"""
Audit service — SQLite-backed command log.

Every executed command is recorded with enough info to reconstruct
the inverse operation (for undo).  Uses aiosqlite so it doesn't
block the async event loop.
"""
from __future__ import annotations

import json
import aiosqlite

from config import AUDIT_DB_PATH

_CREATE_TABLE = """
CREATE TABLE IF NOT EXISTS audit_log (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    session_id  TEXT    NOT NULL,
    command     TEXT    NOT NULL,
    intent      TEXT    NOT NULL,
    diff        TEXT,
    created_at  TEXT    DEFAULT (datetime('now'))
);
"""

_db: aiosqlite.Connection | None = None


async def _get_db() -> aiosqlite.Connection:
    global _db
    if _db is None:
        _db = await aiosqlite.connect(AUDIT_DB_PATH)
        await _db.execute(_CREATE_TABLE)
        await _db.commit()
    return _db


async def log_command(
    session_id: str,
    command: str,
    intent: dict | None,
    diff: dict | None,
) -> None:
    """Insert an audit row."""
    db = await _get_db()
    await db.execute(
        "INSERT INTO audit_log (session_id, command, intent, diff) VALUES (?, ?, ?, ?)",
        (
            session_id,
            command,
            json.dumps(intent or {}, ensure_ascii=False),
            json.dumps(diff or {}, ensure_ascii=False),
        ),
    )
    await db.commit()


async def get_history(session_id: str, limit: int = 50) -> list[dict]:
    """Fetch recent commands for a session (for undo UI)."""
    db = await _get_db()
    cursor = await db.execute(
        "SELECT id, command, intent, diff, created_at FROM audit_log "
        "WHERE session_id = ? ORDER BY id DESC LIMIT ?",
        (session_id, limit),
    )
    rows = await cursor.fetchall()
    return [
        {
            "id": r[0],
            "command": r[1],
            "intent": json.loads(r[2]),
            "diff": json.loads(r[3]),
            "created_at": r[4],
        }
        for r in rows
    ]


async def close() -> None:
    global _db
    if _db is not None:
        await _db.close()
        _db = None