app.py

import os
import requests
import base64
from dotenv import load_dotenv
from mcp.server.fastmcp import FastMCP, Image

load_dotenv()

# --- Configuration ---
# URL of the Flask app API - configurable via environment variable
FLASK_API_URL = os.getenv("FLASK_API_URL", "http://127.0.0.1:5000")

# --- MCP Server Setup ---
mcp = FastMCP(
    name="GeoGuessrAgent",
    host="0.0.0.0",
    port=7860,
)

# --- Game State Management ---
# Store the current game ID and basic state
active_game = {}

# --- Flask API Helper Functions ---
def call_flask_api(endpoint, method='GET', json_data=None):
    """Helper function to call Flask API endpoints"""
    url = f"{FLASK_API_URL}{endpoint}"
    try:
        if method == 'POST':
            response = requests.post(url, json=json_data, headers={'Content-Type': 'application/json'}, timeout=30)
        else:
            response = requests.get(url, timeout=30)
        
        if response.status_code in [200, 201]:
            return response.json()
        else:
            error_msg = f"API call failed: {response.status_code} - {response.text}"
            print(f"Flask API Error: {error_msg}")
            raise Exception(error_msg)
    except requests.exceptions.ConnectionError as e:
        error_msg = f"Could not connect to Flask API at {FLASK_API_URL}. Make sure the Flask server is running. Error: {str(e)}"
        print(f"Connection Error: {error_msg}")
        raise Exception(error_msg)
    except requests.exceptions.Timeout as e:
        error_msg = f"Timeout calling Flask API at {FLASK_API_URL}. Error: {str(e)}"
        print(f"Timeout Error: {error_msg}")
        raise Exception(error_msg)
    except Exception as e:
        error_msg = f"API call error: {str(e)}"
        print(f"General Error: {error_msg}")
        raise Exception(error_msg)

def base64_to_image_bytes(base64_string):
    """Convert base64 string to image bytes"""
    try:
        if not base64_string:
            raise ValueError("Empty base64 string provided")
        
        # Remove any data URL prefix if present
        if base64_string.startswith('data:'):
            base64_string = base64_string.split(',', 1)[1]
        
        # Decode the base64 string
        image_bytes = base64.b64decode(base64_string)
        
        if len(image_bytes) == 0:
            raise ValueError("Decoded image is empty")
        
        print(f"Successfully decoded image: {len(image_bytes)} bytes")
        return image_bytes
        
    except Exception as e:
        print(f"Error decoding base64 image: {e}")
        raise ValueError(f"Failed to decode base64 image: {str(e)}")

# --- MCP Tools ---

@mcp.tool()
def start_game(difficulty: str = "easy", player_name: str = "MCP Agent") -> Image:
    """
    Starts a new GeoGuessr game by calling the Flask API.
    Args:
        difficulty (str): The difficulty of the game ('easy', 'medium', 'hard').
        player_name (str): The name of the player/agent.
    Returns:
        Image: The first Street View image with compass overlay.
    """
    global active_game
    
    # Call Flask API to start game
    game_data = call_flask_api('/start_game', 'POST', {
        'difficulty': difficulty,
        'player_name': player_name
    })
    
    # Store game state
    active_game = {
        'game_id': game_data['game_id'],
        'player_name': game_data['player_name'],
        'game_over': False
    }
    
    # Convert base64 image to bytes and return as Image
    if game_data.get('streetview_image'):
        try:
            image_bytes = base64_to_image_bytes(game_data['streetview_image'])
            print(f"Successfully started game {active_game['game_id']} for player {active_game['player_name']}")
            return Image(data=image_bytes, format="jpeg")
        except Exception as e:
            print(f"Error processing Street View image: {e}")
            raise Exception(f"Failed to process Street View image: {str(e)}")
    else:
        raise Exception("No Street View image received from the game")



@mcp.tool()
def move(direction: str = None, degree: float = None, distance: float = 0.1) -> Image:
    """
    Moves the player in a specified direction by calling the Flask API.
    Args:
        direction (str, optional): Direction to move (N, NE, E, SE, S, SW, W, NW).
        degree (float, optional): Precise direction in degrees (0-360).
        distance (float): Distance to move in kilometers (default: 0.1km = 100m).
    Returns:
        Image: The new Street View image with compass overlay.
    """
    global active_game
    if not active_game or not active_game.get('game_id'):
        raise ValueError("Game not started. Call start_game() first.")
    if active_game.get('game_over'):
        raise ValueError("Game is over.")
    
