# © 2020 James R. Barlow: github.com/jbarlow83
#
# This file is part of OCRmyPDF.
#
# OCRmyPDF is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OCRmyPDF is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with OCRmyPDF.  If not, see <http://www.gnu.org/licenses/>.

import argparse
import importlib
import importlib.util
import sys
from pathlib import Path
from typing import List

import pluggy

from ocrmypdf import pluginspec
from ocrmypdf.cli import get_parser, plugins_only_parser


def get_plugin_manager(plugins: List[str], builtins=True):
    pm = pluggy.PluginManager('ocrmypdf')
    pm.add_hookspecs(pluginspec)

    if builtins:
        all_plugins = [
            'ocrmypdf.builtin_plugins.ghostscript',
            'ocrmypdf.builtin_plugins.tesseract_ocr',
        ] + plugins
    else:
        all_plugins = plugins
    for name in all_plugins:
        if 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)
        pm.register(module)
    return pm


def get_parser_options_plugins(
    args,
) -> (argparse.ArgumentParser, argparse.Namespace, pluggy.PluginManager):
    pre_options, _unused = plugins_only_parser.parse_known_args(args=args)
    plugin_manager = get_plugin_manager(pre_options.plugins)

    parser = get_parser()
    plugin_manager.hook.add_options(parser=parser)

    options = parser.parse_args(args=args)
    return parser, options, plugin_manager