"""
MCP Server for Hugging Face Space Deployment
Uses Server-Sent Events (SSE) transport for remote MCP access
Fully compatible with MCP clients like Claude Desktop
Returns clean JSON without emoji formatting
"""

from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import StreamingResponse, JSONResponse, HTMLResponse, FileResponse
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from typing import Dict, Any, List, Optional
import json
import asyncio
from datetime import datetime
from edgar_client import EdgarDataClient
from financial_analyzer import FinancialAnalyzer
import time
import sys
import signal
import os
from pathlib import Path
from contextlib import contextmanager

# Initialize FastAPI app
app = FastAPI(
    title="SEC Financial Report MCP Server API",
    description="Model Context Protocol Server for SEC EDGAR Financial Data",
    version="2.3.6"
)

# Server startup time for monitoring
server_start_time = time.time()
request_count = 0
error_count = 0

# Configure CORS for remote access
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Request tracking middleware with timeout protection
@app.middleware("http")
async def track_requests(request: Request, call_next):
    global request_count, error_count
    request_count += 1
    start_time = time.time()
    
    try:
        # Set a timeout for the entire request - increased for better reliability
        response = await asyncio.wait_for(
            call_next(request),
            timeout=180.0  # Increased from 120 to 180 seconds (3 minutes)
        )
        if response.status_code >= 400:
            error_count += 1
        return response
    except asyncio.TimeoutError:
        error_count += 1
        print(f"Request timeout after {time.time() - start_time:.2f}s: {request.url.path}")
        return JSONResponse(
            status_code=504,
            content={"error": "Request timeout", "message": "The request took too long to process. Please try again."}
        )
    except Exception as e:
        error_count += 1
        print(f"Request error: {e}")
        raise

# Initialize EDGAR clients
edgar_client = EdgarDataClient(
    user_agent="Juntao Peng Financial Report Metrics App (jtyxabc@gmail.com)"
)

financial_analyzer = FinancialAnalyzer(
    user_agent="Juntao Peng Financial Report Metrics App (jtyxabc@gmail.com)"
)

# Preload company tickers data on startup for better performance
print("[Startup] Preloading company tickers data...")
try:
    edgar_client._load_company_tickers()
    print("[Startup] Company tickers preloaded successfully")
except Exception as e:
    print(f"[Startup] Warning: Failed to preload company tickers: {e}")
    print("[Startup] Will load on first request")


# ==================== MCP Protocol Implementation ====================

class MCPRequest(BaseModel):
    jsonrpc: str = "2.0"
    id: Optional[Any] = None
    method: str
    params: Optional[Dict[str, Any]] = None


class MCPResponse(BaseModel):
    jsonrpc: str = "2.0"
    id: Optional[Any] = None
    result: Optional[Any] = None
    error: Optional[Dict[str, Any]] = None


# MCP Tools Definition
MCP_TOOLS = [
    {
        "name": "search_company",
        "description": "Search for a company by name in SEC EDGAR database. Returns company CIK, name, and ticker symbol.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "company_name": {
                    "type": "string",
                    "description": "Company name to search (e.g., 'Microsoft', 'Apple', 'Tesla')"
                }
            },
            "required": ["company_name"]
        }
    },
    {
        "name": "get_company_info",
        "description": "Get detailed company information including name, tickers, SIC code, and industry description.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "cik": {
                    "type": "string",
                    "description": "Company CIK code (10-digit format, e.g., '0000789019')"
                }
            },
            "required": ["cik"]
        }
    },
    {
        "name": "get_company_filings",
        "description": "Get list of company SEC filings (10-K, 10-Q, 20-F, etc.) with filing dates and document links.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "cik": {
                    "type": "string",
                    "description": "Company CIK code"
                },
                "form_types": {
                    "type": "array",
                    "items": {"type": "string"},
                    "description": "Optional: Filter by form types (e.g., ['10-K', '10-Q'])"
                }
            },
            "required": ["cik"]
        }
    },
    {
        "name": "get_financial_data",
        "description": "Get financial data for a specific period including revenue, net income, EPS, operating expenses, and cash flow.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "cik": {
                    "type": "string",
                    "description": "Company CIK code"
                },
                "period": {
                    "type": "string",
                    "description": "Period in format 'YYYY' for annual or 'YYYYQX' for quarterly (e.g., '2024', '2024Q3')"
                }
            },
            "required": ["cik", "period"]
        }
    },
    {
        "name": "extract_financial_metrics",
        "description": "Extract comprehensive financial metrics for multiple years including both annual and quarterly data. Returns data in chronological order (newest first).",
        "inputSchema": {
            "type": "object",
            "properties": {
                "cik": {
                    "type": "string",
                    "description": "Company CIK code"
                },
                "years": {
                    "type": "integer",
                    "description": "Number of recent years to extract (1-10, default: 3)",
                    "minimum": 1,
                    "maximum": 10,
                    "default": 3
                }
            },
            "required": ["cik"]
        }
    },
    {
        "name": "get_latest_financial_data",
        "description": "Get the most recent financial data available for a company.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "cik": {
                    "type": "string",
                    "description": "Company CIK code"
                }
            },
            "required": ["cik"]
        }
    },
    {
        "name": "advanced_search_company",
        "description": "Advanced search supporting both company name and CIK code. Automatically detects input type.",
        "inputSchema": {
            "type": "object",
            "properties": {
                "company_input": {
                    "type": "string",
                    "description": "Company name, ticker, or CIK code"
                }
            },
            "required": ["company_input"]
        }
    }
]


