}/lib #{destdir}#{prefix}/bin/ruby -v`,
          version_command: "#{prefix}/bin/ruby -v",
          commandline: ["#{prefix}/bin/ruby", "{}"]
        })
      }
    }
  }
end

desc "Install a php"
task :php, [:version] do |t, args|
  version = args[:version]
  id = "php-#{version}"
  url = "http://museum.php.net/php#{version[0]}/#{id}.tar.gz"

  destdir = $datadir + "/env/php/#{id}"
  raise ArgumentError, "already installed?" if Dir.exist?(destdir.to_s)
  prefix = "/usr"

  Dir.mktmpdir { |tmpdir|
    FileUtils.chdir(tmpdir) {
      download(url, "archive.tar.gz")
      system("tar xf archive.tar.gz") or raise("failed to extract")
      FileUtils.chdir(id) {
        retriable {
          system("./configure --prefix=#{prefix} --enable-shared") or raise("failed to configure")
          system("make -j6") or raise("failed to make")
          system("make install INSTALL_ROOT=#{destdir}") or raise("failed to install")
        }

        add_compiler("php", id, {
          version: `LD_LIBRARY_PATH=#{destdir}#{prefix}/lib #{destdir}#{prefix}/bin/php -v`,
          version_command: "#{prefix}/bin/php -v",
          commandline: ["#{prefix}/bin/php", "{}"]
        })
      }
    }
  }
end