from __future__ import division

import re
import os
import sys
import warnings
import platform
import tempfile
from subprocess import Popen, PIPE, STDOUT

from numpy.distutils.cpuinfo import cpu
from numpy.distutils.fcompiler import FCompiler
from numpy.distutils.exec_command import exec_command
from numpy.distutils.misc_util import msvc_runtime_library
from numpy.distutils.compat import get_exception

compilers = ['GnuFCompiler', 'Gnu95FCompiler']

TARGET_R = re.compile("Target: ([a-zA-Z0-9_\-]*)")

# XXX: handle cross compilation
def is_win64():
    return sys.platform == "win32" and platform.architecture()[0] == "64bit"

if is_win64():
    #_EXTRAFLAGS = ["-fno-leading-underscore"]
    _EXTRAFLAGS = []
else:
    _EXTRAFLAGS = []

class GnuFCompiler(FCompiler):
    compiler_type = 'gnu'
    compiler_aliases = ('g77',)
    description = 'GNU Fortran 77 compiler'

    def gnu_version_match(self, version_string):
        """Handle the different versions of GNU fortran compilers"""
        m = re.match(r'GNU Fortran', version_string)
        if not m:
            return None
        m = re.match(r'GNU Fortran\s+95.*?([0-9-.]+)', version_string)
        if m:
            return ('gfortran', m.group(1))
        m = re.match(r'GNU Fortran.*?([0-9-.]+)', version_string)
        if m:
            v = m.group(1)
            if v.startswith('0') or v.startswith('2') or v.startswith('3'):
                # the '0' is for early g77's
                return ('g77', v)
            else:
                # at some point in the 4.x series, the ' 95' was dropped
                # from the version string
                return ('gfortran', v)

    def version_match(self, version_string):
        v = self.gnu_version_match(version_string)
        if not v or v[0] != 'g77':
            return None
        return v[1]

    # 'g77 --version' results
    # SunOS: GNU Fortran (GCC 3.2) 3.2 20020814 (release)
    # Debian: GNU Fortran (GCC) 3.3.3 20040110 (prerelease) (Debian)
    #         GNU Fortran (GCC) 3.3.3 (Debian 20040401)
    #         GNU Fortran 0.5.25 20010319 (prerelease)
    # Redhat: GNU Fortran (GCC 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
    # GNU Fortran (GCC) 3.4.2 (mingw-special)

    possible_executables = ['g77', 'f77']
    executables = {
        'version_cmd'  : [None, "--version"],
        'compiler_f77' : [None, "-g", "-Wall", "-fno-second-underscore"],
        'compiler_f90' : None, # Use --fcompiler=gnu95 for f90 codes
        'compiler_fix' : None,
        'linker_so'    : [None, "-g", "-Wall"],
        'archiver'     : ["ar", "-cr"],
        'ranlib'       : ["ranlib"],
        'linker_exe'   : [None, "-g", "-Wall"]
        }
    module_dir_switch = None
    module_include_switch = None

    # Cygwin: f771: warning: -fPIC ignored for target (all code is
    # position independent)
    if os.name != 'nt' and sys.platform != 'cygwin':
        pic_flags = ['-fPIC']

    # use -mno-cygwin for g77 when Python is not Cygwin-Python
    if sys.platform == 'win32':
        for key in ['version_cmd', 'compiler_f77', 'linker_so', 'linker_exe']:
            executables[key].append('-mno-cygwin')

    g2c = 'g2c'

    suggested_f90_compiler = 'gnu95'

    #def get_linker_so(self):
    #    # win32 linking should be handled by standard linker
    #    # Darwin g77 cannot be used as a linker.
    #    #if re.match(r'(darwin)', sys.platform):
    #    #    return
    #    return FCompiler.get_linker_so(self)

    def get_flags_linker_so(self):
        opt = self.linker_so[1:]
        if sys.platform=='darwin':
            target = os.environ.get('MACOSX_DEPLOYMENT_TARGET', None)
            # If MACOSX_DEPLOYMENT_TARGET is set, we simply trust the value
            # and leave it alone.  But, distutils will complain if the
            # environment's value is different from the one in the Python
            # Makefile used to build Python.  We let disutils handle this
            # error checking.
            if not target:
                # If MACOSX_DEPLOYMENT_TARGET is not set in the environment,
                # we try to get it first from the Python Makefile and then we
                # fall back to setting it to 10.3 to maximize the set of
                # versions we can work with.  This is a reasonable default
                # even when using the official Python dist and those derived
                # from it.
                import distutils.sysconfig as sc
                g = {}
                filename = sc.get_makefile_filename()
                sc.parse_makefile(filename, g)
                target = g.get('MACOSX_DEPLOYMENT_TARGET', '10.3')
                os.environ['MACOSX_DEPLOYMENT_TARGET'] = target
                if target == '10.3':
                    s = 'Env. variable MACOSX_DEPLOYMENT_TARGET set to 10.3'
                    warnings.warn(s)