    
    # Prepare move data
    move_data = {'distance': distance}
    if direction:
        move_data['direction'] = direction
    elif degree is not None:
        move_data['degree'] = degree
    else:
        raise ValueError("Must provide either direction or degree parameter.")
    
    # Call Flask API to move
    game_id = active_game['game_id']
    move_result = call_flask_api(f'/game/{game_id}/move', 'POST', move_data)
    
    # Convert base64 image to bytes and return as Image
    if move_result.get('streetview_image'):
        try:
            image_bytes = base64_to_image_bytes(move_result['streetview_image'])
            direction_info = move_result.get('moved_direction', 'unknown direction')
            distance_info = move_result.get('distance_moved_km', 0) * 1000
            print(f"Successfully moved {direction_info} for {distance_info:.0f}m in game {game_id}")
            return Image(data=image_bytes, format="jpeg")
        except Exception as e:
            print(f"Error processing move Street View image: {e}")
            raise Exception(f"Failed to process move Street View image: {str(e)}")
    else:
        raise Exception("No Street View image received from the move")

@mcp.tool()
def make_placeholder_guess(lat: float, lng: float) -> dict:
    """
    Records a temporary guess for the location (stored locally until final guess).
    Args:
        lat (float): The latitude of the guess.
        lng (float): The longitude of the guess.
    Returns:
        dict: A status message.
    """
    global active_game
    if not active_game or not active_game.get('game_id'):
        raise ValueError("Game not started.")
    if active_game.get('game_over'):
        raise ValueError("Game is over.")

    active_game['placeholder_guess'] = {'lat': lat, 'lng': lng}
    return {"status": "success", "message": f"Placeholder guess recorded: {lat:.6f}, {lng:.6f}"}


@mcp.tool()
def make_final_guess() -> dict:
    """
    Makes the final guess for the active game by calling the Flask API.
    Uses the stored placeholder guess coordinates.
    Returns:
        dict: The results of the guess including distance, score, and actual location.
    """
    global active_game
    if not active_game or not active_game.get('game_id'):
        raise ValueError("Game not started.")
    if active_game.get('game_over'):
        raise ValueError("Game is already over.")
    if 'placeholder_guess' not in active_game:
        raise ValueError("No placeholder guess was made. Call make_placeholder_guess() first.")

    # Get the placeholder guess
    guess_location = active_game['placeholder_guess']
    
    # Call Flask API to make the final guess
    game_id = active_game['game_id']
    guess_result = call_flask_api(f'/game/{game_id}/guess', 'POST', {
        'lat': guess_location['lat'],
        'lng': guess_location['lng']
    })

    # Mark game as over
    active_game['game_over'] = True
    
    return {
        "distance_km": guess_result['distance_km'],
        "score": guess_result['score'],
        "actual_location": guess_result['actual_location'],
        "guess_location": guess_result['guess_location']
    }

@mcp.tool()
def get_game_state() -> dict:
    """
    Gets the current game state from the Flask API.
    Returns:
        dict: Current game state including moves, actions, and game status.
    """
    global active_game
    if not active_game or not active_game.get('game_id'):
        raise ValueError("Game not started.")
    
    game_id = active_game['game_id']
    game_state = call_flask_api(f'/game/{game_id}/state')
    
    # Don't expose the actual coordinates - keep the guessing challenge
    state_info = {
        "game_id": game_state.get('game_id', game_id),
        "player_name": game_state.get('player_name', active_game.get('player_name')),
        "moves": game_state.get('moves', 0),
        "game_over": game_state.get('game_over', False),
        "total_actions": len(game_state.get('actions', [])),
        "guesses_made": len(game_state.get('guesses', [])),
        "placeholder_guess": active_game.get('placeholder_guess')
    }
    
    # Update local game state
    active_game['game_over'] = game_state.get('game_over', False)
    
    return state_info

@mcp.tool()
def test_connection() -> str:
    """
    Simple test to verify MCP server is working.
    Returns:
        str: A test message.
    """
    return "MCP server is working correctly!"

if __name__ == "__main__":
    mcp.run(transport="sse")