import os
import re
import platform 

def GetGCCRoot(rtconfig):
    exec_path = rtconfig.EXEC_PATH
    prefix = rtconfig.PREFIX

    if prefix.endswith('-'):
        prefix = prefix[:-1]

    root_path = os.path.join(exec_path, '..', prefix)

    return root_path

def CheckHeader(rtconfig, filename):
    root = GetGCCRoot(rtconfig)

    fn = os.path.join(root, 'include', filename)
    if os.path.isfile(fn):
        return True

    return False

def GetNewLibVersion(rtconfig):
    version = 'unknown'
    root = GetGCCRoot(rtconfig)

    if CheckHeader(rtconfig, '_newlib_version.h'): # get version from _newlib_version.h file
        f = file(os.path.join(root, 'include', '_newlib_version.h'))
        if f:
            for line in f:
                if line.find('_NEWLIB_VERSION') != -1 and line.find('"') != -1:
                    version = re.search(r'\"([^"]+)\"', line).groups()[0]
    elif CheckHeader(rtconfig, 'newlib.h'): # get version from newlib.h
        f = file(os.path.join(root, 'include', 'newlib.h'))
        if f:
            for line in f:
                if line.find('_NEWLIB_VERSION') != -1 and line.find('"') != -1:
                    version = re.search(r'\"([^"]+)\"', line).groups()[0]

    return version

def GCCResult(rtconfig, str):
    import subprocess

    result = ''

    def checkAndGetResult(pattern, string):
        if re.search(pattern, string):
            return re.search(pattern, string).group(0)
        return None

    gcc_cmd = os.path.join(rtconfig.EXEC_PATH, rtconfig.CC)

    # use temp file to get more information 
    f = file('__tmp.c', 'w')
    if f:
        f.write(str)
        f.close()

        # '-fdirectives-only', 
        if(platform.system() == 'Windows'):
            child = subprocess.Popen([gcc_cmd, '-E', '-P', '__tmp.c'], stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
        else:
            child = subprocess.Popen(gcc_cmd + ' -E -P __tmp.c', stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
        
        stdout, stderr = child.communicate()

        # print(stdout)
        if stderr != '':
            print(stderr)

        have_fdset = 0
        have_sigaction = 0
        have_sigevent = 0
        have_siginfo = 0
        have_sigval = 0
        version = None
        stdc = '1989'
        posix_thread = 0

        for line in stdout.split('\n'):
            if re.search('fd_set', line):
                have_fdset = 1

            # check for sigal
            if re.search('struct[ \t]+sigaction', line):
                have_sigaction = 1
            if re.search('struct[ \t]+sigevent', line):
                have_sigevent = 1
            if re.search('siginfo_t', line):
                have_siginfo = 1
            if re.search('union[ \t]+sigval', line):
                have_sigval = 1

            if re.search('char\* version', line):
                version = re.search(r'\"([^"]+)\"', line).groups()[0]

            if re.findall('iso_c_visible = [\d]+', line):
                stdc = re.findall('[\d]+', line)[0]

            if re.findall('pthread_create', line):
                posix_thread = 1
    
        if have_fdset:
            result += '#define HAVE_FDSET 1\n'

        if have_sigaction:
            result += '#define HAVE_SIGACTION 1\n'
        if have_sigevent:
            result += '#define HAVE_SIGEVENT 1\n'
        if have_siginfo:
            result += '#define HAVE_SIGINFO 1\n'
        if have_sigval:
            result += '#define HAVE_SIGVAL 1\n'

        if version:
            result += '#define GCC_VERSION "%s"\n' % version

        result += '#define STDC "%s"\n' % stdc

        if posix_thread:
            result += '#define LIBC_POSIX_THREADS 1\n'

        os.remove('__tmp.c')

    return result

def GenerateGCCConfig(rtconfig):
    str = ''
    cc_header = ''
    cc_header += '#ifndef CCONFIG_H__\n'
    cc_header += '#define CCONFIG_H__\n'
    cc_header += '/* Automatically generated file; DO NOT EDIT. */\n'
    cc_header += '/* compiler configure file for RT-Thread in GCC*/\n\n'

    if CheckHeader(rtconfig, 'newlib.h'):
        str += '#include <newlib.h>\n'
        cc_header += '#define HAVE_NEWLIB_H 1\n'
        cc_header += '#define LIBC_VERSION "newlib %s"\n\n' % GetNewLibVersion(rtconfig)

    if CheckHeader(rtconfig, 'sys/signal.h'):
        str += '#include <sys/signal.h>\n'
        cc_header += '#define HAVE_SYS_SIGNAL_H 1\n'
    if CheckHeader(rtconfig, 'sys/select.h'):
        str += '#include <sys/select.h>\n'
        cc_header += '#define HAVE_SYS_SELECT_H 1\n'
    if CheckHeader(rtconfig, 'pthread.h'):
        str += "#include <pthread.h>\n"
        cc_header += '#define HAVE_PTHREAD_H 1\n'

    # if CheckHeader(rtconfig, 'sys/dirent.h'):
    #    str += '#include <sys/dirent.h>\n'

    # add some common features
    str += 'const char* version = __VERSION__;\n'
    str += 'const int iso_c_visible = __ISO_C_VISIBLE;\n'
    str += '\n#ifdef HAVE_INITFINI_ARRAY\n'
    str += 'const int init_fini_array = HAVE_INITFINI_ARRAY;\n'
    str += '#endif\n'

    cc_header += '\n'
    cc_header += GCCResult(rtconfig, str)
    cc_header += '\n#endif\n'

    cc_file = file('cconfig.h', 'w')
    if cc_file:
        cc_file.write(cc_header)
        cc_file.close()