import os

import os.path

import sys

import pproc as subprocess

import shlex

# WAF modules

import ccroot

import Options

import Utils

import Logs

import TaskGen

import Build

import re

# these are set from the main wscript file

APPNAME=None

VERSION=None

bld=None

def get_command_template(env, arguments=()):

    cmd = Options.options.command_template or '%s'

    for arg in arguments:

        cmd = cmd + " " + arg

    return cmd

if hasattr(os.path, "relpath"):

    relpath = os.path.relpath # since Python 2.6

else:

    def relpath(path, start=os.path.curdir):

        """Return a relative version of a path"""

        if not path:

            raise ValueError("no path specified")

        start_list = os.path.abspath(start).split(os.path.sep)

        path_list = os.path.abspath(path).split(os.path.sep)

        # Work out how much of the filepath is shared by start and path.

        i = len(os.path.commonprefix([start_list, path_list]))

        rel_list = [os.path.pardir] * (len(start_list)-i) + path_list[i:]

        if not rel_list:

            return os.path.curdir

        return os.path.join(*rel_list)

def find_program(program_name, env):

    launch_dir = os.path.abspath(Options.cwd_launch)

    top_dir = os.path.abspath(Options.launch_dir)

    found_programs = []

    for obj in bld.all_task_gen:

        if not getattr(obj, 'is_ns3_program', False):

            continue

        ## filter out programs not in the subtree starting at the launch dir

        if not (obj.path.abspath().startswith(launch_dir)

                or obj.path.abspath(env).startswith(launch_dir)):

            continue

        name1 = obj.target

        name2 = os.path.join(relpath(obj.path.abspath(), top_dir), obj.target)

        names = [name1, name2]

        found_programs.extend(names)

        if program_name in names:

            return obj

    raise ValueError("program '%s' not found; available programs are: %r"

                     % (program_name, found_programs))

def get_proc_env(os_env=None):

    env = bld.env

    if sys.platform == 'linux2':

        pathvar = 'LD_LIBRARY_PATH'

    elif sys.platform == 'darwin':

        pathvar = 'DYLD_LIBRARY_PATH'

    elif sys.platform == 'win32':

        pathvar = 'PATH'

    elif sys.platform == 'cygwin':

        pathvar = 'PATH'

    elif sys.platform.startswith('freebsd'):

        pathvar = 'LD_LIBRARY_PATH'

    else:

        Logs.warn(("Don't know how to configure "

                        "dynamic library path for the platform %r;"

                        " assuming it's LD_LIBRARY_PATH.") % (sys.platform,))

        pathvar = 'LD_LIBRARY_PATH'        

    proc_env = dict(os.environ)

    if os_env is not None:

        proc_env.update(os_env)

    if pathvar is not None:

        if pathvar in proc_env:

            proc_env[pathvar] = os.pathsep.join(list(env['NS3_MODULE_PATH']) + [proc_env[pathvar]])

        else:

            proc_env[pathvar] = os.pathsep.join(list(env['NS3_MODULE_PATH']))

    pymoddir = bld.path.find_dir('bindings/python').abspath(env)

    pyvizdir = bld.path.find_dir('src/visualizer').abspath()

    if 'PYTHONPATH' in proc_env:

        proc_env['PYTHONPATH'] = os.pathsep.join([pymoddir, pyvizdir] + [proc_env['PYTHONPATH']])

    else:

        proc_env['PYTHONPATH'] = os.pathsep.join([pymoddir, pyvizdir])

    if 'PATH' in proc_env:

        proc_env['PATH'] = os.pathsep.join(list(env['NS3_EXECUTABLE_PATH']) + [proc_env['PATH']])

    else:

        proc_env['PATH'] = os.pathsep.join(list(env['NS3_EXECUTABLE_PATH']))

    return proc_env

def run_argv(argv, env, os_env=None, cwd=None, force_no_valgrind=False):

    proc_env = get_proc_env(os_env)

    if Options.options.valgrind and not force_no_valgrind:

        if Options.options.command_template:

            raise Utils.WafError("Options --command-template and --valgrind are conflicting")

        if not env['VALGRIND']:

            raise Utils.WafError("valgrind is not installed")

        argv = [env['VALGRIND'], "--leak-check=full", "--show-reachable=yes", "--error-exitcode=1"] + argv

        proc = subprocess.Popen(argv, env=proc_env, cwd=cwd, stderr=subprocess.PIPE)

        error = False

        for line in proc.stderr:

            sys.stderr.write(line)

            if "== LEAK SUMMARY" in line:

                error = True

        retval = proc.wait()

        if retval == 0 and error:

            retval = 1

    else:

        try:

