#!/usr/bin/env python3
"""
work-on-task

Validates a task's status for active development, displays its requirements,
and optionally transitions it to 'in_progress'.

Usage:
    ./scripts/work-on-task EX-001
    ./scripts/work-on-task EX-001 --start
    ./scripts/work-on-task EX-001 --force
"""

import argparse
import sys
from pathlib import Path

# Add scripts/lib to Python path
sys.path.insert(0, str(Path(__file__).resolve().parent / "lib"))
from task_context import fetch_task, load_get_task_module


def main():
    parser = argparse.ArgumentParser(description="Validate and begin work on a task.")
    parser.add_argument("task_id", help="Task number or prefixed ID (e.g., 1 or PREFIX-001)")
    parser.add_argument("--start", action="store_true", help="Transition status to 'in_progress'")
    parser.add_argument("--force", action="store_true", help="Proceed even if status is not ready/pending/in_progress")
    parser.add_argument("-f", "--file", dest="file", default=None, help="Path to tasks.md")
    args = parser.parse_args()

    try:
        task = fetch_task(args.task_id, tasks_file=args.file)
    except Exception as e:
        sys.stderr.write(f"Error fetching task {args.task_id}: {e}\n")
        sys.exit(1)

    status = task.get("status", "").strip().lower()
    valid_work_statuses = ["ready", "pending", "in_progress", "in-progress"]
    if status not in valid_work_statuses and not args.force:
        sys.stderr.write(
            f"WARNING: Task {task['id']} is currently in '{task['status']}' status.\n"
            f"Tasks in '{task['status']}' are usually not ready to be worked on directly.\n"
            f"To bypass this check, pass --force.\n"
        )
        sys.exit(2)

    print(f"=== Task {task['id']}: {task['title']} ===")
    print(f"Project: {task['project']}")
    if task.get("epic"):
        print(f"Epic:    {task['epic_label']}")
    print(f"Status:  {task['status']}")
    print(f"Type:    {task['type']}")
    if task.get("description"):
        print("\nRequirements & Description:")
        print(task["description"])

    if args.start and status not in ("in_progress", "in-progress"):
        mod = load_get_task_module()
        update_mod = mod.load_update_tasks_module()
        script_dir = Path(__file__).resolve().parent
        import importlib.machinery
        import importlib.util
        ut_script = script_dir / "update-task"
        loader = importlib.machinery.SourceFileLoader("update_task_mod", str(ut_script))
        spec = importlib.util.spec_from_loader("update_task_mod", loader)
        ut_mod = importlib.util.module_from_spec(spec)
        loader.exec_module(ut_mod)

        ut_mod.update_task_detail(task["id"], status="in_progress", tasks_file=args.file)
        print(f"\n[Status updated to 'in_progress']")


if __name__ == "__main__":
    main()