from __future__ import annotations

import base64
import hashlib
import importlib.metadata
import json
import logging
import pkgutil
import re
from contextlib import suppress
from pathlib import Path
from typing import TYPE_CHECKING, Literal, TypeAlias, TypedDict, cast

import streamlink.plugins
from streamlink.options import Argument, Arguments

# noinspection PyProtectedMember
from streamlink.plugin.plugin import _PLUGINARGUMENT_TYPE_REGISTRY, NO_PRIORITY, NORMAL_PRIORITY, Matcher, Matchers, Plugin
from streamlink.utils.module import exec_module, get_finder


if TYPE_CHECKING:
    from collections.abc import Iterator, Mapping
    from types import ModuleType

    from _typeshed.importlib import PathEntryFinderProtocol


log = logging.getLogger(".".join(__name__.split(".")[:-1]))

# The path to Streamlink's built-in plugins
_PLUGINS_PATH = Path(streamlink.plugins.__path__[0])

# Hardcoded plugins JSON file path
_PLUGINSDATA_PATH = _PLUGINS_PATH / "_plugins.json"
# Hardcoded package name to look up metadata
_PLUGINSDATA_PACKAGENAME = "streamlink"
# The `parts` value of the plugins JSON file contained in the package's `RECORD` metadata file
_PLUGINSDATA_PACKAGEPATH = "streamlink", "plugins", "_plugins.json"


class StreamlinkPlugins:
    """
    Streamlink's session-plugins implementation. This class is responsible for loading plugins and resolving them from URLs.

    See the :attr:`Streamlink.plugins <streamlink.session.Streamlink.plugins>` attribute.

    Unless disabled by the user, Streamlink will try to load built-in plugins lazily, when accessing them for the first time
    while resolving input URLs. This is done by reading and interpreting serialized data of each plugin's
    :func:`pluginmatcher <streamlink.plugin.pluginmatcher>` and :func:`pluginargument <streamlink.plugin.pluginargument>`
    data from a pre-built plugins JSON file which is included in Streamlink's wheel packages.

    Plugins which are sideloaded, either from specific user directories or custom input directories,
    always have a higher priority than built-in plugins.
    """

    def __init__(self, builtin: bool = True, lazy: bool = True):
        # Loaded plugins
        self._plugins: dict[str, type[Plugin]] = {}

        # Data of built-in plugins which can be loaded lazily
        self._matchers: dict[str, Matchers] = {}
        self._arguments: dict[str, Arguments] = {}

        # Attempt to load built-in plugins lazily first
        if builtin and lazy:
            data = StreamlinkPluginsData.load()
            if data:
                self._matchers, self._arguments = data
            else:
                lazy = False

        # Load built-ins if lazy-loading is disabled or if loading plugins data has failed
        if builtin and not lazy:
            self.load_builtin()

    def __getitem__(self, item: str) -> type[Plugin]:
        """Access a loaded plugin class by name"""
        return self._plugins[item]

    def __setitem__(self, key: str, value: type[Plugin]) -> None:
        """Add/override a plugin class by name"""
        self._plugins[key] = value

    def __delitem__(self, key: str) -> None:
        """Remove a loaded plugin by name"""
        self._plugins.pop(key, None)

    def __contains__(self, item: str) -> bool:
        """Check if a plugin is loaded"""
        return item in self._plugins

    def get_names(self) -> list[str]:
        """Get a list of the names of all available plugins"""
        return sorted(self._plugins.keys() | self._matchers.keys())

    def get_loaded(self) -> dict[str, type[Plugin]]:
        """Get a mapping of all loaded plugins"""
        return dict(self._plugins)

    def load_builtin(self) -> bool:
        """Load Streamlink's built-in plugins"""
        return self.load_path(_PLUGINS_PATH)

    def load_path(self, path: str | Path) -> bool:
        """Load plugins from a custom directory"""
        plugins = self._load_plugins_from_path(path)
        self.update(plugins)

        return bool(plugins)

    def update(self, plugins: Mapping[str, type[Plugin]]):
        """Add/override loaded plugins"""
        self._plugins.update(plugins)

    def clear(self):
        """Remove all loaded plugins from the session"""
        self._plugins.clear()