@contextmanager
def timeout_context(seconds):
    """Context manager for timeout on Unix-like systems"""
    def timeout_handler(signum, frame):
        raise TimeoutError(f"Operation timeout after {seconds} seconds")
    
    # Only works on Unix-like systems
    try:
        old_handler = signal.signal(signal.SIGALRM, timeout_handler)
        signal.alarm(seconds)
        try:
            yield
        finally:
            signal.alarm(0)
            signal.signal(signal.SIGALRM, old_handler)
    except (AttributeError, ValueError):
        # Windows or signal not available
        yield


def execute_tool(tool_name: str, arguments: Dict[str, Any]) -> Dict[str, Any]:
    """Execute MCP tool and return clean JSON result with enhanced timeout protection"""
    try:
        # Use context manager for timeout (90 seconds per tool - increased from 60)
        with timeout_context(90):
            if tool_name == "search_company":
                result = edgar_client.search_company_by_name(arguments["company_name"])
                if result:
                    return {
                        "type": "text",
                        "text": json.dumps(result, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No company found with name: {arguments['company_name']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "get_company_info":
                result = edgar_client.get_company_info(arguments["cik"])
                if result:
                    return {
                        "type": "text",
                        "text": json.dumps(result, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No company found with CIK: {arguments['cik']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "get_company_filings":
                form_types = arguments.get("form_types")
                result = edgar_client.get_company_filings(arguments["cik"], form_types)
                if result:
                    # Limit to 20 results
                    limited_result = result[:20]
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "total": len(result),
                            "returned": len(limited_result),
                            "filings": limited_result
                        }, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No filings found for CIK: {arguments['cik']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "get_financial_data":
                result = edgar_client.get_financial_data_for_period(arguments["cik"], arguments["period"])
                if result and "period" in result:
                    return {
                        "type": "text",
                        "text": json.dumps(result, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No financial data found for CIK: {arguments['cik']}, Period: {arguments['period']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "extract_financial_metrics":
                years = arguments.get("years", 3)
                if years < 1 or years > 10:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": "Years parameter must be between 1 and 10"
                        }, ensure_ascii=False)
                    }
                
                metrics = financial_analyzer.extract_financial_metrics(arguments["cik"], years)
                if metrics:
                    formatted = financial_analyzer.format_financial_data(metrics)
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "periods": len(formatted),
                            "data": formatted
                        }, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No financial metrics found for CIK: {arguments['cik']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "get_latest_financial_data":
                result = financial_analyzer.get_latest_financial_data(arguments["cik"])
                if result and "period" in result:
                    return {
                        "type": "text",
                        "text": json.dumps(result, ensure_ascii=False)
                    }
                else:
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": f"No latest financial data found for CIK: {arguments['cik']}"
                        }, ensure_ascii=False)
                    }
            
            elif tool_name == "advanced_search_company" or tool_name == "advanced_search":
                # Support both names for backward compatibility
                result = financial_analyzer.search_company(arguments["company_input"])
                if result.get("error"):
                    return {
                        "type": "text",
                        "text": json.dumps({
                            "error": result["error"]
                        }, ensure_ascii=False)
                    }
                return {
                    "type": "text",
                    "text": json.dumps(result, ensure_ascii=False)
                }
            
            else:
                return {
                    "type": "text",
                    "text": json.dumps({
                        "error": f"Unknown tool: {tool_name}"
                    }, ensure_ascii=False)
                }
    
    except Exception as e:
        return {
            "type": "text",
            "text": json.dumps({
                "error": f"Error executing {tool_name}: {str(e)}"
            }, ensure_ascii=False)
        }


# ==================== MCP Endpoints ====================

@app.post("/message")
async def handle_mcp_message(request: MCPRequest):
    """
    Main MCP message handler
    Supports: initialize, tools/list, tools/call
    """
    method = request.method
    params = request.params or {}
    
    # Handle initialize
    if method == "initialize":
        return MCPResponse(
            id=request.id,
            result={
                "protocolVersion": "2024-11-05",
                "capabilities": {
                    "tools": {}
                },
                "serverInfo": {
                    "name": "sec-financial-data",
                    "version": "2.3.6"
                }
            }
        ).dict()
    
    # Handle tools/list
    elif method == "tools/list":
        return MCPResponse(
            id=request.id,
            result={
                "tools": MCP_TOOLS
            }
        ).dict()
    