            WindowsError

        except NameError:

            retval = subprocess.Popen(argv, env=proc_env, cwd=cwd).wait()

        else:

            try:

                retval = subprocess.Popen(argv, env=proc_env, cwd=cwd).wait()

            except WindowsError, ex:

                raise Utils.WafError("Command %s raised exception %s" % (argv, ex))

    if retval:

        signame = None

        if retval < 0: # signal?

            import signal

            for name, val in vars(signal).iteritems():

                if len(name) > 3 and name[:3] == 'SIG' and name[3] != '_':

                    if val == -retval:

                        signame = name

                        break

        if signame:

            raise Utils.WafError("Command %s terminated with signal %s."

                                 " Run it under a debugger to get more information "

                                 "(./waf --run <program> --command-template=\"gdb --args %%s <args>\")." % (argv, signame))

        else:

            raise Utils.WafError("Command %s exited with code %i" % (argv, retval))

    return retval

def get_run_program(program_string, command_template=None):

    """

    Return the program name and argv of the process that would be executed by

    run_program(program_string, command_template).

    """

    #print "get_run_program_argv(program_string=%r, command_template=%r)" % (program_string, command_template)

    env = bld.env

    if command_template in (None, '%s'):

        argv = shlex.split(program_string)

        #print "%r ==shlex.split==> %r" % (program_string, argv)

        program_name = argv[0]

        try:

            program_obj = find_program(program_name, env)

        except ValueError, ex:

            raise Utils.WafError(str(ex))

        program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))

        #try:

        #    program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))

        #except AttributeError:

        #    raise Utils.WafError("%s does not appear to be a program" % (program_name,))

        execvec = [program_node.abspath(env)] + argv[1:]

    else:

        program_name = program_string

        try:

            program_obj = find_program(program_name, env)

        except ValueError, ex:

            raise Utils.WafError(str(ex))

        program_node = program_obj.path.find_or_declare(ccroot.get_target_name(program_obj))

        #try:

        #    program_node = program_obj.path.find_build(ccroot.get_target_name(program_obj))

        #except AttributeError:

        #    raise Utils.WafError("%s does not appear to be a program" % (program_name,))

        tmpl = command_template % (program_node.abspath(env),)

        execvec = shlex.split(tmpl.replace('\\', '\\\\'))

        #print "%r ==shlex.split==> %r" % (command_template % (program_node.abspath(env),), execvec)

    return program_name, execvec

def run_program(program_string, env, command_template=None, cwd=None, visualize=False):

    """

    if command_template is not None, then program_string == program

    name and argv is given by command_template with %s replaced by the

    full path to the program.  Else, program_string is interpreted as

    a shell command with first name being the program name.

    """

    dummy_program_name, execvec = get_run_program(program_string, command_template)

    if cwd is None:

        if (Options.options.cwd_launch):

            cwd = Options.options.cwd_launch

        else:

            cwd = Options.cwd_launch

    if visualize:

        execvec.append("--SimulatorImplementationType=ns3::VisualSimulatorImpl")

    return run_argv(execvec, env, cwd=cwd)

def run_python_program(program_string, env, visualize=False):

    env = bld.env

    execvec = shlex.split(program_string)

    if (Options.options.cwd_launch):

        cwd = Options.options.cwd_launch

    else:

        cwd = Options.cwd_launch

    if visualize:

        execvec.append("--SimulatorImplementationType=ns3::VisualSimulatorImpl")

    return run_argv([env['PYTHON']] + execvec, env, cwd=cwd)