# middleware.py
from fastapi import Request, Response
from starlette.middleware.base import BaseHTTPMiddleware
import logging
import time
import uuid
import traceback
import httpx
import re
from collections import defaultdict
from typing import Optional

logger = logging.getLogger(__name__)

# Public blocklist URLs
BLOCKLIST_URLS = [
    "https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/firehol_level1.netset",
    "https://raw.githubusercontent.com/firehol/blocklist-ipsets/master/iblocklist_isp.netset",
]


def load_blocklist_from_url(url: str, timeout: int = 10) -> set[str]:
    """Download and parse IP blocklist from URL"""
    ips = set()
    try:
        response = httpx.get(url, timeout=timeout, follow_redirects=True)
        if response.status_code == 200:
            for line in response.text.splitlines():
                line = line.strip()
                if not line or line.startswith("#"):
                    continue
                if re.match(r"^\d+\.\d+\.\d+\.\d+(/\d+)?$", line):
                    ip = line.split("/")[0]
                    ips.add(ip)
            logger.info(f"Loaded {len(ips)} IPs from blocklist: {url}")
    except Exception as e:
        logger.warning(f"Failed to load blocklist from {url}: {e}")
    return ips


def load_public_blocklists() -> set[str]:
    """Load all public blocklists"""
    all_ips = set()
    for url in BLOCKLIST_URLS:
        all_ips.update(load_blocklist_from_url(url))
    logger.info(f"Total blocked IPs from public lists: {len(all_ips)}")
    return all_ips


# Rate limiting config
RATE_LIMIT_REQUESTS = 60  # Max requests per window
RATE_LIMIT_WINDOW = 60  # Window in seconds
_ip_request_counts: dict[str, list[float]] = defaultdict(list)

# IP blocking config (set from main.py)
BLOCKED_IPS: set[str] = set()

# Suspicious paths that indicate bot scanning
SUSPICIOUS_PATHS = {
    ".env", ".env.local", ".env.production", ".env.development", ".env.bak",
    ".env.old", ".env.backup", ".env.orig", ".env.save", ".env~", ".env.swp",
    ".env.copy", ".env.1", ".ENV",
    "appsettings.json", "appsettings.Development.json", "appsettings.Production.json",
    "appsettings.Staging.json", "web.config",
    "phpinfo.php", "info.php", "test.php", "i.php", "phpi.php", "php.php",
    "phptest.php", "server-info.php", "phpinformation.php", "infophp.php",
    "php_info.php", "config.php",
    "actuator/env", "actuator/configprops", "actuator",
    "manage/env", "admin/env", "env",
    "actuator/env/aws", "actuator/env/cloud",
    "_layouts/15/", "_layouts/15/ToolPane.aspx",
    "wp-admin", "wp-login.php", "wordpress",
    "administrator", "phpmyadmin",
    ".git", ".svn", ".hg",
}

def get_client_ip(request: Request) -> str:
    """Extract client IP from request"""
    client_ip = request.client.host if request.client else "unknown"
    forwarded = request.headers.get("x-forwarded-for")
    if forwarded:
        client_ip = forwarded.split(",")[0].strip()
    return client_ip


def is_ip_blocked(client_ip: str) -> bool:
    """Check if IP is blocked"""
    return client_ip in BLOCKED_IPS


def check_rate_limit(client_ip: str) -> bool:
    """Check if IP has exceeded rate limit"""
    now = time.time()
    
    # Clean old requests
    _ip_request_counts[client_ip] = [
        t for t in _ip_request_counts[client_ip]
        if now - t < RATE_LIMIT_WINDOW
    ]
    
    if len(_ip_request_counts[client_ip]) >= RATE_LIMIT_REQUESTS:
        return False
    
    _ip_request_counts[client_ip].append(now)
    return True


def is_suspicious_path(path: str) -> bool:
    """Check if path is suspicious (bot scanning)"""
    path_lower = path.lower()
    
    # Direct match
    if path_lower in SUSPICIOUS_PATHS:
        return True
    
    # Contains suspicious patterns
    suspicious_patterns = [
        ".env", "phpinfo", "actuator", "wp-", "phpmyadmin",
        ".git", ".svn",
    ]
    
    for pattern in suspicious_patterns:
        if pattern in path_lower:
            return True
    
    # Path traversal attempts
    if ".." in path or ".." in path.replace("%2e%2e", "").replace("%252e", ""):
        return True
    
    return False


def set_ip_config(blocked: Optional[set[str]] = None):
    """Configure IP blocking (call from main.py)"""
    global BLOCKED_IPS
    if blocked is not None:
        BLOCKED_IPS = blocked


class LoggingMiddleware(BaseHTTPMiddleware):
    async def dispatch(self, request: Request, call_next):
        request_id = str(uuid.uuid4())[:8]
        client_ip = get_client_ip(request)
        
        # Check if IP is blocked
        if is_ip_blocked(client_ip):
            return Response(status_code=404, content="")
        
        # Check rate limit
        if not check_rate_limit(client_ip):
            logger.warning(f"Rate limited: {client_ip} ({request.url.path})")
            return Response(status_code=429, content="Too many requests")
        
        # Check suspicious path (silent 404 for bots)
        path = request.url.path
        if is_suspicious_path(path):
            # Return 404 without logging - confuse the bots
            return Response(status_code=404, content="")
        
        # Log legitimate requests
        start_time = time.time()
        
        logger.info(f"→ {request.method} {path} (IP: {client_ip}, ID: {request_id})")
        
        try:
            response = await call_next(request)
            duration = (time.time() - start_time) * 1000
            logger.info(f"← {request.method} {path} → {response.status_code} ({duration:.0f}ms) [ID: {request_id}]")
            response.headers["X-Request-ID"] = request_id
            return response
            
        except Exception as e:
            duration = (time.time() - start_time) * 1000
            error_traceback = traceback.format_exc()
            logger.error(f"✗ {request.method} {path} → ERROR: {str(e)} (ID: {request_id})\n{error_traceback}")
            raise