            opt.extend(['-undefined', 'dynamic_lookup', '-bundle'])
        else:
            opt.append("-shared")
        if sys.platform.startswith('sunos'):
            # SunOS often has dynamically loaded symbols defined in the
            # static library libg2c.a  The linker doesn't like this.  To
            # ignore the problem, use the -mimpure-text flag.  It isn't
            # the safest thing, but seems to work. 'man gcc' says:
            # ".. Instead of using -mimpure-text, you should compile all
            #  source code with -fpic or -fPIC."
            opt.append('-mimpure-text')
        return opt

    def get_libgcc_dir(self):
        status, output = exec_command(self.compiler_f77 +
                                      ['-print-libgcc-file-name'],
                                      use_tee=0)
        if not status:
            return os.path.dirname(output)
        return None

    def get_library_dirs(self):
        opt = []
        if sys.platform[:5] != 'linux':
            d = self.get_libgcc_dir()
            if d:
                # if windows and not cygwin, libg2c lies in a different folder
                if sys.platform == 'win32' and not d.startswith('/usr/lib'):
                    d = os.path.normpath(d)
                    if not os.path.exists(os.path.join(d, "lib%s.a" % self.g2c)):
                        d2 = os.path.abspath(os.path.join(d,
                                                          '../../../../lib'))
                        if os.path.exists(os.path.join(d2, "lib%s.a" % self.g2c)):
                            opt.append(d2)
                opt.append(d)
        return opt

    def get_libraries(self):
        opt = []
        d = self.get_libgcc_dir()
        if d is not None:
            g2c = self.g2c + '-pic'
            f = self.static_lib_format % (g2c, self.static_lib_extension)
            if not os.path.isfile(os.path.join(d,f)):
                g2c = self.g2c
        else:
            g2c = self.g2c

        if g2c is not None:
            opt.append(g2c)
        c_compiler = self.c_compiler
        if sys.platform == 'win32' and c_compiler and \
               c_compiler.compiler_type=='msvc':
            # the following code is not needed (read: breaks) when using MinGW
            # in case want to link F77 compiled code with MSVC
            opt.append('gcc')
            runtime_lib = msvc_runtime_library()
            if runtime_lib:
                opt.append(runtime_lib)
        if sys.platform == 'darwin':
            opt.append('cc_dynamic')
        return opt

    def get_flags_debug(self):
        return ['-g']

    def get_flags_opt(self):
        v = self.get_version()
        if v and v<='3.3.3':
            # With this compiler version building Fortran BLAS/LAPACK
            # with -O3 caused failures in lib.lapack heevr,syevr tests.
            opt = ['-O2']
        else:
            opt = ['-O3']
        opt.append('-funroll-loops')
        return opt

    def _c_arch_flags(self):
        """ Return detected arch flags from CFLAGS """
        from distutils import sysconfig
        try:
            cflags = sysconfig.get_config_vars()['CFLAGS']
        except KeyError:
            return []
        arch_re = re.compile(r"-arch\s+(\w+)")
        arch_flags = []
        for arch in arch_re.findall(cflags):
            arch_flags += ['-arch', arch]
        return arch_flags

    def get_flags_arch(self):
        return []

class Gnu95FCompiler(GnuFCompiler):
    compiler_type = 'gnu95'
    compiler_aliases = ('gfortran',)
    description = 'GNU Fortran 95 compiler'

    def version_match(self, version_string):
        v = self.gnu_version_match(version_string)
        if not v or v[0] != 'gfortran':
            return None
        v = v[1]
        if v>='4.':
            # gcc-4 series releases do not support -mno-cygwin option
            pass
        else:
            # use -mno-cygwin flag for gfortran when Python is not Cygwin-Python
            if sys.platform == 'win32':
                for key in ['version_cmd', 'compiler_f77', 'compiler_f90',
                            'compiler_fix', 'linker_so', 'linker_exe']:
                    self.executables[key].append('-mno-cygwin')
        return v

