# Copyright © 2020-2023 Intel Corporation

# 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.
from __future__ import annotations
import itertools
import os
import typing as T

from mesonbuild.interpreterbase.decorators import FeatureNew

from . import ExtensionModule, ModuleReturnValue, ModuleInfo
from .. import mlog
from ..build import (BothLibraries, BuildTarget, CustomTargetIndex, Executable, ExtractedObjects, GeneratedList,
                     CustomTarget, InvalidArguments, Jar, StructuredSources, SharedLibrary)
from ..compilers.compilers import are_asserts_disabled
from ..interpreter.type_checking import DEPENDENCIES_KW, LINK_WITH_KW, SHARED_LIB_KWS, TEST_KWS, OUTPUT_KW, INCLUDE_DIRECTORIES, SOURCES_VARARGS
from ..interpreterbase import ContainerTypeInfo, InterpreterException, KwargInfo, typed_kwargs, typed_pos_args, noPosargs, permittedKwargs
from ..mesonlib import File

if T.TYPE_CHECKING:
    from . import ModuleState
    from ..build import IncludeDirs, LibTypes
    from ..dependencies import Dependency, ExternalLibrary
    from ..interpreter import Interpreter
    from ..interpreter import kwargs as _kwargs
    from ..interpreter.interpreter import SourceInputs, SourceOutputs
    from ..programs import ExternalProgram, OverrideProgram
    from ..interpreter.type_checking import SourcesVarargsType

    from typing_extensions import TypedDict

    class FuncTest(_kwargs.BaseTest):

        dependencies: T.List[T.Union[Dependency, ExternalLibrary]]
        is_parallel: bool
        link_with: T.List[LibTypes]
        rust_args: T.List[str]

    class FuncBindgen(TypedDict):

        args: T.List[str]
        c_args: T.List[str]
        include_directories: T.List[IncludeDirs]
        input: T.List[SourceInputs]
        output: str
        dependencies: T.List[T.Union[Dependency, ExternalLibrary]]


class RustModule(ExtensionModule):

    """A module that holds helper functions for rust."""

    INFO = ModuleInfo('rust', '0.57.0', stabilized='1.0.0')

    def __init__(self, interpreter: Interpreter) -> None:
        super().__init__(interpreter)
        self._bindgen_bin: T.Optional[T.Union[ExternalProgram, Executable, OverrideProgram]] = None
        self.methods.update({
            'test': self.test,
            'bindgen': self.bindgen,
            'proc_macro': self.proc_macro,
        })

    @typed_pos_args('rust.test', str, BuildTarget)
    @typed_kwargs(
        'rust.test',
        *TEST_KWS,
        DEPENDENCIES_KW,
        LINK_WITH_KW.evolve(since='1.2.0'),
        KwargInfo(
            'rust_args',
            ContainerTypeInfo(list, str),
            listify=True,
            default=[],
            since='1.2.0',
        ),
        KwargInfo('is_parallel', bool, default=False),
    )
    def test(self, state: ModuleState, args: T.Tuple[str, BuildTarget], kwargs: FuncTest) -> ModuleReturnValue:
        """Generate a rust test target from a given rust target.

        Rust puts it's unitests inside it's main source files, unlike most
        languages that put them in external files. This means that normally
        you have to define two separate targets with basically the same
        arguments to get tests:

        ```meson
        rust_lib_sources = [...]
        rust_lib = static_library(
            'rust_lib',
            rust_lib_sources,
        )

        rust_lib_test = executable(
            'rust_lib_test',
            rust_lib_sources,
            rust_args : ['--test'],
        )

        test(
            'rust_lib_test',
            rust_lib_test,
            protocol : 'rust',
        )
        ```

        This is all fine, but not very DRY. This method makes it much easier
        to define rust tests:

        ```meson
        rust = import('unstable-rust')

        rust_lib = static_library(
            'rust_lib',
            [sources],
        )

        rust.test('rust_lib_test', rust_lib)
        ```
        """
        if any(isinstance(t, Jar) for t in kwargs.get('link_with', [])):
            raise InvalidArguments('Rust tests cannot link with Jar targets')

        name = args[0]
        base_target: BuildTarget = args[1]
        if not base_target.uses_rust():
            raise InterpreterException('Second positional argument to rustmod.test() must be a rust based target')
        extra_args = kwargs['args']

        # Delete any arguments we don't want passed
        if '--test' in extra_args:
            mlog.warning('Do not add --test to rustmod.test arguments')
            extra_args.remove('--test')
        if '--format' in extra_args:
            mlog.warning('Do not add --format to rustmod.test arguments')
            i = extra_args.index('--format')
            # Also delete the argument to --format
            del extra_args[i + 1]
            del extra_args[i]
        for i, a in enumerate(extra_args):
            if isinstance(a, str) and a.startswith('--format='):
                del extra_args[i]
                break

        # We need to cast here, as currently these don't have protocol in them, but test itself does.
        tkwargs = T.cast('_kwargs.FuncTest', kwargs.copy())

        tkwargs['args'] = extra_args + ['--test', '--format', 'pretty']
        tkwargs['protocol'] = 'rust'

        new_target_kwargs = base_target.original_kwargs.copy()
        # Don't mutate the shallow copied list, instead replace it with a new
        # one
        new_target_kwargs['install'] = False
        new_target_kwargs['dependencies'] = new_target_kwargs.get('dependencies', []) + kwargs['dependencies']
        new_target_kwargs['link_with'] = new_target_kwargs.get('link_with', []) + kwargs['link_with']
        del new_target_kwargs['rust_crate_type']

        lang_args = base_target.extra_args.copy()
        lang_args['rust'] = base_target.extra_args['rust'] + kwargs['rust_args'] + ['--test']
        new_target_kwargs['language_args'] = lang_args

        sources = T.cast('T.List[SourceOutputs]', base_target.sources.copy())
        sources.extend(base_target.generated)

        new_target = Executable(
            name, base_target.subdir, state.subproject, base_target.for_machine,
            sources, base_target.structured_sources,
            base_target.objects, base_target.environment, base_target.compilers,
            new_target_kwargs
        )

        test = self.interpreter.make_test(
            self.interpreter.current_node, (name, new_target), tkwargs)

        return ModuleReturnValue(None, [new_target, test])

