"""
Enhanced Base Extension System for Wuhp Agents
Compatible with the modular app.py - combines state management with capability-based discovery.
"""
from abc import ABC, abstractmethod
from typing import Dict, Any, List, Optional, Callable
from google.genai import types
import json
import datetime
from pathlib import Path


class BaseExtension(ABC):
    """Enhanced base class for all agent extensions with capability-based discovery"""
    
    def __init__(self):
        self.enabled = False
        self.state: Dict[str, Any] = {}
        self._state_validators: Dict[str, Callable] = {}
        self._state_hooks: Dict[str, List[Callable]] = {
            'before_update': [],
            'after_update': [],
            'before_tool_call': [],
            'after_tool_call': []
        }
    
    # ==========================================
    # REQUIRED PROPERTIES (Use @property decorator)
    # ==========================================
    
    @property
    @abstractmethod
    def name(self) -> str:
        """Unique identifier for the extension (lowercase, no spaces)"""
        pass
    
    @property
    @abstractmethod
    def display_name(self) -> str:
        """Human-readable name shown in UI"""
        pass
    
    @property
    @abstractmethod
    def description(self) -> str:
        """Brief description of what the extension does"""
        pass
    
    @property
    def icon(self) -> str:
        """Emoji icon for the extension"""
        return "🔧"
    
    @property
    def version(self) -> str:
        """Extension version for compatibility checking"""
        return "1.0.0"
    
    # ==========================================
    # REQUIRED ABSTRACT METHODS
    # ==========================================
    
    @abstractmethod
    def get_system_context(self) -> str:
        """Returns context to inject into system prompt when enabled"""
        pass
    
    @abstractmethod
    def get_tools(self) -> List[types.Tool]:
        """Returns Gemini function calling tools for this extension"""
        pass
    
    # ==========================================
    # CAPABILITY-BASED DISCOVERY SYSTEM (NEW!)
    # ==========================================
    
    def get_capabilities(self) -> Dict[str, Any]:
        """
        Declare what this extension can do.
        This enables automatic integration without hardcoding.
        
        Returns dict with capabilities like:
        {
            'provides_data': ['stock_history', 'financial_data'],
            'consumes_data': ['numerical_series', 'comparison_data'],
            'creates_output': ['visualization', 'report'],
            'keywords': ['stock', 'price', 'chart', 'graph'],
            'data_outputs': {
                'stock_history': {
                    'format': 'time_series',
                    'fields': ['dates', 'close_prices', 'ticker']
                }
            }
        }
        
        Override this in your extension to declare capabilities!
        """
        return {
            'provides_data': [],
            'consumes_data': [],
            'creates_output': [],
            'keywords': [],
            'data_outputs': {}
        }
    
    def can_consume(self, data_type: str) -> bool:
        """Check if this extension can consume a specific data type"""
        return data_type in self.get_capabilities().get('consumes_data', [])
    
    def can_provide(self, data_type: str) -> bool:
        """Check if this extension can provide a specific data type"""
        return data_type in self.get_capabilities().get('provides_data', [])
    
    def can_create(self, output_type: str) -> bool:
        """Check if this extension can create a specific output"""
        return output_type in self.get_capabilities().get('creates_output', [])
    
    def get_suggested_next_action(self, tool_result: Dict[str, Any], 
                                   available_extensions: List['BaseExtension']) -> Optional[Dict[str, Any]]:
        """
        Given a tool result, suggest what should happen next.
        Returns None or dict with: {'extension': ext_name, 'tool': tool_name, 'reason': str, 'data': dict}
        
        This makes extensions self-aware of their integration opportunities!
        
