"""Project state store for A0 Software Orchestrator."""
import json
import os
from datetime import datetime
from typing import Any, Dict, Optional


def read_json(path: str, default: Any = None) -> Any:
    """Read a JSON file from the project root, return default if not found."""
    try:
        with open(path, "r") as f:
            return json.load(f)
    except (FileNotFoundError, json.JSONDecodeError):
        return default


def write_json(path: str, data: Any) -> None:
    """Write data to a JSON file, creating directories if needed."""
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "w") as f:
        json.dump(data, f, indent=2, default=str)


def append_markdown(path: str, line: str) -> None:
    """Append a line to a markdown file, creating directories if needed."""
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with open(path, "a") as f:
        f.write(line + "\n")


def timestamp() -> str:
    """Return an ISO 8601 timestamp string."""
    return datetime.utcnow().isoformat() + "Z"


def get_project_files(project_root: str) -> Dict[str, str]:
    """Return a dict of known state file paths relative to project_root."""
    return {
        "project_state": os.path.join(project_root, ".a0", "project_state.json"),
        "current_status": os.path.join(project_root, ".a0", "current_status.md"),
        "worklog": os.path.join(project_root, ".a0", "worklog.md"),
        "todo": os.path.join(project_root, ".a0", "todo.md"),
        "known_errors": os.path.join(project_root, ".a0", "known_errors.md"),
        "next_steps": os.path.join(project_root, ".a0", "next_steps.md"),
        "task_graph": os.path.join(project_root, ".a0", "task_graph.json"),
        "orchestrator_mode": os.path.join(project_root, ".a0", "orchestrator_mode.json"),
        "tool_capabilities": os.path.join(project_root, ".a0", "tool_capabilities.json"),
        "resume": os.path.join(project_root, ".a0", "resume.md"),
    }