# Copyright 2013-2019 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# This file contains the detection logic for external dependencies useful for
# development purposes, such as testing, debugging, etc..

import glob
import os
import re
import pathlib
import shutil
import typing as T

from .. import mesonlib, mlog
from ..compilers import AppleClangCCompiler, AppleClangCPPCompiler, detect_compiler_for
from ..environment import get_llvm_tool_names
from ..mesonlib import version_compare, stringlistify, extract_as_list, MachineChoice
from .base import DependencyException, DependencyMethods, strip_system_libdirs, SystemDependency
from .cmake import CMakeDependency
from .configtool import ConfigToolDependency
from .factory import DependencyFactory
from .misc import threads_factory
from .pkgconfig import PkgConfigDependency

if T.TYPE_CHECKING:
    from ..envconfig import MachineInfo
    from .. environment import Environment


def get_shared_library_suffix(environment: 'Environment', for_machine: MachineChoice) -> str:
    """This is only guaranteed to work for languages that compile to machine
    code, not for languages like C# that use a bytecode and always end in .dll
    """
    m = environment.machines[for_machine]
    if m.is_windows():
        return '.dll'
    elif m.is_darwin():
        return '.dylib'
    return '.so'


class GTestDependencySystem(SystemDependency):
    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]) -> None:
        super().__init__(name, environment, kwargs, language='cpp')
        self.main = kwargs.get('main', False)
        self.src_dirs = ['/usr/src/gtest/src', '/usr/src/googletest/googletest/src']
        if not self._add_sub_dependency(threads_factory(environment, self.for_machine, {})):
            self.is_found = False
            return
        self.detect()

    def detect(self) -> None:
        gtest_detect = self.clib_compiler.find_library("gtest", self.env, [])
        gtest_main_detect = self.clib_compiler.find_library("gtest_main", self.env, [])
        if gtest_detect and (not self.main or gtest_main_detect):
            self.is_found = True
            self.compile_args = []
            self.link_args = gtest_detect
            if self.main:
                self.link_args += gtest_main_detect
            self.sources = []
            self.prebuilt = True
        elif self.detect_srcdir():
            self.is_found = True
            self.compile_args = ['-I' + d for d in self.src_include_dirs]
            self.link_args = []
            if self.main:
                self.sources = [self.all_src, self.main_src]
            else:
                self.sources = [self.all_src]
            self.prebuilt = False
        else:
            self.is_found = False

    def detect_srcdir(self) -> bool:
        for s in self.src_dirs:
            if os.path.exists(s):
                self.src_dir = s
                self.all_src = mesonlib.File.from_absolute_file(
                    os.path.join(self.src_dir, 'gtest-all.cc'))
                self.main_src = mesonlib.File.from_absolute_file(
                    os.path.join(self.src_dir, 'gtest_main.cc'))
                self.src_include_dirs = [os.path.normpath(os.path.join(self.src_dir, '..')),
                                         os.path.normpath(os.path.join(self.src_dir, '../include')),
                                         ]
                return True
        return False

    def log_info(self) -> str:
        if self.prebuilt:
            return 'prebuilt'
        else:
            return 'building self'

    def log_tried(self) -> str:
        return 'system'


class GTestDependencyPC(PkgConfigDependency):

    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
        assert name == 'gtest'
        if kwargs.get('main'):
            name = 'gtest_main'
        super().__init__(name, environment, kwargs)


class GMockDependencySystem(SystemDependency):
    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]) -> None:
        super().__init__(name, environment, kwargs, language='cpp')
        self.main = kwargs.get('main', False)
        if not self._add_sub_dependency(threads_factory(environment, self.for_machine, {})):
            self.is_found = False
            return

        # If we are getting main() from GMock, we definitely
        # want to avoid linking in main() from GTest
        gtest_kwargs = kwargs.copy()
        if self.main:
            gtest_kwargs['main'] = False

        # GMock without GTest is pretty much useless
        # this also mimics the structure given in WrapDB,
        # where GMock always pulls in GTest
        found = self._add_sub_dependency(gtest_factory(environment, self.for_machine, gtest_kwargs))
        if not found:
            self.is_found = False
            return