        Example implementation:
        ```python
        # Find visualization extension by capability (NO HARDCODING!)
        viz_ext = next((ext for ext in available_extensions 
                       if ext.can_create('visualization')), None)
        
        if viz_ext and 'dates' in tool_result:
            return {
                'extension': viz_ext.name,
                'tool': 'create_line_chart',
                'reason': 'Data is ready for time-series visualization',
                'data': tool_result
            }
        ```
        
        Override this in your extension to suggest next actions!
        """
        return None
    
    # ==========================================
    # STATE MANAGEMENT
    # ==========================================
    
    def get_state_summary(self, user_id: str) -> Optional[str]:
        """
        Override to provide a human-readable summary of current state.
        This will be included in the system prompt for context awareness.
        Example: "You have 2 active timers and 5 pending tasks"
        """
        return None
    
    def initialize_state(self, user_id: str) -> None:
        """Initialize empty state for a new user"""
        if user_id not in self.state:
            self.state[user_id] = self._get_default_state()
            self._run_hooks('after_update', user_id, self.state[user_id])
    
    def _get_default_state(self) -> Dict[str, Any]:
        """Override to provide default state structure"""
        return {
            'created_at': datetime.datetime.now().isoformat(),
            'last_updated': datetime.datetime.now().isoformat()
        }
    
    def get_state(self, user_id: str) -> Dict[str, Any]:
        """Get state for a specific user"""
        if user_id not in self.state:
            self.initialize_state(user_id)
        return self.state.get(user_id, {})
    
    def update_state(self, user_id: str, updates: Dict[str, Any]) -> None:
        """Update state for a specific user with validation and hooks"""
        if user_id not in self.state:
            self.initialize_state(user_id)
        
        # Run before_update hooks
        self._run_hooks('before_update', user_id, updates)
        
        # Validate updates
        self._validate_state_updates(updates)
        
        # Update timestamp
        updates['last_updated'] = datetime.datetime.now().isoformat()
        
        # Apply updates
        self.state[user_id].update(updates)
        
        # Run after_update hooks
        self._run_hooks('after_update', user_id, self.state[user_id])
    
    def _validate_state_updates(self, updates: Dict[str, Any]) -> None:
        """Validate state updates using registered validators"""
        for key, value in updates.items():
            if key in self._state_validators:
                validator = self._state_validators[key]
                if not validator(value):
                    raise ValueError(f"Invalid value for state key '{key}': {value}")
    
    def register_state_validator(self, key: str, validator: Callable[[Any], bool]) -> None:
        """Register a validation function for a state key"""
        self._state_validators[key] = validator
    
    def add_hook(self, hook_type: str, func: Callable) -> None:
        """Add a hook function to be called at specific points"""
        if hook_type in self._state_hooks:
            self._state_hooks[hook_type].append(func)
    
    def _run_hooks(self, hook_type: str, *args, **kwargs) -> None:
        """Run all registered hooks of a specific type"""
        for hook_func in self._state_hooks.get(hook_type, []):
            try:
                hook_func(*args, **kwargs)
            except Exception as e:
                print(f"Hook error in {self.name}.{hook_type}: {e}")
    
    # ==========================================
    # TOOL EXECUTION
    # ==========================================
    
    def handle_tool_call(self, user_id: str, tool_name: str, args: Dict[str, Any]) -> Any:
        """
        Handle a tool call from Gemini with hooks.
        Override this to implement tool logic, OR override _execute_tool instead.
        """
        # Run before_tool_call hooks
        self._run_hooks('before_tool_call', user_id, tool_name, args)
        
        try:
            # Call the actual tool implementation
            result = self._execute_tool(user_id, tool_name, args)
            
            # Run after_tool_call hooks
            self._run_hooks('after_tool_call', user_id, tool_name, args, result)
            
            return result
        except Exception as e:
            error_result = {
                "success": False,
                "error": str(e),
                "tool": tool_name
            }
            self._run_hooks('after_tool_call', user_id, tool_name, args, error_result)
            return error_result
    
    def _execute_tool(self, user_id: str, tool_name: str, args: Dict[str, Any]) -> Any:
        """
        Override this method to implement actual tool logic.
        This is called by handle_tool_call after running before hooks.
        """
        return {"error": f"Tool {tool_name} not implemented"}
    
    def get_tool_by_name(self, tool_name: str) -> Optional[types.FunctionDeclaration]:
        """Helper to find a specific tool declaration by name"""
        for tool in self.get_tools():
            if hasattr(tool, 'function_declarations'):
                for func_decl in tool.function_declarations:
                    if func_decl.name == tool_name:
                        return func_decl
        return None
    
