#!/usr/bin/env python
#
# Script to build and install Python-bindings.
# Version: 20251125

import copy
import datetime
import glob
import gzip
import platform
import os
import shlex
import shutil
import subprocess
import sys
import tarfile
import zipfile

from setuptools import Extension
from setuptools import setup
from setuptools._distutils.ccompiler import new_compiler
from setuptools.command.build_ext import build_ext
from setuptools.command.sdist import sdist


if (sys.version_info[0], sys.version_info[1]) < (3, 7):
  print(("Unsupported Python version: {0:s}, version 3.7 or higher "
         "required.").format(sys.version))
  sys.exit(1)


class custom_build_ext(build_ext):
  """Custom handler for the build_ext command."""

  def _RunCommand(self, command):
    """Runs the command."""
    arguments = shlex.split(command)
    process = subprocess.Popen(
        arguments, stderr=subprocess.PIPE, stdout=subprocess.PIPE,
        universal_newlines=True)
    if not process:
      raise RuntimeError("Running: {0:s} failed.".format(command))

    output, error = process.communicate()
    if process.returncode != 0:
      error = "\n".join(error.split("\n")[-5:])
      raise RuntimeError("Running: {0:s} failed with error:\n{1:s}.".format(
          command, error))

    return output

  def build_extensions(self):
    """Set up the build extensions."""
    # TODO: move build customization here?
    build_ext.build_extensions(self)

  def run(self):
    """Runs the build extension."""
    compiler = new_compiler(compiler=self.compiler)
    if compiler.compiler_type == "msvc":
      self.define = [
          ("_CRT_SECURE_NO_WARNINGS", ""),
          ("UNICODE", ""),
      ]

    else:
      command = "sh configure --disable-nls --disable-shared-libs"
      output = self._RunCommand(command)

      print_line = False
      for line in output.split("\n"):
        line = line.rstrip()
        if line == "configure:":
          print_line = True

        if print_line:
          print(line)

      self.define = [
          ("HAVE_CONFIG_H", ""),
      ]

    build_ext.run(self)


class custom_sdist(sdist):
  """Custom handler for the sdist command."""

  def run(self):
    """Builds a source distribution (sdist) package."""
    if self.formats != ["gztar"] and self.formats != ["zip"]:
      print("'setup.py sdist' unsupported format.")
      sys.exit(1)

    if glob.glob("*.tar.gz"):
      print("'setup.py sdist' remove existing *.tar.gz files from "
            "source directory.")
      sys.exit(1)

    command = "make dist"
    exit_code = subprocess.call(command, shell=True)
    if exit_code != 0:
      raise RuntimeError("Running: {0:s} failed.".format(command))

    if not os.path.exists(self.dist_dir):
      os.mkdir(self.dist_dir)

    source_package_file = glob.glob("*.tar.gz")[0]
    source_package_prefix, _, source_package_suffix = (
        source_package_file.partition("-"))
    sdist_package_file = "{0:s}_python-{1:s}".format(
        source_package_prefix, source_package_suffix)
    sdist_package_file = os.path.join(self.dist_dir, sdist_package_file)
    os.rename(source_package_file, sdist_package_file)

    # Create and add the PKG-INFO file to the source package.
    with gzip.open(sdist_package_file, "rb") as input_file:
      with open(sdist_package_file[:-3], "wb") as output_file:
        shutil.copyfileobj(input_file, output_file)
    os.remove(sdist_package_file)

    self.distribution.metadata.write_pkg_info(".")
    pkg_info_path = "{0:s}-{1:s}/PKG-INFO".format(
        source_package_prefix, source_package_suffix[:-7])
    with tarfile.open(sdist_package_file[:-3], "a:") as tar_file:
      tar_file.add("PKG-INFO", arcname=pkg_info_path)
    os.remove("PKG-INFO")

    with open(sdist_package_file[:-3], "rb") as input_file:
      with gzip.open(sdist_package_file, "wb") as output_file:
        shutil.copyfileobj(input_file, output_file)
    os.remove(sdist_package_file[:-3])