        # GMock may be a library or just source.
        # Work with both.
        gmock_detect = self.clib_compiler.find_library("gmock", self.env, [])
        gmock_main_detect = self.clib_compiler.find_library("gmock_main", self.env, [])
        if gmock_detect and (not self.main or gmock_main_detect):
            self.is_found = True
            self.link_args += gmock_detect
            if self.main:
                self.link_args += gmock_main_detect
            self.prebuilt = True
            return

        for d in ['/usr/src/googletest/googlemock/src', '/usr/src/gmock/src', '/usr/src/gmock']:
            if os.path.exists(d):
                self.is_found = True
                # Yes, we need both because there are multiple
                # versions of gmock that do different things.
                d2 = os.path.normpath(os.path.join(d, '..'))
                self.compile_args += ['-I' + d, '-I' + d2, '-I' + os.path.join(d2, 'include')]
                all_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock-all.cc'))
                main_src = mesonlib.File.from_absolute_file(os.path.join(d, 'gmock_main.cc'))
                if self.main:
                    self.sources += [all_src, main_src]
                else:
                    self.sources += [all_src]
                self.prebuilt = False
                return

        self.is_found = False

    def log_info(self) -> str:
        if self.prebuilt:
            return 'prebuilt'
        else:
            return 'building self'

    def log_tried(self) -> str:
        return 'system'


class GMockDependencyPC(PkgConfigDependency):

    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
        assert name == 'gmock'
        if kwargs.get('main'):
            name = 'gmock_main'
        super().__init__(name, environment, kwargs)


class LLVMDependencyConfigTool(ConfigToolDependency):
    """
    LLVM uses a special tool, llvm-config, which has arguments for getting
    c args, cxx args, and ldargs as well as version.
    """
    tool_name = 'llvm-config'
    __cpp_blacklist = {'-DNDEBUG'}

    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
        self.tools = get_llvm_tool_names('llvm-config')

        # Fedora starting with Fedora 30 adds a suffix of the number
        # of bits in the isa that llvm targets, for example, on x86_64
        # and aarch64 the name will be llvm-config-64, on x86 and arm
        # it will be llvm-config-32.
        if environment.machines[self.get_for_machine_from_kwargs(kwargs)].is_64_bit:
            self.tools.append('llvm-config-64')
        else:
            self.tools.append('llvm-config-32')

        # It's necessary for LLVM <= 3.8 to use the C++ linker. For 3.9 and 4.0
        # the C linker works fine if only using the C API.
        super().__init__(name, environment, kwargs, language='cpp')
        self.provided_modules: T.List[str] = []
        self.required_modules: mesonlib.OrderedSet[str]  = mesonlib.OrderedSet()
        self.module_details:   T.List[str] = []
        if not self.is_found:
            return

        self.provided_modules = self.get_config_value(['--components'], 'modules')
        modules = stringlistify(extract_as_list(kwargs, 'modules'))
        self.check_components(modules)
        opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
        self.check_components(opt_modules, required=False)

        cargs = mesonlib.OrderedSet(self.get_config_value(['--cppflags'], 'compile_args'))
        self.compile_args = list(cargs.difference(self.__cpp_blacklist))

        if version_compare(self.version, '>= 3.9'):
            self._set_new_link_args(environment)
        else:
            self._set_old_link_args()
        self.link_args = strip_system_libdirs(environment, self.for_machine, self.link_args)
        self.link_args = self.__fix_bogus_link_args(self.link_args)
        if not self._add_sub_dependency(threads_factory(environment, self.for_machine, {})):
            self.is_found = False
            return

    def __fix_bogus_link_args(self, args: T.List[str]) -> T.List[str]:
        """This function attempts to fix bogus link arguments that llvm-config
        generates.

