#!/usr/bin/env python3

import argparse
import contextlib
import json
import os
import platform
import re
import site
import shutil
import subprocess
import sys
import tempfile
import pathlib
import signal

from distutils.sysconfig import get_python_lib
from distutils.util import strtobool

from scripts.common import get_meson
from scripts.common import git
from scripts.common import win32_get_short_path_name
from scripts.common import get_wine_shortpath

SCRIPTDIR = os.path.dirname(os.path.realpath(__file__))
PREFIX_DIR = os.path.join(SCRIPTDIR, 'prefix')
# Use '_build' as the builddir instead of 'build'
DEFAULT_BUILDDIR = os.path.join(SCRIPTDIR, 'build')
if not os.path.exists(DEFAULT_BUILDDIR):
    DEFAULT_BUILDDIR = os.path.join(SCRIPTDIR, '_build')

TYPELIB_REG = re.compile(r'.*\.typelib$')
SHAREDLIB_REG = re.compile(r'\.so|\.dylib|\.dll')

# libdir is expanded from option of the same name listed in the `meson
# introspect --buildoptions` output.
GSTPLUGIN_FILEPATH_REG_TEMPLATE = r'.*/{libdir}/gstreamer-1.0/[^/]+$'
GSTPLUGIN_FILEPATH_REG = None

def listify(o):
    if isinstance(o, str):
        return [o]
    if isinstance(o, list):
        return o
    raise AssertionError('Object {!r} must be a string or a list'.format(o))

def stringify(o):
    if isinstance(o, str):
        return o
    if isinstance(o, list):
        if len(o) == 1:
            return o[0]
        raise AssertionError('Did not expect object {!r} to have more than one element'.format(o))
    raise AssertionError('Object {!r} must be a string or a list'.format(o))

def prepend_env_var(env, var, value, sysroot):
    if value.startswith(sysroot):
        value = value[len(sysroot):]
    # Try not to exceed maximum length limits for env vars on Windows
    if os.name == 'nt':
        value = win32_get_short_path_name(value)
    env_val = env.get(var, '')
    val = os.pathsep + value + os.pathsep
    # Don't add the same value twice
    if val in env_val or env_val.startswith(value + os.pathsep):
        return
    env[var] = val + env_val
    env[var] = env[var].replace(os.pathsep + os.pathsep, os.pathsep).strip(os.pathsep)

def is_library_target_and_not_plugin(target, filename):
    '''
    Don't add plugins to PATH/LD_LIBRARY_PATH because:
    1. We don't need to
    2. It causes us to exceed the PATH length limit on Windows and Wine
    '''
    if not target['type'].startswith('shared'):
        return False
    if not target['installed']:
        return False
    # Check if this output of that target is a shared library
    if not SHAREDLIB_REG.search(filename):
        return False
    # Check if it's installed to the gstreamer plugin location
    for install_filename in listify(target['install_filename']):
        if install_filename.endswith(os.path.basename(filename)):
            break
    else:
        # None of the installed files in the target correspond to the built
        # filename, so skip
        return False

    global GSTPLUGIN_FILEPATH_REG
    if GSTPLUGIN_FILEPATH_REG is None:
        GSTPLUGIN_FILEPATH_REG = re.compile(GSTPLUGIN_FILEPATH_REG_TEMPLATE)
    if GSTPLUGIN_FILEPATH_REG.search(install_filename.replace('\\', '/')):
        return False
    return True


def get_wine_subprocess_env(options, env):
    with open(os.path.join(options.builddir, 'meson-info', 'intro-buildoptions.json')) as f:
        buildoptions = json.load(f)

    prefix, = [o for o in buildoptions if o['name'] == 'prefix']
    path = os.path.normpath(os.path.join(prefix['value'], 'bin'))
    prepend_env_var(env, "PATH", path, options.sysroot)
    wine_path = get_wine_shortpath(
        options.wine.split(' '),
        [path] + env.get('WINEPATH', '').split(';')
    )
    if options.winepath:
        wine_path += ';' + options.winepath
    env['WINEPATH'] = wine_path
    env['WINEDEBUG'] = 'fixme-all'

    return env


def get_subprocess_env(options, gst_version):
    env = os.environ.copy()

