from __future__ import annotations

from datetime import datetime, timezone
import json
from pathlib import Path
from typing import Any


def utc_now_iso() -> str:
    """Return current UTC time in ISO-8601 format."""
    return datetime.now(timezone.utc).isoformat()


def log(message: str) -> None:
    """Print a timestamped log line."""
    print(f"[{utc_now_iso()}] {message}")


def get_workspace_root(current_file: str | Path) -> Path:
    """Infer workspace root from a script path inside code/."""
    current = Path(current_file).resolve()
    return current.parents[1]


def get_prompt_dir(workspace_root: Path, prompt_folder: str) -> Path:
    """Resolve prompts/<prompt_folder> directory safely."""
    folder = prompt_folder.strip().strip("/")
    if not folder:
        raise ValueError("Prompt folder argument is empty")
    target = (workspace_root / "prompts" / folder).resolve()
    prompts_root = (workspace_root / "prompts").resolve()
    if prompts_root not in target.parents and target != prompts_root:
        raise ValueError("Prompt folder escapes prompts root")
    if not target.exists() or not target.is_dir():
        raise FileNotFoundError(f"Prompt folder not found: {target}")
    return target


def read_prompt_texts(prompt_dir: Path) -> dict[str, str]:
    """Read all .txt files from prompt directory."""
    result: dict[str, str] = {}
    for txt_file in sorted(prompt_dir.glob("*.txt")):
        result[txt_file.name] = txt_file.read_text(encoding="utf-8")
    return result


def read_json(path: Path, default: Any = None) -> Any:
    """Read JSON file; return default when missing."""
    if not path.exists():
        return default
    return json.loads(path.read_text(encoding="utf-8"))


def write_json(path: Path, data: Any) -> None:
    """Write JSON with stable formatting."""
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(json.dumps(data, indent=2, sort_keys=True), encoding="utf-8")