"""Local metadata-only trajectories; raw values are deliberately not persisted.

Hashes can still reveal low-entropy secrets via guessing. Persist HMACs instead,
using a per-store key kept outside the database. Rich training records require a
separate reviewed, redacted ingestion path.
"""
import hashlib
import hmac
import json
from pathlib import Path
import secrets
import sqlite3
from time import time


class Recorder:
    def __init__(self, path):
        path = Path(path)
        path.parent.mkdir(parents=True, exist_ok=True)
        keyfile = path.with_suffix('.key')
        try:
            with keyfile.open('xb') as handle:
                handle.write(secrets.token_bytes(32))
            keyfile.chmod(0o600)
        except FileExistsError:
            pass
        self.key = keyfile.read_bytes()
        if len(self.key) != 32:
            raise ValueError('invalid recording key')
        self.db = sqlite3.connect(path)
        self.db.execute('''CREATE TABLE IF NOT EXISTS events (
            id INTEGER PRIMARY KEY, created REAL, task TEXT, epoch INTEGER,
            sequence INTEGER, state_key TEXT, action_key TEXT, kind TEXT,
            status TEXT, code TEXT, wall_ms REAL, cpu_ms REAL)''')

    def private_key(self, value):
        return hmac.new(self.key, value.encode('utf-8'), hashlib.sha256).hexdigest()

    def record(self, decision, state, outcome):
        ticket = decision.ticket
        self.db.execute('INSERT INTO events VALUES (NULL,?,?,?,?,?,?,?,?,?,?,?)',
            (time(), ticket.task_id, ticket.epoch, ticket.sequence,
             self.private_key(state.state_hash if state else ''),
             self.private_key(decision.action.encode()), decision.action.kind.name,
             outcome.status, outcome.code, outcome.wall_ms, outcome.cpu_ms))
        self.db.commit()

    def close(self):
        self.db.close()