    env["CURRENT_GST"] = os.path.normpath(SCRIPTDIR)
    env["GST_VERSION"] = gst_version
    env["GST_VALIDATE_SCENARIOS_PATH"] = os.path.normpath(
        "%s/subprojects/gst-devtools/validate/data/scenarios" % SCRIPTDIR)
    env["GST_VALIDATE_PLUGIN_PATH"] = os.path.normpath(
        "%s/subprojects/gst-devtools/validate/plugins" % options.builddir)
    env["GST_VALIDATE_APPS_DIR"] = os.path.normpath(
        "%s/subprojects/gst-editing-services/tests/validate" % SCRIPTDIR)
    env["GST_ENV"] = 'gst-' + gst_version
    env["GST_REGISTRY"] = os.path.normpath(options.builddir + "/registry.dat")
    prepend_env_var(env, "PATH", os.path.normpath(
        "%s/subprojects/gst-devtools/validate/tools" % options.builddir),
        options.sysroot)

    if options.wine:
        return get_wine_subprocess_env(options, env)

    prepend_env_var(env, "PATH", os.path.join(SCRIPTDIR, 'meson'),
        options.sysroot)

    env["GST_PLUGIN_SYSTEM_PATH"] = ""
    env["GST_PLUGIN_SCANNER"] = os.path.normpath(
        "%s/subprojects/gstreamer/libs/gst/helpers/gst-plugin-scanner" % options.builddir)
    env["GST_PTP_HELPER"] = os.path.normpath(
        "%s/subprojects/gstreamer/libs/gst/helpers/gst-ptp-helper" % options.builddir)

    if os.name == 'nt':
        lib_path_envvar = 'PATH'
    elif platform.system() == 'Darwin':
        lib_path_envvar = 'DYLD_LIBRARY_PATH'
    else:
        lib_path_envvar = 'LD_LIBRARY_PATH'

    prepend_env_var(env, "GST_PLUGIN_PATH", os.path.join(SCRIPTDIR, 'subprojects',
                                                        'gst-python', 'plugin'),
                    options.sysroot)
    prepend_env_var(env, "GST_PLUGIN_PATH", os.path.join(PREFIX_DIR, 'lib',
                                                        'gstreamer-1.0'),
                    options.sysroot)
    prepend_env_var(env, "GST_PLUGIN_PATH", os.path.join(options.builddir, 'subprojects',
                                                         'libnice', 'gst'),
                    options.sysroot)
    prepend_env_var(env, "GST_VALIDATE_SCENARIOS_PATH",
                    os.path.join(PREFIX_DIR, 'share', 'gstreamer-1.0',
                                 'validate', 'scenarios'),
                    options.sysroot)
    prepend_env_var(env, "GI_TYPELIB_PATH", os.path.join(PREFIX_DIR, 'lib',
                                                         'lib', 'girepository-1.0'),
                    options.sysroot)
    prepend_env_var(env, "PKG_CONFIG_PATH", os.path.join(PREFIX_DIR, 'lib', 'pkgconfig'),
                    options.sysroot)

    # gst-indent
    prepend_env_var(env, "PATH", os.path.join(SCRIPTDIR, 'gstreamer', 'tools'),
                    options.sysroot)

    # tools: gst-launch-1.0, gst-inspect-1.0
    prepend_env_var(env, "PATH", os.path.join(options.builddir, 'subprojects',
                                              'gstreamer', 'tools'),
                    options.sysroot)
    prepend_env_var(env, "PATH", os.path.join(options.builddir, 'subprojects',
                                              'gst-plugins-base', 'tools'),
                    options.sysroot)

    # Library and binary search paths
    prepend_env_var(env, "PATH", os.path.join(PREFIX_DIR, 'bin'),
                    options.sysroot)
    if lib_path_envvar != 'PATH':
        prepend_env_var(env, lib_path_envvar, os.path.join(PREFIX_DIR, 'lib'),
                        options.sysroot)
        prepend_env_var(env, lib_path_envvar, os.path.join(PREFIX_DIR, 'lib64'),
                        options.sysroot)
    elif 'QMAKE' in os.environ:
        # There's no RPATH on Windows, so we need to set PATH for the qt5 DLLs
        prepend_env_var(env, 'PATH', os.path.dirname(os.environ['QMAKE']),
                        options.sysroot)

    meson = get_meson()
    targets_s = subprocess.check_output(meson + ['introspect', options.builddir, '--targets'])
    targets = json.loads(targets_s.decode())
    paths = set()
    mono_paths = set()
    srcdir_path = pathlib.Path(options.srcdir)

