# License: EPL
import os
import sys
import traceback

try:
    xrange
except:
    xrange = range

#===============================================================================
# Things that are dependent on having the pydevd debugger
#===============================================================================
def log_debug(msg):
    import pydev_log
    pydev_log.debug(msg)

def log_error_once(msg):
    import pydev_log
    pydev_log.error_once(msg)

pydev_src_dir = os.path.dirname(__file__)

def _get_python_c_args(host, port, indC, args):
    return ("import sys; sys.path.append(r'%s'); import pydevd; "
            "pydevd.settrace(host='%s', port=%s, suspend=False, trace_only_current_thread=False, patch_multiprocessing=True); %s"
            ) % (
        pydev_src_dir,
        host,
        port,
        args[indC + 1])

def _get_host_port():
    import pydevd
    host, port = pydevd.dispatch()
    return host, port

def _is_managed_arg(arg):
    if arg.endswith('pydevd.py'):
        return True
    return False

def _on_forked_process():
    import pydevd
    pydevd.threadingCurrentThread().__pydevd_main_thread = True
    pydevd.settrace_forked()

def _on_set_trace_for_new_thread():
    from pydevd_comm import GetGlobalDebugger
    global_debugger = GetGlobalDebugger()
    if global_debugger is not None:
        global_debugger.SetTrace(global_debugger.trace_dispatch)

#===============================================================================
# Things related to monkey-patching
#===============================================================================
def is_python(path):
    if path.endswith("'") or path.endswith('"'):
        path = path[1:len(path) - 1]
    filename = os.path.basename(path).lower()
    for name in ['python', 'jython', 'pypy']:
        if filename.find(name) != -1:
            return True

    return False

def patch_args(args):
    try:
        log_debug("Patching args: %s" % str(args))

        import sys
        new_args = []
        i = 0
        if len(args) == 0:
            return args

        if is_python(args[0]):
            try:
                indC = args.index('-c')
            except ValueError:
                indC = -1

            if indC != -1:
                host, port = _get_host_port()

                if port is not None:
                    new_args.extend(args)
                    new_args[indC + 1] = _get_python_c_args(host, port, indC, args)
                    return new_args
            else:
                new_args.append(args[0])
        else:
            log_debug("Process is not python, returning.")
            return args

        i = 1
        while i < len(args):
            if args[i].startswith('-'):
                new_args.append(args[i])
            else:
                break
            i += 1

        if _is_managed_arg(args[i]):  # no need to add pydevd twice
            return args

        for x in sys.original_argv:
            if sys.platform == "win32" and not x.endswith('"'):
                arg = '"%s"' % x
            else:
                arg = x
            new_args.append(arg)
            if x == '--file':
                break

        while i < len(args):
            new_args.append(args[i])
            i += 1

        return new_args
    except:
        traceback.print_exc()
        return args


def args_to_str(args):
    quoted_args = []
    for x in args:
        if x.startswith('"') and x.endswith('"'):
            quoted_args.append(x)
        else:
            x = x.replace('"', '\\"')
            quoted_args.append('"%s"' % x)

    return ' '.join(quoted_args)


def str_to_args_windows(args):
    # see http:#msdn.microsoft.com/en-us/library/a1y7w461.aspx
    result = []

    DEFAULT = 0
    ARG = 1
    IN_DOUBLE_QUOTE = 2

    state = DEFAULT
    backslashes = 0
    buf = ''

    args_len = len(args)
    for i in xrange(args_len):
        ch = args[i]
        if (ch == '\\'):
            backslashes += 1
            continue
        elif (backslashes != 0):
            if ch == '"':
                while backslashes >= 2:
                    backslashes -= 2
                    buf += '\\'
                if (backslashes == 1):
                    if (state == DEFAULT):
                        state = ARG

                    buf += '"'
                    backslashes = 0
                    continue
                # else fall through to switch
            else:
                # false alarm, treat passed backslashes literally...
                if (state == DEFAULT):
                    state = ARG

