# Copyright 2018 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.
from __future__ import annotations

'''This module provides helper functions for generating documentation using hotdoc'''

import os, subprocess
import typing as T

from . import ExtensionModule, ModuleReturnValue, ModuleInfo
from .. import build, mesonlib, mlog
from ..build import CustomTarget, CustomTargetIndex
from ..dependencies import Dependency, InternalDependency
from ..interpreterbase import (
    InvalidArguments, noPosargs, noKwargs, typed_kwargs, FeatureDeprecated,
    ContainerTypeInfo, KwargInfo, typed_pos_args
)
from ..interpreter.interpreterobjects import _CustomTargetHolder
from ..interpreter.type_checking import NoneType
from ..mesonlib import File, MesonException
from ..programs import ExternalProgram

if T.TYPE_CHECKING:
    from typing_extensions import TypedDict

    from . import ModuleState
    from ..environment import Environment
    from ..interpreter import Interpreter
    from ..interpreterbase import TYPE_kwargs, TYPE_var

    _T = T.TypeVar('_T')

    class GenerateDocKwargs(TypedDict):
        sitemap: T.Union[str, File, CustomTarget, CustomTargetIndex]
        index: T.Union[str, File, CustomTarget, CustomTargetIndex]
        project_version: str
        html_extra_theme: T.Optional[str]
        include_paths: T.List[str]
        dependencies: T.List[T.Union[Dependency, build.StaticLibrary, build.SharedLibrary, CustomTarget, CustomTargetIndex]]
        depends: T.List[T.Union[CustomTarget, CustomTargetIndex]]
        gi_c_source_roots: T.List[str]
        extra_assets: T.List[str]
        extra_extension_paths: T.List[str]
        subprojects: T.List['HotdocTarget']
        install: bool

def ensure_list(value: T.Union[_T, T.List[_T]]) -> T.List[_T]:
    if not isinstance(value, list):
        return [value]
    return value


MIN_HOTDOC_VERSION = '0.8.100'

file_types = (str, File, CustomTarget, CustomTargetIndex)


class HotdocExternalProgram(ExternalProgram):
    def run_hotdoc(self, cmd: T.List[str]) -> int:
        return subprocess.run(self.get_command() + cmd, stdout=subprocess.DEVNULL).returncode


class HotdocTargetBuilder:

    def __init__(self, name: str, state: ModuleState, hotdoc: HotdocExternalProgram, interpreter: Interpreter, kwargs):
        self.hotdoc = hotdoc
        self.build_by_default = kwargs.pop('build_by_default', False)
        self.kwargs = kwargs
        self.name = name
        self.state = state
        self.interpreter = interpreter
        self.include_paths: mesonlib.OrderedSet[str] = mesonlib.OrderedSet()

        self.builddir = state.environment.get_build_dir()
        self.sourcedir = state.environment.get_source_dir()
        self.subdir = state.subdir
        self.build_command = state.environment.get_build_command()

        self.cmd: T.List[TYPE_var] = ['conf', '--project-name', name, "--disable-incremental-build",
                                      '--output', os.path.join(self.builddir, self.subdir, self.name + '-doc')]

        self._extra_extension_paths = set()
        self.extra_assets = set()
        self.extra_depends = []
        self._subprojects = []

    def process_known_arg(self, option: str, argname: T.Optional[str] = None, value_processor: T.Optional[T.Callable] = None) -> None:
        if not argname:
            argname = option.strip("-").replace("-", "_")

        value = self.kwargs.pop(argname)
        if value is not None and value_processor:
            value = value_processor(value)

        self.set_arg_value(option, value)

    def set_arg_value(self, option: str, value: TYPE_var) -> None:
        if value is None:
            return

