#!/usr/bin/env python3
"""Prepare the canonical bounded task context for a Blender/WBV2 task."""

from __future__ import annotations

import argparse
import json
import shutil
import subprocess
from pathlib import Path

from wbv2_runtime import CONTROL_ROOT, ROOT, queue_pointer


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("task_id", nargs="?", help="task id; defaults to the authoritative queue pointer")
    parser.add_argument("--output", type=Path, help="optional copy of the generated task-context.json")
    args = parser.parse_args()
    task = args.task_id or queue_pointer().get("task")
    if not task:
        parser.error("queue has no current WBV2 task")
    task_context = CONTROL_ROOT.parent / str(task) / "task-context.json"
    manifest_path = CONTROL_ROOT.parent / str(task) / "manifest.json"
    try:
        manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
    except (OSError, json.JSONDecodeError):
        manifest = {}
    # Completed manifests bind their task-context hash. Do not regenerate that
    # file on a status-only resume; a fresh context would be evidence drift.
    write_context = not (manifest.get("status") == "done" and task_context.is_file())
    command = ["node", "tools/web/check-task-context.mjs", "--task", str(task)]
    if write_context:
        command.append("--write")
    result = subprocess.run(command, cwd=ROOT, text=True, capture_output=True, check=False)
    output = result.stdout or result.stderr
    if output:
        print(output, end="" if output.endswith("\n") else "\n")
    if result.returncode != 0:
        return result.returncode
    generated = task_context
    if args.output:
        args.output.parent.mkdir(parents=True, exist_ok=True)
        shutil.copyfile(generated, args.output)
        print(f"context-copy={args.output}")
    payload = json.loads(generated.read_text(encoding="utf-8"))
    totals = payload.get("size", {})
    print(f"WBV2 CONTEXT READY: task={task} bytes={totals.get('totalBytes', totals.get('total_bytes', '-'))} output={generated.relative_to(ROOT)}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())