# API Routes - Complete REST API for MasterLLM
# File: api_routes.py

from fastapi import APIRouter, HTTPException, UploadFile, File, Form
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from typing import Optional, List, Dict, Any
import json
import os
import uuid
from datetime import datetime

# Import our services
from services.pipeline_generator import generate_pipeline, format_pipeline_for_display
from services.pipeline_executor import execute_pipeline_streaming, execute_pipeline
from services.session_manager import session_manager

router = APIRouter(prefix="/api/v1", tags=["MasterLLM API"])


# ========================
# REQUEST/RESPONSE MODELS
# ========================

class PipelineRequest(BaseModel):
    user_input: str
    file_path: Optional[str] = None
    session_id: Optional[str] = None
    prefer_bedrock: bool = True

class ExecuteRequest(BaseModel):
    pipeline: Dict[str, Any]
    file_path: str
    session_id: Optional[str] = None
    prefer_bedrock: bool = True

class SessionCreate(BaseModel):
    user_id: Optional[str] = None
    metadata: Optional[Dict[str, Any]] = None

class MessageAdd(BaseModel):
    role: str
    content: str
    metadata: Optional[Dict[str, Any]] = None


# ========================
# SESSION ENDPOINTS
# ========================

@router.post("/sessions")
async def create_session(request: SessionCreate):
    """Create a new user session"""
    try:
        session_id = session_manager.create_session(
            user_id=request.user_id,
            metadata=request.metadata
        )
        
        return {
            "success": True,
            "session_id": session_id,
            "message": "Session created successfully"
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/sessions/{session_id}")
async def get_session(session_id: str):
    """Get session data"""
    session = session_manager.get_session(session_id)
    
    if not session:
        raise HTTPException(status_code=404, detail="Session not found")
    
    return {
        "success": True,
        "session": session
    }


@router.get("/sessions/{session_id}/stats")
async def get_session_stats(session_id: str):
    """Get session statistics"""
    stats = session_manager.get_session_stats(session_id)
    
    if not stats:
        raise HTTPException(status_code=404, detail="Session not found")
    
    return {
        "success": True,
        "stats": stats
    }


@router.get("/sessions/{session_id}/history")
async def get_session_history(session_id: str, limit: int = 50):
    """Get conversation history for a session"""
    history = session_manager.get_session_history(session_id, limit)
    
    return {
        "success": True,
        "history": history,
        "count": len(history)
    }


@router.post("/sessions/{session_id}/messages")
async def add_message(session_id: str, message: MessageAdd):
    """Add a message to session history"""
    success = session_manager.add_message(
        session_id=session_id,
        role=message.role,
        content=message.content,
        metadata=message.metadata
    )
    
    if not success:
        raise HTTPException(status_code=500, detail="Failed to add message")
    
    return {
        "success": True,
        "message": "Message added successfully"
    }


# ========================
# PIPELINE GENERATION ENDPOINTS
# ========================

@router.post("/pipeline/generate")
async def generate_pipeline_api(request: PipelineRequest):
    """
    Generate a pipeline from user input using Bedrock (priority) or Gemini (fallback)
    """
    try:
        pipeline = generate_pipeline(
            user_input=request.user_input,
            file_path=request.file_path,
            prefer_bedrock=request.prefer_bedrock
        )
        
        # Add to session if provided
        if request.session_id:
            session_manager.update_session(
                request.session_id,
                {
                    "proposed_pipeline": pipeline,
                    "state": "pipeline_proposed"
                }
            )
        
        # Format for display
        formatted = format_pipeline_for_display(pipeline)
        
        return {
            "success": True,
            "pipeline": pipeline,
            "formatted_display": formatted,
            "generator": pipeline.get("_generator"),
            "model": pipeline.get("_model")
        }
    
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


# ========================
# PIPELINE EXECUTION ENDPOINTS
# ========================

@router.post("/pipeline/execute")
async def execute_pipeline_api(request: ExecuteRequest):
    """
    Execute a pipeline (non-streaming) using Bedrock (priority) or CrewAI (fallback)
    """
    try:
        result = execute_pipeline(
            pipeline=request.pipeline,
            file_path=request.file_path,
            session_id=request.session_id,
            prefer_bedrock=request.prefer_bedrock
        )
        