        if isinstance(value, bool):
            if value:
                self.cmd.append(option)
        elif isinstance(value, list):
            # Do not do anything on empty lists
            if value:
                # https://bugs.python.org/issue9334 (from 2010 :( )
                # The syntax with nargs=+ is inherently ambiguous
                # A workaround for this case is to simply prefix with a space
                # every value starting with a dash
                escaped_value = []
                for e in value:
                    if isinstance(e, str) and e.startswith('-'):
                        escaped_value += [' %s' % e]
                    else:
                        escaped_value += [e]
                if option:
                    self.cmd.extend([option] + escaped_value)
                else:
                    self.cmd.extend(escaped_value)
        else:
            # argparse gets confused if value(s) start with a dash.
            # When an option expects a single value, the unambiguous way
            # to specify it is with =
            if isinstance(value, str):
                self.cmd.extend([f'{option}={value}'])
            else:
                self.cmd.extend([option, value])

    def check_extra_arg_type(self, arg: str, value: TYPE_var) -> None:
        if isinstance(value, list):
            for v in value:
                self.check_extra_arg_type(arg, v)
            return

        valid_types = (str, bool, File, build.IncludeDirs, CustomTarget, CustomTargetIndex, build.BuildTarget)
        if not isinstance(value, valid_types):
            raise InvalidArguments('Argument "{}={}" should be of type: {}.'.format(
                arg, value, [t.__name__ for t in valid_types]))

    def process_extra_args(self) -> None:
        for arg, value in self.kwargs.items():
            option = "--" + arg.replace("_", "-")
            self.check_extra_arg_type(arg, value)
            self.set_arg_value(option, value)

    def get_value(self, types, argname, default=None, value_processor=None,
                  mandatory=False, force_list=False):
        if not isinstance(types, list):
            types = [types]
        try:
            uvalue = value = self.kwargs.pop(argname)
            if value_processor:
                value = value_processor(value)

            for t in types:
                if isinstance(value, t):
                    if force_list and not isinstance(value, list):
                        return [value], uvalue
                    return value, uvalue
            raise MesonException(f"{argname} field value {value} is not valid,"
                                 f" valid types are {types}")
        except KeyError:
            if mandatory:
                raise MesonException(f"{argname} mandatory field not found")

            if default is not None:
                return default, default

        return None, None

    def add_extension_paths(self, paths: T.Union[T.List[str], T.Set[str]]) -> None:
        for path in paths:
            if path in self._extra_extension_paths:
                continue

            self._extra_extension_paths.add(path)
            self.cmd.extend(["--extra-extension-path", path])

    def replace_dirs_in_string(self, string: str) -> str:
        return string.replace("@SOURCE_ROOT@", self.sourcedir).replace("@BUILD_ROOT@", self.builddir)

    def process_gi_c_source_roots(self) -> None:
        if self.hotdoc.run_hotdoc(['--has-extension=gi-extension']) != 0:
            return

        value = self.kwargs.pop('gi_c_source_roots')
        value.extend([
            os.path.join(self.sourcedir, self.state.root_subdir),
            os.path.join(self.builddir, self.state.root_subdir)
        ])

        self.cmd += ['--gi-c-source-roots'] + value

    def process_dependencies(self, deps: T.List[T.Union[Dependency, build.StaticLibrary, build.SharedLibrary, CustomTarget, CustomTargetIndex]]) -> T.List[str]:
        cflags = set()
        for dep in mesonlib.listify(ensure_list(deps)):
            if isinstance(dep, InternalDependency):
                inc_args = self.state.get_include_args(dep.include_directories)
                cflags.update([self.replace_dirs_in_string(x)
                               for x in inc_args])
                cflags.update(self.process_dependencies(dep.libraries))
                cflags.update(self.process_dependencies(dep.sources))
                cflags.update(self.process_dependencies(dep.ext_deps))
            elif isinstance(dep, Dependency):
                cflags.update(dep.get_compile_args())
            elif isinstance(dep, (build.StaticLibrary, build.SharedLibrary)):
                self.extra_depends.append(dep)
                for incd in dep.get_include_dirs():
                    cflags.update(incd.get_incdirs())
            elif isinstance(dep, HotdocTarget):
                # Recurse in hotdoc target dependencies
                self.process_dependencies(dep.get_target_dependencies())
                self._subprojects.extend(dep.subprojects)
                self.process_dependencies(dep.subprojects)
                self.include_paths.add(os.path.join(self.builddir, dep.hotdoc_conf.subdir))
                self.cmd += ['--extra-assets=' + p for p in dep.extra_assets]
                self.add_extension_paths(dep.extra_extension_paths)
            elif isinstance(dep, (CustomTarget, build.BuildTarget)):
                self.extra_depends.append(dep)
            elif isinstance(dep, CustomTargetIndex):
                self.extra_depends.append(dep.target)