                while backslashes > 0:
                    backslashes -= 1
                    buf += '\\'
                # fall through to switch
        if ch in (' ', '\t'):
            if (state == DEFAULT):
                # skip
                continue
            elif (state == ARG):
                state = DEFAULT
                result.append(buf)
                buf = ''
                continue

        if state in (DEFAULT, ARG):
            if ch == '"':
                state = IN_DOUBLE_QUOTE
            else:
                state = ARG
                buf += ch

        elif state == IN_DOUBLE_QUOTE:
            if ch == '"':
                if (i + 1 < args_len and args[i + 1] == '"'):
                    # Undocumented feature in Windows:
                    # Two consecutive double quotes inside a double-quoted argument are interpreted as
                    # a single double quote.
                    buf += '"'
                    i += 1
                elif len(buf) == 0:
                    # empty string on Windows platform. Account for bug in constructor of
                    # JDK's java.lang.ProcessImpl.
                    result.append("\"\"")
                    state = DEFAULT
                else:
                    state = ARG
            else:
                buf += ch

        else:
            raise RuntimeError('Illegal condition')

    if len(buf) > 0 or state != DEFAULT:
        result.append(buf)

    return result


def patch_arg_str_win(arg_str):
    args = str_to_args_windows(arg_str)
    if not is_python(args[0]):
        return arg_str
    arg_str = args_to_str(patch_args(args))
    log_debug("New args: %s" % arg_str)
    return arg_str


def monkey_patch_module(module, funcname, create_func):
    if hasattr(module, funcname):
        original_name = 'original_' + funcname
        if not hasattr(module, original_name):
            setattr(module, original_name, getattr(module, funcname))
            setattr(module, funcname, create_func(original_name))


def monkey_patch_os(funcname, create_func):
    monkey_patch_module(os, funcname, create_func)


def warn_multiproc():
    log_error_once(
        "pydev debugger: New process is launching (breakpoints won't work in the new process).\n"
        "pydev debugger: To debug that process please enable 'Attach to subprocess automatically while debugging?' option in the debugger settings.\n")


def create_warn_multiproc(original_name):

    def new_warn_multiproc(*args):
        import os

        warn_multiproc()

        return getattr(os, original_name)(*args)
    return new_warn_multiproc


def create_execl(original_name):
    def new_execl(path, *args):
        '''
os.execl(path, arg0, arg1, ...)
os.execle(path, arg0, arg1, ..., env)
os.execlp(file, arg0, arg1, ...)
os.execlpe(file, arg0, arg1, ..., env)
        '''
        import os
        args = patch_args(args)
        return getattr(os, original_name)(path, *args)
    return new_execl


def create_execv(original_name):
    def new_execv(path, args):
        '''
os.execv(path, args)
os.execvp(file, args)
        '''
        import os
        return getattr(os, original_name)(path, patch_args(args))
    return new_execv


def create_execve(original_name):
    """
os.execve(path, args, env)
os.execvpe(file, args, env)
    """
    def new_execve(path, args, env):
        import os
        return getattr(os, original_name)(path, patch_args(args), env)
    return new_execve


def create_spawnl(original_name):
    def new_spawnl(mode, path, *args):
        '''
os.spawnl(mode, path, arg0, arg1, ...)
os.spawnlp(mode, file, arg0, arg1, ...)
        '''
        import os
        args = patch_args(args)
        return getattr(os, original_name)(mode, path, *args)
    return new_spawnl


def create_spawnv(original_name):
    def new_spawnv(mode, path, args):
        '''
os.spawnv(mode, path, args)
os.spawnvp(mode, file, args)
        '''
        import os
        return getattr(os, original_name)(mode, path, patch_args(args))
    return new_spawnv


def create_spawnve(original_name):
    """
os.spawnve(mode, path, args, env)
os.spawnvpe(mode, file, args, env)
    """
    def new_spawnve(mode, path, args, env):
        import os
        return getattr(os, original_name)(mode, path, patch_args(args), env)
    return new_spawnve


