"""
Context Engineering System
Implements the complete context engineering framework for optimal LLM performance
Based on the three-step evolution: Retrieval/Generation → Processing → Management
"""

import json
import logging
from typing import Dict, List, Any, Optional, Tuple
from datetime import datetime, timedelta
from dataclasses import dataclass, field
import hashlib
from collections import deque
import numpy as np
from pathlib import Path

logger = logging.getLogger(__name__)


@dataclass
class ContextChunk:
    """A unit of context with metadata"""
    content: str
    source: str
    timestamp: datetime
    relevance_score: float = 0.0
    token_count: int = 0
    embedding: Optional[np.ndarray] = None
    metadata: Dict = field(default_factory=dict)
    compression_ratio: float = 1.0
    access_count: int = 0
    last_accessed: Optional[datetime] = None
    
    def update_access(self):
        """Update access statistics"""
        self.access_count += 1
        self.last_accessed = datetime.now()


class DataFlywheel:
    """
    NVIDIA's concept: Continuous improvement through input/output pairing
    Learns from successful context usage to optimize future retrievals
    """
    
    def __init__(self, storage_path: str = "flywheel_data.json"):
        self.storage_path = Path(storage_path)
        self.successful_contexts: List[Dict] = []
        self.feedback_pairs: List[Tuple[str, str, float]] = []  # (input, output, score)
        self.pattern_cache: Dict[str, List[str]] = {}
        self.load()
        
    def record_success(
        self,
        input_context: str,
        output: str,
        success_score: float,
        context_chunks: List[ContextChunk]
    ):
        """Record successful context usage for learning"""
        self.successful_contexts.append({
            'timestamp': datetime.now().isoformat(),
            'input': input_context[:500],  # Truncate for storage
            'output': output[:500],
            'score': success_score,
            'chunks_used': [c.source for c in context_chunks],
            'avg_relevance': np.mean([c.relevance_score for c in context_chunks])
        })
        
        # Update pattern cache
        key = self._generate_pattern_key(input_context)
        if key not in self.pattern_cache:
            self.pattern_cache[key] = []
        self.pattern_cache[key].extend([c.source for c in context_chunks])
        
        self.save()
        
    def get_recommended_sources(self, query: str) -> List[str]:
        """Get recommended context sources based on past successes"""
        key = self._generate_pattern_key(query)
        
        if key in self.pattern_cache:
            # Return most frequently used sources for similar queries
            sources = self.pattern_cache[key]
            from collections import Counter
            return [s for s, _ in Counter(sources).most_common(5)]
        
        return []
    
    def _generate_pattern_key(self, text: str) -> str:
        """Generate pattern key for caching"""
        # Simple keyword extraction for pattern matching
        keywords = sorted(set(text.lower().split()[:10]))
        return hashlib.md5('_'.join(keywords).encode()).hexdigest()[:8]
    
    def save(self):
        """Persist flywheel data"""
        data = {
            'successful_contexts': self.successful_contexts[-100:],  # Keep last 100
            'pattern_cache': {k: v[-20:] for k, v in self.pattern_cache.items()}  # Keep last 20 per pattern
        }
        with open(self.storage_path, 'w') as f:
            json.dump(data, f, indent=2)
    
    def load(self):
        """Load flywheel data"""
        if self.storage_path.exists():
            try:
                with open(self.storage_path, 'r') as f:
                    data = json.load(f)
                self.successful_contexts = data.get('successful_contexts', [])
                self.pattern_cache = data.get('pattern_cache', {})
            except Exception as e:
                logger.error(f"Error loading flywheel data: {e}")


class ContextProcessor:
    """
    Step 2: Process and refine raw context
    Handles chunking, embedding, relevance scoring, and compression
    """
    
    def __init__(self, max_chunk_size: int = 500, overlap: int = 50):
        self.max_chunk_size = max_chunk_size
        self.overlap = overlap
        
    def process_context(
        self,
        raw_context: str,
        query: str,
        source: str = "unknown"
    ) -> List[ContextChunk]:
        """Process raw context into optimized chunks"""
        
