"""SQLite database for landmarks and offline queue."""
import sqlite3
import threading
import json

DB_PATH = "/data/adacam/adacam.db"
_local = threading.local()


def get_conn():
    """Get thread-local database connection."""
    if not hasattr(_local, "conn"):
        _local.conn = sqlite3.connect(DB_PATH, check_same_thread=False)
        _local.conn.row_factory = sqlite3.Row
    return _local.conn


def init():
    """Initialize database schema."""
    conn = get_conn()
    conn.executescript("""
        CREATE TABLE IF NOT EXISTS landmarks (
            id INTEGER PRIMARY KEY,
            class_label TEXT,
            class_label_confidence REAL,
            overall_confidence REAL,
            lat REAL, lon REAL, alt REAL,
            azimuth REAL,
            width INTEGER, height INTEGER,
            ts INTEGER,
            forwarded INTEGER DEFAULT 0
        );
        CREATE TABLE IF NOT EXISTS forward_queue (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            payload TEXT,
            created_at INTEGER DEFAULT (strftime('%s','now'))
        );
        CREATE INDEX IF NOT EXISTS idx_landmarks_ts ON landmarks(ts DESC);
        CREATE INDEX IF NOT EXISTS idx_landmarks_forwarded ON landmarks(forwarded);
    """)
    conn.commit()


def insert_landmark(data):
    """Insert a landmark detection."""
    conn = get_conn()
    conn.execute("""
        INSERT INTO landmarks (id, class_label, class_label_confidence, overall_confidence,
                               lat, lon, alt, azimuth, width, height, ts)
        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
    """, (data.get("id"), data["class_label"], data.get("class_label_confidence"),
          data.get("overall_confidence"), data.get("lat"), data.get("lon"),
          data.get("alt"), data.get("azimuth"), data.get("width"),
          data.get("height"), data.get("ts")))
    conn.commit()
    return conn.execute("SELECT last_insert_rowid()").fetchone()[0]


def get_last_landmarks(n):
    """Get last N landmarks."""
    conn = get_conn()
    rows = conn.execute("SELECT * FROM landmarks ORDER BY ts DESC LIMIT ?", (n,)).fetchall()
    return [dict(r) for r in rows]


def queue_forward(payload):
    """Queue a payload for later forwarding."""
    conn = get_conn()
    conn.execute("INSERT INTO forward_queue (payload) VALUES (?)", (json.dumps(payload),))
    conn.commit()


def pop_queue(limit=50):
    """Pop items from forward queue."""
    conn = get_conn()
    rows = conn.execute("SELECT id, payload FROM forward_queue ORDER BY id LIMIT ?", (limit,)).fetchall()
    if rows:
        ids = [r["id"] for r in rows]
        conn.execute(f"DELETE FROM forward_queue WHERE id IN ({','.join('?'*len(ids))})", ids)
        conn.commit()
    return [(r["id"], json.loads(r["payload"])) for r in rows]


def mark_forwarded(landmark_id):
    """Mark a landmark as forwarded."""
    conn = get_conn()
    conn.execute("UPDATE landmarks SET forwarded = 1 WHERE id = ?", (landmark_id,))
    conn.commit()