# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*-
# vi: set ft=python sts=4 ts=4 sw=4 et:
"""
Build helpers for setup.py

Includes package dependency checks, and code to build the documentation

To build the docs, run::

    python setup.py build_sphinx
    
"""

# Standard library imports
import sys
import os
from os.path import join as pjoin, dirname
import zipfile
import warnings
import shutil
from distutils.cmd import Command
from distutils.command.clean import clean
from distutils.version import LooseVersion
from distutils.dep_util import newer_group
from distutils.errors import DistutilsError

from numpy.distutils.misc_util import appendpath
from numpy.distutils import log

# Sphinx import
try:
    from sphinx.setup_command import BuildDoc
except ImportError:
    have_sphinx = False
else:
    have_sphinx = True

# Get project related strings.  Please do not change this line to use
# execfile because execfile is not available in Python 3
_info_fname = pjoin('nipy', 'info.py')
INFO_VARS = {}
exec(open(_info_fname, 'rt').read(), {}, INFO_VARS)

DOC_BUILD_DIR = os.path.join('build', 'html')

CYTHON_MIN_VERSION = INFO_VARS['cython_min_version']

################################################################################
# Distutils Command class for installing nipy to a temporary location. 
class TempInstall(Command):
    temp_install_dir = os.path.join('build', 'install')

    def run(self):
        """ build and install nipy in a temporary location. """
        install = self.distribution.get_command_obj('install')
        install.install_scripts = self.temp_install_dir
        install.install_base    = self.temp_install_dir
        install.install_platlib = self.temp_install_dir 
        install.install_purelib = self.temp_install_dir 
        install.install_data    = self.temp_install_dir 
        install.install_lib     = self.temp_install_dir 
        install.install_headers = self.temp_install_dir 
        install.run()

        # Horrible trick to reload nipy with our temporary instal
        for key in sys.modules.keys():
            if key.startswith('nipy'):
                sys.modules.pop(key, None)
        sys.path.append(os.path.abspath(self.temp_install_dir))
        # Pop the cwd
        sys.path.pop(0)
        import nipy

    def initialize_options(self):
        pass
    
    def finalize_options(self):
        pass


################################################################################
# Distutils Command class for API generation 
class APIDocs(TempInstall):
    description = \
    """generate API docs """

    user_options = [
        ('None', None, 'this command has no options'),
        ]


    def run(self):
        # First build the project and install it to a temporary location.
        TempInstall.run(self)
        os.chdir('doc')
        try:
            # We are running the API-building script via an
            # system call, but overriding the import path.
            toolsdir = os.path.abspath(pjoin('..', 'tools'))
            build_templates = pjoin(toolsdir, 'build_modref_templates.py')
            cmd = """%s -c 'import sys; sys.path.append("%s"); sys.path.append("%s"); execfile("%s", dict(__name__="__main__"))'""" \
                % (sys.executable, 
                   toolsdir,
                   self.temp_install_dir,
                   build_templates)
            os.system(cmd)
        finally:
            os.chdir('..')


################################################################################
# Code to copy the sphinx-generated html docs in the distribution.
def relative_path(filename):
    """ Return the relative path to the file, assuming the file is
        in the DOC_BUILD_DIR directory.
    """
    length = len(os.path.abspath(DOC_BUILD_DIR)) + 1
    return os.path.abspath(filename)[length:]



################################################################################
# Distutils Command class to clean
class Clean(clean):

    def run(self):
        clean.run(self)
        api_path = os.path.join('doc', 'api', 'generated')
        if os.path.exists(api_path):
            print "Removing %s" % api_path
            shutil.rmtree(api_path)
        if os.path.exists(DOC_BUILD_DIR):
            print "Removing %s" % DOC_BUILD_DIR 
            shutil.rmtree(DOC_BUILD_DIR)


################################################################################
# Distutils Command class build the docs
if have_sphinx:
    class MyBuildDoc(BuildDoc):
        """ Sub-class the standard sphinx documentation building system, to
            add logics for API generation and matplotlib's plot directive.
        """

        def run(self):
            self.run_command('api_docs')
            # We need to be in the doc directory for to plot_directive
            # and API generation to work
            os.chdir('doc')
            try:
                BuildDoc.run(self)
            finally:
                os.chdir('..')
            self.zip_docs()

        def zip_docs(self):
            if not os.path.exists(DOC_BUILD_DIR):
                raise OSError, 'Doc directory does not exist.'
            target_file = os.path.join('doc', 'documentation.zip')
            # ZIP_DEFLATED actually compresses the archive. However, there
            # will be a RuntimeError if zlib is not installed, so we check
            # for it. ZIP_STORED produces an uncompressed zip, but does not
            # require zlib.
            try:
                zf = zipfile.ZipFile(target_file, 'w', 
                                            compression=zipfile.ZIP_DEFLATED)
            except RuntimeError:
                warnings.warn('zlib not installed, storing the docs '
                                'without compression')
                zf = zipfile.ZipFile(target_file, 'w', 
                                            compression=zipfile.ZIP_STORED)    

