# linuxbrew-core
# https://github.com/Homebrew/linuxbrew-core/commit/8f8f34572def3b707dd1d400bdad04709a32cff6#diff-e10cba5c137d2afef5935658363f2e15
# https://github.com/Homebrew/linuxbrew-core/commits/master?branch=master&path%5B%5D=Formula&path%5B%5D=python@2.rb

class PythonAT2 < Formula
  desc 'Interpreted, interactive, object-oriented programming language'
  homepage 'https://www.python.org/'
  url 'https://www.python.org/ftp/python/2.7.18/Python-2.7.18.tar.xz'
  sha256 'b62c0e7937551d0cc02b8fd5cb0f544f9405bafc9a54d3808ed4594812edef43'
  license 'Python-2.0'

  livecheck do
    url 'https://www.python.org/ftp/python/'
    regex(%r{href=.*?v?(3\.9(?:\.\d+)*)/?["' >]}i)
  end

  bottle do
    root_url 'https://github.com/curoky/homebrew-tap/releases/download/bottles'
    sha256 x86_64_linux: 'f049f5f59c027c0c97fb6b2bb36486f66f394009dd2923ce03cb4ae7464a7e6a'
  end

  # setuptools remembers the build flags python is built with and uses them to
  # build packages later. Xcode-only systems need different flags.
  pour_bottle? do
    on_macos do
      reason <<~EOS
        The bottle needs the Apple Command Line Tools to be installed.
          You can install them, if desired, with:
            xcode-select --install
      EOS
      satisfy { MacOS::CLT.installed? }
    end
  end

  keg_only :versioned_formula
  depends_on 'gcc' => :build
  depends_on 'pkg-config' => :build
  depends_on 'gdbm'
  depends_on 'openssl@1.1'
  depends_on 'readline'
  depends_on 'sqlite'
  depends_on 'tcl-tk'
  depends_on 'xz'

  uses_from_macos 'bzip2'
  uses_from_macos 'libffi'
  uses_from_macos 'ncurses'
  uses_from_macos 'unzip'
  uses_from_macos 'zlib'

  resource 'setuptools' do
    url 'https://files.pythonhosted.org/packages/b2/40/4e00501c204b457f10fe410da0c97537214b2265247bc9a5bc6edd55b9e4/setuptools-44.1.1.zip'
  end

  resource 'pip' do
    url 'https://files.pythonhosted.org/packages/53/7f/55721ad0501a9076dbc354cc8c63ffc2d6f1ef360f49ad0fbcce19d68538/pip-20.3.4.tar.gz'
  end

  resource 'wheel' do
    url 'https://files.pythonhosted.org/packages/ed/46/e298a50dde405e1c202e316fa6a3015ff9288423661d7ea5e8f22f589071/wheel-0.36.2.tar.gz'
  end

  def lib_cellar
    on_macos do
      return prefix / "Frameworks/Python.framework/Versions/#{version.major_minor}/lib/python#{version.major_minor}"
    end
    on_linux do
      return prefix / "lib/python#{version.major_minor}"
    end
  end

  def site_packages_cellar
    lib_cellar / 'site-packages'
  end

  # The HOMEBREW_PREFIX location of site-packages.
  def site_packages
    HOMEBREW_PREFIX / "lib/python#{version.major_minor}/site-packages"
  end

  def install
    ENV['CONFIG_SHELL'] = '/bin/sh'
    gcc = Formula['gcc']
    gcc_major_ver = gcc.any_installed_version.major
    on_linux do
      ENV['CC'] = gcc.opt_bin / "gcc-#{gcc_major_ver}"
      ENV['CXX'] = gcc.opt_bin / "g++-#{gcc_major_ver}"
    end

    # Unset these so that installing pip and setuptools puts them where we want
    # and not into some other Python the user has installed.
    ENV['PYTHONHOME'] = nil
    ENV['PYTHONPATH'] = nil

    # The --enable-optimization and --with-lto flags diverge from what upstream
    # python does for their macOS binary releases. They have chosen not to apply
    # these flags because they want one build that will work across many macOS
    # releases. Homebrew is not so constrained because the bottling
    # infrastructure specializes for each macOS major release.
    args = %W[
      --prefix=#{prefix}
      --enable-ipv6
      --datarootdir=#{share}
      --datadir=#{share}
      --with-dbmliborder=gdbm:ndbm
      --without-ensurepip
    ]
    # https://stackoverflow.com/questions/8010384/pyunicodeucs4-fromencodedobject-error
    args << '--enable-unicode=ucs4'

    on_macos do
      args << "--enable-framework=#{frameworks}"
      args << '--with-dtrace'