        return [f.strip('-I') for f in cflags]

    def process_extra_assets(self) -> None:
        self._extra_assets = self.kwargs.pop('extra_assets')

        for assets_path in self._extra_assets:
            self.cmd.extend(["--extra-assets", assets_path])

    def process_subprojects(self) -> None:
        value = self.kwargs.pop('subprojects')

        self.process_dependencies(value)
        self._subprojects.extend(value)

    def flatten_config_command(self) -> T.List[str]:
        cmd = []
        for arg in mesonlib.listify(self.cmd, flatten=True):
            if isinstance(arg, File):
                arg = arg.absolute_path(self.state.environment.get_source_dir(),
                                        self.state.environment.get_build_dir())
            elif isinstance(arg, build.IncludeDirs):
                for inc_dir in arg.get_incdirs():
                    cmd.append(os.path.join(self.sourcedir, arg.get_curdir(), inc_dir))
                    cmd.append(os.path.join(self.builddir, arg.get_curdir(), inc_dir))

                continue
            elif isinstance(arg, (build.BuildTarget, CustomTarget)):
                self.extra_depends.append(arg)
                arg = self.interpreter.backend.get_target_filename_abs(arg)
            elif isinstance(arg, CustomTargetIndex):
                self.extra_depends.append(arg.target)
                arg = self.interpreter.backend.get_target_filename_abs(arg)

            cmd.append(arg)

        return cmd

    def generate_hotdoc_config(self) -> None:
        cwd = os.path.abspath(os.curdir)
        ncwd = os.path.join(self.sourcedir, self.subdir)
        mlog.log('Generating Hotdoc configuration for: ', mlog.bold(self.name))
        os.chdir(ncwd)
        if self.hotdoc.run_hotdoc(self.flatten_config_command()) != 0:
            raise MesonException('hotdoc failed to configure')
        os.chdir(cwd)

    def ensure_file(self, value: T.Union[str, File, CustomTarget, CustomTargetIndex]) -> T.Union[File, CustomTarget, CustomTargetIndex]:
        if isinstance(value, list):
            res = []
            for val in value:
                res.append(self.ensure_file(val))
            return res

        if isinstance(value, str):
            return File.from_source_file(self.sourcedir, self.subdir, value)

        return value

    def ensure_dir(self, value: str) -> str:
        if os.path.isabs(value):
            _dir = value
        else:
            _dir = os.path.join(self.sourcedir, self.subdir, value)

        if not os.path.isdir(_dir):
            raise InvalidArguments(f'"{_dir}" is not a directory.')

        return os.path.relpath(_dir, os.path.join(self.builddir, self.subdir))

    def check_forbidden_args(self) -> None:
        for arg in ['conf_file']:
            if arg in self.kwargs:
                raise InvalidArguments(f'Argument "{arg}" is forbidden.')

    def make_targets(self) -> T.Tuple[HotdocTarget, mesonlib.ExecutableSerialisation]:
        self.check_forbidden_args()
        self.process_known_arg("--index", value_processor=self.ensure_file)
        self.process_known_arg("--project-version")
        self.process_known_arg("--sitemap", value_processor=self.ensure_file)
        self.process_known_arg("--html-extra-theme", value_processor=self.ensure_dir)
        self.include_paths.update(self.ensure_dir(v) for v in self.kwargs.pop('include_paths'))
        self.process_known_arg('--c-include-directories', argname="dependencies", value_processor=self.process_dependencies)
        self.process_gi_c_source_roots()
        self.process_extra_assets()
        self.add_extension_paths(self.kwargs.pop('extra_extension_paths'))
        self.process_subprojects()
        self.extra_depends.extend(self.kwargs.pop('depends'))

