"""SQLite-Helfer für den Collector (Schema-Init + Schreibzugriffe)."""

import os
import sqlite3
from datetime import datetime
from pathlib import Path

SCHEMA_PATH = Path(__file__).with_name("schema.sql")


def get_db_path() -> str:
    return os.environ.get("DB_PATH", "/data/charges.db")


def connect() -> sqlite3.Connection:
    path = get_db_path()
    Path(path).parent.mkdir(parents=True, exist_ok=True)
    conn = sqlite3.connect(path)
    conn.row_factory = sqlite3.Row
    # Bewusst KEIN WAL: Der web-Container liest die DB read-only aus einem
    # anderen Prozess. Eine readonly-Verbindung kann eine WAL-Datenbank ohne
    # aktiven Writer/-shm nicht öffnen ("attempt to write a readonly database").
    # Rollback-Journal (Default) lässt readonly-Reads jederzeit zu.
    return conn


def init_db() -> None:
    """Legt Schema idempotent an und setzt install_date beim ersten Start."""
    schema = SCHEMA_PATH.read_text(encoding="utf-8")
    conn = connect()
    try:
        conn.executescript(schema)
        conn.execute(
            "INSERT OR IGNORE INTO meta (key, value) VALUES ('install_date', ?)",
            (datetime.now().isoformat(timespec="seconds"),),
        )
        conn.commit()
    finally:
        conn.close()


def insert_charge(start_time: str, end_time: str, duration_s: int, energy_wh: float) -> None:
    conn = connect()
    try:
        conn.execute(
            """INSERT INTO charges (start_time, end_time, duration_s, energy_wh, created_at)
               VALUES (?, ?, ?, ?, ?)""",
            (start_time, end_time, duration_s, energy_wh,
             datetime.now().isoformat(timespec="seconds")),
        )
        conn.commit()
    finally:
        conn.close()