def create_fork_exec(original_name):
    """
_posixsubprocess.fork_exec(args, executable_list, close_fds, ... (13 more))
    """
    def new_fork_exec(args, *other_args):
        import _posixsubprocess
        args = patch_args(args)
        return getattr(_posixsubprocess, original_name)(args, *other_args)
    return new_fork_exec


def create_CreateProcess(original_name):
    """
CreateProcess(*args, **kwargs)
    """
    def new_CreateProcess(appName, commandLine, *args):
        try:
            import _subprocess
        except ImportError:
            import _winapi as _subprocess
        return getattr(_subprocess, original_name)(appName, patch_arg_str_win(commandLine), *args)
    return new_CreateProcess


def create_CreateProcessWarnMultiproc(original_name):
    """
CreateProcess(*args, **kwargs)
    """
    def new_CreateProcess(*args):
        try:
            import _subprocess
        except ImportError:
            import _winapi as _subprocess
        warn_multiproc()
        return getattr(_subprocess, original_name)(*args)
    return new_CreateProcess


def create_fork(original_name):
    def new_fork():
        import os
        child_process = getattr(os, original_name)()  # fork
        if not child_process:
            _on_forked_process()
        return child_process
    return new_fork


def patch_new_process_functions():
    # os.execl(path, arg0, arg1, ...)
    # os.execle(path, arg0, arg1, ..., env)
    # os.execlp(file, arg0, arg1, ...)
    # os.execlpe(file, arg0, arg1, ..., env)
    # os.execv(path, args)
    # os.execve(path, args, env)
    # os.execvp(file, args)
    # os.execvpe(file, args, env)
    monkey_patch_os('execl', create_execl)
    monkey_patch_os('execle', create_execl)
    monkey_patch_os('execlp', create_execl)
    monkey_patch_os('execlpe', create_execl)
    monkey_patch_os('execv', create_execv)
    monkey_patch_os('execve', create_execve)
    monkey_patch_os('execvp', create_execv)
    monkey_patch_os('execvpe', create_execve)

    # os.spawnl(mode, path, ...)
    # os.spawnle(mode, path, ..., env)
    # os.spawnlp(mode, file, ...)
    # os.spawnlpe(mode, file, ..., env)
    # os.spawnv(mode, path, args)
    # os.spawnve(mode, path, args, env)
    # os.spawnvp(mode, file, args)
    # os.spawnvpe(mode, file, args, env)

    monkey_patch_os('spawnl', create_spawnl)
    monkey_patch_os('spawnle', create_spawnl)
    monkey_patch_os('spawnlp', create_spawnl)
    monkey_patch_os('spawnlpe', create_spawnl)
    monkey_patch_os('spawnv', create_spawnv)
    monkey_patch_os('spawnve', create_spawnve)
    monkey_patch_os('spawnvp', create_spawnv)
    monkey_patch_os('spawnvpe', create_spawnve)

    if sys.platform != 'win32':
        monkey_patch_os('fork', create_fork)
        try:
            import _posixsubprocess
            monkey_patch_module(_posixsubprocess, 'fork_exec', create_fork_exec)
        except ImportError:
            pass
    else:
        # Windows
        try:
            import _subprocess
        except ImportError:
            import _winapi as _subprocess
        monkey_patch_module(_subprocess, 'CreateProcess', create_CreateProcess)


def patch_new_process_functions_with_warning():
    monkey_patch_os('execl', create_warn_multiproc)
    monkey_patch_os('execle', create_warn_multiproc)
    monkey_patch_os('execlp', create_warn_multiproc)
    monkey_patch_os('execlpe', create_warn_multiproc)
    monkey_patch_os('execv', create_warn_multiproc)
    monkey_patch_os('execve', create_warn_multiproc)
    monkey_patch_os('execvp', create_warn_multiproc)
    monkey_patch_os('execvpe', create_warn_multiproc)
    monkey_patch_os('spawnl', create_warn_multiproc)
    monkey_patch_os('spawnle', create_warn_multiproc)
    monkey_patch_os('spawnlp', create_warn_multiproc)
    monkey_patch_os('spawnlpe', create_warn_multiproc)
    monkey_patch_os('spawnv', create_warn_multiproc)
    monkey_patch_os('spawnve', create_warn_multiproc)
    monkey_patch_os('spawnvp', create_warn_multiproc)
    monkey_patch_os('spawnvpe', create_warn_multiproc)