      # Override LLVM_AR to be plain old system ar.
      # https://bugs.python.org/issue43109
      args << 'LLVM_AR=/usr/bin/ar'
    end
    on_linux do
      args << '--enable-shared'
      # Required for the _ctypes module
      # see https://github.com/Linuxbrew/homebrew-core/pull/1007#issuecomment-252421573
      args << '--with-system-ffi'
    end

    # Python re-uses flags when building native modules.
    # Since we don't want native modules prioritizing the brew
    # include path, we move them to [C|LD]FLAGS_NODIST.
    # Note: Changing CPPFLAGS causes issues with dbm, so we
    # leave it as-is.
    cflags         = []
    cflags_nodist  = ["-I#{HOMEBREW_PREFIX}/include"]
    ldflags        = ["-L#{HOMEBREW_PREFIX}/lib", "-L#{Formula['zlib'].opt_lib}",
                      "-L#{Formula['gdbm'].opt_lib}"]
    ldflags_nodist = ["-L#{HOMEBREW_PREFIX}/lib"]
    cppflags       = ["-I#{HOMEBREW_PREFIX}/include", "-I#{Formula['zlib'].opt_include}",
                      "-I#{Formula['gdbm'].opt_include}"]

    if MacOS.sdk_path_if_needed
      # Help Python's build system (setuptools/pip) to build things on SDK-based systems
      # The setup.py looks at "-isysroot" to get the sysroot (and not at --sysroot)
      cflags  << "-isysroot #{MacOS.sdk_path}" << "-I#{MacOS.sdk_path}/usr/include"
      ldflags << "-isysroot #{MacOS.sdk_path}"
      # For the Xlib.h, Python needs this header dir with the system Tk
      # Yep, this needs the absolute path where zlib needed a path relative
      # to the SDK.
      cflags  << "-I#{MacOS.sdk_path}/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers"
    end
    # Avoid linking to libgcc https://mail.python.org/pipermail/python-dev/2012-February/116205.html
    args << "MACOSX_DEPLOYMENT_TARGET=#{MacOS.version.to_f}"

    args << "--with-tcltk-includes=-I#{Formula['tcl-tk'].opt_include}"
    args << "--with-tcltk-libs=-L#{Formula['tcl-tk'].opt_lib} -ltcl8.6 -ltk8.6"

    # We want our readline and openssl! This is just to outsmart the detection code,
    # superenv handles that cc finds includes/libs!
    inreplace 'setup.py' do |s|
      s.gsub! "do_readline = self.compiler.find_library_file(lib_dirs, 'readline')",
              "do_readline = '#{Formula['readline'].opt_lib}/libhistory.dylib'"
      s.gsub! '/usr/local/ssl', Formula['openssl@1.1'].opt_prefix
    end

    inreplace 'setup.py' do |s|
      s.gsub! 'sqlite_setup_debug = False', 'sqlite_setup_debug = True'
      s.gsub! 'for d_ in inc_dirs + sqlite_inc_paths:',
              "for d_ in ['#{Formula['sqlite'].opt_include}']:"

      # Allow sqlite3 module to load extensions:
      # https://docs.python.org/library/sqlite3.html#f1
      s.gsub! 'sqlite_defines.append(("SQLITE_OMIT_LOAD_EXTENSION", "1"))', ''
    end

    # Allow python modules to use ctypes.find_library to find homebrew's stuff
    # even if homebrew is not a /usr/local/lib. Try this with:
    # `brew install enchant && pip install pyenchant`
    inreplace './Lib/ctypes/macholib/dyld.py' do |f|
      f.gsub! 'DEFAULT_LIBRARY_FALLBACK = [',
              "DEFAULT_LIBRARY_FALLBACK = [ '#{HOMEBREW_PREFIX}/lib', '#{Formula['openssl@1.1'].opt_lib}',"
      f.gsub! 'DEFAULT_FRAMEWORK_FALLBACK = [', "DEFAULT_FRAMEWORK_FALLBACK = [ '#{HOMEBREW_PREFIX}/Frameworks',"
    end

    args << "CFLAGS=#{cflags.join(' ')}" unless cflags.empty?
    args << "CFLAGS_NODIST=#{cflags_nodist.join(' ')}" unless cflags_nodist.empty?
    args << "LDFLAGS=#{ldflags.join(' ')}" unless ldflags.empty?
    args << "LDFLAGS_NODIST=#{ldflags_nodist.join(' ')}" unless ldflags_nodist.empty?
    args << "CPPFLAGS=#{cppflags.join(' ')}" unless cppflags.empty?

