"""Append-only experiment log utilities."""
import json
import os
from datetime import datetime, timezone

LOG_PATH = os.path.expanduser('~/.claude/autoresearch/log.jsonl')


def append_entry(entry: dict, path: str = LOG_PATH) -> None:
    entry = dict(entry)  # don't mutate caller's dict
    entry.setdefault('ts', datetime.now(timezone.utc).isoformat())
    os.makedirs(os.path.dirname(os.path.abspath(path)), exist_ok=True)
    with open(path, 'a') as f:
        f.write(json.dumps(entry) + '\n')


def read_entries(path: str = LOG_PATH) -> list:
    if not os.path.exists(path):
        return []
    entries = []
    with open(path) as f:
        for line in f:
            line = line.strip()
            if not line:
                continue
            try:
                entries.append(json.loads(line))
            except json.JSONDecodeError:
                pass
    return entries