    def iter_arguments(self) -> Iterator[tuple[str, Arguments]]:
        """Iterate through all plugins and their :class:`Arguments <streamlink.options.Arguments>`"""
        yield from (
            (name, plugin.arguments)
            for name, plugin in self._plugins.items()
            if plugin.arguments
        )  # fmt: skip
        yield from (
            (name, arguments)
            for name, arguments in self._arguments.items()
            if arguments and name not in self._plugins
        )  # fmt: skip

    def iter_matchers(self) -> Iterator[tuple[str, Matchers]]:
        """Iterate through all plugins and their :class:`Matchers <streamlink.plugin.plugin.Matchers>`"""
        yield from (
            (name, plugin.matchers)
            for name, plugin in self._plugins.items()
            if plugin.matchers
        )  # fmt: skip
        yield from (
            (name, matchers)
            for name, matchers in self._matchers.items()
            if matchers and name not in self._plugins
        )  # fmt: skip

    def match_url(self, url: str) -> tuple[str, type[Plugin]] | None:
        """Find a matching plugin by URL and load plugins which haven't been loaded yet"""
        match: str | None = None
        priority: int = NO_PRIORITY

        for name, matchers in self.iter_matchers():
            for matcher in matchers:
                if matcher.priority > priority and matcher.pattern.match(url) is not None:
                    match = name
                    priority = matcher.priority

        if match is None:
            return None

        # plugin not loaded yet?
        # if a custom plugin with the same name has already been loaded, skip loading the built-in plugin
        if match not in self._plugins:
            log.debug(f"Loading plugin: {match}")
            lookup = self._load_plugin_from_path(match, _PLUGINS_PATH)
            if not lookup:
                return None
            self._plugins[match] = lookup[1]

        return match, self._plugins[match]

    def _load_plugin_from_path(self, name: str, path: Path) -> tuple[ModuleType, type[Plugin]] | None:
        finder = get_finder(path)

        return self._load_plugin_from_finder(name, finder)

    def _load_plugins_from_path(self, path: str | Path) -> dict[str, type[Plugin]]:
        plugins: dict[str, type[Plugin]] = {}
        for finder, name, _ in pkgutil.iter_modules([str(path)]):
            finder = cast("PathEntryFinderProtocol", finder)
            lookup = self._load_plugin_from_finder(name, finder=finder)
            if lookup is None:
                continue
            mod, plugin = lookup
            if (name in self._plugins or name in self._matchers) and mod.__file__:
                with Path(mod.__file__).open("rb") as fh:
                    sha256 = hashlib.sha256(fh.read())
                log.info(f"Plugin {name} is being overridden by {mod.__file__} (sha256:{sha256.hexdigest()})")
            plugins[name] = plugin

        return plugins

    @staticmethod
    def _load_plugin_from_finder(name: str, finder: PathEntryFinderProtocol) -> tuple[ModuleType, type[Plugin]] | None:
        try:
            # set the full plugin module name, even for sideloaded plugins
            mod = exec_module(finder, f"streamlink.plugins.{name}", override=True)
        except ImportError as err:
            log.exception(f"Failed to load plugin {name} from {err.path}\n")
            return None

        if not hasattr(mod, "__plugin__") or not issubclass(mod.__plugin__, Plugin):
            return None

        return mod, mod.__plugin__


_RE_STRIP_JSON_COMMENTS = re.compile(rb"^(?:\s*//[^\n]*\n+)+")

if TYPE_CHECKING:
    _TListOfConstants: TypeAlias = list[bool | int | float | str | None]
    _TConstantOrListOfConstants: TypeAlias = bool | int | float | str | _TListOfConstants | None
    _TMappingOfConstantOrListOfConstants: TypeAlias = dict[str, _TConstantOrListOfConstants]


class _TPluginMatcherData(TypedDict):
    pattern: str
    flags: int | None
    priority: int | None
    name: str | None


class _TPluginArgumentData(TypedDict):
    name: str
    action: str | None
    nargs: int | Literal["*", "?", "+"] | None
    const: _TConstantOrListOfConstants
    default: _TConstantOrListOfConstants
    type: str | None
    type_args: _TListOfConstants | None
    type_kwargs: _TMappingOfConstantOrListOfConstants | None
    choices: _TListOfConstants | None
    required: bool | None
    help: str | None
    metavar: str | list[str] | None
    dest: str | None
    requires: str | list[str] | None
    prompt: str | None
    sensitive: bool | None
    argument_name: str | None


