# Copyright 2012-2016 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.

import configparser, os, shlex, subprocess
import typing

from . import mesonlib
from .mesonlib import EnvironmentException, MachineChoice, PerMachine
from . import mlog


# These classes contains all the data pulled from configuration files (native
# and cross file currently), and also assists with the reading environment
# variables.
#
# At this time there isn't an ironclad difference between this an other sources
# of state like `coredata`. But one rough guide is much what is in `coredata` is
# the *output* of the configuration process: the final decisions after tests.
# This, on the other hand has *inputs*. The config files are parsed, but
# otherwise minimally transformed. When more complex fallbacks (environment
# detection) exist, they are defined elsewhere as functions that construct
# instances of these classes.


known_cpu_families = (
    'aarch64',
    'arc',
    'arm',
    'e2k',
    'ia64',
    'mips',
    'mips64',
    'parisc',
    'ppc',
    'ppc64',
    'riscv32',
    'riscv64',
    'rl78',
    'rx',
    's390x',
    'sparc',
    'sparc64',
    'x86',
    'x86_64'
)

class MesonConfigFile:
    @classmethod
    def parse_datafile(cls, filename):
        config = configparser.ConfigParser()
        try:
            with open(filename, 'r') as f:
                config.read_file(f, filename)
        except FileNotFoundError:
            raise EnvironmentException('File not found: %s.' % filename)
        return cls.from_config_parser(config)

    @classmethod
    def from_config_parser(cls, parser: configparser.ConfigParser):
        out = {}
        # This is a bit hackish at the moment.
        for s in parser.sections():
            section = {}
            for entry in parser[s]:
                value = parser[s][entry]
                # Windows paths...
                value = value.replace('\\', '\\\\')
                if ' ' in entry or '\t' in entry or "'" in entry or '"' in entry:
                    raise EnvironmentException('Malformed variable name %s in cross file..' % entry)
                try:
                    res = eval(value, {'__builtins__': None}, {'true': True, 'false': False})
                except Exception:
                    raise EnvironmentException('Malformed value in cross file variable %s.' % entry)

                for i in (res if isinstance(res, list) else [res]):
                    if not isinstance(i, (str, int, bool)):
                        raise EnvironmentException('Malformed value in cross file variable %s.' % entry)

                section[entry] = res

            out[s] = section
        return out

class Properties:
    def __init__(
            self,
            properties: typing.Optional[typing.Dict[str, typing.Union[str, typing.List[str]]]] = None):
        self.properties = properties or {}

    def has_stdlib(self, language):
        return language + '_stdlib' in self.properties

    def get_stdlib(self, language):
        return self.properties[language + '_stdlib']

    def get_root(self):
        return self.properties.get('root', None)

    def get_sys_root(self):
        return self.properties.get('sys_root', None)

    def __eq__(self, other):
        if isinstance(other, type(self)):
            return self.properties == other.properties
        return NotImplemented

    # TODO consider removing so Properties is less freeform
    def __getitem__(self, key):
        return self.properties[key]

    # TODO consider removing so Properties is less freeform
    def __contains__(self, item):
        return item in self.properties

    # TODO consider removing, for same reasons as above
    def get(self, key, default=None):
        return self.properties.get(key, default)

class MachineInfo:
    def __init__(self, system, cpu_family, cpu, endian):
        self.system = system
        self.cpu_family = cpu_family
        self.cpu = cpu
        self.endian = endian

    def __eq__(self, other):
        if self.__class__ is not other.__class__:
            return NotImplemented
        return \
            self.system == other.system and \
            self.cpu_family == other.cpu_family and \
            self.cpu == other.cpu and \
            self.endian == other.endian

    def __ne__(self, other):
        if self.__class__ is not other.__class__:
            return NotImplemented
        return not self.__eq__(other)

    def __repr__(self):
        return '<MachineInfo: {} {} ({})>'.format(self.system, self.cpu_family, self.cpu)

    @staticmethod
    def from_literal(literal):
        minimum_literal = {'cpu', 'cpu_family', 'endian', 'system'}
        if set(literal) < minimum_literal:
            raise EnvironmentException(
                'Machine info is currently {}\n'.format(literal) +
                'but is missing {}.'.format(minimum_literal - set(literal)))

        cpu_family = literal['cpu_family']
        if cpu_family not in known_cpu_families:
            mlog.warning('Unknown CPU family %s, please report this at https://github.com/mesonbuild/meson/issues/new' % cpu_family)

        endian = literal['endian']
        if endian not in ('little', 'big'):
            mlog.warning('Unknown endian %s' % endian)

        return MachineInfo(
            literal['system'],
            cpu_family,
            literal['cpu'],
            endian)

    def is_windows(self):
        """
        Machine is windows?
        """
        return self.system == 'windows'

    def is_cygwin(self):
        """
        Machine is cygwin?
        """
        return self.system == 'cygwin'

    def is_linux(self):
        """
        Machine is linux?
        """
        return self.system == 'linux'

    def is_darwin(self):
        """
        Machine is Darwin (iOS/OS X)?
        """
        return self.system in ('darwin', 'ios')

    def is_android(self):
        """
        Machine is Android?
        """
        return self.system == 'android'

    def is_haiku(self):
        """
        Machine is Haiku?
        """
        return self.system == 'haiku'

    def is_openbsd(self):
        """
        Machine is OpenBSD?
        """
        return self.system == 'openbsd'

    # Various prefixes and suffixes for import libraries, shared libraries,
    # static libraries, and executables.
    # Versioning is added to these names in the backends as-needed.

    def get_exe_suffix(self):
        if self.is_windows() or self.is_cygwin():
            return 'exe'
        else:
            return ''

    def get_object_suffix(self):
        if self.is_windows():
            return 'obj'
        else:
            return 'o'

    def libdir_layout_is_win(self):
        return self.is_windows() \
            or self.is_cygwin()

class PerMachineDefaultable(PerMachine):
    """Extends `PerMachine` with the ability to default from `None`s.
    """
    def __init__(self):
        super().__init__(None, None, None)

    def default_missing(self):
        """Default host to buid and target to host.