        Currently it works around the following:
            - FreeBSD: when statically linking -l/usr/lib/libexecinfo.so will
              be generated, strip the -l in cases like this.
            - Windows: We may get -LIBPATH:... which is later interpreted as
              "-L IBPATH:...", if we're using an msvc like compilers convert
              that to "/LIBPATH", otherwise to "-L ..."
        """

        new_args = []
        for arg in args:
            if arg.startswith('-l') and arg.endswith('.so'):
                new_args.append(arg.lstrip('-l'))
            elif arg.startswith('-LIBPATH:'):
                cpp = self.env.coredata.compilers[self.for_machine]['cpp']
                new_args.extend(cpp.get_linker_search_args(arg.lstrip('-LIBPATH:')))
            else:
                new_args.append(arg)
        return new_args

    def __check_libfiles(self, shared: bool) -> None:
        """Use llvm-config's --libfiles to check if libraries exist."""
        mode = '--link-shared' if shared else '--link-static'

        # Set self.required to true to force an exception in get_config_value
        # if the returncode != 0
        restore = self.required
        self.required = True

        try:
            # It doesn't matter what the stage is, the caller needs to catch
            # the exception anyway.
            self.link_args = self.get_config_value(['--libfiles', mode], '')
        finally:
            self.required = restore

    def _set_new_link_args(self, environment: 'Environment') -> None:
        """How to set linker args for LLVM versions >= 3.9"""
        try:
            mode = self.get_config_value(['--shared-mode'], 'link_args')[0]
        except IndexError:
            mlog.debug('llvm-config --shared-mode returned an error')
            self.is_found = False
            return

        if not self.static and mode == 'static':
            # If llvm is configured with LLVM_BUILD_LLVM_DYLIB but not with
            # LLVM_LINK_LLVM_DYLIB and not LLVM_BUILD_SHARED_LIBS (which
            # upstream doesn't recommend using), then llvm-config will lie to
            # you about how to do shared-linking. It wants to link to a a bunch
            # of individual shared libs (which don't exist because llvm wasn't
            # built with LLVM_BUILD_SHARED_LIBS.
            #
            # Therefore, we'll try to get the libfiles, if the return code is 0
            # or we get an empty list, then we'll try to build a working
            # configuration by hand.
            try:
                self.__check_libfiles(True)
            except DependencyException:
                lib_ext = get_shared_library_suffix(environment, self.for_machine)
                libdir = self.get_config_value(['--libdir'], 'link_args')[0]
                # Sort for reproducibility
                matches = sorted(glob.iglob(os.path.join(libdir, f'libLLVM*{lib_ext}')))
                if not matches:
                    if self.required:
                        raise
                    self.is_found = False
                    return

                self.link_args = self.get_config_value(['--ldflags'], 'link_args')
                libname = os.path.basename(matches[0]).rstrip(lib_ext).lstrip('lib')
                self.link_args.append(f'-l{libname}')
                return
        elif self.static and mode == 'shared':
            # If, however LLVM_BUILD_SHARED_LIBS is true # (*cough* gentoo *cough*)
            # then this is correct. Building with LLVM_BUILD_SHARED_LIBS has a side
            # effect, it stops the generation of static archives. Therefore we need
            # to check for that and error out on static if this is the case
            try:
                self.__check_libfiles(False)
            except DependencyException:
                if self.required:
                    raise
                self.is_found = False
                return

        link_args = ['--link-static', '--system-libs'] if self.static else ['--link-shared']
        self.link_args = self.get_config_value(
            ['--libs', '--ldflags'] + link_args + list(self.required_modules),
            'link_args')

    def _set_old_link_args(self) -> None:
        """Setting linker args for older versions of llvm.

        Old versions of LLVM bring an extra level of insanity with them.
        llvm-config will provide the correct arguments for static linking, but
        not for shared-linnking, we have to figure those out ourselves, because
        of course we do.
        """
        if self.static:
            self.link_args = self.get_config_value(
                ['--libs', '--ldflags', '--system-libs'] + list(self.required_modules),
                'link_args')
        else:
            # llvm-config will provide arguments for static linking, so we get
            # to figure out for ourselves what to link with. We'll do that by
            # checking in the directory provided by --libdir for a library
            # called libLLVM-<ver>.(so|dylib|dll)
            libdir = self.get_config_value(['--libdir'], 'link_args')[0]

            expected_name = f'libLLVM-{self.version}'
            re_name = re.compile(fr'{expected_name}.(so|dll|dylib)$')

            for file_ in os.listdir(libdir):
                if re_name.match(file_):
                    self.link_args = [f'-L{libdir}',
                                      '-l{}'.format(os.path.splitext(file_.lstrip('lib'))[0])]
                    break
            else:
                raise DependencyException(
                    'Could not find a dynamically linkable library for LLVM.')

    def check_components(self, modules: T.List[str], required: bool = True) -> None:
        """Check for llvm components (modules in meson terms).

