"""
SQLite database utilities for persistent settings storage.
"""

from __future__ import annotations

import json
import logging
import sqlite3
import threading
from contextlib import contextmanager
from datetime import datetime
from pathlib import Path
from typing import Any

logger = logging.getLogger('intercept.database')

# Database file location
DB_DIR = Path(__file__).parent.parent / 'instance'
DB_PATH = DB_DIR / 'intercept.db'

# Thread-local storage for connections
_local = threading.local()


def get_db_path() -> Path:
    """Get the database file path, creating directory if needed."""
    DB_DIR.mkdir(parents=True, exist_ok=True)
    return DB_PATH


def get_connection() -> sqlite3.Connection:
    """Get a thread-local database connection."""
    if not hasattr(_local, 'connection') or _local.connection is None:
        db_path = get_db_path()
        _local.connection = sqlite3.connect(str(db_path), check_same_thread=False)
        _local.connection.row_factory = sqlite3.Row
        # Enable foreign keys
        _local.connection.execute('PRAGMA foreign_keys = ON')
    return _local.connection


@contextmanager
def get_db():
    """Context manager for database operations."""
    conn = get_connection()
    try:
        yield conn
        conn.commit()
    except Exception:
        conn.rollback()
        raise


def init_db() -> None:
    """Initialize the database schema."""
    db_path = get_db_path()
    logger.info(f"Initializing database at {db_path}")

    with get_db() as conn:
        # Settings table for key-value storage
        conn.execute('''
            CREATE TABLE IF NOT EXISTS settings (
                key TEXT PRIMARY KEY,
                value TEXT NOT NULL,
                value_type TEXT DEFAULT 'string',
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        ''')

        # Signal history table for graphs
        conn.execute('''
            CREATE TABLE IF NOT EXISTS signal_history (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                mode TEXT NOT NULL,
                device_id TEXT NOT NULL,
                signal_strength REAL,
                timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                metadata TEXT
            )
        ''')

        # Create index for faster queries
        conn.execute('''
            CREATE INDEX IF NOT EXISTS idx_signal_history_mode_device
            ON signal_history(mode, device_id, timestamp)
        ''')

        # Device correlation table
        conn.execute('''
            CREATE TABLE IF NOT EXISTS device_correlations (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                wifi_mac TEXT,
                bt_mac TEXT,
                confidence REAL,
                first_seen TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                last_seen TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                metadata TEXT,
                UNIQUE(wifi_mac, bt_mac)
            )
        ''')

        logger.info("Database initialized successfully")


def close_db() -> None:
    """Close the thread-local database connection."""
    if hasattr(_local, 'connection') and _local.connection is not None:
        _local.connection.close()
        _local.connection = None


# =============================================================================
# Settings Functions
# =============================================================================

def get_setting(key: str, default: Any = None) -> Any:
    """
    Get a setting value by key.

    Args:
        key: Setting key
        default: Default value if not found

    Returns:
        Setting value (auto-converted from JSON for complex types)
    """
    with get_db() as conn:
        cursor = conn.execute(
            'SELECT value, value_type FROM settings WHERE key = ?',
            (key,)
        )
        row = cursor.fetchone()

        if row is None:
            return default

        value, value_type = row['value'], row['value_type']

        # Convert based on type
        if value_type == 'json':
            try:
                return json.loads(value)
            except json.JSONDecodeError:
                return default
        elif value_type == 'int':
            return int(value)
        elif value_type == 'float':
            return float(value)
        elif value_type == 'bool':
            return value.lower() in ('true', '1', 'yes')
        else:
            return value


def set_setting(key: str, value: Any) -> None:
    """
    Set a setting value.

    Args:
        key: Setting key
        value: Setting value (will be JSON-encoded for complex types)
    """
    # Determine value type and string representation
    if isinstance(value, bool):
        value_type = 'bool'
        str_value = 'true' if value else 'false'
    elif isinstance(value, int):
        value_type = 'int'
        str_value = str(value)
    elif isinstance(value, float):
        value_type = 'float'
        str_value = str(value)
    elif isinstance(value, (dict, list)):
        value_type = 'json'
        str_value = json.dumps(value)
    else:
        value_type = 'string'
        str_value = str(value)

    with get_db() as conn:
        conn.execute('''
            INSERT INTO settings (key, value, value_type, updated_at)
            VALUES (?, ?, ?, CURRENT_TIMESTAMP)
            ON CONFLICT(key) DO UPDATE SET
                value = excluded.value,
                value_type = excluded.value_type,
                updated_at = CURRENT_TIMESTAMP
        ''', (key, str_value, value_type))


def delete_setting(key: str) -> bool:
    """
    Delete a setting.

