import py, os, sys, re
from pypy.translator.platform import CompilationError, ExecutionResult
from pypy.translator.platform import log, _run_subprocess
from pypy.translator.platform import Platform, posix
from pypy.tool import autopath

def Windows(cc=None):
    if cc == 'mingw32':
        return MingwPlatform(cc)
    else:
        return MsvcPlatform(cc)

def _get_msvc_env(vsver):
    try:
        toolsdir = os.environ['VS%sCOMNTOOLS' % vsver]
    except KeyError:
        return None

    vcvars = os.path.join(toolsdir, 'vsvars32.bat')

    import subprocess
    popen = subprocess.Popen('"%s" & set' % (vcvars,),
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)

    stdout, stderr = popen.communicate()
    if popen.wait() != 0:
        return

    env = {}

    stdout = stdout.replace("\r\n", "\n")
    for line in stdout.split("\n"):
        if '=' not in line:
            continue
        key, value = line.split('=', 1)
        if key.upper() in ['PATH', 'INCLUDE', 'LIB']:
            env[key.upper()] = value
    log.msg("Updated environment with %s" % (vcvars,))
    return env

def find_msvc_env():
    # First, try to get the compiler which served to compile python
    msc_pos = sys.version.find('MSC v.')
    if msc_pos != -1:
        msc_ver = int(sys.version[msc_pos+6:msc_pos+10])
        # 1300 -> 70, 1310 -> 71, 1400 -> 80, 1500 -> 90
        vsver = (msc_ver / 10) - 60
        env = _get_msvc_env(vsver)

        if env is not None:
            return env

    # Then, try any other version
    for vsver in (100, 90, 80, 71, 70): # All the versions I know
        env = _get_msvc_env(vsver)

        if env is not None:
            return env

    log.error("Could not find a Microsoft Compiler")
    # Assume that the compiler is already part of the environment

msvc_compiler_environ = find_msvc_env()

class MsvcPlatform(Platform):
    name = "msvc"
    so_ext = 'dll'
    exe_ext = 'exe'

    cc = 'cl.exe'
    link = 'link.exe'

    cflags = ['/MD', '/O2']
    link_flags = []
    standalone_only = []
    shared_only = []
    environ = None

    def __init__(self, cc=None):
        Platform.__init__(self, 'cl.exe')
        if msvc_compiler_environ:
            self.c_environ = os.environ.copy()
            self.c_environ.update(msvc_compiler_environ)
            # XXX passing an environment to subprocess is not enough. Why?
            os.environ.update(msvc_compiler_environ)

        # detect version of current compiler
        returncode, stdout, stderr = _run_subprocess(self.cc, '',
                                                     env=self.c_environ)
        r = re.search('[Vv]ersion\W([0-9]+)\.([0-9]+)', stderr)
        if r is not None:
            self.version = int(''.join(r.groups())) / 10 - 60
        else:
            # Probably not a msvc compiler...
            self.version = 0

        # Try to find a masm assembler
        returncode, stdout, stderr = _run_subprocess('ml.exe', '',
                                                     env=self.c_environ)
        r = re.search('Macro Assembler', stderr)
        if r is None and os.path.exists('c:/masm32/bin/ml.exe'):
            self.masm = 'c:/masm32/bin/ml.exe'
        else:
            self.masm = 'ml.exe'

        # Install debug options only when interpreter is in debug mode
        if sys.executable.lower().endswith('_d.exe'):
            self.cflags = ['/MDd', '/Z7', '/Od']
            self.link_flags = ['/debug']

            # Increase stack size, for the linker and the stack check code.
            stack_size = 8 << 20  # 8 Mb
            self.link_flags.append('/STACK:%d' % stack_size)
            # The following symbol is used in c/src/stack.h
            self.cflags.append('/DMAX_STACK_SIZE=%d' % (stack_size - 1024))

        if hasattr(sys, 'exec_prefix'):
            self.add_cpython_dirs = True
        else:
            # We are certainly running pypy-c
            self.add_cpython_dirs = False

    def _preprocess_dirs(self, include_dirs):
        if self.add_cpython_dirs:
            return include_dirs + (py.path.local(sys.exec_prefix).join('PC'),)
        return include_dirs

    def _includedirs(self, include_dirs):
        return ['/I%s' % (idir,) for idir in include_dirs]

    def _libs(self, libraries):
        return ['%s.lib' % (lib,) for lib in libraries]

    def _libdirs(self, library_dirs):
        return ['/LIBPATH:%s' % (ldir,) for ldir in library_dirs]

    def _linkfiles(self, link_files):
        return list(link_files)

    def _args_for_shared(self, args):
        return ['/dll'] + args

    def check___thread(self):
        # __declspec(thread) does not seem to work when using assembler.
        # Returning False will cause the program to use TlsAlloc functions.
        # see src/thread_nt.h
        return False

    def _link_args_from_eci(self, eci, standalone):
        # Windows needs to resolve all symbols even for DLLs
        args = super(MsvcPlatform, self)._link_args_from_eci(eci, standalone=True)
        return args + ['/EXPORT:%s' % symbol for symbol in eci.export_symbols]

    def _compile_c_file(self, cc, cfile, compile_args):
        oname = cfile.new(ext='obj')
        args = ['/nologo', '/c'] + compile_args + [str(cfile), '/Fo%s' % (oname,)]
        self._execute_c_compiler(cc, args, oname)
        return oname

    def _link(self, cc, ofiles, link_args, standalone, exe_name):
        args = ['/nologo'] + [str(ofile) for ofile in ofiles] + link_args
        args += ['/out:%s' % (exe_name,), '/incremental:no']
        if not standalone:
            args = self._args_for_shared(args)