        The required option is whether the module is required, not whether LLVM
        is required.
        """
        for mod in sorted(set(modules)):
            status = ''

            if mod not in self.provided_modules:
                if required:
                    self.is_found = False
                    if self.required:
                        raise DependencyException(
                            f'Could not find required LLVM Component: {mod}')
                    status = '(missing)'
                else:
                    status = '(missing but optional)'
            else:
                self.required_modules.add(mod)

            self.module_details.append(mod + status)

    def log_details(self) -> str:
        if self.module_details:
            return 'modules: ' + ', '.join(self.module_details)
        return ''

class LLVMDependencyCMake(CMakeDependency):
    def __init__(self, name: str, env: 'Environment', kwargs: T.Dict[str, T.Any]) -> None:
        self.llvm_modules = stringlistify(extract_as_list(kwargs, 'modules'))
        self.llvm_opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
        super().__init__(name, env, kwargs, language='cpp')

        # Cmake will always create a statically linked binary, so don't use
        # cmake if dynamic is required
        if not self.static:
            self.is_found = False
            mlog.warning('Ignoring LLVM CMake dependency because dynamic was requested')
            return

        if self.traceparser is None:
            return

        # Extract extra include directories and definitions
        inc_dirs = self.traceparser.get_cmake_var('PACKAGE_INCLUDE_DIRS')
        defs = self.traceparser.get_cmake_var('PACKAGE_DEFINITIONS')
        # LLVM explicitly uses space-separated variables rather than semicolon lists
        if len(defs) == 1:
            defs = defs[0].split(' ')
        temp = ['-I' + x for x in inc_dirs] + defs
        self.compile_args += [x for x in temp if x not in self.compile_args]
        if not self._add_sub_dependency(threads_factory(env, self.for_machine, {})):
            self.is_found = False
            return

    def _main_cmake_file(self) -> str:
        # Use a custom CMakeLists.txt for LLVM
        return 'CMakeListsLLVM.txt'

    def _extra_cmake_opts(self) -> T.List[str]:
        return ['-DLLVM_MESON_MODULES={}'.format(';'.join(self.llvm_modules + self.llvm_opt_modules))]

    def _map_module_list(self, modules: T.List[T.Tuple[str, bool]], components: T.List[T.Tuple[str, bool]]) -> T.List[T.Tuple[str, bool]]:
        res = []
        for mod, required in modules:
            cm_targets = self.traceparser.get_cmake_var(f'MESON_LLVM_TARGETS_{mod}')
            if not cm_targets:
                if required:
                    raise self._gen_exception(f'LLVM module {mod} was not found')
                else:
                    mlog.warning('Optional LLVM module', mlog.bold(mod), 'was not found')
                    continue
            for i in cm_targets:
                res += [(i, required)]
        return res

    def _original_module_name(self, module: str) -> str:
        orig_name = self.traceparser.get_cmake_var(f'MESON_TARGET_TO_LLVM_{module}')
        if orig_name:
            return orig_name[0]
        return module


class ValgrindDependency(PkgConfigDependency):
    '''
    Consumers of Valgrind usually only need the compile args and do not want to
    link to its (static) libraries.
    '''
    def __init__(self, env: 'Environment', kwargs: T.Dict[str, T.Any]):
        super().__init__('valgrind', env, kwargs)

    def get_link_args(self, language: T.Optional[str] = None, raw: bool = False) -> T.List[str]:
        return []


class ZlibSystemDependency(SystemDependency):

    def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
        super().__init__(name, environment, kwargs)

        m = self.env.machines[self.for_machine]

