import os
import json
import requests
from cryptography.fernet import Fernet

RESOURCES_FOLDER = "resources"
CREDENTIALS_FILE = os.path.join(RESOURCES_FOLDER, "credentials.enc")
KEY_FILE = os.path.join(RESOURCES_FOLDER, "key.key")
SERVER_SETTINGS_FILE = os.path.join(RESOURCES_FOLDER, "server_settings.enc")

# --- Encryption Utilities ---

def generate_key():
    """Generate and save a key for encryption."""
    if not os.path.exists(KEY_FILE):
        key = Fernet.generate_key()
        with open(KEY_FILE, "wb") as key_file:
            key_file.write(key)

def load_key():
    """Load the encryption key."""
    with open(KEY_FILE, "rb") as key_file:
        return key_file.read()

def encrypt_data(data):
    """Encrypt data using the encryption key."""
    key = load_key()
    fernet = Fernet(key)
    return fernet.encrypt(data.encode())

def decrypt_data(data):
    """Decrypt data using the encryption key."""
    key = load_key()
    fernet = Fernet(key)
    return fernet.decrypt(data).decode()

# --- Server Settings ---
def check_server_settings():
    """Load and decrypt server settings from file."""
    if not os.path.exists(SERVER_SETTINGS_FILE):
        return None
    try:
        with open(SERVER_SETTINGS_FILE, "rb") as file:
            encrypted_data = file.read()
            decrypted_data = decrypt_data(encrypted_data)
            settings = json.loads(decrypted_data)
            return settings
    except Exception as e:
        print(f"Failed to load server settings: {e}")
        return None

def save_server_settings(settings_data):
    """Encrypt and save server settings."""
    encrypted_data = encrypt_data(json.dumps(settings_data))
    with open(SERVER_SETTINGS_FILE, "wb") as file:
        file.write(encrypted_data)

# --- Traccar Server Connection ---
def test_connection(server_url, username=None, password=None, token=None):
    """
    Test the connection with the Traccar server.
    Returns: dict with 'status' (bool) and 'message' (str)
    """
    if not server_url:
        return {"status": False, "message": "Please provide the server URL."}
    if not token and (not username or not password):
        return {"status": False, "message": "Please provide either a token or username and password."}
    try:
        headers = {"Authorization": f"Bearer {token}"} if token else None
        auth = None if token else (username, password)
        response = requests.get(f"{server_url}/api/server", headers=headers, auth=auth, timeout=10)
        if response.status_code == 200:
            return {"status": True, "message": "Connection successful! Server is reachable."}
        else:
            return {"status": False, "message": f"Error: {response.status_code} - {response.reason}"}
    except requests.exceptions.Timeout:
        return {"status": False, "message": "Connection timed out. Please try again."}
    except requests.exceptions.RequestException as e:
        return {"status": False, "message": f"Connection failed: {str(e)}"}

# --- Device Fetching ---
def get_devices_from_server():
    """Retrieve a mapping of device names to IDs from the Traccar server."""
    settings = check_server_settings()
    if not settings:
        return None
    server_url = settings.get("server_url")
    token = settings.get("token")
    if not server_url or not token:
        return None
    headers = {"Authorization": f"Bearer {token}"}
    try:
        response = requests.get(f"{server_url}/api/devices", headers=headers)
        if response.status_code == 200:
            devices = response.json()
            return {device.get("name", "Unnamed Device"): device.get("id", "Unknown ID") for device in devices}
        else:
            print(f"Error: {response.status_code} - {response.reason}")
            return None
    except Exception as e:
        print(f"Error retrieving devices: {str(e)}")
        return None

# --- Route Saving ---
def save_route_to_file(route_name, positions, base_folder="resources/projects"):
    """
    Save the given positions as a route in resources/projects/<route_name>/positions.json.
    Returns (success, message, file_path)
    """
    if not route_name:
        return False, "Please enter a route name.", None
    if not positions:
        return False, "No positions to save.", None

    folder_path = os.path.join(base_folder, route_name)
    os.makedirs(folder_path, exist_ok=True)
    file_path = os.path.join(folder_path, "positions.json")
    try:
        with open(file_path, "w") as f:
            json.dump(positions, f, indent=2)
        return True, f"Route '{route_name}' saved!", file_path
    except Exception as e:
        return False, f"Failed to save route: {str(e)}", None

def fetch_positions(server_url, token, device_id, from_time, to_time):
    """
    Fetch positions from the Traccar API.
    Returns (positions, error_message)
    """
    url = f"{server_url}/api/reports/route"
    headers = {"Authorization": f"Bearer {token}", "Accept": "application/json"}
    params = {
        "deviceId": device_id,
        "from": from_time,
        "to": to_time
    }
    try:
        response = requests.get(url, params=params, headers=headers, timeout=15)
        if response.status_code == 200:
            return response.json(), None
        elif response.status_code == 400:
            return None, "Bad Request: Please check the request payload and token."
        else:
            return None, f"Failed: {response.status_code} - {response.reason}"
    except requests.exceptions.RequestException as e:
        return None, f"Error fetching positions: {str(e)}"

def fetch_positions_for_selected_day(settings, device_mapping, device_name, start_date, end_date, start_hour, end_hour):
    """
    Fetch positions for the selected day/device using Traccar API.
    Returns (positions, error_message)
    """
    if not settings:
        return [], "Server settings not found."

    server_url = settings.get("server_url")
    token = settings.get("token")
    device_id = device_mapping.get(device_name)
    if not device_id:
        return [], "Device ID not found."

    from_time = f"{start_date}T{start_hour}:00:00Z"
    to_time = f"{end_date}T{end_hour}:59:59Z"

    positions, error = fetch_positions(server_url, token, device_id, from_time, to_time)
    if error:
        return [], error
    return positions, None