    system './configure', *args
    system 'make'

    ENV.deparallelize do
      # Tell Python not to install into /Applications (default for framework builds)
      system 'make', 'install', "PYTHONAPPSDIR=#{prefix}"
      on_macos do
        system 'make', 'frameworkinstallextras', "PYTHONAPPSDIR=#{pkgshare}"
      end
    end

    on_macos do
      # Prevent third-party packages from building against fragile Cellar paths
      inreplace [lib_cellar / '_sysconfigdata.py',
                 lib_cellar / 'config/Makefile',
                 frameworks / 'Python.framework/Versions/Current/lib/pkgconfig/python-2.7.pc'],
                prefix, opt_prefix

      # Fixes setting Python build flags for certain software
      # See: https://github.com/Homebrew/homebrew/pull/20182
      # https://bugs.python.org/issue3588
      inreplace lib_cellar / 'config/Makefile' do |s|
        s.change_make_var! 'LINKFORSHARED',
                           '-u _PyMac_Error $(PYTHONFRAMEWORKINSTALLDIR)/Versions/$(VERSION)/$(PYTHONFRAMEWORK)'
      end
    end

    # Symlink the pkgconfig files into HOMEBREW_PREFIX so they're accessible.
    (lib / 'pkgconfig').install_symlink Dir["#{frameworks}/Python.framework/Versions/Current/lib/pkgconfig/*"]

    # Remove the site-packages that Python created in its Cellar.
    site_packages_cellar.rmtree

    # Remove 2to3 because Python 3 also installs it
    rm bin / '2to3'

    # A fix, because python and python@2 both want to install Python.framework
    # and therefore we can't link both into HOMEBREW_PREFIX/Frameworks
    # https://github.com/Homebrew/homebrew/issues/15943
    if OS.mac?
      %w[Headers Python Resources].each { |f| rm(prefix / "Frameworks/Python.framework/#{f}") }
      rm prefix / 'Frameworks/Python.framework/Versions/Current'
    end

    (libexec / 'setuptools').install resource('setuptools')
    (libexec / 'pip').install resource('pip')
    (libexec / 'wheel').install resource('wheel')
  end

  def post_install
    # Avoid conflicts with lingering unversioned files from Python 3
    rm_f %W[
      #{HOMEBREW_PREFIX}/bin/easy_install
      #{HOMEBREW_PREFIX}/bin/pip
      #{HOMEBREW_PREFIX}/bin/wheel
    ]

    # Fix up the site-packages so that user-installed Python software survives
    # minor updates, such as going from 2.7.0 to 2.7.1:

    # Create a site-packages in HOMEBREW_PREFIX/lib/python#{version.major_minor}/site-packages
    site_packages.mkpath

    # Symlink the prefix site-packages into the cellar.
    site_packages_cellar.unlink if site_packages_cellar.exist?
    site_packages_cellar.parent.install_symlink site_packages

    # Write our sitecustomize.py
    rm_rf Dir["#{site_packages}/sitecustomize.py[co]"]
    (site_packages / 'sitecustomize.py').atomic_write(sitecustomize) if OS.mac?

    # Remove old setuptools installations that may still fly around and be
    # listed in the easy_install.pth. This can break setuptools build with
    # zipimport.ZipImportError: bad local file header
    # setuptools-0.9.5-py3.3.egg
    rm_rf Dir["#{site_packages}/setuptools*"]
    rm_rf Dir["#{site_packages}/distribute*"]
    rm_rf Dir["#{site_packages}/pip[-_.][0-9]*", "#{site_packages}/pip"]

    setup_args = ['-s', 'setup.py', '--no-user-cfg', 'install', '--force',
                  '--verbose',
                  '--single-version-externally-managed',
                  '--record=installed.txt',
                  "--install-scripts=#{bin}",
                  "--install-lib=#{site_packages}"]

    (libexec / 'setuptools').cd { system "#{bin}/python", *setup_args }
    (libexec / 'pip').cd { system "#{bin}/python", *setup_args }
    (libexec / 'wheel').cd { system "#{bin}/python", *setup_args }