        # I'm not sure this is entirely correct. What if we're cross compiling
        # from something to macOS?
        if ((m.is_darwin() and isinstance(self.clib_compiler, (AppleClangCCompiler, AppleClangCPPCompiler))) or
                m.is_freebsd() or m.is_dragonflybsd()):
            # No need to set includes,
            # on macos xcode/clang will do that for us.
            # on freebsd zlib.h is in /usr/include

            self.is_found = True
            self.link_args = ['-lz']
        elif m.is_windows():
            # Without a clib_compiler we can't find zlib, s just give up.
            if self.clib_compiler is None:
                self.is_found = False
                return

            if self.clib_compiler.get_argument_syntax() == 'msvc':
                libs = ['zlib1' 'zlib']
            else:
                libs = ['z']
            for lib in libs:
                l = self.clib_compiler.find_library(lib, environment, [])
                h = self.clib_compiler.has_header('zlib.h', '', environment, dependencies=[self])
                if l and h[0]:
                    self.is_found = True
                    self.link_args = l
                    break
            else:
                return
        else:
            mlog.debug(f'Unsupported OS {m.system}')
            return

        v, _ = self.clib_compiler.get_define('ZLIB_VERSION', '#include <zlib.h>', self.env, [], [self])
        self.version = v.strip('"')


class JDKSystemDependency(SystemDependency):
    def __init__(self, environment: 'Environment', kwargs: T.Dict[str, T.Any]):
        super().__init__('jdk', environment, kwargs)

        m = self.env.machines[self.for_machine]

        if 'java' not in environment.coredata.compilers[self.for_machine]:
            detect_compiler_for(environment, 'java', self.for_machine)
        self.javac = environment.coredata.compilers[self.for_machine]['java']
        self.version = self.javac.version

        if 'version' in kwargs and not version_compare(self.version, kwargs['version']):
            mlog.error(f'Incorrect JDK version found ({self.version}), wanted {kwargs["version"]}')
            self.is_found = False
            return

        self.java_home = environment.properties[self.for_machine].get_java_home()
        if not self.java_home:
            self.java_home = pathlib.Path(shutil.which(self.javac.exelist[0])).resolve().parents[1]

        platform_include_dir = self.__machine_info_to_platform_include_dir(m)
        if platform_include_dir is None:
            mlog.error("Could not find a JDK platform include directory for your OS, please open an issue or provide a pull request.")
            self.is_found = False
            return

        java_home_include = self.java_home / 'include'
        self.compile_args.append(f'-I{java_home_include}')
        self.compile_args.append(f'-I{java_home_include / platform_include_dir}')
        self.is_found = True

    @staticmethod
    def __machine_info_to_platform_include_dir(m: 'MachineInfo') -> T.Optional[str]:
        """Translates the machine information to the platform-dependent include directory

        When inspecting a JDK release tarball or $JAVA_HOME, inside the `include/` directory is a
        platform dependent folder that must be on the target's include path in addition to the
        parent `include/` directory.
        """
        if m.is_linux():
            return 'linux'
        elif m.is_windows():
            return 'win32'
        elif m.is_darwin():
            return 'darwin'

        return None


llvm_factory = DependencyFactory(
    'LLVM',
    [DependencyMethods.CMAKE, DependencyMethods.CONFIG_TOOL],
    cmake_class=LLVMDependencyCMake,
    configtool_class=LLVMDependencyConfigTool,
)

gtest_factory = DependencyFactory(
    'gtest',
    [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
    pkgconfig_class=GTestDependencyPC,
    system_class=GTestDependencySystem,
)

gmock_factory = DependencyFactory(
    'gmock',
    [DependencyMethods.PKGCONFIG, DependencyMethods.SYSTEM],
    pkgconfig_class=GMockDependencyPC,
    system_class=GMockDependencySystem,
)

zlib_factory = DependencyFactory(
    'zlib',
    [DependencyMethods.PKGCONFIG, DependencyMethods.CMAKE, DependencyMethods.SYSTEM],
    cmake_name='ZLIB',
    system_class=ZlibSystemDependency,
)