    # 'gfortran --version' results:
    # XXX is the below right?
    # Debian: GNU Fortran 95 (GCC 4.0.3 20051023 (prerelease) (Debian 4.0.2-3))
    #         GNU Fortran 95 (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)
    # OS X: GNU Fortran 95 (GCC) 4.1.0
    #       GNU Fortran 95 (GCC) 4.2.0 20060218 (experimental)
    #       GNU Fortran (GCC) 4.3.0 20070316 (experimental)

    possible_executables = ['gfortran', 'f95']
    executables = {
        'version_cmd'  : ["<F90>", "--version"],
        'compiler_f77' : [None, "-Wall", "-ffixed-form",
                          "-fno-second-underscore"] + _EXTRAFLAGS,
        'compiler_f90' : [None, "-Wall", "-fno-second-underscore"] + _EXTRAFLAGS,
        'compiler_fix' : [None, "-Wall", "-ffixed-form",
                          "-fno-second-underscore"] + _EXTRAFLAGS,
        'linker_so'    : ["<F90>", "-Wall"],
        'archiver'     : ["ar", "-cr"],
        'ranlib'       : ["ranlib"],
        'linker_exe'   : [None, "-Wall"]
        }

    module_dir_switch = '-J'
    module_include_switch = '-I'

    g2c = 'gfortran'

    def _universal_flags(self, cmd):
        """Return a list of -arch flags for every supported architecture."""
        if not sys.platform == 'darwin':
            return []
        arch_flags = []
        # get arches the C compiler gets.
        c_archs = self._c_arch_flags()
        if "i386" in c_archs:
            c_archs[c_archs.index("i386")] = "i686"
        # check the arches the Fortran compiler supports, and compare with
        # arch flags from C compiler
        for arch in ["ppc", "i686", "x86_64", "ppc64"]:
            if _can_target(cmd, arch) and arch in c_archs:
                arch_flags.extend(["-arch", arch])
        return arch_flags

    def get_flags(self):
        flags = GnuFCompiler.get_flags(self)
        arch_flags = self._universal_flags(self.compiler_f90)
        if arch_flags:
            flags[:0] = arch_flags
        return flags

    def get_flags_linker_so(self):
        flags = GnuFCompiler.get_flags_linker_so(self)
        arch_flags = self._universal_flags(self.linker_so)
        if arch_flags:
            flags[:0] = arch_flags
        return flags

    def get_library_dirs(self):
        opt = GnuFCompiler.get_library_dirs(self)
        if sys.platform == 'win32':
            c_compiler = self.c_compiler
            if c_compiler and c_compiler.compiler_type == "msvc":
                target = self.get_target()
                if target:
                    d = os.path.normpath(self.get_libgcc_dir())
                    root = os.path.join(d, os.pardir, os.pardir, os.pardir, os.pardir)
                    mingwdir = os.path.normpath(os.path.join(root, target, "lib"))
                    full = os.path.join(mingwdir, "libmingwex.a")
                    if os.path.exists(full):
                        opt.append(mingwdir)
        return opt

    def get_libraries(self):
        opt = GnuFCompiler.get_libraries(self)
        if sys.platform == 'darwin':
            opt.remove('cc_dynamic')
        if sys.platform == 'win32':
            c_compiler = self.c_compiler
            if c_compiler and c_compiler.compiler_type == "msvc":
                if "gcc" in opt:
                    i = opt.index("gcc")
                    opt.insert(i+1, "mingwex")
                    opt.insert(i+1, "mingw32")
            # XXX: fix this mess, does not work for mingw
            if is_win64():
                c_compiler = self.c_compiler
                if c_compiler and c_compiler.compiler_type == "msvc":
                    return []
                else:
                    raise NotImplementedError("Only MS compiler supported with gfortran on win64")
        return opt

    def get_target(self):
        status, output = exec_command(self.compiler_f77 +
                                      ['-v'],
                                      use_tee=0)
        if not status:
            m = TARGET_R.search(output)
            if m:
                return m.group(1)
        return ""

    def get_flags_opt(self):
        if is_win64():
            return ['-O0']
        else:
            return GnuFCompiler.get_flags_opt(self)

def _can_target(cmd, arch):
    """Return true is the command supports the -arch flag for the given
    architecture."""
    newcmd = cmd[:]
    fid, filename = tempfile.mkstemp(suffix=".f")
    try:
        d = os.path.dirname(filename)
        output = os.path.splitext(filename)[0] + ".o"
        try:
            newcmd.extend(["-arch", arch, "-c", filename])
            p = Popen(newcmd, stderr=STDOUT, stdout=PIPE, cwd=d)
            p.communicate()
            return p.returncode == 0
        finally:
            if os.path.exists(output):
                os.remove(output)
    finally:
        os.remove(filename)
    return False

if __name__ == '__main__':
    from distutils import log
    log.set_verbosity(2)
    compiler = GnuFCompiler()
    compiler.customize()
    print(compiler.get_version())
    raw_input('Press ENTER to continue...')
    try:
        compiler = Gnu95FCompiler()
        compiler.customize()
        print(compiler.get_version())
    except Exception:
        msg = get_exception()
        print(msg)
    raw_input('Press ENTER to continue...')