    # ==========================================
    # LIFECYCLE HOOKS
    # ==========================================
    
    def on_enable(self, user_id: str) -> Optional[str]:
        """
        Called when extension is enabled for a user.
        Return a message to show to the user, or None.
        """
        self.initialize_state(user_id)
        self.enabled = True
        return None
    
    def on_disable(self, user_id: str) -> Optional[str]:
        """
        Called when extension is disabled for a user.
        Return a message to show to the user, or None.
        """
        self.enabled = False
        return None
    
    def get_proactive_message(self, user_id: str) -> Optional[str]:
        """
        Called periodically to check if extension wants to proactively message user.
        Return message string or None.
        Override this to implement proactive notifications (timers, reminders, etc.)
        """
        return None
    
    # ==========================================
    # PERSISTENCE
    # ==========================================
    
    def serialize_state(self, user_id: str) -> str:
        """Serialize state to JSON for persistence"""
        return json.dumps(self.get_state(user_id), indent=2, default=str)
    
    def deserialize_state(self, user_id: str, state_json: str) -> None:
        """Load state from JSON"""
        try:
            loaded = json.loads(state_json)
            self.state[user_id] = loaded
        except Exception as e:
            print(f"Error loading state for {self.name}: {e}")
    
    def save_state_to_file(self, user_id: str, filepath: Optional[str] = None) -> str:
        """Save state to a file"""
        if filepath is None:
            filepath = f"state_{self.name}_{user_id}.json"
        
        state_path = Path(filepath)
        state_path.parent.mkdir(parents=True, exist_ok=True)
        
        with open(state_path, 'w') as f:
            f.write(self.serialize_state(user_id))
        
        return str(state_path)
    
    def load_state_from_file(self, user_id: str, filepath: str) -> bool:
        """Load state from a file"""
        try:
            with open(filepath, 'r') as f:
                state_json = f.read()
            self.deserialize_state(user_id, state_json)
            return True
        except Exception as e:
            print(f"Error loading state from {filepath}: {e}")
            return False
    
    def clear_state(self, user_id: str) -> None:
        """Clear all state for a user (useful for testing/reset)"""
        self.state[user_id] = self._get_default_state()
    
    def export_state(self, user_id: str) -> Dict[str, Any]:
        """Export state in a format suitable for external use"""
        return {
            'extension': self.name,
            'version': self.version,
            'exported_at': datetime.datetime.now().isoformat(),
            'state': self.get_state(user_id)
        }
    
    def import_state(self, user_id: str, exported_data: Dict[str, Any]) -> bool:
        """Import state from exported data with version checking"""
        try:
            if exported_data.get('extension') != self.name:
                print(f"Extension name mismatch: {exported_data.get('extension')} != {self.name}")
                return False
            
            # Could add version compatibility checks here
            
            self.state[user_id] = exported_data['state']
            return True
        except Exception as e:
            print(f"Error importing state: {e}")
            return False
    
    # ==========================================
    # DEPENDENCIES & VALIDATION
    # ==========================================
    
    def get_dependencies(self) -> List[str]:
        """
        Return list of other extension names this extension depends on.
        The orchestrator can use this to ensure dependencies are loaded.
        """
        return []
    
    def validate_dependencies(self, available_extensions: List[str]) -> bool:
        """Check if all required dependencies are available"""
        deps = self.get_dependencies()
        return all(dep in available_extensions for dep in deps)
    