        install = self.kwargs.pop('install')
        self.process_extra_args()

        fullname = self.name + '-doc'
        hotdoc_config_name = fullname + '.json'
        hotdoc_config_path = os.path.join(
            self.builddir, self.subdir, hotdoc_config_name)
        with open(hotdoc_config_path, 'w', encoding='utf-8') as f:
            f.write('{}')

        self.cmd += ['--conf-file', hotdoc_config_path]
        self.include_paths.add(os.path.join(self.builddir, self.subdir))
        self.include_paths.add(os.path.join(self.sourcedir, self.subdir))

        depfile = os.path.join(self.builddir, self.subdir, self.name + '.deps')
        self.cmd += ['--deps-file-dest', depfile]

        for path in self.include_paths:
            self.cmd.extend(['--include-path', path])

        if self.state.environment.coredata.get_option(mesonlib.OptionKey('werror', subproject=self.state.subproject)):
            self.cmd.append('--fatal-warnings')
        self.generate_hotdoc_config()

        target_cmd = self.build_command + ["--internal", "hotdoc"] + \
            self.hotdoc.get_command() + ['run', '--conf-file', hotdoc_config_name] + \
            ['--builddir', os.path.join(self.builddir, self.subdir)]

        target = HotdocTarget(fullname,
                              subdir=self.subdir,
                              subproject=self.state.subproject,
                              environment=self.state.environment,
                              hotdoc_conf=File.from_built_file(
                                  self.subdir, hotdoc_config_name),
                              extra_extension_paths=self._extra_extension_paths,
                              extra_assets=self._extra_assets,
                              subprojects=self._subprojects,
                              command=target_cmd,
                              extra_depends=self.extra_depends,
                              outputs=[fullname],
                              sources=[],
                              depfile=os.path.basename(depfile),
                              build_by_default=self.build_by_default)

        install_script = None
        if install:
            datadir = os.path.join(self.state.get_option('prefix'), self.state.get_option('datadir'))
            devhelp = self.kwargs.get('devhelp_activate', False)
            if not isinstance(devhelp, bool):
                FeatureDeprecated.single_use('hotdoc.generate_doc() devhelp_activate must be boolean', '1.1.0', self.state.subproject)
                devhelp = False
            if devhelp:
                install_from = os.path.join(fullname, 'devhelp')
                install_to = os.path.join(datadir, 'devhelp')
            else:
                install_from = os.path.join(fullname, 'html')
                install_to = os.path.join(datadir, 'doc', self.name, 'html')

            install_script = self.state.backend.get_executable_serialisation(self.build_command + [
                "--internal", "hotdoc",
                "--install", install_from,
                "--docdir", install_to,
                '--name', self.name,
                '--builddir', os.path.join(self.builddir, self.subdir)] +
                self.hotdoc.get_command() +
                ['run', '--conf-file', hotdoc_config_name])
            install_script.tag = 'doc'

        return (target, install_script)


class HotdocTargetHolder(_CustomTargetHolder['HotdocTarget']):
    def __init__(self, target: HotdocTarget, interp: Interpreter):
        super().__init__(target, interp)
        self.methods.update({'config_path': self.config_path_method})

    @noPosargs
    @noKwargs
    def config_path_method(self, *args: T.Any, **kwargs: T.Any) -> str:
        conf = self.held_object.hotdoc_conf.absolute_path(self.interpreter.environment.source_dir,
                                                          self.interpreter.environment.build_dir)
        return conf


class HotdocTarget(CustomTarget):
    def __init__(self, name: str, subdir: str, subproject: str, hotdoc_conf: File,
                 extra_extension_paths: T.Set[str], extra_assets: T.List[str],
                 subprojects: T.List['HotdocTarget'], environment: Environment, **kwargs: T.Any):
        super().__init__(name, subdir, subproject, environment, **kwargs, absolute_paths=True)
        self.hotdoc_conf = hotdoc_conf
        self.extra_extension_paths = extra_extension_paths
        self.extra_assets = extra_assets
        self.subprojects = subprojects

    def __getstate__(self) -> dict:
        # Make sure we do not try to pickle subprojects
        res = self.__dict__.copy()
        res['subprojects'] = []

        return res


class HotDocModule(ExtensionModule):