    build_options_s = subprocess.check_output(meson + ['introspect', options.builddir, '--buildoptions'])
    build_options = json.loads(build_options_s.decode())
    libdir, = [o['value'] for o in build_options if o['name'] == 'libdir']
    libdir = libdir.replace('\\', '/')

    global GSTPLUGIN_FILEPATH_REG_TEMPLATE
    GSTPLUGIN_FILEPATH_REG_TEMPLATE = GSTPLUGIN_FILEPATH_REG_TEMPLATE.format(libdir=libdir)

    for target in targets:
        filenames = listify(target['filename'])
        for filename in filenames:
            root = os.path.dirname(filename)
            if srcdir_path / "subprojects/gst-devtools/validate/plugins" in (srcdir_path / root).parents:
                continue
            if filename.endswith('.dll'):
                mono_paths.add(os.path.join(options.builddir, root))
            if TYPELIB_REG.search(filename):
                prepend_env_var(env, "GI_TYPELIB_PATH",
                                os.path.join(options.builddir, root),
                                options.sysroot)
            elif is_library_target_and_not_plugin(target, filename):
                prepend_env_var(env, lib_path_envvar,
                                os.path.join(options.builddir, root),
                                options.sysroot)
            elif target['type'] == 'executable' and target['installed']:
                paths.add(os.path.join(options.builddir, root))

    with open(os.path.join(options.builddir, 'GstPluginsPath.json')) as f:
        for plugin_path in json.load(f):
            prepend_env_var(env, 'GST_PLUGIN_PATH', plugin_path,
                            options.sysroot)

    for p in paths:
        prepend_env_var(env, 'PATH', p, options.sysroot)

    if os.name != 'nt':
        for p in mono_paths:
            prepend_env_var(env, "MONO_PATH", p, options.sysroot)

    presets = set()
    encoding_targets = set()
    pkg_dirs = set()
    python_dirs = set(["%s/subprojects/gstreamer/libs/gst/helpers/" % options.srcdir])
    if '--installed' in subprocess.check_output(meson + ['introspect', '-h']).decode():
        installed_s = subprocess.check_output(meson + ['introspect', options.builddir, '--installed'])
        for path, installpath in json.loads(installed_s.decode()).items():
            installpath_parts = pathlib.Path(installpath).parts
            path_parts = pathlib.Path(path).parts

            # We want to add all python modules to the PYTHONPATH
            # in a manner consistent with the way they would be imported:
            # For example if the source path /home/meh/foo/bar.py
            # is to be installed in /usr/lib/python/site-packages/foo/bar.py,
            # we want to add /home/meh to the PYTHONPATH.
            # This will only work for projects where the paths to be installed
            # mirror the installed directory layout, for example if the path
            # is /home/meh/baz/bar.py and the install path is
            # /usr/lib/site-packages/foo/bar.py , we will not add anything
            # to PYTHONPATH, but the current approach works with pygobject
            # and gst-python at least.
            if 'site-packages' in installpath_parts:
                install_subpath = os.path.join(*installpath_parts[installpath_parts.index('site-packages') + 1:])
                if path.endswith(install_subpath):
                    python_dirs.add(path[:len (install_subpath) * -1])

            if path.endswith('.prs'):
                presets.add(os.path.dirname(path))
            elif path.endswith('.gep'):
                encoding_targets.add(
                    os.path.abspath(os.path.join(os.path.dirname(path), '..')))
            elif path.endswith('.pc'):
                # Is there a -uninstalled pc file for this file?
                uninstalled = "{0}-uninstalled.pc".format(path[:-3])
                if os.path.exists(uninstalled):
                    pkg_dirs.add(os.path.dirname(path))

            if path.endswith('gstomx.conf'):
                prepend_env_var(env, 'GST_OMX_CONFIG_DIR', os.path.dirname(path),
                                options.sysroot)

        for p in presets:
            prepend_env_var(env, 'GST_PRESET_PATH', p, options.sysroot)

        for t in encoding_targets:
            prepend_env_var(env, 'GST_ENCODING_TARGET_PATH', t, options.sysroot)

        for pkg_dir in pkg_dirs:
            prepend_env_var(env, "PKG_CONFIG_PATH", pkg_dir, options.sysroot)
    prepend_env_var(env, "PKG_CONFIG_PATH", os.path.join(options.builddir,
                                                         'subprojects',
                                                         'gst-plugins-good',
                                                         'pkgconfig'),
                    options.sysroot)

    for python_dir in python_dirs:
        prepend_env_var(env, 'PYTHONPATH', python_dir, options.sysroot)

    mesonpath = os.path.join(SCRIPTDIR, "meson")
    if os.path.join(mesonpath):
        # Add meson/ into PYTHONPATH if we are using a local meson
        prepend_env_var(env, 'PYTHONPATH', mesonpath, options.sysroot)