        This allows just specifying nothing in the native case, just host in the
        cross non-compiler case, and just target in the native-built
        cross-compiler case.
        """
        if self.host is None:
            self.host = self.build
        if self.target is None:
            self.target = self.host

    def miss_defaulting(self):
        """Unset definition duplicated from their previous to None

        This is the inverse of ''default_missing''. By removing defaulted
        machines, we can elaborate the original and then redefault them and thus
        avoid repeating the elaboration explicitly.
        """
        if self.target == self.host:
            self.target = None
        if self.host == self.build:
            self.host = None

class MachineInfos(PerMachineDefaultable):
    def matches_build_machine(self, machine: MachineChoice):
        return self.build == self[machine]

class BinaryTable:
    def __init__(self, binaries = {}, fallback = True):
        self.binaries = binaries
        self.fallback = fallback
        for name, command in self.binaries.items():
            if not isinstance(command, (list, str)):
                # TODO generalize message
                raise mesonlib.MesonException(
                    'Invalid type {!r} for binary {!r} in cross file'
                    ''.format(command, name))

    # Map from language identifiers to environment variables.
    evarMap = {
        # Compilers
        'c': 'CC',
        'cpp': 'CXX',
        'cs': 'CSC',
        'd': 'DC',
        'fortran': 'FC',
        'objc': 'OBJC',
        'objcpp': 'OBJCXX',
        'rust': 'RUSTC',
        'vala': 'VALAC',

        # Binutils
        'strip': 'STRIP',
        'ar': 'AR',
        'windres': 'WINDRES',

        'cmake': 'CMAKE',
        'qmake': 'QMAKE',
        'pkgconfig': 'PKG_CONFIG',
    }

    @classmethod
    def detect_ccache(cls):
        try:
            has_ccache = subprocess.call(['ccache', '--version'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        except OSError:
            has_ccache = 1
        if has_ccache == 0:
            cmdlist = ['ccache']
        else:
            cmdlist = []
        return cmdlist

    @classmethod
    def _warn_about_lang_pointing_to_cross(cls, compiler_exe, evar):
        evar_str = os.environ.get(evar, 'WHO_WOULD_CALL_THEIR_COMPILER_WITH_THIS_NAME')
        if evar_str == compiler_exe:
            mlog.warning('''Env var %s seems to point to the cross compiler.
This is probably wrong, it should always point to the native compiler.''' % evar)

    @classmethod
    def parse_entry(cls, entry):
        compiler = mesonlib.stringlistify(entry)
        # Ensure ccache exists and remove it if it doesn't
        if compiler[0] == 'ccache':
            compiler = compiler[1:]
            ccache = cls.detect_ccache()
        else:
            ccache = []
        # Return value has to be a list of compiler 'choices'
        return compiler, ccache

    def lookup_entry(self, name):
        """Lookup binary

        Returns command with args as list if found, Returns `None` if nothing is
        found.

        First tries looking in explicit map, then tries environment variable.
        """
        # Try explict map, don't fall back on env var
        command = self.binaries.get(name)
        if command is not None:
            command = mesonlib.stringlistify(command)
            # Relies on there being no "" env var
            evar = self.evarMap.get(name, "")
            self._warn_about_lang_pointing_to_cross(command[0], evar)
        elif self.fallback:
            # Relies on there being no "" env var
            evar = self.evarMap.get(name, "")
            command = os.environ.get(evar)
            if command is not None:
                command = shlex.split(command)
        return command

class Directories:

    """Data class that holds information about directories for native and cross
    builds.
    """

    def __init__(self, bindir: typing.Optional[str] = None, datadir: typing.Optional[str] = None,
                 includedir: typing.Optional[str] = None, infodir: typing.Optional[str] = None,
                 libdir: typing.Optional[str] = None, libexecdir: typing.Optional[str] = None,
                 localedir: typing.Optional[str] = None, localstatedir: typing.Optional[str] = None,
                 mandir: typing.Optional[str] = None, prefix: typing.Optional[str] = None,
                 sbindir: typing.Optional[str] = None, sharedstatedir: typing.Optional[str] = None,
                 sysconfdir: typing.Optional[str] = None):
        self.bindir = bindir
        self.datadir = datadir
        self.includedir = includedir
        self.infodir = infodir
        self.libdir = libdir
        self.libexecdir = libexecdir
        self.localedir = localedir
        self.localstatedir = localstatedir
        self.mandir = mandir
        self.prefix = prefix
        self.sbindir = sbindir
        self.sharedstatedir = sharedstatedir
        self.sysconfdir = sysconfdir

    def __contains__(self, key: str) -> str:
        return hasattr(self, key)

    def __getitem__(self, key: str) -> str:
        return getattr(self, key)

    def __setitem__(self, key: str, value: typing.Optional[str]) -> None:
        setattr(self, key, value)

    def __iter__(self) -> typing.Iterator[typing.Tuple[str, str]]:
        return iter(self.__dict__.items())