    # When building from source, these symlinks will not exist, since
    # post_install happens after linking.
    %w[pip pip2 wheel pip#{version.major_minor} easy_install easy_install-#{version.major_minor}].each do |e|
      (HOMEBREW_PREFIX / 'bin').install_symlink bin / e
    end

    # Help distutils find brewed stuff when building extensions
    include_dirs = [HOMEBREW_PREFIX / 'include', Formula['openssl@1.1'].opt_include,
                    Formula['sqlite'].opt_include, Formula['tcl-tk'].opt_include]
    library_dirs = [HOMEBREW_PREFIX / 'lib', Formula['openssl@1.1'].opt_lib,
                    Formula['sqlite'].opt_lib, Formula['tcl-tk'].opt_lib]

    cfg = lib_cellar / 'distutils/distutils.cfg'

    cfg.atomic_write <<~EOS
      [install]
      prefix=#{HOMEBREW_PREFIX}
      [build_ext]
      include_dirs=#{include_dirs.join ':'}
      library_dirs=#{library_dirs.join ':'}
    EOS
  end

  def sitecustomize
    <<~EOS
      # This file is created by Homebrew and is executed on each python startup.
      # Don't print from here, or else python command line scripts may fail!
      # <https://docs.brew.sh/Homebrew-and-Python>
      import re
      import os
      import sys
      if sys.version_info[0] != 2:
          # This can only happen if the user has set the PYTHONPATH for 3.x and run Python 2.x or vice versa.
          # Every Python looks at the PYTHONPATH variable and we can't fix it here in sitecustomize.py,
          # because the PYTHONPATH is evaluated after the sitecustomize.py. Many modules (e.g. PyQt4) are
          # built only for a specific version of Python and will fail with cryptic error messages.
          # In the end this means: Don't set the PYTHONPATH permanently if you use different Python versions.
          exit('Your PYTHONPATH points to a site-packages dir for Python 2.x but you are running Python ' +
               str(sys.version_info[0]) + '.x!\\n     PYTHONPATH is currently: "' + str(os.environ['PYTHONPATH']) + '"\\n' +
               '     You should `unset PYTHONPATH` to fix this.')
      # Only do this for a brewed python:
      if os.path.realpath(sys.executable).startswith('#{rack}'):
          # Shuffle /Library site-packages to the end of sys.path and reject
          # paths in /System pre-emptively (#14712)
          library_site = '/Library/Python/2.7/site-packages'
          library_packages = [p for p in sys.path if p.startswith(library_site)]
          sys.path = [p for p in sys.path if not p.startswith(library_site) and
                                             not p.startswith('/System')]
          # .pth files have already been processed so don't use addsitedir
          sys.path.extend(library_packages)
          # the Cellar site-packages is a symlink to the HOMEBREW_PREFIX
          # site_packages; prefer the shorter paths
          long_prefix = re.compile(r'#{rack}/[0-9\._abrc]+/Frameworks/Python\.framework/Versions/2\.7/lib/python2\.7/site-packages')
          sys.path = [long_prefix.sub('#{site_packages}', p) for p in sys.path]
          # LINKFORSHARED (and python-config --ldflags) return the
          # full path to the lib (yes, "Python" is actually the lib, not a
          # dir) so that third-party software does not need to add the
          # -F/#{HOMEBREW_PREFIX}/Frameworks switch.
          try:
              from _sysconfigdata import build_time_vars
              build_time_vars['LINKFORSHARED'] = '-u _PyMac_Error #{opt_prefix}/Frameworks/Python.framework/Versions/2.7/Python'
          except:
              pass  # remember: don't print here. Better to fail silently.
          # Set the sys.executable to use the opt_prefix
          sys.executable = '#{opt_bin}/python2.7'
    EOS
  end

  test do
    # Check if sqlite is ok, because we build with --enable-loadable-sqlite-extensions
    # and it can occur that building sqlite silently fails if OSX's sqlite is used.
    system "#{bin}/python#{version.major_minor}", '-c', 'import sqlite3'

    # check to see if we can create a venv
    # system "#{bin}/python#{version.major_minor}", "-m", "venv", testpath/"myvenv"

    # Check if some other modules import. Then the linked libs are working.
    system "#{bin}/python#{version.major_minor}", '-c', 'import gdbm'
    system "#{bin}/python#{version.major_minor}", '-c', 'import zlib'
    on_macos do
      # system "#{bin}/python#{version.major_minor}", "-c", "import tkinter; root = tkinter.Tk()"
    end

    system bin / 'pip', 'list', '--format=columns'
  end
end