    # For devhelp books
    if not 'XDG_DATA_DIRS' in env or not env['XDG_DATA_DIRS']:
        # Preserve default paths when empty
        prepend_env_var(env, 'XDG_DATA_DIRS', '/usr/local/share/:/usr/share/', '')

    prepend_env_var (env, 'XDG_DATA_DIRS', os.path.join(options.builddir,
                                                        'subprojects',
                                                        'gst-docs',
                                                        'GStreamer-doc'),
                     options.sysroot)

    return env

def get_windows_shell():
    command = ['powershell.exe' ,'-noprofile', '-executionpolicy', 'bypass', '-file', 'cmd_or_ps.ps1']
    result = subprocess.check_output(command)
    return result.decode().strip()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(prog="gstreamer-uninstalled")

    parser.add_argument("--builddir",
                        default=DEFAULT_BUILDDIR,
                        help="The meson build directory")
    parser.add_argument("--srcdir",
                        default=SCRIPTDIR,
                        help="The top level source directory")
    parser.add_argument("--sysroot",
                        default='',
                        help="The sysroot path used during cross-compilation")
    parser.add_argument("--wine",
                        default='',
                        help="Build a wine env based on specified wine command")
    parser.add_argument("--winepath",
                        default='',
                        help="Exra path to set to WINEPATH.")
    options, args = parser.parse_known_args()

    if not os.path.exists(options.builddir):
        print("GStreamer not built in %s\n\nBuild it and try again" %
              options.builddir)
        exit(1)
    options.builddir = os.path.abspath(options.builddir)

    if not os.path.exists(options.srcdir):
        print("The specified source dir does not exist" %
              options.srcdir)
        exit(1)

    # The following incantation will retrieve the current branch name.
    gst_version = git("rev-parse", "--symbolic-full-name", "--abbrev-ref", "HEAD",
                      repository_path=options.srcdir).strip('\n')

    if options.wine:
        gst_version += '-' + os.path.basename(options.wine)

    if not args:
        if os.name == 'nt':
            shell = get_windows_shell()
            if shell == 'powershell.exe':
                args = ['powershell.exe']
                args += ['-NoLogo', '-NoExit']
                prompt = 'function global:prompt {  "[gst-' + gst_version + '"+"] PS " + $PWD + "> "}'
                args += ['-Command', prompt]
            else:
                args = [os.environ.get("COMSPEC", r"C:\WINDOWS\system32\cmd.exe")]
                args += ['/k', 'prompt [gst-{}] $P$G'.format(gst_version)]
        else:
            args = [os.environ.get("SHELL", os.path.realpath("/bin/sh"))]
        if "bash" in args[0] and not strtobool(os.environ.get("GST_BUILD_DISABLE_PS1_OVERRIDE", r"FALSE")):
            tmprc = tempfile.NamedTemporaryFile(mode='w')
            bashrc = os.path.expanduser('~/.bashrc')
            if os.path.exists(bashrc):
                with open(bashrc, 'r') as src:
                    shutil.copyfileobj(src, tmprc)
            tmprc.write('\nexport PS1="[gst-%s] $PS1"' % gst_version)
            tmprc.flush()
            # Let the GC remove the tmp file
            args.append("--rcfile")
            args.append(tmprc.name)
        if 'fish' in args[0]:
            # Ignore SIGINT while using fish as the shell to make it behave
            # like other shells such as bash and zsh.
            # See: https://gitlab.freedesktop.org/gstreamer/gst-build/issues/18
            signal.signal(signal.SIGINT, lambda x, y: True)
            # Set the prompt
            args.append('--init-command')
            prompt_cmd = '''functions --copy fish_prompt original_fish_prompt
            function fish_prompt
                echo -n '[gst-{}] '(original_fish_prompt)
            end'''.format(gst_version)
            args.append(prompt_cmd)
    try:
        exit(subprocess.call(args, close_fds=False,
                             env=get_subprocess_env(options, gst_version)))
    except subprocess.CalledProcessError as e:
        exit(e.returncode)