        # 1. Chunk the context
        chunks = self._chunk_text(raw_context)
        
        # 2. Create ContextChunk objects
        context_chunks = []
        for chunk_text in chunks:
            chunk = ContextChunk(
                content=chunk_text,
                source=source,
                timestamp=datetime.now(),
                token_count=len(chunk_text.split()),
                relevance_score=self._calculate_relevance(chunk_text, query)
            )
            
            # 3. Apply compression if needed
            if chunk.token_count > 100:
                chunk.content, chunk.compression_ratio = self._compress_text(chunk_text)
            
            context_chunks.append(chunk)
        
        # 4. Sort by relevance
        context_chunks.sort(key=lambda c: c.relevance_score, reverse=True)
        
        return context_chunks
    
    def _chunk_text(self, text: str) -> List[str]:
        """Smart chunking with overlap"""
        words = text.split()
        chunks = []
        
        for i in range(0, len(words), self.max_chunk_size - self.overlap):
            chunk = ' '.join(words[i:i + self.max_chunk_size])
            chunks.append(chunk)
        
        return chunks
    
    def _calculate_relevance(self, chunk: str, query: str) -> float:
        """Calculate relevance score between chunk and query"""
        # Simple keyword overlap scoring (would use embeddings in production)
        query_words = set(query.lower().split())
        chunk_words = set(chunk.lower().split())
        
        if not query_words:
            return 0.0
        
        overlap = len(query_words & chunk_words)
        return overlap / len(query_words)
    
    def _compress_text(self, text: str) -> Tuple[str, float]:
        """Compress text by removing redundancy"""
        # Simple compression: remove duplicate sentences
        sentences = text.split('.')
        unique_sentences = []
        seen = set()
        
        for sent in sentences:
            sent_clean = sent.strip().lower()
            if sent_clean and sent_clean not in seen:
                unique_sentences.append(sent.strip())
                seen.add(sent_clean)
        
        compressed = '. '.join(unique_sentences)
        if unique_sentences and not compressed.endswith('.'):
            compressed += '.'
        
        compression_ratio = len(compressed) / len(text) if text else 1.0
        return compressed, compression_ratio


class MemoryHierarchy:
    """
    Hierarchical memory system with different levels
    L1: Hot cache (immediate access)
    L2: Working memory (recent contexts)
    L3: Long-term storage (compressed historical)
    """
    
    def __init__(
        self,
        l1_size: int = 10,
        l2_size: int = 100,
        l3_path: str = "long_term_memory.json"
    ):
        self.l1_cache: deque = deque(maxlen=l1_size)  # Most recent/relevant
        self.l2_memory: deque = deque(maxlen=l2_size)  # Working memory
        self.l3_storage_path = Path(l3_path)
        self.l3_index: Dict[str, Dict] = {}  # Index for long-term storage
        self.load_l3()
        
    def add_context(self, chunk: ContextChunk):
        """Add context to appropriate memory level"""
        # High relevance goes to L1
        if chunk.relevance_score > 0.8:
            self.l1_cache.append(chunk)
        # Medium relevance to L2
        elif chunk.relevance_score > 0.5:
            self.l2_memory.append(chunk)
        # Everything gets indexed in L3
        self._add_to_l3(chunk)
        
    def retrieve(
        self,
        query: str,
        max_chunks: int = 10,
        recency_weight: float = 0.3
    ) -> List[ContextChunk]:
        """Retrieve relevant context from all memory levels"""
        all_chunks = []
        
        # Get from all levels
        all_chunks.extend(list(self.l1_cache))
        all_chunks.extend(list(self.l2_memory))
        
        # Score chunks considering both relevance and recency
        now = datetime.now()
        for chunk in all_chunks:
            # Calculate recency score (0-1, where 1 is most recent)
            age_hours = (now - chunk.timestamp).total_seconds() / 3600
            recency_score = max(0, 1 - (age_hours / 168))  # Decay over a week
            
            # Combine relevance and recency
            chunk.metadata['combined_score'] = (
                chunk.relevance_score * (1 - recency_weight) +
                recency_score * recency_weight
            )
        