    @noPosargs
    @typed_kwargs(
        'rust.bindgen',
        KwargInfo('c_args', ContainerTypeInfo(list, str), default=[], listify=True),
        KwargInfo('args', ContainerTypeInfo(list, str), default=[], listify=True),
        KwargInfo(
            'input',
            ContainerTypeInfo(list, (File, GeneratedList, BuildTarget, BothLibraries, ExtractedObjects, CustomTargetIndex, CustomTarget, str), allow_empty=False),
            default=[],
            listify=True,
            required=True,
        ),
        INCLUDE_DIRECTORIES.evolve(since_values={ContainerTypeInfo(list, str): '1.0.0'}),
        OUTPUT_KW,
        DEPENDENCIES_KW.evolve(since='1.0.0'),
    )
    def bindgen(self, state: ModuleState, args: T.List, kwargs: FuncBindgen) -> ModuleReturnValue:
        """Wrapper around bindgen to simplify it's use.

        The main thing this simplifies is the use of `include_directory`
        objects, instead of having to pass a plethora of `-I` arguments.
        """
        header, *_deps = self.interpreter.source_strings_to_files(kwargs['input'])

        # Split File and Target dependencies to add pass to CustomTarget
        depends: T.List[SourceOutputs] = []
        depend_files: T.List[File] = []
        for d in _deps:
            if isinstance(d, File):
                depend_files.append(d)
            else:
                depends.append(d)

        # Copy to avoid subsequent calls mutating the original
        # TODO: if we want this to be per-machine we'll need a native kwarg
        clang_args = state.environment.properties.host.get_bindgen_clang_args().copy()

        for i in state.process_include_dirs(kwargs['include_directories']):
            # bindgen always uses clang, so it's safe to hardcode -I here
            clang_args.extend([f'-I{x}' for x in i.to_string_list(
                state.environment.get_source_dir(), state.environment.get_build_dir())])
        if are_asserts_disabled(state.environment.coredata.options):
            clang_args.append('-DNDEBUG')

        for de in kwargs['dependencies']:
            for i in de.get_include_dirs():
                clang_args.extend([f'-I{x}' for x in i.to_string_list(
                    state.environment.get_source_dir(), state.environment.get_build_dir())])
            clang_args.extend(de.get_all_compile_args())
            for s in de.get_sources():
                if isinstance(s, File):
                    depend_files.append(s)
                elif isinstance(s, CustomTarget):
                    depends.append(s)

        # We only want include directories and defines, other things may not be valid
        cargs = state.get_option('args', state.subproject, lang='c')
        assert isinstance(cargs, list), 'for mypy'
        for a in itertools.chain(state.global_args.get('c', []), state.project_args.get('c', []), cargs):
            if a.startswith(('-I', '/I', '-D', '/D', '-U', '/U')):
                clang_args.append(a)

        if self._bindgen_bin is None:
            self._bindgen_bin = state.find_program('bindgen')

        name: str
        if isinstance(header, File):
            name = header.fname
        elif isinstance(header, (BuildTarget, BothLibraries, ExtractedObjects, StructuredSources)):
            raise InterpreterException('bindgen source file must be a C header, not an object or build target')
        else:
            name = header.get_outputs()[0]

        cmd = self._bindgen_bin.get_command() + \
            [
                '@INPUT@', '--output',
                os.path.join(state.environment.build_dir, '@OUTPUT@')
            ] + \
            kwargs['args'] + ['--'] + kwargs['c_args'] + clang_args + \
            ['-MD', '-MQ', '@INPUT@', '-MF', '@DEPFILE@']

        target = CustomTarget(
            f'rustmod-bindgen-{name}'.replace('/', '_'),
            state.subdir,
            state.subproject,
            state.environment,
            cmd,
            [header],
            [kwargs['output']],
            depfile='@PLAINNAME@.d',
            extra_depends=depends,
            depend_files=depend_files,
            backend=state.backend,
            description='Generating bindings for Rust {}',
        )

        return ModuleReturnValue([target], [target])

    # Allow a limited set of kwargs, but still use the full set of typed_kwargs()
    # because it could be setting required default values.
    @FeatureNew('rust.proc_macro', '1.3.0')
    @permittedKwargs({'rust_args', 'rust_dependency_map', 'sources', 'dependencies', 'extra_files',
                      'link_args', 'link_depends', 'link_with', 'override_options'})
    @typed_pos_args('rust.proc_macro', str, varargs=SOURCES_VARARGS)
    @typed_kwargs('rust.proc_macro', *SHARED_LIB_KWS, allow_unknown=True)
    def proc_macro(self, state: ModuleState, args: T.Tuple[str, SourcesVarargsType], kwargs: _kwargs.SharedLibrary) -> SharedLibrary:
        kwargs['native'] = True  # type: ignore
        kwargs['rust_crate_type'] = 'proc-macro'  # type: ignore
        kwargs['rust_args'] = kwargs['rust_args'] + ['--extern', 'proc_macro']
        target = state._interpreter.build_target(state.current_node, args, kwargs, SharedLibrary)
        return target


def initialize(interp: Interpreter) -> RustModule:
    return RustModule(interp)