    # ==========================================
    # LOGGING & METRICS
    # ==========================================
    
    def log_activity(self, user_id: str, activity: str, details: Dict[str, Any] = None) -> None:
        """
        Log extension activity for debugging/auditing.
        Override to implement custom logging.
        """
        timestamp = datetime.datetime.now().isoformat()
        log_entry = {
            'timestamp': timestamp,
            'extension': self.name,
            'activity': activity,
            'details': details or {}
        }
        
        # Store in state
        state = self.get_state(user_id)
        if 'activity_log' not in state:
            state['activity_log'] = []
        
        state['activity_log'].append(log_entry)
        
        # Keep only last 100 entries
        if len(state['activity_log']) > 100:
            state['activity_log'] = state['activity_log'][-100:]
    
    def get_recent_activity(self, user_id: str, limit: int = 10) -> List[Dict[str, Any]]:
        """Get recent activity log entries"""
        state = self.get_state(user_id)
        activity_log = state.get('activity_log', [])
        return activity_log[-limit:]
    
    def get_metrics(self, user_id: str) -> Dict[str, Any]:
        """
        Override to provide usage metrics/statistics.
        Example: {"total_timers_created": 15, "active_timers": 2}
        """
        return {}
    
    def health_check(self, user_id: str) -> Dict[str, Any]:
        """
        Perform a health check on the extension state.
        Returns dict with 'healthy': bool and optional 'issues': list
        """
        return {
            'healthy': True,
            'extension': self.name,
            'version': self.version
        }


# ==========================================
# HELPER FUNCTIONS FOR CAPABILITY MATCHING
# ==========================================

def find_extensions_with_capability(extensions: List[BaseExtension], 
                                    capability_type: str,
                                    capability_value: str) -> List[BaseExtension]:
    """
    Helper function to find extensions with a specific capability.
    
    Args:
        extensions: List of extension instances to search
        capability_type: 'provides_data', 'consumes_data', or 'creates_output'
        capability_value: The specific capability to search for
    
    Returns:
        List of extensions that have the specified capability
    
    Example:
        viz_extensions = find_extensions_with_capability(
            all_extensions, 'creates_output', 'visualization'
        )
    """
    matching = []
    for ext in extensions:
        caps = ext.get_capabilities().get(capability_type, [])
        if capability_value in caps:
            matching.append(ext)
    return matching


def get_data_flow_possibilities(extensions: List[BaseExtension]) -> List[Dict[str, Any]]:
    """
    Analyze a list of extensions and return all possible data flow chains.
    
    Returns list of dicts with:
        {
            'provider': extension_name,
            'data_type': data_type,
            'consumers': [list of extension names that can consume this data]
        }
    
    Example usage:
        flows = get_data_flow_possibilities(enabled_extensions)
        for flow in flows:
            print(f"{flow['provider']} produces {flow['data_type']}")
            print(f"  → can be consumed by: {', '.join(flow['consumers'])}")
    """
    flows = []
    
    for provider in extensions:
        provided_data = provider.get_capabilities().get('provides_data', [])
        
        for data_type in provided_data:
            consumers = [
                ext.name for ext in extensions
                if ext.can_consume(data_type) and ext.name != provider.name
            ]
            
            if consumers:
                flows.append({
                    'provider': provider.name,
                    'data_type': data_type,
                    'consumers': consumers
                })
    
    return flows


def detect_relevant_extensions(query: str, extensions: List[BaseExtension]) -> List[str]:
    """
    Detect which extensions are relevant to a query based on keywords.
    
    Args:
        query: The user's query string
        extensions: List of available extensions
    
    Returns:
        List of extension names that are relevant to the query
    
    Example:
        query = "Show me a chart of AAPL stock prices"
        relevant = detect_relevant_extensions(query, all_extensions)
        # Returns: ['yfinance', 'visualization']
    """
    query_lower = query.lower()
    relevant = []
    
    for ext in extensions:
        keywords = ext.get_capabilities().get('keywords', [])
        if any(keyword.lower() in query_lower for keyword in keywords):
            relevant.append(ext.name)
    
    return relevant