"""
Flare – Main Application (Refactored with Event-Driven Architecture)
====================================================================
"""
# FastAPI imports
from fastapi import FastAPI, WebSocket, Request, status
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse, JSONResponse
from fastapi.middleware.cors import CORSMiddleware
from fastapi.encoders import jsonable_encoder

# Standard library
import uvicorn
import os
from pathlib import Path
import mimetypes
import uuid
import traceback
from datetime import datetime
import asyncio
import time
from pydantic import ValidationError
from dotenv import load_dotenv

# Event-driven architecture imports
from chat_session.event_bus import event_bus
from chat_session.state_orchestrator import StateOrchestrator
from chat_session.websocket_manager import WebSocketManager
from chat_session.resource_manager import ResourceManager
from stt.stt_lifecycle_manager import STTLifecycleManager
from tts.tts_lifecycle_manager import TTSLifecycleManager
from llm.llm_lifecycle_manager import LLMLifecycleManager
from stt.audio_buffer_manager import AudioBufferManager

# Project imports
from routes.admin_routes import router as admin_router, start_cleanup_task
from llm.llm_startup import run_in_thread
from chat_session.session import session_store, start_session_cleanup
from config.config_provider import ConfigProvider

# Logger imports
from utils.logger import log_error, log_info, log_warning

# Exception imports
from utils.exceptions import (
    DuplicateResourceError,
    RaceConditionError,
    ValidationError as FlareValidationError,
    ResourceNotFoundError,
    AuthenticationError,
    AuthorizationError,
    ConfigurationError,
    get_http_status_code,
    FlareException
)

# Load .env file if exists
load_dotenv()

ALLOWED_ORIGINS = os.getenv("ALLOWED_ORIGINS", "http://localhost:4200").split(",")

# ===================== Environment Setup =====================
def setup_environment():
    """Setup environment based on deployment mode"""
    cfg = ConfigProvider.get()

    log_info("=" * 60)
    log_info("🚀 Flare Starting", version="2.0.0")
    log_info(f"🔌 LLM Provider: {cfg.global_config.llm_provider.name}")
    log_info(f"🎤 TTS Provider: {cfg.global_config.tts_provider.name}")
    log_info(f"🎧 STT Provider: {cfg.global_config.stt_provider.name}")
    log_info("=" * 60)

    if cfg.global_config.is_cloud_mode():
        log_info("☁️  Cloud Mode: Using HuggingFace Secrets")
        log_info("📌 Required secrets: JWT_SECRET, FLARE_TOKEN_KEY")

        # Check for provider-specific tokens
        llm_config = cfg.global_config.get_provider_config("llm", cfg.global_config.llm_provider.name)
        if llm_config and llm_config.requires_repo_info:
            log_info("📌 LLM requires SPARK_TOKEN for repository operations")
    else:
        log_info("🏢 On-Premise Mode: Using .env file")
        if not Path(".env").exists():
            log_warning("⚠️  WARNING: .env file not found!")
            log_info("📌 Copy .env.example to .env and configure it")

# Run setup
setup_environment()

# Fix MIME types for JavaScript files
mimetypes.add_type("application/javascript", ".js")
mimetypes.add_type("text/css", ".css")

app = FastAPI(
    title="Flare Orchestration Service",
    version="2.0.0",
    description="LLM-driven intent & API flow engine with multi-provider support",
)

# CORS for development
if os.getenv("ENVIRONMENT", "development") == "development":
    app.add_middleware(
        CORSMiddleware,
        allow_origins=ALLOWED_ORIGINS,
        allow_credentials=True,
        allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
        allow_headers=["*"],
        max_age=3600,
        expose_headers=["X-Request-ID"]
    )
    log_info(f"🔧 CORS enabled for origins: {ALLOWED_ORIGINS}")

# Request ID middleware
@app.middleware("http")
async def add_request_id(request: Request, call_next):
    """Add request ID for tracking"""
    request_id = str(uuid.uuid4())
    request.state.request_id = request_id

    # Log request start
    log_info(
        "Request started",
        request_id=request_id,
        method=request.method,
        path=request.url.path,
        client=request.client.host if request.client else "unknown"
    )

    try:
        response = await call_next(request)

