#!/usr/bin/env python3
"""example.py — Demonstrates core Python features for Doom Emacs workflow.

Navigate: C-M-a/e (function boundaries), SPC s i (imenu), gd (definition)
Format:   SPC m f (ruff format), Run: SPC m r
"""

import argparse
from dataclasses import dataclass, field


@dataclass
class Task:
    """A simple task with priority and tags."""

    title: str
    priority: int = 0
    tags: list[str] = field(default_factory=list)
    done: bool = False

    def mark_done(self) -> None:
        self.done = True

    def summary(self) -> str:
        status = "DONE" if self.done else "TODO"
        tag_str = ", ".join(self.tags) if self.tags else "none"
        return f"[{status}] {self.title} (p{self.priority}, tags: {tag_str})"


def filter_tasks(tasks: list[Task], *, min_priority: int = 0) -> list[Task]:
    """Return undone tasks with priority >= min_priority."""
    return [t for t in tasks if not t.done and t.priority >= min_priority]


def load_tasks_from_file(path: str) -> list[Task]:
    """Load tasks from a simple text file (one title per line)."""
    tasks: list[Task] = []
    try:
        with open(path, encoding="utf-8") as fh:
            for i, line in enumerate(fh):
                title = line.strip()
                if title:
                    tasks.append(Task(title=title, priority=i % 3))
    except FileNotFoundError:
        print(f"File not found: {path}, using demo tasks")
        tasks = [
            Task("Write tests", priority=2, tags=["dev"]),
            Task("Update docs", priority=1, tags=["docs"]),
            Task("Deploy v2", priority=2, tags=["ops", "dev"]),
        ]
    return tasks


def main() -> None:
    parser = argparse.ArgumentParser(description="Task manager demo")
    parser.add_argument("-f", "--file", default="tasks.txt", help="Task file")
    parser.add_argument("-p", "--priority", type=int, default=1, help="Min priority")
    args = parser.parse_args()

    tasks = load_tasks_from_file(args.file)
    tasks[0].mark_done()

    important = filter_tasks(tasks, min_priority=args.priority)
    print(f"Open tasks (priority >= {args.priority}):")
    for task in important:
        print(f"  {task.summary()}")


if __name__ == "__main__":
    main()