    if sys.platform != 'win32':
        monkey_patch_os('fork', create_warn_multiproc)
        try:
            import _posixsubprocess
            monkey_patch_module(_posixsubprocess, 'fork_exec', create_warn_multiproc)
        except ImportError:
            pass
    else:
        # Windows
        try:
            import _subprocess
        except ImportError:
            import _winapi as _subprocess
        monkey_patch_module(_subprocess, 'CreateProcess', create_CreateProcessWarnMultiproc)


class _NewThreadStartupWithTrace:

    def __init__(self, original_func, args, kwargs):
        self.original_func = original_func
        self.args = args
        self.kwargs = kwargs

    def __call__(self):
        _on_set_trace_for_new_thread()
        return self.original_func(*self.args, **self.kwargs)


class _NewThreadStartupWithoutTrace:

    def __init__(self, original_func, args, kwargs):
        self.original_func = original_func
        self.args = args
        self.kwargs = kwargs

    def __call__(self):
        return self.original_func(*self.args, **self.kwargs)

_UseNewThreadStartup = _NewThreadStartupWithTrace


def _get_threading_modules_to_patch():
    threading_modules_to_patch = []
    try:
        import thread as _thread
        threading_modules_to_patch.append(_thread)
    except:
        import _thread
        threading_modules_to_patch.append(_thread)
    return threading_modules_to_patch

threading_modules_to_patch = _get_threading_modules_to_patch()


def patch_thread_module(thread):

    if getattr(thread, '_original_start_new_thread', None) is None:
        _original_start_new_thread = thread._original_start_new_thread = thread.start_new_thread
    else:
        _original_start_new_thread = thread._original_start_new_thread

    class ClassWithPydevStartNewThread:

        def pydev_start_new_thread(self, function, args=(), kwargs={}):
            '''
            We need to replace the original thread.start_new_thread with this function so that threads started
            through it and not through the threading module are properly traced.
            '''
            return _original_start_new_thread(_UseNewThreadStartup(function, args, kwargs), ())

    # This is a hack for the situation where the thread.start_new_thread is declared inside a class, such as the one below
    # class F(object):
    #    start_new_thread = thread.start_new_thread
    #
    #    def start_it(self):
    #        self.start_new_thread(self.function, args, kwargs)
    # So, if it's an already bound method, calling self.start_new_thread won't really receive a different 'self' -- it
    # does work in the default case because in builtins self isn't passed either.
    pydev_start_new_thread = ClassWithPydevStartNewThread().pydev_start_new_thread

    try:
        # We need to replace the original thread.start_new_thread with this function so that threads started through
        # it and not through the threading module are properly traced.
        thread.start_new_thread = pydev_start_new_thread
        thread.start_new = pydev_start_new_thread
    except:
        pass


def patch_thread_modules():
    for t in threading_modules_to_patch:
        patch_thread_module(t)


def undo_patch_thread_modules():
    for t in threading_modules_to_patch:
        try:
            t.start_new_thread = t._original_start_new_thread
        except:
            pass

        try:
            t.start_new = t._original_start_new_thread
        except:
            pass


def disable_trace_thread_modules():
    '''
    Can be used to temporarily stop tracing threads created with thread.start_new_thread.
    '''
    global _UseNewThreadStartup
    _UseNewThreadStartup = _NewThreadStartupWithoutTrace


def enable_trace_thread_modules():
    '''
    Can be used to start tracing threads created with thread.start_new_thread again.
    '''
    global _UseNewThreadStartup
    _UseNewThreadStartup = _NewThreadStartupWithTrace


def get_original_start_new_thread(threading_module):
    try:
        return threading_module._original_start_new_thread
    except:
        return threading_module.start_new_thread
