from __future__ import annotations
import json
from pathlib import Path
from typing import Dict, Any, List
from .logger import setup_logger

logger = setup_logger(__name__)


def _load_json(path: Path) -> Dict[str, Any]:
    return json.loads(path.read_text(encoding="utf-8"))


def _write_json(path: Path, obj: Dict[str, Any]) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(
        json.dumps(obj, ensure_ascii=False, indent=2), encoding="utf-8"
    )


def run_step_manifest(step_dir: Path, executor) -> Dict[str, Any]:
    manifest_path = step_dir / "manifest.json"
    if not manifest_path.exists():
        raise FileNotFoundError(f"manifest.json not found in {step_dir}")
    manifest = _load_json(manifest_path)
    result = executor(step_dir, manifest)
    # Basic contract
    result_path = step_dir / "result.json"
    _write_json(result_path, result)
    return result


def resolve_prev_output_uri(prev_step_dir: Path, output_name: str) -> str:
    result_path = prev_step_dir / "result.json"
    if not result_path.exists():
        raise FileNotFoundError(f"Missing result.json in {prev_step_dir}")
    res = _load_json(result_path)
    outs: List[Dict[str, Any]] = res.get("outputs") or []
    for o in outs:
        if o.get("name") == output_name:
            return str(o.get("uri"))
    raise RuntimeError(f"Output '{output_name}' not found in {result_path}")