        if self.version >= 80:
            # Tell the linker to generate a manifest file
            temp_manifest = ofile.dirpath().join(
                ofile.purebasename + '.manifest')
            args += ["/MANIFESTFILE:%s" % (temp_manifest,)]

        self._execute_c_compiler(self.link, args, exe_name)

        if self.version >= 80:
            # Now, embed the manifest into the program
            if standalone:
                mfid = 1
            else:
                mfid = 2
            out_arg = '-outputresource:%s;%s' % (exe_name, mfid)
            args = ['-nologo', '-manifest', str(temp_manifest), out_arg]
            self._execute_c_compiler('mt.exe', args, exe_name)

        return exe_name

    def _handle_error(self, returncode, stderr, stdout, outname):
        if returncode != 0:
            # Microsoft compilers write compilation errors to stdout
            stderr = stdout + stderr
            errorfile = outname.new(ext='errors')
            errorfile.write(stderr)
            stderrlines = stderr.splitlines()
            for line in stderrlines:
                log.ERROR(line)
            raise CompilationError(stdout, stderr)


    def gen_makefile(self, cfiles, eci, exe_name=None, path=None):
        cfiles = [py.path.local(f) for f in cfiles]
        cfiles += [py.path.local(f) for f in eci.separate_module_files]

        if path is None:
            path = cfiles[0].dirpath()

        pypypath = py.path.local(autopath.pypydir)

        if exe_name is None:
            exe_name = cfiles[0].new(ext=self.exe_ext)

        m = NMakefile(path)
        m.exe_name = exe_name
        m.eci = eci

        def pypyrel(fpath):
            rel = py.path.local(fpath).relto(pypypath)
            if rel:
                return os.path.join('$(PYPYDIR)', rel)
            else:
                return fpath

        rel_cfiles = [m.pathrel(cfile) for cfile in cfiles]
        rel_ofiles = [rel_cfile[:-2]+'.obj' for rel_cfile in rel_cfiles]
        m.cfiles = rel_cfiles

        rel_includedirs = [pypyrel(incldir) for incldir in eci.include_dirs]

        m.comment('automatically generated makefile')
        definitions = [
            ('PYPYDIR', autopath.pypydir),
            ('TARGET', exe_name.basename),
            ('DEFAULT_TARGET', '$(TARGET)'),
            ('SOURCES', rel_cfiles),
            ('OBJECTS', rel_ofiles),
            ('LIBS', self._libs(eci.libraries)),
            ('LIBDIRS', self._libdirs(eci.library_dirs)),
            ('INCLUDEDIRS', self._includedirs(rel_includedirs)),
            ('CFLAGS', self.cflags + list(eci.compile_extra)),
            ('LDFLAGS', self.link_flags + list(eci.link_extra)),
            ('CC', self.cc),
            ('CC_LINK', self.link),
            ('MASM', self.masm),
            ]
        for args in definitions:
            m.definition(*args)

        rules = [
            ('all', '$(DEFAULT_TARGET)', []),
            ('.c.obj', '', '$(CC) /nologo $(CFLAGS) /Fo$@ /c $< $(INCLUDEDIRS)'),
            ]

        for rule in rules:
            m.rule(*rule)

        if self.version < 80:
            m.rule('$(TARGET)', '$(OBJECTS)',
                   '$(CC_LINK) /nologo $(LDFLAGS) $(OBJECTS) /out:$@ $(LIBDIRS) $(LIBS)')
        else:
            m.rule('$(TARGET)', '$(OBJECTS)',
                   ['$(CC_LINK) /nologo $(LDFLAGS) $(OBJECTS) /out:$@ $(LIBDIRS) $(LIBS) /MANIFESTFILE:$*.manifest',
                    'mt.exe -nologo -manifest $*.manifest -outputresource:$@;1',
                    ])

        return m

    def execute_makefile(self, path_to_makefile):
        if isinstance(path_to_makefile, NMakefile):
            path = path_to_makefile.makefile_dir
        else:
            path = path_to_makefile
        log.execute('make in %s' % (path,))
        oldcwd = path.chdir()
        try:
            returncode, stdout, stderr = _run_subprocess(
                'nmake',
                ['/nologo', '/f', str(path.join('Makefile'))])
        finally:
            oldcwd.chdir()

        self._handle_error(returncode, stdout, stderr, path.join('make'))

class NMakefile(posix.GnuMakefile):
    def write(self, out=None):
        # nmake expands macros when it parses rules.
        # Write all macros before the rules.
        if out is None:
            f = self.makefile_dir.join('Makefile').open('w')
        else:
            f = out
        for line in self.lines:
            if not isinstance(line, posix.Rule):
                line.write(f)
        for line in self.lines:
            if isinstance(line, posix.Rule):
                line.write(f)
        f.flush()
        if out is None:
            f.close()


class MingwPlatform(posix.BasePosix):
    name = 'mingw32'
    standalone_only = []
    shared_only = []
    cflags = ['-O3']
    link_flags = []
    so_ext = 'dll'

    def __init__(self, cc=None):
        Platform.__init__(self, 'gcc')

    def _args_for_shared(self, args):
        return ['-shared'] + args

    def include_dirs_for_libffi(self):
        return []

    def library_dirs_for_libffi(self):
        return []

    def _handle_error(self, returncode, stderr, stdout, outname):
        # Mingw tools write compilation errors to stdout
        super(MingwPlatform, self)._handle_error(
            returncode, stderr + stdout, '', outname)