        # Add request ID to response headers
        response.headers["X-Request-ID"] = request_id

        # Log request completion
        log_info(
            "Request completed",
            request_id=request_id,
            status_code=response.status_code,
            method=request.method,
            path=request.url.path
        )

        return response
    except Exception as e:
        log_error(
            "Request failed",
            request_id=request_id,
            error=str(e),
            traceback=traceback.format_exc()
        )
        raise

# ===================== Event-Driven Architecture Initialization =====================
@app.on_event("startup")
async def startup_event():
    """Initialize event-driven components on startup"""
    try:
        # Initialize event bus
        await event_bus.start()
        log_info("✅ Event bus started")

        # Initialize resource manager
        resource_manager = ResourceManager(event_bus)
        await resource_manager.start()
        log_info("✅ Resource manager started")

        # Initialize managers
        state_orchestrator = StateOrchestrator(event_bus)
        websocket_manager = WebSocketManager(event_bus)
        audio_buffer_manager = AudioBufferManager(event_bus)
        stt_manager = STTLifecycleManager(event_bus, resource_manager)
        tts_manager = TTSLifecycleManager(event_bus, resource_manager)
        llm_manager = LLMLifecycleManager(event_bus, resource_manager)

        # Store in app state for access in routes
        app.state.event_bus = event_bus
        app.state.resource_manager = resource_manager
        app.state.state_orchestrator = state_orchestrator
        app.state.websocket_manager = websocket_manager
        app.state.audio_buffer_manager = audio_buffer_manager
        app.state.stt_manager = stt_manager
        app.state.tts_manager = tts_manager
        app.state.llm_manager = llm_manager

        log_info("✅ All managers initialized")

        # Start existing background tasks
        run_in_thread()  # Start LLM startup notifier if needed
        start_cleanup_task()  # Activity log cleanup
        start_session_cleanup()  # Session cleanup

        log_info("✅ Background tasks started")

    except Exception as e:
        log_error("❌ Failed to start event-driven components", error=str(e), traceback=traceback.format_exc())
        raise

@app.on_event("shutdown")
async def shutdown_event():
    """Cleanup event-driven components on shutdown"""
    try:
        # Stop event bus
        await event_bus.stop()
        log_info("✅ Event bus stopped")

        # Stop resource manager
        if hasattr(app.state, 'resource_manager'):
            await app.state.resource_manager.stop()
            log_info("✅ Resource manager stopped")

        # Close all WebSocket connections
        if hasattr(app.state, 'websocket_manager'):
            await app.state.websocket_manager.close_all_connections()
            log_info("✅ All WebSocket connections closed")

    except Exception as e:
        log_error("❌ Error during shutdown", error=str(e))

# ---------------- Core chat/session routes --------------------------
from routes.chat_handler import router as chat_router
app.include_router(chat_router, prefix="/api")

# ---------------- Audio (TTS/STT) routes ------------------------------
from routes.audio_routes import router as audio_router
app.include_router(audio_router, prefix="/api")

# ---------------- Admin API routes ----------------------------------
app.include_router(admin_router, prefix="/api/admin")

# ---------------- WebSocket route for real-time chat ------------------
@app.websocket("/ws/conversation/{session_id}")
async def websocket_route(websocket: WebSocket, session_id: str):
    """Handle WebSocket connections using the new WebSocketManager"""
    if hasattr(app.state, 'websocket_manager'):
        await app.state.websocket_manager.handle_connection(websocket, session_id)
    else:
        log_error("WebSocketManager not initialized")
        await websocket.close(code=1011, reason="Server not ready")

# ---------------- Test endpoint for event-driven flow ------------------
@app.post("/api/test/realtime")
async def test_realtime():
    """Test endpoint for event-driven realtime flow"""
    from chat_session.event_bus import Event, EventType

    try:
        # Create a test session
        session = session_store.create_session(
            project_name="kronos_jet",
            version_no=1,
            is_realtime=True
        )

        # Get version config
        cfg = ConfigProvider.get()
        project = next((p for p in cfg.projects if p.name == "kronos_jet"), None)
        if project:
            version = next((v for v in project.versions if v.no == 1), None)
            if version:
                session.set_version_config(version)