    Args:
        key: Setting key

    Returns:
        True if setting was deleted, False if not found
    """
    with get_db() as conn:
        cursor = conn.execute('DELETE FROM settings WHERE key = ?', (key,))
        return cursor.rowcount > 0


def get_all_settings() -> dict[str, Any]:
    """Get all settings as a dictionary."""
    with get_db() as conn:
        cursor = conn.execute('SELECT key, value, value_type FROM settings')
        settings = {}

        for row in cursor:
            key, value, value_type = row['key'], row['value'], row['value_type']

            if value_type == 'json':
                try:
                    settings[key] = json.loads(value)
                except json.JSONDecodeError:
                    settings[key] = value
            elif value_type == 'int':
                settings[key] = int(value)
            elif value_type == 'float':
                settings[key] = float(value)
            elif value_type == 'bool':
                settings[key] = value.lower() in ('true', '1', 'yes')
            else:
                settings[key] = value

        return settings


# =============================================================================
# Signal History Functions
# =============================================================================

def add_signal_reading(
    mode: str,
    device_id: str,
    signal_strength: float,
    metadata: dict | None = None
) -> None:
    """Add a signal strength reading."""
    with get_db() as conn:
        conn.execute('''
            INSERT INTO signal_history (mode, device_id, signal_strength, metadata)
            VALUES (?, ?, ?, ?)
        ''', (mode, device_id, signal_strength, json.dumps(metadata) if metadata else None))


def get_signal_history(
    mode: str,
    device_id: str,
    limit: int = 100,
    since_minutes: int = 60
) -> list[dict]:
    """
    Get signal history for a device.

    Args:
        mode: Mode (wifi, bluetooth, adsb, etc.)
        device_id: Device identifier (MAC, ICAO, etc.)
        limit: Maximum number of readings
        since_minutes: Only get readings from last N minutes

    Returns:
        List of signal readings with timestamp
    """
    with get_db() as conn:
        cursor = conn.execute('''
            SELECT signal_strength, timestamp, metadata
            FROM signal_history
            WHERE mode = ? AND device_id = ?
              AND timestamp > datetime('now', ?)
            ORDER BY timestamp DESC
            LIMIT ?
        ''', (mode, device_id, f'-{since_minutes} minutes', limit))

        results = []
        for row in cursor:
            results.append({
                'signal': row['signal_strength'],
                'timestamp': row['timestamp'],
                'metadata': json.loads(row['metadata']) if row['metadata'] else None
            })

        return list(reversed(results))  # Return in chronological order


def cleanup_old_signal_history(max_age_hours: int = 24) -> int:
    """
    Remove old signal history entries.

    Args:
        max_age_hours: Maximum age in hours

    Returns:
        Number of deleted entries
    """
    with get_db() as conn:
        cursor = conn.execute('''
            DELETE FROM signal_history
            WHERE timestamp < datetime('now', ?)
        ''', (f'-{max_age_hours} hours',))
        return cursor.rowcount


# =============================================================================
# Device Correlation Functions
# =============================================================================

def add_correlation(
    wifi_mac: str,
    bt_mac: str,
    confidence: float,
    metadata: dict | None = None
) -> None:
    """Add or update a device correlation."""
    with get_db() as conn:
        conn.execute('''
            INSERT INTO device_correlations (wifi_mac, bt_mac, confidence, metadata, last_seen)
            VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP)
            ON CONFLICT(wifi_mac, bt_mac) DO UPDATE SET
                confidence = excluded.confidence,
                last_seen = CURRENT_TIMESTAMP,
                metadata = excluded.metadata
        ''', (wifi_mac, bt_mac, confidence, json.dumps(metadata) if metadata else None))


def get_correlations(min_confidence: float = 0.5) -> list[dict]:
    """Get all device correlations above minimum confidence."""
    with get_db() as conn:
        cursor = conn.execute('''
            SELECT wifi_mac, bt_mac, confidence, first_seen, last_seen, metadata
            FROM device_correlations
            WHERE confidence >= ?
            ORDER BY confidence DESC
        ''', (min_confidence,))

        results = []
        for row in cursor:
            results.append({
                'wifi_mac': row['wifi_mac'],
                'bt_mac': row['bt_mac'],
                'confidence': row['confidence'],
                'first_seen': row['first_seen'],
                'last_seen': row['last_seen'],
                'metadata': json.loads(row['metadata']) if row['metadata'] else None
            })

        return results