        # Save execution to session
        if request.session_id:
            session_manager.save_pipeline_execution(
                session_id=request.session_id,
                pipeline=request.pipeline,
                result=result,
                file_path=request.file_path,
                executor=result.get("executor", "unknown")
            )
            
            session_manager.update_session(
                request.session_id,
                {
                    "state": "completed",
                    "last_result": result
                }
            )
        
        return {
            "success": True,
            "result": result,
            "executor": result.get("executor")
        }
    
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@router.post("/pipeline/execute/stream")
async def execute_pipeline_stream_api(request: ExecuteRequest):
    """
    Execute a pipeline with streaming updates using Bedrock (priority) or CrewAI (fallback)
    """
    def event_stream():
        try:
            for event in execute_pipeline_streaming(
                pipeline=request.pipeline,
                file_path=request.file_path,
                session_id=request.session_id,
                prefer_bedrock=request.prefer_bedrock
            ):
                # Format as Server-Sent Events
                yield f"data: {json.dumps(event)}\n\n"
                
                # Save final result to session
                if event.get("type") == "final" and request.session_id:
                    session_manager.save_pipeline_execution(
                        session_id=request.session_id,
                        pipeline=request.pipeline,
                        result=event.get("data"),
                        file_path=request.file_path,
                        executor=event.get("executor", "unknown")
                    )
        
        except Exception as e:
            error_event = {
                "type": "error",
                "error": str(e)
            }
            yield f"data: {json.dumps(error_event)}\n\n"
    
    return StreamingResponse(
        event_stream(),
        media_type="text/event-stream"
    )


# ========================
# FILE UPLOAD ENDPOINT
# ========================

@router.post("/upload")
async def upload_file(
    file: UploadFile = File(...),
    session_id: Optional[str] = Form(None)
):
    """
    Upload a document for processing
    """
    try:
        # Create uploads directory if it doesn't exist
        upload_dir = "uploads"
        os.makedirs(upload_dir, exist_ok=True)
        
        # Generate unique filename
        file_ext = os.path.splitext(file.filename)[1]
        unique_filename = f"{uuid.uuid4()}{file_ext}"
        file_path = os.path.join(upload_dir, unique_filename)
        
        # Save file
        with open(file_path, "wb") as f:
            content = await file.read()
            f.write(content)
        
        # Update session if provided
        if session_id:
            session_manager.update_session(
                session_id,
                {"current_file": file_path}
            )
        
        return {
            "success": True,
            "file_path": file_path,
            "filename": file.filename,
            "size_bytes": len(content)
        }
    
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


# ========================
# PIPELINE HISTORY ENDPOINTS
# ========================

@router.get("/pipelines/history")
async def get_pipeline_history(
    session_id: Optional[str] = None,
    limit: int = 10
):
    """Get pipeline execution history"""
    executions = session_manager.get_pipeline_executions(
        session_id=session_id,
        limit=limit
    )
    
    return {
        "success": True,
        "executions": executions,
        "count": len(executions)
    }


@router.get("/pipelines/stats")
async def get_pipeline_stats():
    """Get overall pipeline execution statistics"""
    # This would query the pipeline executions collection
    # For now, return basic stats
    return {
        "success": True,
        "stats": {
            "total_executions": 0,
            "bedrock_executions": 0,
            "crewai_executions": 0,
            "avg_duration_seconds": 0
        }
    }


# ========================
# HEALTH CHECK
# ========================

@router.get("/health")
async def health_check():
    """API health check"""
    return {
        "status": "healthy",
        "timestamp": datetime.now().isoformat(),
        "version": "2.0.0",
        "features": {
            "bedrock_available": os.getenv("AWS_ACCESS_KEY_ID") is not None,
            "gemini_available": os.getenv("GOOGLE_API_KEY") is not None,
            "mongodb_connected": session_manager.sessions_col is not None
        }
    }