    # Handle tools/call
    elif method == "tools/call":
        tool_name = params.get("name")
        arguments = params.get("arguments", {})
        
        if not tool_name:
            return MCPResponse(
                id=request.id,
                error={
                    "code": -32602,
                    "message": "Missing tool name"
                }
            ).dict()
        
        result = execute_tool(tool_name, arguments)
        
        return MCPResponse(
            id=request.id,
            result={
                "content": [result]
            }
        ).dict()
    
    else:
        return MCPResponse(
            id=request.id,
            error={
                "code": -32601,
                "message": f"Method not found: {method}"
            }
        ).dict()


@app.get("/sse")
async def sse_endpoint(request: Request):
    """
    Server-Sent Events endpoint for MCP transport
    Keeps connection alive and handles MCP messages
    """
    async def event_stream():
        # Send initial endpoint message
        init_message = {
            "jsonrpc": "2.0",
            "method": "endpoint",
            "params": {
                "endpoint": "/message"
            }
        }
        yield f"data: {json.dumps(init_message)}\n\n"
        
        # Keep connection alive with optimized ping interval
        try:
            while True:
                await asyncio.sleep(20)  # 20 seconds ping interval for stability
                # Send ping to keep connection alive
                ping_message = {
                    "jsonrpc": "2.0",
                    "method": "ping",
                    "timestamp": datetime.now().isoformat()
                }
                yield f"data: {json.dumps(ping_message)}\n\n"
        except asyncio.CancelledError:
            pass
    
    return StreamingResponse(
        event_stream(),
        media_type="text/event-stream",
        headers={
            "Cache-Control": "no-cache, no-transform",
            "Connection": "keep-alive",
            "X-Accel-Buffering": "no",
            "Content-Type": "text/event-stream"
        }
    )


@app.get("/", response_class=HTMLResponse)
async def root():
    """Interactive landing page with tool testing functionality"""
    # Get the path to the templates directory
    current_dir = Path(__file__).parent
    template_path = current_dir / "templates" / "index.html"
    
    # Read and return the HTML file
    try:
        with open(template_path, "r", encoding="utf-8") as f:
            html_content = f.read()
        return HTMLResponse(content=html_content)
    except FileNotFoundError:
        # Enhanced error message with debugging information
        import os
        debug_info = f"""
        <h1>Error: Template not found</h1>
        <h2>Debugging Information:</h2>
        <p><strong>Looking for:</strong> {template_path.absolute()}</p>
        <p><strong>Exists:</strong> {template_path.exists()}</p>
        <p><strong>Current dir:</strong> {current_dir.absolute()}</p>
        <h3>Directory contents:</h3>
        <pre>{chr(10).join(os.listdir(current_dir))}</pre>
        <h3>Fix:</h3>
        <p>Ensure Dockerfile contains: <code>COPY templates/ templates/</code></p>
        """
        return HTMLResponse(content=debug_info, status_code=500)


@app.get("/tools")
async def list_tools():
    """List all available MCP tools (for documentation)"""
    return {"tools": MCP_TOOLS}


@app.get("/health")
async def health_check():
    """Enhanced health check endpoint with diagnostics"""
    uptime_seconds = time.time() - server_start_time
    return {
        "status": "healthy",
        "server": "sec-financial-data",
        "version": "2.3.6",
        "protocol": "MCP",
        "transport": "SSE",
        "tools_count": len(MCP_TOOLS),
        "uptime_seconds": round(uptime_seconds, 2),
        "python_version": sys.version,
        "request_count": request_count,
        "error_count": error_count,
        "error_rate": round(error_count / max(request_count, 1) * 100, 2),
        "timestamp": datetime.now().isoformat()
    }


@app.get("/ready")
async def readiness_check():
    """Readiness check for load balancers"""
    try:
        # Quick validation that clients are initialized
        if edgar_client and financial_analyzer:
            return {"status": "ready", "timestamp": datetime.now().isoformat()}
        else:
            raise HTTPException(status_code=503, detail="Services not initialized")
    except Exception as e:
        raise HTTPException(status_code=503, detail=f"Not ready: {str(e)}")


@app.api_route("/api/{path:path}", methods=["GET", "POST", "PUT", "DELETE"])
async def redirect_old_api(path: str):
    """Handle old REST API endpoints with helpful message"""
    return JSONResponse(
        status_code=404,
        content={
            "error": "API endpoint not found",
            "message": "This server now uses the MCP (Model Context Protocol).",
            "migration_guide": {
                "old_endpoint": f"/api/{path}",
                "new_method": "Use MCP protocol via POST /message",
                "documentation": "Visit / for setup instructions",
                "example": {
                    "method": "POST",
                    "url": "/message",
                    "body": {
                        "jsonrpc": "2.0",
                        "id": 1,
                        "method": "tools/call",
                        "params": {
                            "name": "advanced_search_company",
                            "arguments": {"company_input": "Microsoft"}
                        }
                    }
                }
            },
            "available_tools": "/tools",
            "health_check": "/health"
        }
    )


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(
        "mcp_server_sse:app",
        host="0.0.0.0",
        port=7860,
        reload=True
    )