        # Publish session started event
        await app.state.event_bus.publish(Event(
            type=EventType.SESSION_STARTED,
            session_id=session.session_id,
            data={
                "session": session,
                "has_welcome": bool(version and version.welcome_prompt),
                "welcome_text": version.welcome_prompt if version and version.welcome_prompt else "Hoş geldiniz!"
            }
        ))

        return {
            "session_id": session.session_id,
            "message": "Test session created. Connect via WebSocket to continue."
        }

    except Exception as e:
        log_error("Test endpoint error", error=str(e))
        raise HTTPException(500, f"Test failed: {str(e)}")

# ---------------- Exception Handlers ----------------------------------
@app.exception_handler(Exception)
async def global_exception_handler(request: Request, exc: Exception):
    """Handle all unhandled exceptions"""
    request_id = getattr(request.state, 'request_id', 'unknown')

    # Log the full exception
    log_error(
        "Unhandled exception",
        request_id=request_id,
        endpoint=str(request.url),
        method=request.method,
        error=str(exc),
        error_type=type(exc).__name__,
        traceback=traceback.format_exc()
    )

    # Special handling for FlareExceptions
    if isinstance(exc, FlareException):
        status_code = get_http_status_code(exc)
        response_body = {
            "error": type(exc).__name__,
            "message": str(exc),
            "request_id": request_id,
            "timestamp": datetime.utcnow().isoformat(),
            "details": getattr(exc, 'details', {})
        }

        # Special message for race conditions
        if isinstance(exc, RaceConditionError):
            response_body["user_action"] = "Please reload the data and try again"

        return JSONResponse(
            status_code=status_code,
            content=jsonable_encoder(response_body)
        )

    # Generic error response
    return JSONResponse(
        status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
        content=jsonable_encoder({
            "error": "InternalServerError",
            "message": "An unexpected error occurred. Please try again later.",
            "request_id": request_id,
            "timestamp": datetime.utcnow().isoformat()
        })
    )

# Add custom exception handlers
@app.exception_handler(DuplicateResourceError)
async def duplicate_resource_handler(request: Request, exc: DuplicateResourceError):
    """Handle duplicate resource errors"""
    return JSONResponse(
        status_code=409,
        content={
            "detail": str(exc),
            "error_type": "duplicate_resource",
            "resource_type": exc.details.get("resource_type"),
            "identifier": exc.details.get("identifier")
        }
    )

@app.exception_handler(RaceConditionError)
async def race_condition_handler(request: Request, exc: RaceConditionError):
    """Handle race condition errors"""
    return JSONResponse(
        status_code=409,
        content=exc.to_http_detail()
    )

@app.exception_handler(FlareValidationError)
async def validation_error_handler(request: Request, exc: FlareValidationError):
    """Handle validation errors"""
    return JSONResponse(
        status_code=422,
        content={
            "detail": str(exc),
            "error_type": "validation_error",
            "details": exc.details
        }
    )

@app.exception_handler(ResourceNotFoundError)
async def resource_not_found_handler(request: Request, exc: ResourceNotFoundError):
    """Handle resource not found errors"""
    return JSONResponse(
        status_code=404,
        content={
            "detail": str(exc),
            "error_type": "resource_not_found",
            "resource_type": exc.details.get("resource_type"),
            "identifier": exc.details.get("identifier")
        }
    )

@app.exception_handler(AuthenticationError)
async def authentication_error_handler(request: Request, exc: AuthenticationError):
    """Handle authentication errors"""
    return JSONResponse(
        status_code=401,
        content={
            "detail": str(exc),
            "error_type": "authentication_error"
        }
    )

@app.exception_handler(AuthorizationError)
async def authorization_error_handler(request: Request, exc: AuthorizationError):
    """Handle authorization errors"""
    return JSONResponse(
        status_code=403,
        content={
            "detail": str(exc),
            "error_type": "authorization_error"
        }
    )

@app.exception_handler(ConfigurationError)
async def configuration_error_handler(request: Request, exc: ConfigurationError):
    """Handle configuration errors"""
    return JSONResponse(
        status_code=500,
        content={
            "detail": str(exc),
            "error_type": "configuration_error",
            "config_key": exc.details.get("config_key")
        }
    )

# ---------------- Metrics endpoint -----------------
@app.get("/metrics")
async def get_metrics():
    """Get system metrics including event-driven components"""
    import psutil
    import gc

