from collections import defaultdict
from pathlib import Path
from typing import Optional

from ..entry import Entry, EntryDetector
from .util import PresetUtil
from .value import ValueResolver

__all__ = ("PresetEntryDetector",)


class PresetEntryDetector(EntryDetector):
    def __init__(self, filename: Path):
        self._preset = PresetUtil.resolve_preset(filename)

    def detect_entry(self, basepath: Path) -> Optional["Entry"]:
        tasks = defaultdict(list)
        for preset_name, preset in self._preset.presets.items():
            filename = basepath / preset.filename
            if filename.exists():
                value_resolver = ValueResolver(basepath)
                for task_name, task_pack in preset.tasks.items():
                    for task_item_name, task in task_pack.items():
                        if value_resolver.check_conditions(task.conditions):
                            variables = (
                                {
                                    k: value_resolver.resolve_value(v)
                                    for k, v in task.variables.items()
                                }
                                if task.variables
                                else {}
                            )
                            tasks[task_name] += [
                                command.format(**variables) for command in task.commands
                            ]
        if tasks:
            return Entry(tasks, basepath)