        # Sort by combined score
        all_chunks.sort(
            key=lambda c: c.metadata.get('combined_score', 0),
            reverse=True
        )
        
        # Update access statistics
        for chunk in all_chunks[:max_chunks]:
            chunk.update_access()
        
        return all_chunks[:max_chunks]
    
    def _add_to_l3(self, chunk: ContextChunk):
        """Add to long-term storage index"""
        key = hashlib.md5(chunk.content.encode()).hexdigest()[:16]
        
        self.l3_index[key] = {
            'source': chunk.source,
            'timestamp': chunk.timestamp.isoformat(),
            'relevance': chunk.relevance_score,
            'summary': chunk.content[:100],  # Store summary only
            'access_count': chunk.access_count
        }
        
        # Periodically save
        if len(self.l3_index) % 10 == 0:
            self.save_l3()
    
    def save_l3(self):
        """Save long-term memory to disk"""
        with open(self.l3_storage_path, 'w') as f:
            json.dump(self.l3_index, f, indent=2)
    
    def load_l3(self):
        """Load long-term memory from disk"""
        if self.l3_storage_path.exists():
            try:
                with open(self.l3_storage_path, 'r') as f:
                    self.l3_index = json.load(f)
            except Exception as e:
                logger.error(f"Error loading L3 memory: {e}")


class MultiModalContext:
    """
    Handle different types of context beyond text
    Temporal, spatial, participant states, intentional, cultural
    """
    
    def __init__(self):
        self.temporal_context: List[Dict] = []  # Time-based relationships
        self.spatial_context: Dict = {}  # Location/geometry
        self.participant_states: Dict[str, Dict] = {}  # Entity tracking
        self.intentional_context: Dict = {}  # Goals and motivations
        self.cultural_context: Dict = {}  # Social/cultural nuances
        
    def add_temporal_context(
        self,
        event: str,
        timestamp: datetime,
        duration: Optional[timedelta] = None,
        related_events: List[str] = None
    ):
        """Add time-based context"""
        self.temporal_context.append({
            'event': event,
            'timestamp': timestamp,
            'duration': duration,
            'related': related_events or []
        })
        
        # Sort by timestamp
        self.temporal_context.sort(key=lambda x: x['timestamp'])
    
    def add_participant_state(
        self,
        participant_id: str,
        state: Dict,
        timestamp: Optional[datetime] = None
    ):
        """Track participant/entity states over time"""
        if participant_id not in self.participant_states:
            self.participant_states[participant_id] = {
                'current': state,
                'history': []
            }
        else:
            # Archive current state
            self.participant_states[participant_id]['history'].append({
                'state': self.participant_states[participant_id]['current'],
                'timestamp': timestamp or datetime.now()
            })
            self.participant_states[participant_id]['current'] = state
    
    def add_intentional_context(
        self,
        goal: str,
        motivation: str,
        constraints: List[str] = None,
        priority: float = 0.5
    ):
        """Add goals and motivations"""
        self.intentional_context[goal] = {
            'motivation': motivation,
            'constraints': constraints or [],
            'priority': priority,
            'added': datetime.now()
        }
    
    def get_multimodal_summary(self) -> Dict:
        """Get summary of all context types"""
        return {
            'temporal_events': len(self.temporal_context),
            'tracked_participants': len(self.participant_states),
            'active_goals': len(self.intentional_context),
            'has_spatial': bool(self.spatial_context),
            'has_cultural': bool(self.cultural_context)
        }


class ContextEngineer:
    """
    Main context engineering orchestrator
    Implements the complete 3-step framework
    """
    
    def __init__(self):
        self.flywheel = DataFlywheel()
        self.processor = ContextProcessor()
        self.memory = MemoryHierarchy()
        self.multimodal = MultiModalContext()
        
    def engineer_context(
        self,
        query: str,
        raw_sources: List[Tuple[str, str]],  # (source_name, content)
        multimodal_data: Optional[Dict] = None
    ) -> Dict[str, Any]:
        """
        Complete context engineering pipeline
        Step 1: Retrieval & Generation
        Step 2: Processing
        Step 3: Management
        """
        