    INFO = ModuleInfo('hotdoc', '0.48.0')

    def __init__(self, interpreter: Interpreter):
        super().__init__(interpreter)
        self.hotdoc = HotdocExternalProgram('hotdoc')
        if not self.hotdoc.found():
            raise MesonException('hotdoc executable not found')
        version = self.hotdoc.get_version(interpreter)
        if not mesonlib.version_compare(version, f'>={MIN_HOTDOC_VERSION}'):
            raise MesonException(f'hotdoc {MIN_HOTDOC_VERSION} required but not found.)')

        self.methods.update({
            'has_extensions': self.has_extensions,
            'generate_doc': self.generate_doc,
        })

    @noKwargs
    @typed_pos_args('hotdoc.has_extensions', varargs=str, min_varargs=1)
    def has_extensions(self, state: ModuleState, args: T.Tuple[T.List[str]], kwargs: TYPE_kwargs) -> bool:
        return self.hotdoc.run_hotdoc([f'--has-extension={extension}' for extension in args[0]]) == 0

    @typed_pos_args('hotdoc.generate_doc', str)
    @typed_kwargs(
        'hotdoc.generate_doc',
        KwargInfo('sitemap', file_types, required=True),
        KwargInfo('index', file_types, required=True),
        KwargInfo('project_version', str, required=True),
        KwargInfo('html_extra_theme', (str, NoneType)),
        KwargInfo('include_paths', ContainerTypeInfo(list, str), listify=True, default=[]),
        # --c-include-directories
        KwargInfo(
            'dependencies',
            ContainerTypeInfo(list, (Dependency, build.StaticLibrary, build.SharedLibrary,
                                     CustomTarget, CustomTargetIndex)),
            listify=True,
            default=[],
        ),
        KwargInfo(
            'depends',
            ContainerTypeInfo(list, (CustomTarget, CustomTargetIndex)),
            listify=True,
            default=[],
            since='0.64.1',
        ),
        KwargInfo('gi_c_source_roots', ContainerTypeInfo(list, str), listify=True, default=[]),
        KwargInfo('extra_assets', ContainerTypeInfo(list, str), listify=True, default=[]),
        KwargInfo('extra_extension_paths', ContainerTypeInfo(list, str), listify=True, default=[]),
        KwargInfo('subprojects', ContainerTypeInfo(list, HotdocTarget), listify=True, default=[]),
        KwargInfo('install', bool, default=False),
        allow_unknown=True
    )
    def generate_doc(self, state: ModuleState, args: T.Tuple[str], kwargs: GenerateDocKwargs) -> ModuleReturnValue:
        project_name = args[0]
        if any(isinstance(x, (CustomTarget, CustomTargetIndex)) for x in kwargs['dependencies']):
            FeatureDeprecated.single_use('hotdoc.generate_doc dependencies argument with custom_target',
                                         '0.64.1', state.subproject, 'use `depends`', state.current_node)
        builder = HotdocTargetBuilder(project_name, state, self.hotdoc, self.interpreter, kwargs)
        target, install_script = builder.make_targets()
        targets: T.List[T.Union[HotdocTarget, mesonlib.ExecutableSerialisation]] = [target]
        if install_script:
            targets.append(install_script)

        return ModuleReturnValue(target, targets)


def initialize(interpreter: Interpreter) -> HotDocModule:
    mod = HotDocModule(interpreter)
    mod.interpreter.append_holder_map(HotdocTarget, HotdocTargetHolder)
    return mod