            for root, dirs, files in os.walk(DOC_BUILD_DIR):
                relative = relative_path(root)
                if not relative.startswith('.doctrees'):
                    for f in files:
                        zf.write(os.path.join(root, f), 
                                os.path.join(relative, 'html_docs', f))
            zf.close()

        def finalize_options(self):
            """ Override the default for the documentation build
                directory.
            """
            self.build_dir = os.path.join(*DOC_BUILD_DIR.split(os.sep)[:-1])
            BuildDoc.finalize_options(self)

else: # failed Sphinx import
    # Raise an error when trying to build docs
    class MyBuildDoc(Command):
        user_options = []
        def run(self):
            raise ImportError(
                "Sphinx is not installed, docs cannot be built")
        def initialize_options(self):
            pass
        def finalize_options(self):
            pass


# The command classes for distutils, used by setup.py
cmdclass = {'api_docs': APIDocs,
            'clean': Clean,
            'build_sphinx': MyBuildDoc}


# Dependency checks
def package_check(pkg_name, version=None,
                  optional=False,
                  checker=LooseVersion,
                  version_getter=None,
                  messages=None
                  ):
    ''' Check if package `pkg_name` is present, and correct version

    Parameters
    ----------
    pkg_name : str
       name of package as imported into python
    version : {None, str}, optional
       minimum version of the package that we require. If None, we don't
       check the version.  Default is None
    optional : {False, True}, optional
       If False, raise error for absent package or wrong version;
       otherwise warn
    checker : callable, optional
       callable with which to return comparable thing from version
       string.  Default is ``distutils.version.LooseVersion``
    version_getter : {None, callable}:
       Callable that takes `pkg_name` as argument, and returns the
       package version string - as in::
       
          ``version = version_getter(pkg_name)``

       If None, equivalent to::

          mod = __import__(pkg_name); version = mod.__version__``
    messages : None or dict, optional
       dictionary giving output messages
    '''
    if version_getter is None:
        def version_getter(pkg_name):
            mod = __import__(pkg_name)
            return mod.__version__
    if messages is None:
        messages = {}
    msgs = {
         'missing': 'Cannot import package "%s" - is it installed?',
         'missing opt': 'Missing optional package "%s"',
         'opt suffix' : '; you may get run-time errors',
         'version too old': 'You have version %s of package "%s"' 
         ' but we need version >= %s', }
    msgs.update(messages)
    try:
        __import__(pkg_name)
    except ImportError:
        if not optional:
            raise RuntimeError(msgs['missing'] % pkg_name)
        log.warn(msgs['missing opt'] % pkg_name +
                 msgs['opt suffix'])
        return
    if not version:
        return
    try:
        have_version = version_getter(pkg_name)
    except AttributeError:
        raise RuntimeError('Cannot find version for %s' % pkg_name)
    if checker(have_version) < checker(version):
        if optional:
            log.warn(msgs['version too old'] + msgs['opt suffix'],
                     have_version,
                     pkg_name,
                     version)
        else:
            raise RuntimeError(msgs['version too old'],
                               have_version,
                               pkg_name,
                               version)


def have_good_cython():
    try:
        from Cython.Compiler.Version import version
    except ImportError:
        return False
    return LooseVersion(version) >= LooseVersion(CYTHON_MIN_VERSION)


def generate_a_pyrex_source(self, base, ext_name, source, extension):
    ''' Monkey patch for numpy build_src.build_src method

    Uses Cython instead of Pyrex.
    '''
    good_cython = have_good_cython()
    if self.inplace or not good_cython:
        target_dir = dirname(base)
    else:
        target_dir = appendpath(self.build_src, dirname(base))
    target_file = pjoin(target_dir, ext_name + '.c')
    depends = [source] + extension.depends
    sources_changed = newer_group(depends, target_file, 'newer') 
    if self.force or sources_changed:
        if good_cython:
            # add distribution (package-wide) include directories, in order
            # to pick up needed .pxd files for cython compilation
            incl_dirs = extension.include_dirs[:]
            dist_incl_dirs = self.distribution.include_dirs
            if not dist_incl_dirs is None:
                incl_dirs += dist_incl_dirs
            import Cython.Compiler.Main
            log.info("cythonc:> %s" % (target_file))
            self.mkpath(target_dir)
            options = Cython.Compiler.Main.CompilationOptions(
                defaults=Cython.Compiler.Main.default_options,
                include_path=incl_dirs,
                output_file=target_file)
            cython_result = Cython.Compiler.Main.compile(source,
                                                       options=options)
            if cython_result.num_errors != 0:
                raise DistutilsError("%d errors while compiling "
                                     "%r with Cython"
                                     % (cython_result.num_errors, source))
        elif sources_changed and os.path.isfile(target_file):
            raise DistutilsError("Cython >=%s required for compiling %r"
                                 " because sources (%s) have changed" %
                                 (CYTHON_MIN_VERSION, source, ','.join(depends)))
        else:
            raise DistutilsError("Cython >=%s required for compiling %r"
                                 " but not available" %
                                 (CYTHON_MIN_VERSION, source))
    return target_file