# SPDX-FileCopyrightText: 2022 James R. Barlow
# SPDX-License-Identifier: MPL-2.0

"""Plugin manager using pluggy."""

from __future__ import annotations

import importlib
import importlib.util
import pkgutil
import sys
from collections.abc import Sequence
from pathlib import Path

import pluggy

import ocrmypdf.builtin_plugins
from ocrmypdf import pluginspec


class OcrmypdfPluginManager(pluggy.PluginManager):
    """pluggy.PluginManager that can fork.

    Capable of reconstructing itself in child workers.

    Arguments:
        setup_func: callback that initializes the plugin manager with all
            standard plugins
    """

    def __init__(
        self,
        *args,
        plugins: Sequence[str | Path],
        builtins: bool = True,
        **kwargs,
    ):
        self.__init_args = args
        self.__init_kwargs = kwargs
        self.__plugins = plugins
        self.__builtins = builtins
        super().__init__(*args, **kwargs)
        self.setup_plugins()

    def __getstate__(self):
        state = dict(
            init_args=self.__init_args,
            plugins=self.__plugins,
            builtins=self.__builtins,
            init_kwargs=self.__init_kwargs,
        )
        return state

    def __setstate__(self, state):
        self.__init__(
            *state['init_args'],
            plugins=state['plugins'],
            builtins=state['builtins'],
            **state['init_kwargs'],
        )

    def setup_plugins(self):
        self.add_hookspecs(pluginspec)

        # 1. Register builtins
        if self.__builtins:
            for module in sorted(
                pkgutil.iter_modules(ocrmypdf.builtin_plugins.__path__)
            ):
                name = f'ocrmypdf.builtin_plugins.{module.name}'
                module = importlib.import_module(name)
                self.register(module)

        # 2. Register setuptools plugins
        self.load_setuptools_entrypoints('ocrmypdf')

        # 3. Register plugins specified on command line
        for name in self.__plugins:
            if isinstance(name, Path) or name.endswith('.py'):
                # Import by filename
                module_name = Path(name).stem
                spec = importlib.util.spec_from_file_location(module_name, name)
                module = importlib.util.module_from_spec(spec)
                sys.modules[module_name] = module
                spec.loader.exec_module(module)
            else:
                # Import by dotted module name
                module = importlib.import_module(name)
            self.register(module)


def get_plugin_manager(
    plugins: Sequence[str | Path] | None = None, builtins=True
) -> OcrmypdfPluginManager:
    return OcrmypdfPluginManager(
        project_name='ocrmypdf',
        plugins=plugins if plugins is not None else [],
        builtins=builtins,
    )


__all__ = ['OcrmypdfPluginManager', 'get_plugin_manager']