class _TPluginData(TypedDict):
    matchers: list[_TPluginMatcherData]
    arguments: list[_TPluginArgumentData]


class StreamlinkPluginsData:
    @classmethod
    def load(cls) -> tuple[dict[str, Matchers], dict[str, Arguments]] | None:
        # specific errors get logged, others are ignored intentionally
        with suppress(Exception):
            content = _PLUGINSDATA_PATH.read_bytes()

            cls._validate(content)

            return cls._parse(content)

        return None

    @staticmethod
    def _validate(content: bytes) -> None:
        # find plugins JSON checksum in package metadata
        # https://packaging.python.org/en/latest/specifications/recording-installed-packages/#the-record-file
        mode, filehash = next(
            (packagepath.hash.mode, packagepath.hash.value)
            for packagepath in importlib.metadata.files(_PLUGINSDATA_PACKAGENAME) or []
            if packagepath.hash is not None and packagepath.parts == _PLUGINSDATA_PACKAGEPATH
        )
        if mode not in hashlib.algorithms_guaranteed or not filehash:
            log.error("Unknown plugins data hash mode, falling back to loading all plugins")
            raise Exception

        # compare checksums
        hashalg = getattr(hashlib, mode)
        hashobj = hashalg(content)
        digest = base64.urlsafe_b64encode(hashobj.digest()).decode("utf-8").rstrip("=")
        if digest != filehash:
            log.error("Plugins data checksum mismatch, falling back to loading all plugins")
            raise Exception

    @classmethod
    def _parse(cls, content: bytes) -> tuple[dict[str, Matchers], dict[str, Arguments]]:
        content = _RE_STRIP_JSON_COMMENTS.sub(b"", content)
        data: dict[str, _TPluginData] = json.loads(content)

        try:
            matchers = cls._build_matchers(data)
        except Exception:
            log.exception("Error while loading pluginmatcher data from JSON")
            raise

        try:
            arguments = cls._build_arguments(data)
        except Exception:
            log.exception("Error while loading pluginargument data from JSON")
            raise

        return matchers, arguments

    @classmethod
    def _build_matchers(cls, data: dict[str, _TPluginData]) -> dict[str, Matchers]:
        res = {}
        for pluginname, plugindata in data.items():
            matchers = Matchers()
            for m in plugindata.get("matchers") or []:
                matcher = cls._build_matcher(m)
                matchers.add(matcher)

            res[pluginname] = matchers

        return res

    @staticmethod
    def _build_matcher(data: _TPluginMatcherData) -> Matcher:
        return Matcher(
            pattern=re.compile(data.get("pattern"), data.get("flags") or 0),
            priority=data.get("priority") or NORMAL_PRIORITY,
            name=data.get("name"),
        )

    @classmethod
    def _build_arguments(cls, data: dict[str, _TPluginData]) -> dict[str, Arguments]:
        res = {}
        for pluginname, plugindata in data.items():
            if not plugindata.get("arguments"):
                continue
            arguments = Arguments()
            for a in reversed(plugindata.get("arguments") or []):
                if argument := cls._build_argument(a):
                    arguments.add(argument)

            res[pluginname] = arguments

        return res

    @staticmethod
    def _build_argument(data: _TPluginArgumentData) -> Argument | None:
        name = data.get("name")
        type_data = data.get("type")
        if not type_data:
            argument_type = None
        elif argument_type := _PLUGINARGUMENT_TYPE_REGISTRY.get(type_data):
            type_args = data.get("type_args") or ()
            type_kwargs = data.get("type_kwargs") or {}
            if type_args or type_kwargs:
                argument_type = argument_type(*type_args, **type_kwargs)
        else:
            return None

        return Argument(
            name=name,
            action=data.get("action"),
            nargs=data.get("nargs"),
            const=data.get("const"),
            default=data.get("default"),
            type=argument_type,
            choices=data.get("choices"),
            required=data.get("required") or False,
            help=data.get("help"),
            metavar=data.get("metavar"),
            dest=data.get("dest"),
            requires=data.get("requires"),
            prompt=data.get("prompt"),
            sensitive=data.get("sensitive") or False,
            argument_name=data.get("argument_name"),
        )
