"""
Flare – Main Application (Refactored)
=====================================
"""
# 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
from pydantic import ValidationError
from dotenv import load_dotenv

# Project imports
from websocket_handler import websocket_endpoint
from admin_routes import router as admin_router, start_cleanup_task
from llm_startup import run_in_thread
from session import session_store, start_session_cleanup
from config_provider import ConfigProvider

# Logger imports (utils.log yerine)
from logger import log_error, log_info, log_warning

# Exception imports
from exceptions import (
    DuplicateResourceError, 
    RaceConditionError, 
    ValidationError, 
    ResourceNotFoundError,
    AuthenticationError,
    AuthorizationError,
    ConfigurationError,
    get_http_status_code
)

# 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

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

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

# ---------------- Audio (TTS/STT) routes ------------------------------
from 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")

# ---------------- Exception Handlers ----------------------------------
# Add global exception handler
@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 = format_error_response(exc, request_id)
        
        # 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(ValidationError)
async def validation_error_handler(request: Request, exc: ValidationError):
    """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"""
    import psutil
    import gc
    
    # Memory info
    process = psutil.Process()
    memory_info = process.memory_info()
    
    # Session stats
    session_stats = session_store.get_session_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,
        "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"""
    return {
        "status": "ok",
        "version": "2.0.0",
        "timestamp": datetime.utcnow().isoformat(),
        "environment": os.getenv("ENVIRONMENT", "development")
    }

# ---------------- WebSocket route for real-time STT ------------------
@app.websocket("/ws/conversation/{session_id}")
async def conversation_websocket(websocket: WebSocket, session_id: str):
    await websocket_endpoint(websocket, session_id)
    
# ---------------- 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)