    # Memory info
    process = psutil.Process()
    memory_info = process.memory_info()

    # Session stats
    session_stats = session_store.get_session_stats()

    # Event-driven component stats
    event_stats = {}
    if hasattr(app.state, 'stt_manager'):
        event_stats['stt'] = app.state.stt_manager.get_stats()
    if hasattr(app.state, 'tts_manager'):
        event_stats['tts'] = app.state.tts_manager.get_stats()
    if hasattr(app.state, 'llm_manager'):
        event_stats['llm'] = app.state.llm_manager.get_stats()
    if hasattr(app.state, 'websocket_manager'):
        event_stats['websocket'] = {
            'active_connections': app.state.websocket_manager.get_connection_count()
        }
    if hasattr(app.state, 'resource_manager'):
        event_stats['resources'] = app.state.resource_manager.get_stats()
    if hasattr(app.state, 'audio_buffer_manager'):
        event_stats['audio_buffers'] = app.state.audio_buffer_manager.get_all_stats()

    metrics = {
        "memory": {
            "rss_mb": memory_info.rss / 1024 / 1024,
            "vms_mb": memory_info.vms / 1024 / 1024,
            "percent": process.memory_percent()
        },
        "cpu": {
            "percent": process.cpu_percent(interval=0.1),
            "num_threads": process.num_threads()
        },
        "sessions": session_stats,
        "event_driven_components": event_stats,
        "gc": {
            "collections": gc.get_count(),
            "objects": len(gc.get_objects())
        },
        "uptime_seconds": time.time() - process.create_time()
    }

    return metrics

# ---------------- Health probe (HF Spaces watchdog) -----------------
@app.get("/api/health")
def health_check():
    """Health check endpoint - moved to /api/health"""
    # Check if event-driven components are healthy
    event_bus_healthy = hasattr(app.state, 'event_bus') and app.state.event_bus._running

    return {
        "status": "ok" if event_bus_healthy else "degraded",
        "version": "2.0.0",
        "timestamp": datetime.utcnow().isoformat(),
        "environment": os.getenv("ENVIRONMENT", "development"),
        "event_driven": {
            "event_bus": "running" if event_bus_healthy else "not_running",
            "managers": {
                "state_orchestrator": "initialized" if hasattr(app.state, 'state_orchestrator') else "not_initialized",
                "websocket_manager": "initialized" if hasattr(app.state, 'websocket_manager') else "not_initialized",
                "stt_manager": "initialized" if hasattr(app.state, 'stt_manager') else "not_initialized",
                "tts_manager": "initialized" if hasattr(app.state, 'tts_manager') else "not_initialized",
                "llm_manager": "initialized" if hasattr(app.state, 'llm_manager') else "not_initialized"
            }
        }
    }

# ---------------- Serve static files ------------------------------------
# UI static files (production build)
static_path = Path(__file__).parent / "static"
if static_path.exists():
    app.mount("/static", StaticFiles(directory=str(static_path)), name="static")

    # Serve index.html for all non-API routes (SPA support)
    @app.get("/", response_class=FileResponse)
    async def serve_index():
        """Serve Angular app"""
        index_path = static_path / "index.html"
        if index_path.exists():
            return FileResponse(str(index_path))
        else:
            return JSONResponse(
                status_code=404,
                content={"error": "UI not found. Please build the Angular app first."}
            )

    # Catch-all route for SPA
    @app.get("/{full_path:path}")
    async def serve_spa(full_path: str):
        """Serve Angular app for all routes"""
        # Skip API routes
        if full_path.startswith("api/"):
            return JSONResponse(status_code=404, content={"error": "Not found"})

        # Serve static files
        file_path = static_path / full_path
        if file_path.exists() and file_path.is_file():
            return FileResponse(str(file_path))

        # Fallback to index.html for SPA routing
        index_path = static_path / "index.html"
        if index_path.exists():
            return FileResponse(str(index_path))

        return JSONResponse(status_code=404, content={"error": "Not found"})
else:
    log_warning(f"⚠️  Static files directory not found at {static_path}")
    log_warning("   Run 'npm run build' in flare-ui directory to build the UI")

    @app.get("/")
    async def no_ui():
        """No UI available"""
        return JSONResponse(
            status_code=503,
            content={
                "error": "UI not available",
                "message": "Please build the Angular UI first. Run: cd flare-ui && npm run build",
                "api_docs": "/docs"
            }
        )

if __name__ == "__main__":
    log_info("🌐 Starting Flare backend on port 7860...")
    uvicorn.run(app, host="0.0.0.0", port=7860)