class Libressl < Formula
  desc "Version of the SSL/TLS protocol forked from OpenSSL"
  homepage "http://www.libressl.org/"
  url "http://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.2.3.tar.gz"
  sha256 "a1ccc21adf91d60e99246031b99c930c9af5e1b1b5a61b1bec87beef6f16d882"

  bottle do
    sha256 "bfbaf13c9c7b920d2894bb867934dea3d0cb2d41312f83d47cb57cc478ef1c38" => :el_capitan
    sha256 "a4e4afd644d5a603e99ad091a87c10cf132b40b7e8bf3990971223e49a290591" => :yosemite
    sha256 "fcebe2fdce64cbbd8d6b2e3fe0bd876b5591decfc87f614f754013ed170077a7" => :mavericks
    sha256 "aa98a4c2a616a67e7352ee1dd9432d03703a2f26804fbba45e8d915d2fa05ed6" => :mountain_lion
  end

  head do
    url "https://github.com/libressl-portable/portable.git"

    depends_on "automake" => :build
    depends_on "autoconf" => :build
    depends_on "libtool" => :build
  end

  keg_only "LibreSSL is not linked to prevent conflict with the system OpenSSL."

  def install
    args = %W[
      --disable-dependency-tracking
      --disable-silent-rules
      --prefix=#{prefix}
      --with-openssldir=#{etc}/libressl
      --sysconfdir=#{etc}/libressl
    ]

    # https://github.com/libressl-portable/portable/issues/121
    args << "--disable-asm" if MacOS.version <= :snow_leopard

    system "./autogen.sh" if build.head?
    system "./configure", *args
    system "make"
    system "make", "check"
    system "make", "install"
  end

  def post_install
    keychains = %w[
      /Library/Keychains/System.keychain
      /System/Library/Keychains/SystemRootCertificates.keychain
    ]

    certs_list = `security find-certificate -a -p #{keychains.join(" ")}`
    certs = certs_list.scan(
      /-----BEGIN CERTIFICATE-----.*?-----END CERTIFICATE-----/m
    )

    valid_certs = certs.select do |cert|
      IO.popen("openssl x509 -inform pem -checkend 0 -noout", "w") do |openssl_io|
        openssl_io.write(cert)
        openssl_io.close_write
      end

      $?.success?
    end

    # LibreSSL install a default pem - We prefer to use OS X for consistency.
    rm_f etc/"libressl/cert.pem"
    (etc/"libressl/cert.pem").atomic_write(valid_certs.join("\n"))
  end

  def caveats; <<-EOS.undent
    A CA file has been bootstrapped using certificates from the system
    keychain. To add additional certificates, place .pem files in
      #{etc}/libressl/certs

    and run
      #{opt_bin}/openssl certhash #{etc}/libressl/certs
    EOS
  end

  test do
    # Make sure the necessary .cnf file exists, otherwise LibreSSL gets moody.
    assert (HOMEBREW_PREFIX/"etc/libressl/openssl.cnf").exist?,
            "LibreSSL requires the .cnf file for some functionality"

    # Check LibreSSL itself functions as expected.
    (testpath/"testfile.txt").write("This is a test file")
    expected_checksum = "e2d0fe1585a63ec6009c8016ff8dda8b17719a637405a4e23c0ff81339148249"
    system "#{bin}/openssl", "dgst", "-sha256", "-out", "checksum.txt", "testfile.txt"
    open("checksum.txt") do |f|
      checksum = f.read(100).split("=").last.strip
      assert_equal checksum, expected_checksum
    end
  end
end