    # Convert the .tar.gz into a .zip
    if self.formats == ["zip"]:
      zip_sdist_package_file = "{0:s}.zip".format(sdist_package_file[:-7])

      with tarfile.open(sdist_package_file, "r|gz") as tar_file:
        with zipfile.ZipFile(
            zip_sdist_package_file, "w", zipfile.ZIP_DEFLATED) as zip_file:
          for tar_file_entry in tar_file:
            file_entry = tar_file.extractfile(tar_file_entry)
            if tar_file_entry.isfile():
              modification_time = datetime.datetime.fromtimestamp(
                  tar_file_entry.mtime)
              zip_modification_time = (
                  modification_time.year, modification_time.month,
                  modification_time.day, modification_time.hour,
                  modification_time.minute, modification_time.second)
              zip_info = zipfile.ZipInfo(
                  date_time=zip_modification_time,
                  filename=tar_file_entry.name)
              zip_info.external_attr = (tar_file_entry.mode & 0xff) << 16

              file_data = file_entry.read()
              zip_file.writestr(zip_info, file_data)

      os.remove(sdist_package_file)
      sdist_package_file = zip_sdist_package_file

    # Inform setuptools what files were created.
    dist_files = getattr(self.distribution, "dist_files", [])
    dist_files.append(("sdist", "", sdist_package_file))


class ProjectInformation(object):
  """Project information."""

  def __init__(self):
    """Initializes project information."""
    super(ProjectInformation, self).__init__()
    self.include_directories = []
    self.library_name = None
    self.library_names = []
    self.library_version = None

    self._ReadConfigureAc()
    self._ReadMakefileAm()

  @property
  def module_name(self):
    """The Python module name."""
    return "py{0:s}".format(self.library_name[3:])

  def _ReadConfigureAc(self):
    """Reads configure.ac to initialize the project information."""
    with open("configure.ac", "r", encoding="utf-8") as file_object:
      found_ac_init = False
      found_library_name = False
      for line in file_object.readlines():
        line = line.strip()
        if found_library_name:
          library_version = line[1:-2]
          self.library_version = library_version
          break

        elif found_ac_init:
          library_name = line[1:-2]
          self.library_name = library_name
          found_library_name = True

        elif line.startswith("AC_INIT"):
          found_ac_init = True

    if not self.library_name or not self.library_version:
      raise RuntimeError(
          "Unable to find library name and version in: configure.ac")

  def _ReadMakefileAm(self):
    """Reads Makefile.am to initialize the project information."""
    if not self.library_name:
      raise RuntimeError("Missing library name")

    with open("Makefile.am", "r", encoding="utf-8") as file_object:
      found_subdirs = False
      for line in file_object.readlines():
        line = line.strip()
        if found_subdirs:
          library_name, _, _ = line.partition(" ")

          self.include_directories.append(library_name)

          if library_name.startswith("lib"):
            self.library_names.append(library_name)

          if library_name == self.library_name:
            break

        elif line.startswith("SUBDIRS"):
          found_subdirs = True

    if not self.include_directories or not self.library_names:
      raise RuntimeError(
          "Unable to find include directories and library names in: "
          "Makefile.am")


project_information = ProjectInformation()

CMDCLASS = {
  "build_ext": custom_build_ext,
  "sdist": custom_sdist}

SOURCES = []

# TODO: replace by detection of MSC
DEFINE_MACROS = []
if platform.system() == "Windows":
  DEFINE_MACROS.append(("WINVER", "0x0501"))
  # TODO: determine how to handle third party DLLs.
  for library_name in project_information.library_names:
    if library_name != project_information.library_name:
      definition = "HAVE_LOCAL_{0:s}".format(library_name.upper())

    DEFINE_MACROS.append((definition, ""))

# Put everything inside the Python module to prevent issues with finding
# shared libaries since pip does not integrate well with the system package
# management.
for library_name in project_information.library_names:
  for source_file in glob.glob(os.path.join(library_name, "*.[ly]")):
    generated_source_file = "{0:s}.c".format(source_file[:-2])
    if not os.path.exists(generated_source_file):
      raise RuntimeError("Missing generated source file: {0:s}".format(
          generated_source_file))

  source_files = glob.glob(os.path.join(library_name, "*.c"))
  SOURCES.extend(source_files)

source_files = glob.glob(os.path.join(project_information.module_name, "*.c"))
SOURCES.extend(source_files)

# TODO: find a way to detect missing python.h
# e.g. on Ubuntu python-dev is not installed by python-pip

setup_args = dict(
    cmdclass=CMDCLASS,
    ext_modules=[
        Extension(
            project_information.module_name,
            define_macros=DEFINE_MACROS,
            include_dirs=project_information.include_directories,
            libraries=[],
            library_dirs=[],
            sources=SOURCES
        )
    ]
)
setup(**setup_args)