        # Step 1: Retrieval & Generation
        # Get recommended sources from flywheel
        recommended = self.flywheel.get_recommended_sources(query)
        
        # Prioritize recommended sources
        prioritized_sources = []
        for source_name, content in raw_sources:
            priority = 2.0 if source_name in recommended else 1.0
            prioritized_sources.append((source_name, content, priority))
        
        # Step 2: Processing
        all_chunks = []
        for source_name, content, priority in prioritized_sources:
            chunks = self.processor.process_context(content, query, source_name)
            
            # Apply priority boost
            for chunk in chunks:
                chunk.relevance_score *= priority
            
            all_chunks.extend(chunks)
        
        # Add to memory hierarchy
        for chunk in all_chunks:
            self.memory.add_context(chunk)
        
        # Step 3: Management
        # Retrieve optimized context
        final_chunks = self.memory.retrieve(query, max_chunks=10)
        
        # Add multimodal context if provided
        if multimodal_data:
            for key, value in multimodal_data.items():
                if key == 'temporal':
                    for event in value:
                        self.multimodal.add_temporal_context(**event)
                elif key == 'participants':
                    for pid, state in value.items():
                        self.multimodal.add_participant_state(pid, state)
                elif key == 'goals':
                    for goal, details in value.items():
                        self.multimodal.add_intentional_context(goal, **details)
        
        # Build final context
        context = {
            'primary_context': '\n\n'.join([c.content for c in final_chunks[:5]]),
            'supporting_context': '\n'.join([c.content for c in final_chunks[5:10]]),
            'metadata': {
                'total_chunks': len(all_chunks),
                'selected_chunks': len(final_chunks),
                'avg_relevance': np.mean([c.relevance_score for c in final_chunks]) if final_chunks else 0,
                'compression_ratio': np.mean([c.compression_ratio for c in final_chunks]) if final_chunks else 1,
                'sources_used': list(set(c.source for c in final_chunks)),
                'multimodal': self.multimodal.get_multimodal_summary()
            },
            'chunks': final_chunks  # For feedback loop
        }
        
        return context
    
    def record_feedback(
        self,
        context: Dict,
        output: str,
        success_score: float
    ):
        """Record feedback for continuous improvement"""
        self.flywheel.record_success(
            context['primary_context'],
            output,
            success_score,
            context['chunks']
        )
    
    def optimize_memory(self):
        """Optimize memory by removing low-value chunks"""
        # This would implement memory pruning based on:
        # - Access frequency
        # - Age
        # - Relevance scores
        # - Compression potential
        pass


# Demo usage
def demo_context_engineering():
    """Demonstrate context engineering"""
    
    engineer = ContextEngineer()
    
    # Sample sources
    sources = [
        ("resume", "10 years experience in Python, AI, Machine Learning..."),
        ("job_description", "Looking for senior AI engineer with Python skills..."),
        ("company_research", "TechCorp is a leading AI company focused on NLP...")
    ]
    
    # Multimodal context
    multimodal = {
        'temporal': [
            {
                'event': 'Application deadline',
                'timestamp': datetime.now() + timedelta(days=7)
            }
        ],
        'participants': {
            'applicant': {'status': 'preparing', 'confidence': 0.8}
        },
        'goals': {
            'get_interview': {
                'motivation': 'Career advancement',
                'constraints': ['Remote only'],
                'priority': 0.9
            }
        }
    }
    
    # Engineer context
    context = engineer.engineer_context(
        query="Write a cover letter for AI engineer position",
        raw_sources=sources,
        multimodal_data=multimodal
    )
    
    print("Engineered Context:")
    print(f"Primary: {context['primary_context'][:200]}...")
    print(f"Metadata: {context['metadata']}")
    
    # Simulate success and record feedback
    engineer.record_feedback(context, "Generated cover letter...", 0.9)
    
    print("\nFlywheel learned patterns for future use!")


if __name__ == "__main__":
    demo_context_engineering()